bluuebunny/crossref_metadata_2025 huggingface dataset:
Coronary arterial remodeling in differing clinical presentations of unstable angina pectoris—an intravascular ultrasound study
Authors: Iwami Takahiro , Nishioka Toshihiko , Fishbein Michael C. , Luo Huai , Jeon Doo‐Soo , Miyamoto Takashi , Wakeyama Takatoshi , Iida Hiroshi , Takaki Akira , Oda Tetsuro , Mochizuki Mamoru , Ogawa Hiroshi , Siegel Robert J
Published: June 2007

Background: Coronary arterial remodeling influences the clinical presentation of ischemic heart disease; however, there is little information on the relationship between coronary arterial remodeling and the type of angina pectoris that patients manifest.

Hypothesis: The study was undertaken to determine the difference of coronary arterial remodeling in patients with different types of angina pectoris.

Methods: We analyzed 100 patients with ischemic heart disease using intravascular ultrasound (IVUS). Intracoronary IVUS images of proximal reference (PR), distal reference (DR), and target lesion were recorded, and intraluminal area (LA) and external elastic membrane (EEM) were measured. We defined a remodeling index as 100 × (lesion EEM — [PR‐EEM + DR‐EEM]/2) / ([PR‐EEM + DR‐EEM]/2). Cases were classified into three groups according to the clinical history (Group 1a: de novo unstable angina pectoris, Group 1b: accelerating unstable angina pectoris, and Group 2; stable angina pectoris).

Results: The remodeling index in Group 1a was significantly larger than that in Groups 1b and 2 (18.6 ±28.5 vs. 5.3 ± 27.1 and 18.6 ± 28.5 vs. —2.7 ± 17.6, p = 0.0347 and p = 0.0005, respectively), but there was no statistical difference in remodeling index between Groups 1b and 2.

Conclusions: Our results indicate that positive coronary arterial remodeling is more prevalent in patients with new onset of angina pectoris. The specific type of coronary arterial remodeling may affect the clinical presentation of patients with coronary artery disease.
Coronary flow velocity reserve in hypertensive patients with left ventricular systolic dysfunction
Authors: Pereira Valéria Fontenelle Angelim , De Carvalho Frimm Clovis , Rodrigues Ana Clara Tude , Tsutsui Jeane Mike , Cúri Mariana , Mady Charles , Ramires José Antonio Franchini
Published: June 2007

Background: Hypertensive microvascular disease is speculated to be a limiting factor for the ability of left ventricular (LV) hypertrophy to maintain LV systolic function in systemic hypertension. The role of coronary reserve, which may be affected by microvascular disease, remains uncertain in the pathophysiology of hypertensive heart disease.

Hypothesis: A progressive impairment of coronary flow velocity reserve (CFVR) according to the presence and severity of LV systolic dysfunction is anticipated to occur in hypertension.

Methods: According to the absence or presence of LV dysfunction (LV fractional shortening ‐ FS% < 30), two groups of hypertensive patients were investigated: HP1 (n = 9, FS% = 36 ± 6) and HP2 (n = 13, FS% = 18 ± 6). Eight normal subjects (NL) served as controls (LVFS% = 35 ± 3). Doppler blood flow velocity was obtained from the left anterior descending coronary artery using transesophageal echocardiography before and during 6‐min continuous adenosine infusion (140 μg·kg‐1 ·min‐1 intravenous). The CFVR was calculated as the ratio of maximal to baseline peak diastolic flow velocities.

Results: The comparison among NL, HP1, and HP2 groups showed statistically different (p < 0.05) mass index (101 ± 18, 172 ± 46, and 257 ± 54 g·m‐2), end‐systolic wall stress (76.9 ± 14.4, 78.4 ± 23.9, and 174.5 ± 43.0 103·dyn·cm‐2), and CFVR (3.5 ± 0.6, 3.2 ± 0.4, and 2.6 ± 0.8), respectively. The CFVR correlated significantly and directly with LVFS% (r = 0.40) and correlated inversely with both mass index (r = −0.54) and end‐systolic stress (r = −0.40). Conclusions: These results indicate that CFVR impairment is weakly related to LV dysfunction in hypertension.
Adaptive mechanisms of left ventricular diastolic function to the physiologic load of pregnancy
Authors: Moran Adrian M. , Colan Steven D. , Mauer Mary Beth , Geva Tal
Published: June 2007

Background: Pregnancy is associated with marked alteration in cardiovascular hemodynamics. Recent reports have characterized the effects on cardiac systolic function. Little has been written on the influences of loading conditions on Doppler measures of diastolic function during pregnancy.

Hypothesis: Stage of pregnancy has an impact on Doppler indices of diastolic function independent of loading conditions, systolic function, and heart rate.

Method: Thirty healthy women were prospectively evaluated by serial echocardiography and Doppler examinations at six time periods: 10‐12, 18‐20, 28‐30, 36‐38 weeks gestation, 2‐4 and 12‐14 weeks postpartum. The related effects on indices of diastolic function and its interaction with load, heart rate, mass, and systolic function were determined.

Results: Compared with the nonpregnant state, early (E) velocity increased (0.7 ± 0.1‐0.9 ± 0.1 m/s, p = 0.0001), peaking at 18 weeks and returning to normal levels during late pregnancy. Atrial phase (A) velocity peaked at 18 weeks (0.48 ± 0.12‐0.60 ± 0.13 m/s, p = 0.0001), remaining high throughout the rest of pregnancy. Consequently, the E/A ratio fell significantly during late pregnancy, from 1.9 ± 0.4 to 1.4 ± 0.3 (p = 0.02). In addition, mean acceleration was significantly increased in early pregnancy with a peak at 18 weeks (7.4 ± 1.3 m/s2), returning to nonpregnant level at term (5.7 ± 1.4 m/s2, p = 0.0001). Generalized estimating equation using multivariate regression analysis demonstrated that rising heart rate and stroke volume index had an independent effect on A velocity, and that contractility and preload had an independent effect on E velocity. Pregnancy itself had an independent influence on early filling, not explained by the other parameters.

