bluuebunny/crossref_metadata_2025_split huggingface dataset:
P5627Automated detection of calcified plaques in coronary optical coherence tomography images using image segmentation based on machine learning
Authors: Gangl C , Roth C , Dalos D , Delle-Karth G , Neunteufl T , Berger R 
Published: October 2019

Abstract

Background and aim
Automated image recognition based on machine learning methods was proven to be feasible in several medical imaging applications recently. Beside image classification methods to categorize input images for example into healthy or suspicious, image segmentation allows accurate localization of pathologies and thereby facilitates a wide area of applications. Because of the unique composition of every machine learning problem the applicability of image segmentation methods for detecting coronary pathologies in optical coherence tomography images remains unclear. Furthermore, the prediction accuracy of deep learning methods usually depends on vast amounts of training data which are often not available for particular medical questions. Therefore special strategies need to be applied to achieve satisfying results with smaller training datasets. We aimed to investigate the applicability of machine learning methods for plaque detection in coronary OCT images, especially considering the challenge of a small training dataset.

Methods
Originating from a dataset of 104 OCT frames containing calcified plaques, we performed image preprocessing using a custom build OCT image processing software to crop the luminal part as well as the areas outside the circular OCT signal to reduce entropy. Furthermore, plaques were identified and marked by an experienced OCT analyst, drawing plaque-enclosing polygonal masks using the same software. We also performed common image augmentation strategies, primarily applying rotation and zoom operations. Subsequently, we split the samples randomly into training, validation and test datasets (80:10:10%). To train the segmentation model, we fed the training and validation samples into an U-Net Convolutional Neuronal Network implementation with domain-specific adaptions using the RMSprop optimizer based on the publicly available PyTorch library.

Results
After 50 training epochs, we could achieve a prediction accuracy of 74.4% with the current configuration measured by the Sørensen–Dice coefficient comparing the similarity of the predicted plaque masks with the ground truth samples (figure 1 illustrates an exemplary comparison between predicted and ground truth plaque masks).
Exemplary projection of a predicted mask

Conclusion
We were able to show that image segmentation based on machine learning strategies is a feasible way for automated plaque detection in coronary OCT imaging even based on small training datasets. Larger training datasets are necessary to raise prediction accuracy.
P5631The impact of plaque type on strut embedment/protrusion and shear stress distribution in bioresorbable scaffold
Authors: Tenekecioglu E , Torii R , Katagiri Y , Dijkstra J , Modolo R , Pekkan K , Bourantas C , Serruys P W 
Published: October 2019

Abstract

Background and aim
Scaffold design and plaque characteristics influence implantation outcomes and local flow dynamics in treated coronary segments. Our aim is to assess the impact of strut embedment/protrusion of bioresorbable scaffold on local shear stress distribution in different atherosclerotic plaque types.

Method
Fifteen Absorb everolimus-eluting Bioresorbable Vascular Scaffolds were implanted in human epicardial coronary arteries. Optical coherence tomography (OCT) was performed post-scaffold implantation and strut embedment/protrusion were analyzed using a dedicated software. OCT data was fused with angiography to reconstruct three-dimensional coronary anatomy. Blood flow simulation was performed and wall shear stress (WSS) was estimated in each scaffolded surface and the relationship between strut embedment/protrusion and WSS was evaluated.

Results
There were 9083 struts analysed. Ninety-seven percent of the struts (n=8840) were well apposed and 243 (3%) were malapposed. At cross-section level (n=1289), strut embedment was significantly increased in fibroatheromatous plaques (76±48μm) and decreased in fibro-calcific plaques (35±52 μm). Compatible with strut embedment, WSS was significantly higher in lipid-rich fibroatheromatous plaques (1.50±0.81Pa), whereas significantly decreased in fibro-calcified plaques (1.05±0.91Pa). After categorization of WSS as low (<1.0 Pa) and normal/high WSS (≥1.0 Pa), the percent of low-WSS in the plaque subgroups were 30.1%, 31.1%, 25.4% and 36.2% for non-diseased vessel wall, fibrous plaque, fibro-atheromatous plaque and fibro-calcific plaque, respectively (p-overall<0.001).
Table 1. Cross-section level Embedment/Protrusion and WSS according to the plaque type Plaque type Embedment depth (μm) Protrusion distance (μm) WSS (Pa) Non-atherosclerotic intimal thickening/normal vessel wall (n=2275) 47±34*Δ¥ 123±34¶Ξπ 1.44±0.9θ§£ Fibrous (n=4191) 53±40*#& 118±38¶Ψ‡ 1.24±0.78αθ∞ Fibroatheromatous (n=2027) 76±48#ΦΔ 94.6±46Ω†Ψπ 1.50±0.81Σ§α Fibro-calcific (n=590) 35±52&Φ¥ 139±50‡†Ξ 1.05±0.91∞£Σ For embedment: *p=0.09, #p<0.001, &p<0.001, Φp<0.0001, Δp<0.0001, ¥p<0.0001. For protrusion: ¶p=0.74, Ξp<0.0001, πp<0.0001, Ψp<0.0001, ‡p<0.0001, †p<0.0001. For WSS: θp<0.001, §p=0.06, £p<0.0001, αp<0.0001, ∞p<0.0001, Ωp<0.0001. n=total strut number in each plaque type, p-values come from mixed-effects regression analysis.