Conclusions: During normal pregnancy, there is a reversible shift in transmitral flow velocities from early to late filling with a decrease in acceleration, consistent with an increase in ventricular compliance. Changes in heart rate, preload, and contractility, as well as stage of pregnancy influence this alteration.
Shear‐induced platelet aggregation increases in patients with proximal and severe coronary artery stenosis
Authors: Kawano Koichi , Yoshino Hideaki , Aoki Nobuo , Udagawa Hiroshi , Watanuki Atsushi , Hioki Yoshiko , Hasumura Yukihisa , Yasumura Toshikaki , Homori Masashi , Murata Mitsuru , Ikeda Yasuo , Ishikawa Kyozo
Published: June 2007

Background: Shear stress generated in stenosed arteries promotes platelet thrombi formation at the stenosed sites by accelerating the binding of von Willebrand factor (vWF) to platelets. Shear‐induced platelet aggregation (SIPA) has been studied in acute coronary syndromes, but not in chronic coronary disease.

Hypothesis: We investigated the effect of both the site and severity of coronary stenosis on SIPAin patients with chronic coronary artery disease.

Methods: Shear‐induced platelet aggregation was measured using platelet‐rich plasma in 49 patients (41 men and 8 women; mean age 61 ± 10 years) with coronary artery disease to evaluate the association between the extent of SIPA and coronary angiographic findings. Stenoses > 75% were considered severe. In all, 62 healthy individuals (54 men and 18 women; mean age 45 ± 7 years) served as controls. The correlation between SIPA and the site and severity of the coronary lesion, and parameters of coagulation and fibrinolysis were evaluated.

Results: Shear‐induced platelet aggregation was increased in the stenosis group (69.0 ± 10.6%) compared with the controls (57.7 ± 10.3%, p < 0.0001). Patients with severe stenosis in the proximal segments had significantly increased SIPA (p< 0.0001) and vWF larger multimer concentration (p < 0.0001) compared with the control group. A significant correlation existed between SIPA and the vWF larger multimer concentrationinall subjects studied (r= 0.422, p<0.0001).

Conclusions: Shear‐induced platelet aggregation is increased in patients with severe stenosis of the proximal coronary arteries and correlates with plasma concentrations of vWF larger multimers, suggesting that severe stenosis in the proximal segments is not only associated with an increased risk of significant my ocardial ischemia, but may also generate high shear stress in the stenosed artery and increase plasma vWF larger multimers, thereby promoting the formation of platelet thrombi.
The effect of aortic valve replacement on N‐terminal natriuretic propeptides in patients with aortic stenosis
Authors: Qi Wei , Mathisen Per , Kjekshus John , Simonsen Svein , Endresen Knut , Bjørnerheim Reidar , Hall Christian
Published: June 2007

Background: Increased plasma concentrations of natriuretic peptides have been demonstrated to be associated with increased intracardiac pressure and left ventricular (LV) hypertrophy. After aortic valve replacement (AVR) in aortic stenosis patients, there is a relief of the left outflow obstruction with a substantial hemodynamic improvement. This is followed by a gradual regression of the LV hypertrophy.

Hypothesis: After AVR, reduction in LV filling pressure is expected to occur rapidly, while regression of LV hypertrophy will take place over a longer time period. On this basis we hypothesized that the plasma levels of N‐terminal proatrial natriuretic peptide (NT‐proANP) would be reduced early in the postoperative period, while N‐terminal probrain natriuretic peptide (NT‐proBNP), through its closer reflection of LV hypertrophy, would be sustained for a longer period.

Methods: Two groups of patients with aortic stenosis undergoing AVR were followed for 4 and 12 months, respectively. Plasma concentrations of NT‐pro ANP and NT‐proBNP were measured before and after AVR and related to preoperative findings and changes in the aortic valve area index.

Results: Before AVR, the patients had significantly increased plasma levels of NT‐pro ANP and NT‐proBNP. After AVR, NT‐ pro ANP was decreased at 4 and 12 months but remained elevated compared with controls. N‐terminal‐proBNP tended to decrease, but did not change significantly. When the patients were followed for 12 months, only those with elevated preoperative pulmonary capillary wedge pressure had decreased peptide levels (NT‐proANP: p = 0.017, NT‐proBNP: p = 0.058). There was no regression of LV hypertrophy. The patients with the largest postoperative valve area index [1.27 (1.10‐1.55) cm2/m2] had the largest reduction of NT‐proBNP (47%). Those with the smallest valve area index [0.67 (0.54‐0.73) cm2/m2] had no decrease in NT‐proBNP.

Conclusions: Our study suggests that a reduction in left atrial pressure is the main factor causing the change of NT‐proANP level after AVR. A small prosthetic valve orifice area with a high aortic valve gradient might prevent regression of LV hypertrophy, thus representing a stimulus for increased cardiac secretion of NT‐proBNP.
New parameters in the interpretation of exercise testing in women: QTC dispersion and QT dispersion ratio difference
Authors: Özdemr Kurtuluş , Altunkeser Bulent B. , Aydin Mustafa , Özeren Ali , Dams Gulizar , Gok Hasan
Published: June 2007

Background: It has been reported that the increase of QT dispersion (QTD) that occurs due to increased inhomogeneity of the ventricular repolarization because of transient ischemia obtained by standard 12‐lead electrocardiogram (ECG), the changes during exercise, and the differences between exercise and rest increase the accuracy of exercise test in the diagnosis of coronary artery disease (CAD).

Hypothesis: This study was designed to investigate the value of QTD parameters, which are reported to increase the diagnostic accuracy of exercise test in women.

Methods: Ninety‐seven women who had undergone coronary angiography and exercise test were evaluated for diagnosis of chest pain. QT dispersion was calculated using the measurements of the highest and lowest values of QT interval obtained by ECG during peak exercise. The QTc using Bazett's equation, and the QTD ratio (QTDR) using QT/RR were calculated, and QTcD and QTD ratios were obtained. The difference between QTcD and QTDR was determined by extracting the rest values from the exercise values.

Results: The groups with normal coronaries (n = 48), single‐vessel CAD (n= 24), and multivessel CAD (n= 25) were compared. The obtained QTD parameters at peak exercise and their differences between exercise and rest were found to be significantly increased in patients with CAD (p<0.001).

Furthermore, these parameters were found to be higher in the patients with multivessel CAD than in those with single‐vessel disease (p < 0.05). With the parameters QTcD > 60 ms and QTDR > 10%, greater sensitivity and specificity were obtained compared with ST‐segment depression. The highest diagnostic accuracy was obtained with the QTD parameters calculated from the differences between rest and exercise values. The diagnostic accuracy of the difference of QTcD > 15 ms and the difference of QTDR > 5% was relatively higher than the other parameters (sensitivity, specificity, and negative and positive predictor values are 84,88,84, 87% and 84, 96, 85, 95%, respectively).

Conclusion: The use of QTD parameters as variables of ECG, which is easily obtainable in the evaluation of exercise ECG in women, increases the diagnostic accuracy of the exercise test. In addition, the evaluation of QTD variables may provide information about the incidence of CAD.
The effect of intracoronary fibroblast growth factor‐2 on restenosis after primary angioplasty or stent placement in a pig model of atherosclerosis
Authors: Post Mark J. , Laham Roger J. , Kuntz Richard E. , Novicki Deborah , Simons Michael
Published: June 2007

Background: Therapeutic angiogenesis, if combined with primary percutaneous transluminal coronary angioplasty or stent placement, could improve the outcome of patients suffering from multifocal coronary disease.

Hypothesis: Because of the concern that angiogenic growth factors might promote restenosis, we studied the effect of a single intracoronary administration of recombinant fibroblast growth factor (rFGF)‐2 on restenosis after balloon angioplasty and stent placement in a pig model of coronary atherosclerosis.

Methods: In 24 Yucatan minipigs, coronary lesions were induced by arterial injury and 3 months of atherogenic diet. After 3 months, repeat catheterization was performed with balloon dilation or stent placement at the injured sites, with a follow‐up of 6 weeks. Results were monitored using quantitative angiography, intravascular ultrasound (IVUS), and histomorphometry.

Results: Intracoronary rFGF‐22 μg/kg did not affect neoin‐tima formation or remodeling in this model. A small but significant aggravation of late lumenloss was observed in the reference segments of the rFGF‐2‐treated group. Angiographic and echographic late lumen loss, intimal hyperplasia, and arterial remodeling, as well as histologic neointima were all similar in the rFGF‐2‐ and the vehicle‐treated group. Confirming earlier studies from our group and those of others, stented arteries compared with balloon‐dilated arteries had increased angiographic late lumen loss, a trend toward increased intimal hyperplasia and decreased remodeling.

Conclusion: We conclude that rFGF‐2 does not aggravate restenosis after balloon dilation or stenting in this pig model of coronary atherosclerosis. Future combinations of angioplasty and therapeutic angiogenesis in a single session should be pursued as a feasible and safe strategy.
Cardioversion of atrial fibrillation with ibutilide: When is it most effective?
Authors: Das Mithilesh Kumar , Cheriparambil Kuruvilla , Bedi Ashwini , Kassotis John , Reddy Chatla V. R. , Saul Barry , Makan Majesh
Published: June 2007

Background: Atrial fibrillation (AF) is found in 1% of persons above the age of 60 years. More than 5% of the population older than 69 years and about 14% of octogenarians are at risk for this arrhythmia. It is estimated that 1.5 to 3 million persons in the United States alone suffer from AF. The public health implications and attendant morbidity are a significant drain on our health care system.

Hypothesis: The purpose of this study was to determine the clinical and echocardiographic predictors of success in converting AF of ≥ 24 h duration.

Methods: Demographic and clinical and echocardiographic parameters of 101 patients with recent onset AF (> 24 h) who received ibutilide were studied.

Results: Of 101 patients, 56 (55%) converted to sinus rhythm. Age, gender, hypertension, diabetes mellitus, left ventricular ejection fraction (≤ 35%), congestive heart failure, and previous medication for rate control had no significant effect on the conversion rate. Conversion rate was only 30% (9/30 patients) in the presence of an enlarged left atrium (LA > 5 cm) and 37.7% (23/61 patients) in the presence of mitral valve disease (MVD), whereas the conversion rate was 82.5% (33/40 patients) in the absence of MVD and 85% (29/34 patients) in the absence of both enlarged LA and MVD (p =< 0.001). Patients with coronary artery disease (CAD) also exhibited a significantly greater response to ibutilide than patients without CAD (77 vs. 46%, p‐value 0.005).