Conclusion
The composition of the underlying plaque influences strut embedment which seems to have effect on WSS. The struts deeply embedded in lipid-rich fibroatheromas plaques resulted in higher WSS compared to the other plaque types.
P5632Different impact of lesion length on fractional flow reserve in intermediate coronary lesions between each coronary artery
Authors: Shibutani H , Fujii K , Matsumura K , Otagaki M , Morishita S , Bando K , Motohiro M , Umemura S , Sugita H , Tanaka M , Shiojima I 
Published: October 2019

Abstract

Background
Previous studies reported that lesion length was an important geometric parameter in addition to the degree of stenosis in the determinant of functional significance of coronary artery stenosis. Nevertheless, the optimal cutoff value of lesion length for predicting functional significance for each coronary artery has not yet been evaluated, though previous studies revealed that the cutoff value of minimum lumen diameter measured on coronary angiography (CAG) to predict fractional flow reserve (FFR) <0.80 is different for each coronary artery

Purpose
This study evaluated whether the impact of lesion length on functional significance is similar between each coronary artery for lesions with intermediate stenosis.

Methods
Patients with suspected coronary artery disease who had at least one intermediate coronary lesion (luminal diameter stenosis of 70 to 80% by visual estimation on CAG) and underwent FFR measurement for the evaluation of myocardial ischemia were evaluated. Quantitative coronary angiography analysis including percent diameter stenosis and lesion length was performed. FFR was measured as the ratio of the mean distal coronary artery pressure to the mean aortic pressure during maximal hyperemia induced by intravenous infusion of adenosine triphosphate (150 μg /kg/min). The area under the receiver operating characteristics (ROC) curve was estimated for the best cutoff value as a predictor of FFR value of ≤0.80 for each coronary artery.

Results
A total of 221 de novo lesions that underwent FFR measurement were enrolled. The average FFR value was 0.81±0.07. Although lesion length was similar among the lesions with an FFR >0.80 at different locations, the mean lesion length was significantly longer for lesions in the right coronary artery (RCA) with an FFR ≤0.80 than for those in the left anterior descending artery (LAD) and left circumflex artery (13.4±3.4 versus 8.6±3.1 versus 12.0±3.7 mm, p<0.001). ROC analysis demonstrated that the optimal cutoff value of lesion length for predicting an FFR ≤0.80 was 10.0 mm in the LAD (0.56 area under the curve, 48% sensitivity, 76% specificity), whereas 13.1 mm in the RCA (0.84 area under the curve, 67% sensitivity, 93% specificity) (Figure).
ROC analysis of LL for FFR≤0.80

Conclusions
A longer lesion length is required to achieve FFR<0.80 in the RCA than in the other arteries. This may suggest the low possibility of an FFR ≤0.80 when stenosis is focal and short in the RCA with stenosis of 70 to 80% by visual estimation on CAG.
P5639Risk stratification for mortality using electrocardiographic markers based on 24-hour holter recordings: the JANIES-SHD study
Authors: Kinoshita T , Hashimoto K , Yoshioka K , Miwa Y , Yodogawa K , Watanabe E , Nakamura K , Nakagawa M , Nakamura K , Watanabe T , Yusu S , Tachibana M , Nakahara S , Mizumaki K , Ikeda T 
Published: October 2019

Abstract

Background
Recent guidelines have stated that reduced left ventricular ejection fraction (LVEF) is the gold standard marker for identifying patients at risk for cardiac mortality. Although reduced LVEF identifies patients at an increased risk of cardiac arrest, sudden cardiac deaths (SCDs) occur considerably more often in patients with relatively preserved LVEF. Current guidelines on SCD risk stratification do not adequately cover this general population pool. Several noninvasive electrocardiographic (ECG) risk stratifiers that reflect depolarization abnormality, repolarization abnormality, and autonomic imbalance have been evaluated so far. With current therapeutic advances using new medicines or devices, an LVEF is often preserved in patients with structural heart disease (SHD). However, the usefulness of noninvasive ECG markers for risk stratification in such a patient population has not yet been elucidated.