Conclusion: As a therapy for cardioversion of AF, ibutilide is most effective in a selected subgroup patients, such as in patients with CAD and in patients without MVD and/ormarkedly enlarged left atrium.
Triggering effect of physical and mental stress on spontaneous ventricular tachyarrhythmias in patients with implantable cardioverter‐defibrillators
Authors: Fries Roland , König Jochem , Schäfers Hans‐Joachim , Böhm Michael
Published: June 2007

Background: Physical and mental stress as well as sexual activity are potential triggering factors of acute coronary events and sudden cardiac death.

Hypothesis: These factors may also trigger recurrence of spontaneous ventricular tachyarrhythmias in patients with implantable cardioverter‐defibrillators (ICDs).

Methods: We performed a case‐crossover study in 43 consecutive patients with 95 symptomatic, ICD‐documented tachyarrhythmic events and calculated the relative risk of tachyarrhythmia recurrence during physical and mental stress. Physical and mental activity was graded on a 4‐step intensity scale, and stress was defined as physical exertion or mental stress with an intensity grade ≥ II during or up to 1 h before arrhythmia recurrence. Relative risk was determined taking into account the habitual weekly stress frequency of each patient.

Results: Physical stress was present in 26% (n = 25), mental stress in 24% (n = 23), and sexual activity in 2% (n = 2) of analyzed events. The weekly habitual stress frequency was 8 ± 8 (median 7) for physical stress, 6 ± 6 (median 4) for mental stress, and 0.5 ± 0.5 (median 0.25) for sexual activity. Thus, relative risk of arrhythmia recurrence during the presence of stress was 7.5 for physical activity (95% confidence interval [CI] 5.2–11.1), 9.5 (CI 6.3–14.5) for mental activity, and 7.5 (CI 2.3–24.8) for sexual activity.

Conclusions: Physical and mental stress as well as sexual activity are factors that significantly increase relative risk of spontaneous recurrence of sustained ventricular tachyarrhythmias in patients with ICDs. Consideration of this stress‐related relative risk increase may contribute to avoidance of harmful shock delivery in ICD recipients.
Effects of simvastatin, an HMG‐CoA reductase inhibitor, in patients with hypertriglyceridemia
Authors: Isaacsohn Jonathan , Hunninghake Donald , Schrott Helmut , Dujovne Carlos A. , Knopp Robert , Weiss Stuart R. , Bays Harold , Crousei John R. , Davidson Michael H. , Keilson Leonardm , McKenney James , Korenman Stanleyg , Dobs Adrians , Stein Evan , Krauss Ronald M. , MacCubbin Darbie , Cho Meeh Yung , Plotkin Diane J. , Mitchel YALE B.
Published: June 2007

Background: Patients with elevated levels of serum triglyc‐erides (TG) often have other associated lipid abnormalities (e.g., low levels of high‐density lipoprotein cholesterol [HDL‐C]) and are at increased risk of developing coronary heart disease. Although the therapeutic benefits of 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitors (statins) in hypercholesterolemic patients have been well established, less is known about the effects of statins in patient populations with hypertriglyceridemia.

Hypothesis: The purpose of this study was to evaluate the lipoprotein‐altering efficacy of simvastatin in hypertriglyceri‐demic patients.

Methods: This was a multicenter, randomized, double‐blind, placebo‐controlled study. In all, 195 patients with fasting serum triglyceride levels between 300 and 900 mg/dl received once daily doses of placebo or simvastatin 20,40, or 80 mg for 6 weeks.

Results: Compared with placebo, simvastatin treatment across all doses resulted in significant reductions (p < 0.05–<0.001) in serum levels of triglycerides (‐20 to–31% decrease) and TG‐rich lipoprotein particles. Significant (p< 0.001) reductions were also seen in low‐density lipoprotein cholesterol (‐25 to‐35%)andnon‐HDL‐C(‐26to‐40%). Levels of HDL‐C were increased (7‐11%) in the simvastatin groups compared with placebo (p < 0.05‐ < 0.001).

Conclusion: The results of this study demonstrate the beneficial effects of simvastatin in patients with hypertriglyceridemia.
Prevalence and risk factors for erectile dysfunction in men with diabetes, hypertension, or both diseases: A community survey among 1,412 Israeli men
Authors: Roth Are , Kalter‐Lftbovhx Ofra , Kerbis Yehuda , Tekenbaum‐Koren Ella , Chen Juza , Sobol Tamar , Raz Ilamar
Published: June 2007

Background: Erectile dysfunction (ED) and cardiovascular disease share common risk factors and may be further aggravated by medical treatment for reducing them.

Hypothesis: The study was undertaken to assess the prevalence of ED in patients with diabetes (DM), hypertension (HTN), or both diseases, and to evaluate the effect of patient age, medical treatment, and disease duration and control on the prevalence of ED in tins population.

Methods; A group of 150 primary practitioners who had patients with known DM and or HTN conducted a survey. utilizine IIEF‐15, a 15‐itemmultidunensional. self‐admnistered questionnaire used for the clinical assessment of ED.

Results: In all, 1,412 patients were included: 37%liadDM, 38% had HTN, and 25% had both diseases. Then mean age was 55,58, and 60 yean, and 62,46, and 67% had some degree of ED, respectively The prevalence of ED increased with age and disease duration m each age group and was higher in subjects with DM than in those with HTN, especially in those aged < 65 years. Poor glycemic control was associated with a higher prevalence rate of ED early in the course of the disease. There was no significant difference in the prevalence of ED according to type and number of antihypertensive drugs.

Conclusions: Erectile dysfunction is common among patients at high risk for cardiovascular disease because of diabetes and or HTN. Diabetic men are affected earlier than those wife HTN. Given the high frequency of ED in young patients wife these risk tartars, physicians should encourage an open discussion on the subject during routine visits to promote early detection and treatment.
Matrix metalloproteinases and coronary artery diseases
Authors: Ikeda Uichi , Shimada Kazuyuki
Published: June 2007

Matrix metalloproteinases (MMPs) play an important role in cardiovascular remodeling by degrading the extracellular matrix. Enhanced MMP expression has been detected in the atherosclerotic plaque, and activation of MMPs appears to be involved in the vulnerability of the plaque. Circulating MMP levels are elevated in patients with acute myocardial infarction and unstable angina. Increased MMP expression is also observed after coronary angioplasty, which is related to late loss index after the procedure. These observations suggest that MMP expression may be not only related to instability of the plaque, but also to the formation of restenotic lesions. The development of therapeutic drugs targeted specifically against MMPs may be useful in the prevention of atherosclerotic lesion development, plaque rupture, and restenosis.
Understanding implantable cardioverter defibrillator shocks and storms: Medical and psychosocial considerations for research and clinical care
Authors: Sears Samuel F. , Conti Jamie B.
Published: June 2007

The experience of shock is the distinguishing feature for patients with implantable cardioverter defibrillators (ICDs) and is associated with diminished psychological functioning and quality of life. Multiple shocks and ICD storm are a relatively common event among patients with ICDs (10‐20%) and may present specific challenging medical and psychological management for the attending health care providers. This paper examines the medical and psychological aspects of ICD shocks and storms and describes a model of biopsychosocial management for patients following the experience of ICD storm. Successful management of patients post shock includes the use of antiarrhythmic medications and careful attention to the causality of the shocks via stored electrograms. The psychological management includes specific attention to debriefing post‐shock feelings and attributions, preventing avoidance behavior, and facilitating positive “return to life” actions. Preliminary research examining formal psychosocial treatment supports a cognitive behavioral strategy to reduce psychological distress and facilitate quality of life. Collectively, these data suggest that interdisciplinary management of patients with multiple ICD shocks or the experience of ICD storm is advised, and routine psychological consultation may be indicated for the patient post ICD storm to reduce the possibility of symptoms of post‐traumatic stress.
Effects of long‐term transdermal nitrate treatment on left ventricular function in patients following myocardial infarction
Authors: Kiraly Csaba , Kiss Attila , Timar Sandor , Kristof Eva , Hegedus Ida , Edes Istvan
Published: June 2007

Background: Nitrates are widely used for the treatment of myocardial infarction (MI). The large megatrials (GISSI‐3 and ISIS‐4) did not in fact demonstrate a significant decrease in mortality in the nitrate‐treated group. However, examination of the number of postinfarction angina episodes and the occurrence of cardiogenic shock in the GISSI‐3 study did reveal significant decreases.

Hypothesis: It was hypothesized that chronic nitrate treatment after an MI preserves left ventricular systolic and/or diastolic functions.

Methods: Patients were divided into two groups: those receiving chronic nitrate treatment for 6 months after an MI (n = 30), and those without such treatment (n = 29). Echocardiography was performed 3, 14, 42, and 180 days after the infarction. The changes in early diastolic and atrial contraction‐related mitral valve inflow pattern and deceleration time were assayed. Alterations in systolic, diastolic, and atrial reverse flow velocities in the pulmonary vein were measured, as were ejection fraction (EF), the number of registered angina episodes, and the maximal ST‐segment depression in response to the stress test.

Results: During the 6‐month study period, the increase in systolic pulmonary venous flow velocity was significantly larger in the nitrate group than in the controls. The decreases in the velocities of the diastolic and the atrial reverse flow were also more pronounced in the nitrate group than in the controls. The EF was improved only in the nitrate group. Examination of the maximal ST‐segment depression in response to the stress test revealed a significant decrease in the nitrate group only. There were no significant differences between the two groups in the number of registered angina episodes or mitral inflow pattern.

Conclusions: The study showed that prolonged nitrate treatment after an MI may help preserve diastolic left ventricular function.
Fibrin D‐dimer: A marker of psychosocial distress and its implications for research in stress‐related coronary artery disease
Authors: Von Känel Roland , Dimsdale Joel E.
Published: June 2007

Psychosocial factors might mediate their adverse impact on coronary arteries by eliciting a hypercoagulable state via changes in sympathetic nervous system activity. A recent meta‐analysis of prospective studies reported an association of the hypercoagulability marker D‐dimer with an increased risk for coronary events. This review provides evidence that an elevated plasma D‐dimer level is a suitable marker for acute and chronic psychosocial distress. Prospective studies need to show whether stress‐related changes in D‐dimer may help explain the increased coronary risk with psychosocial distress.
Prospective comparison of coronary artery remodeling between acute coronary syndrome and stable angina in single‐vessel disease: Correlation between C‐reactive protein and extent of arterial remodeling
Authors: Hong Myeong‐Ki , Park Seong‐Wook , Lee Cheol Whan , Kim Young‐Hak , Kim June‐Hong , Song Jong‐Min , Kang Duk‐Hyun , Song Jae‐Kwan , Kim Jae‐Joong , Park Seung‐Jung
Published: June 2007

Background: Retrospective intravascular ultrasound (IVUS) studies showed that positive remodeling of coronary artery was associated with unstable clinical presentation. However, no prospective IVUS study has been performed to demonstrate such relationship. The relationship between C‐reactive protein (CRP) and coronary artery remodeling is unknown.

Hypothesis: Positive remodeling might be related with acute coronary syndrome in the prospective IVUS study. C‐reactive protein levels might be associated with coronary artery remodeling.