Purpose
This study aimed to assess clinical indices and ECG markers based on 24-hour Holter ECG recordings for predicting cardiac mortality in patients with SHD who have left ventricular dysfunction (LVD) but relatively preserved LVEF.

Methods
In total, 1,829 patients were enrolled into the Japanese Multicenter Observational Prospective Study (JANIES study). In this study, we analyzed data of 719 patients (569 men, age 64±13 years) with SHD including mainly ischemic heart disease (65.8%). As ECG markers based on 24-hour Holter recordings, nonsustained ventricular tachycardia (NSVT), ventricular late potentials, and heart rate turbulence (HRT) were assessed. The primary endpoint was all-cause mortality, and the secondary endpoint was fatal arrhythmic events.

Results
During a mean follow-up of 21±11 months, all-cause mortality was eventually observed in 39 patients (5.4%). Among those patients, 32 patients (82%) suffered from cardiac causes such as heart failure and arrhythmia. Multivariate Cox regression analysis showed that after adjustment for age and LVEF, documented NSVT (hazard ratio=2.82, 95% confidence interval [CI]: 1.38–5.76, P=0.005) and abnormal HRT (hazard ratio=2.31, 95% CI: 1.15–4.65, P=0.02) were significantly associated with the primary endpoint. These two ECG markers also had significant predictive values with the secondary endpoint. The combined assessment documented NSVT and abnormal HRT improved predictive accuracy.

Conclusion
This study demonstrated that combined assessment of documented NSVT and abnormal HRT based on 24-hour Holter ECG recordings are recommended for predicting future serious events in SHD patients who have relatively preserved LVEF.

Acknowledgement/Funding
Grants-in-Aid (21590909, 24591074, and 15K09103 to T.I.) for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technol
P5645Lifetime sex-specific sudden cardiac death prediction using ECG global electrical heterogeneity: the atherosclerosis risk in communities (ARIC) study
Authors: Howell S , Perez-Alday E , German D , Bender A , Rogovoy N , Haq K , Tereshchenko L 
Published: October 2019

Abstract

Background
Sex-based differences in sudden cardiac death (SCD) exist and screening methods for SCD are inadequate.

Purpose
To develop sex-specific lifetime risk prediction models using electrocardiographic (ECG) global electrical heterogeneity (GEH) and clinical characteristics.

Methods
Participants from the Atherosclerosis Risk in Communities study with analyzable ECGs (n=14,725; age, 54.2±5.8 yrs; 55% female, 74% white) were followed up for 24.4 years (median). Traditional ECG and GEH variables were measured on 12-lead ECGs. A Cox regression model was used to develop a prediction model. In women, the final model included race, age, coronary heart disease (CHD), stroke, hypertension, diabetes, smoking, high-density lipoprotein, albumin, uric acid, education level, heart rate, QTc, sum absolute QRST integral, spatial peak QRS-T angle. In men, the final prediction model included age, race, CHD, stroke, hypertension, diabetes, total cholesterol, physical activity, smoking, serum phosphorus, albumin, chronic kidney disease, spatial area QRS-T angle, area spatial ventricular gradient (SVG) elevation and magnitude, and peak SVG magnitude.