Methods: Preintervention IVUS images were prospectively obtained in 93 patients with single‐vessel disease (30 for acute coronary syndrome and 63 for stable angina). Serum sample for CRP measurement was collected 24 h prior to coronary intervention. The remodeling index was defined as a ratio of (lesion/average reference) external elastic membrane area. Positive remodeling was defined as a remodeling index > 1.05 and negative remodeling as a remodeling index < 0.95.

Results: The remodeling index was 0.99 ± 0.13 in acute coronary syndrome versus 0.95 ± 0.12 in stable angina (p = 0.048). Positive remodeling was associated with acute coronary syndrome (43 vs. 19%), whereas negative remodeling was more frequent in stable angina (49 vs. 33%) (p = 0.047). C‐reactive protein levels were significantly higher in acute coronary syndrome than in stable angina (1.4 ± 2.0 vs. 0.5 ± 0.6 mg/dl, respectively, p = 0.002). However, there was no significant correlation between CRP levels and remodeling index (r = 0.078, p = 0.475).

Conclusions: Positive remodeling may be related with acute coronary syndrome in the prospective IVUS analysis. C‐reactive protein levels may not predict the extent of arterial remodeling.
Predictive value of heart rate variability for the recurrence of chronic atrial fibrillation after electrical cardioversion
Authors: Akyürek ÖMer , Diker Erdem , Güldal Muharrem , Oral Derviş
Published: June 2007

Background: The relation between heart rate variability (HRV) and occurrence of atrial fibrillation (AF) in paroxysmal AF has been well studied, but there are controversial observations regarding the relation of HRV parameters to the recurrence of chronic AF after cardioversion.

Hypothesis: The present study compared HRV parameters of patients with chronic AF on the second day of cardioversion with a healthy control group and investigated their predictive value for AF recurrence.

Methods: Forty‐one patients with chronic AF (> 3 months), who had various underlying cardiovascular disorders, were enrolled to the study. Of these, 31 patients were successfully cardioverted by external direct current shock, but 27 patients fulfilled the entry criteria. Twenty healthy subjects served as a control group. On the second day of restoration of sinus rhythm, 24‐h Holter recording was obtained and the following time‐domain indices of HRV were measured: SDNN (the standard deviation of the mean RR interval expressed in ms), SDANN (the SD of the averages of RR intervals in all 5‐min segments of the 24‐h recording), rMSSD (the root mean square of differences of successive RR intervals), and pNN50 (the percentage of adjacent RR intervals that differed by more than 50 ms). Patients were followed‐up for 6 weeks for recurrence of AF.

Results: After cardioversion, SDNN and SDANN were found to be significantly lower in the AF group than in the control group (86.4 ± 31.7 ms vs. 142.1 ± 40.2 ms, and 57 ± 17.4 ms vs. 124.4 ± 37.7 ms, p < 0.001 and p < 0.001, respectively). The indices of vagal modulation of heart rate (rMSS and pNN50) were not different between the AF group and the control group. Recurrence of AF was observed in 15 patients. In these patients, all HRV parameters were significantly depressed compared with those with maintained sinus rhythm. Logistic regression analysis revealed that only decreased pNN50 was an independent predictor of AF relapse (relative risk = 1.5, p = 0.02, 95% confidence interval 1.1‐2.2). There was also a trend toward a shortened SDNN as a predictor of AF recurrences.

Conclusion: Suppressed HRV parameters and decreased vagal tone are probably a risk factor for AF recurrences after cardioversion to sinus rhythm in a specific subset of patients with chronic AF.
Significance of exercise‐induced ST changes in leads AVR, V5, and V1. Discrimination of patients with single‐ or multivessel coronary artery disease
Authors: Michaelides Andreas P. , Psomadaki Zoi D. , Aigyptiadou Maria‐Niki K. , Richter Dimitris J. , Andrikopoulos George K. , Dilaveris Polychronis E. , Tsioufis Konstantinos , Tousoulis Dimitris , Stefanadis Christodoulos I. , Toutouzas Pavlos K.
Published: June 2007

Background: It is known that exercise‐induced ST‐segment elevation in lead V1 (V1‐E) detects left anterior descending (LAD) stenosis. It was also postulated that ST elevation in aVR and simultaneous ST depression in V5 (aVR‐E + V5‐D) is a marker of ischemia due to significant stenosis of the LAD in patients with single‐vessel disease.

Hypothesis: This study was undertaken to investigate the significance of the concomitant appearance of both electrocar‐diographic (ECG) ischemic markers, and of each of them alone during exercise, to detect either LAD stenosis as single‐vessel coronary artery disease (CAD), or multivessel CAD involving LAD stenosis.

Methods: A total of 196 consecutive patients (152 men and 44 women, mean age 54 ± 7 years) with at least one of these ECG markers, who underwent treadmill exercise testing with the Bruce protocol and coronary arteriography, were studied.

Results: Patients were divided into three groups. In Group A (83 patients with V1‐E + aVR‐E & V5‐D), 93% of patients with single‐vessel disease had significant LAD stenosis (p < 0.001), whereas 75% of patients with double‐vessel disease had significant stenoses of the LAD and the left circumflex (LCx) coronary arteries (p < 0.01). In Group B (97 patients with aVR‐E & V5‐D but without V1‐E), 43% of patients with single‐vessel disease had significant LAD stenosis (p < 0.08), whereas 85% of patients with double‐vessel disease had significant stenoses of the LAD and the right coronary artery (RCA) (p < 0.01). In Group C (16 patients with only V1‐E), 60% of patients with single‐vessel disease had significant LAD stenosis (p < 0.05), whereas 75% of patients with double‐vessel disease had significant LAD and LCx stenoses (p < 0.05).

Conclusions: The concomitant appearance of exercise‐induced ST elevation in lead V1, ST elevation in lead aVR, and ST depression in lead V5, as well as the isolated appearance of ST elevation in lead V1 detect significant LAD stenosis as single‐vessel disease, or significant stenoses of LAD and LCx arteries in patients with double‐vessel disease, whereas the appearance of ST elevation in aVR & ST depression in V5 but without ST elevation in V1 correlates strongly with significant LAD and RCA stenoses and usually indicates double‐vessel disease.
Opportunities for improvement in the diagnosis and treatment of heart failure
Authors: McCullough Peter A. , Philbin Edward F. , Spertus John A. , Sandberg Keisha R. , Sullivan Roberta A. , Kaatz Scott
Published: June 2007

Background: Improved treatment of congestive heart failure (CHF) can slow disease progression, promote clinical stability, and prolong survival.

Hypothesis: Patterns in diagnostic test utilization and pharmacotherapy among patients with newly diagnosed heart failure may affect outcomes.

Methods: Claims data were analyzed from all diagnostic procedures and prescriptions from 1995 to 1998 in 3,353 patients with heart failure diagnosed within 1 year. Rates of diagnostic testing and categories of drugs prescribed were the main outcome measures. Demographic variables and type of provider were analyzed within a setting whose access to care was controlled.

Results: Rates of diagnostic testing with respect to basic, metabolic/endocrine, alternative diagnoses, underlying ischemia, and left ventricular function varied as a function of gender, age, race, and primary versus specialty care provider. Only 4.7% of patients underwent all diagnostics and treatments recommended in current guidelines. However, those patients (27.5%) who underwent an evaluation for ischemic heart disease and were prescribed vasodilators or beta blockers enjoyed the lowest crude mortality.

Conclusions: There are multiple opportunities apparent to improve the initial diagnostic and therapeutic care of patients with heart failure. There appears to be an early survival benefit with respect to use of vasodilators and beta blockers within the first year of treatment.
Isometric handgrip exercise during dobutamine‐atropine stress echocardiography increases heart rate acceleration and decreases study duration and dobutamine and atropine dosage
Authors: Yao Siu‐Sun , Moldenhauer Sonja , Sherrid Mark V.
Published: June 2007

Background: Dobutamine‐atropine stress echocardiography (DASE) is an established test for the diagnosis and risk stratification of patients with coronary artery disease. Atropine use to attain target heart rate prolongs test time.

Hypothesis: The aim of this study was to assess the utility of isometric handgrip exercise (33% maximal voluntary contraction X 4 min) with DASE.

Methods: We prospectively evaluated 131 patients undergoing DASE randomized to handgrip exercise or no handgrip. Effect of handgrip exercise on endpoints: time to target heart rate (85% maximum predicted), recovery time, total test time, mean dobutamine and atropine dosage, and the number of ischemic responses were assessed. Effect of current beta‐blocker medication use was also evaluated.

Results: Heart rate rose more quickly in the handgrip group. At 6‐10 min (peak handgrip), mean heart rate rose 51 ± 14 beats/min in the handgrip group compared with 38 ± 18 beats/min in the no handgrip group (p < 0.0001). With handgrip, overall dobutamine study time was reduced by a mean of 4.3 min (16.4 ± 6.9 vs. 20.7 ± 8.4, p = 0.004) in all patients, and by a mean of 5.9 min in patients not on beta‐blocker medication (p = 0.001). The handgrip group also had a lower mean dose of dobutamine (25.8 ± 13.5 vs. 32.4 ± 16.4 mg, p = 0.025). The mean atropine dose was also lower (0.2 ± 0.4 vs. 0.4 ± 0.5 mg, p = 0.04). Handgrip exercise, however, did not decrease endpoints in patients on beta‐blocker medication.

Conclusions: Use of isometric handgrip exercise with DASE decreases time to target heart rate, recovery time, overall study time, and mean dosage of dobutamine and atropine. In patients not on beta‐blocker medication, handgrip exercise should be routinely incorporated into all DASE protocols.
Rationale and design of the randomized, multicenter, Cilostazol for restenosis (CREST) trial
Authors: Douglas John S. , Weintraub William S. , Holmes David
Published: June 2007

Restenosis of a segment of diseased coronary artery following metallic stenting is a common clinical problem and a major limitation of the procedure. Systemic pharmacologic interventions to deal with this problem have met with little success. Several small studies suggest that cilostazol, a phosphodiesterase III inhibitor whose pharmacologic properties include antiplatelet, antithrombotic, and vasodilatory effects; a beneficial effect on serum lipids; and in vitro inhibition of smooth muscle cell proliferation, may help prevent platelet aggregation and impede the accumulation of new intimal tissue in the stented artery. The Cilostazol for RESTenosis (CREST) trial will aim to evaluate more definitively the ability of cilostazol to prevent restenosis following uncomplicated stent implantation for de novo coronary artery stenosis. In this randomized, double‐blind, multicenter study, 700 patients will receive clopidogrel, aspirin, and either cilostazol or placebo after successful intracoronary stent implantation. The primary endpoint is minimal luminal diameter (MLD) of the first lesion stented after 6 months; secondary endpoints include MLD in all lesions, mean percent diameter stenosis, target lesion revascularization, and major angiographic endpoints. Safety endpoints are abnormal complete blood count and liver function tests at 1, 3, and 6 months. The trial has been initiated, and enrollment is anticipated to be concluded in 2003. Cilostazol has properties that may reduce or avert in‐stent coronary restenosis. The CREST trial is a large, rigorously conducted trial that may corroborate the favorable effects of cilostazol on coronary stent restenosis suggested by earlier studies.
Magnetocardiography in coronary artery disease with a new system in an unshielded setting
Authors: Hailer Birgit , Chaikovsky Illja , Auth‐Eisernitz Sabine , Schäfer Harald , Steinberg Fritz , Grönemeyer Dietrich H. W.
Published: June 2007

Background: The noninvasive detection of coronary artery disease (CAD) remains a clinical challenge. Magnetocardiography is a completely noninvasive method that permits the registration of cardiac electrical activity at multiple sites in a plane above the chest cage without the need for electrodes. In contrast to the electrocardiogram (ECG) which suffers from boundary effects and a variety of potential artifacts (electrode placement, etc.) the MCG is unaffected by such impediments as the magnetic field is unaltered by surrounding tissues.

Hypothesis: Magnetocardiography with a newly developed single‐channel system in an unshielded setting should be a better qualitative diagnostic tool than the standard ECG for the detection and assessment of CAD.

Methods: In all, 52 patients with angiographically documented CAD and unimpaired ventricular function as well as 55 controls were included in this study. A standard 12‐lead ECG was obtained in all subjects. The MCG recordings were taken from 36 positions under resting conditions. From these, current density vector maps were generated during the ST‐T interval. Each map was then classified using a classification system with a scale from 0 (normal) to 4 (grossly abnormal).

Results: While the ECG was normal in all subjects, the MCG in the controls was classified as category 0, 1, or 2. However, in patients with abnormal coronary angiograms, mainly maps in categories 3 and 4 were seen (p < 0.05).

Conclusion: A single‐channel magnetometer in an unshielded setting reveals significant differences between normals and patients with CAD with normal ECG on the basis of current density reconstruction during the ST segment when measured under resting conditions. This method might be suitable for the noninvasive detection of CAD.
Differential effects of simvastatin and atorvastatin on high‐density lipoprotein cholesterol and apolipoprotein A‐I are consistent across hypercholesterolemic patient subgroups
Authors: Davidson Michael H. , Ose Leiv , Frohlich Jiri , Scott Russell S. , Dujovne Carlos A. , Escobar Ivan D. , Bertolami Marcelo C. , Cihon Frank , MacCubbin Darbie L. , Mercuri Michele
Published: June 2007

Background: In addition to lowering plasma levels of low‐density lipoprotein cholesterol (LDL‐C), statins also raise high‐density lipoprotein cholesterol (HDL‐C).

Hypothesis: Recent studies have shown that treatment with simvastatin results in larger increases in HDL‐C than those seen with atorvastatin. The results of three clinical studies are analyzed, comparing the effects of simvastatin and atorvastatin on HDL‐C and apolipoprotein A‐I (apo A‐I) in the total cohort and in several subgroups of hypercholesterolemic patients. The three studies were all multicenter, randomized clinical trials that included simvastatin (20–80 mg) and atorvastatin (10–80 mg) treatment arms. The subgroup analyses performed were gender; age (<65 and ≥65 years); baseline HDL‐C (male: < 40 or ≥ 40 mg/dl; female: < 45 or ≥ 45 mg/dl), baseline LDL‐C (< 160 or ≥ 160 mg/dl), and baseline triglycerides (< 200 or ≥ 200 mg/dl).

Results: Both drugs produced similar increases in HDL‐C levels at low doses; however, at higher drug doses (40 and 80 mg), HDL‐C showed a significantly greater increase with simvastatin than with atorvastatin (p< 0.05 to <0.001). Therefore, while HDL‐C remained consistently elevated across all doses of simvastatin, there appeared to be a pattern of decreasing HDL‐C with an increasing dose of atorvastatin. A similar negative dose response pattern was also observed with apo A‐I in atorvastatin‐treated patients, suggesting a reduction in the number of circulating HDL particles at higher doses. Both drugs reduced LDL‐C and triglycerides in a dose‐dependent fashion, with atorvastatin showing slightly greater effects. The differential effects of atorvastatin and simvastatin on HDL‐C and apo A‐I were observed for both the whole study cohorts and all subgroups examined; thus, no consistent treatment‐by‐subgroup interactions were observed.

Conclusion: The data presented show that, across different hypercholesterolemic patient subgroups, simvastatin increases HDL‐C and apo A‐I more than atorvastatin at higher doses, with evidence of a negative dose response effect on HDL‐C and apo A‐I with atorvastatin, but not simvastatin.
Insulin resistance and maximal oxygen uptake
Authors: Seibæk Marie , Vestergaard Henrik , Burchardt Hans , Sloth Carsten , Torp‐Pedersen Christian , Nielsen Steen Levin , Hildebrandt Per , Pedersen Oluf
Published: June 2007

Background: Type 2 diabetes, coronary atherosclerosis, and physical fitness all correlate with insulin resistance, but the relative importance of each component is unknown.

Hypothesis: This study was undertaken to determine the relationship between insulin resistance, maximal oxygen uptake, and the presence of either diabetes or ischemic heart disease.

Methods: The study population comprised 33 patients with and without diabetes and ischemic heart disease. Insulin resistance was measured by a hyperinsulinemic euglycemic clamp; maximal oxygen uptake was measured during a bicycle exercise test.

Results: There was a strong correlation between maximal oxygen uptake and insulin‐stimulated glucose uptake (r = 0.7, p = 0.001), and maximal oxygen uptake was the only factor of importance for determining insulin sensitivity in a model, which also included the presence of diabetes and ischemic heart disease.

Conclusion: Maximal oxygen uptake may be a more important determinant for insulin sensitivity than ischemic heart disease and type 2 diabetes.