Results
There were a total of 530 SCDs. Our prediction models showed robust prediction of SCD in both sexes [(Harrell's C-statistic women 0.863 (95% CI 0.845–0.882), men 0.786 (95% CI 0.786–0.803)]. In women when ECG and GEH variables were added to clinical variables, the net reclassification improved by 9% (P=0.001) (Table). In men there was no significant reclassification improvement.
Net reclassification Lifetime SCD Risk: Clinical + ECG + GEH Variables Women Men <5% 5–15% >15% Total <5% 5–15% >15% Total SCD Cases <5% 82 14 0 96 103 16 0 119 5–15% 7 59 10 76 12 116 12 140 >15% 0 0 20 20 0 5 74 79 Lifetime SCD Risk: Total 89 73 30 192 115 137 86 338 Clinical Variables Only Non-Cases <5% 6,956 131 2 7,089 4,411 264 0 4,675 5–15% 180 509 42 731 210 1,059 48 1,317 >15% 0 28 84 112 0 56 214 270 Total 7,136 668 128 7,932 4,621 1,379 262 6,262

Conclusions
We were the first to develop sex-specific lifetime SCD prediction models. The addition of ECG GEH to clinical variables improved SCD risk reclassification in women, but not in men. Prediction of SCD was more accurate in women as compared to men.
P5646Risk factor paradox in STEMI-related sudden cardiac arrest
Authors: Karam N , Bataille S , Marijon E , Loyeau A , Tafflet M , Lamhaut L , Pires V , Boche T , Dupas F , Le Bail G , Allonneau A , Juliard J M , Lapostolle F , Lambert Y , Jouven X 
Published: October 2019

Abstract

Background
Cardiovascular risk factors (CVRF) are associated with an increased risk of atherosclerosis and ST-segment elevation myocardial infarction (STEMI). Sudden cardiac arrest (SCA) is currently the most feared complication of STEMI. The impact of CVRF on the rate of SCA is still unknown.

Purpose
To assess the association between CVRF and pre-hospital SCA during acute STEMI.

Methods
Data were taken between 2006 and 2014 from the e-MUST study that enrolls all STEMI managed by EMS in the Greater Paris Area, including those dead before hospital admission. Characteristics of patients who presented SCA were compared to those of patients who did not, and multivariable logistic regression was developed including all variables that differed between the two groups, in order to identify characteristics associated with an increased risk of SCA.

Results
Over the study period, 13,253 STEMI patients were included (median age 60.1 [51.4 - 73.0], 78.1% males). Among them, 7,513 patients (58.1%) had ≥2 CVRF, 3,979 (30.8%) had 1 CVRF, and 1,432 (11.1%) did not present any CVRF. Pre-hospital SCA witnessed by emergency medical services occurred in 749 (5.6%) patients. SCA victims were younger compared to the non-SCA group (58.0 vs. 60.3 years (P<0.001), with a higher proportion of patients without known CVRF (17.2 vs. 10.7%, P<0.001). There was no statistical difference in sex ratio (77.5% vs. 78.2%, P=0.69) and presence of past history of coronary artery disease (18.7% vs. 19.5%, P=0.56). Patients with ≥2 CVRF had the lowest rate of SCA (4.6%), while the highest SCA rate occurred among patients without CVRF (8.9%). On multivariate analysis, the presence of ≥2 CVRF was associated with a twice-lower risk of SCA (OR 0.52, 95% CI 0.41–0.65, P<0.001, when the group without risk factors was taken as a reference group).

Conclusion
The prevalence of CVRF is high among patients presenting STEMI. However, once STEMI has occurred, presence of CVRF is associated with a lower rate of SCA per STEMI, creating a risk factor paradox in STEMI-related SCA.
P5650Improvement in ejection fraction predicts heart failure after catheter ablation for atrial fibrillation in patients with left ventricular systolic dysfunction: from the KPAF registry
Authors: Fujimoto H , Doi N , Hirai K , Naito M , Shizuta S , Kobori A , Inoue K , Kaitani K , Kurotobi T , Morishima I , Satomi K , Yamaji H , Nakazawa Y , Kusano K , Kimura T 
Published: October 2019

Abstract

Introduction
The presence of atrial fibrillation (AF) in patients with reduced left ventricular ejection fraction (LVEF) is associated with increased risks of mortality and hospitalization for heart failure (HF). Although prior studies reported that catheter ablation (CA) for AF in low LVEF patients reduced risks of all-cause mortality and HF hospitalization, the predictors of worsening HF after ablation has not been adequately evaluated.

Purpose
The purpose of this study was to investigate the impact of improvement in LVEF after AF ablation on the incidence of subsequent HF hospitalization in patients with low LVEF.

Methods
The Kansai Plus Atrial Fibrillation (KPAF) Registry is a multicenter registry enrolling 5,013 consecutive patients undergoing first-time ablation for AF. The current study population consisted of 1,031 patients with reduced LVEF of <60%. We divided the study population into 3 groups according to LVEF at follow-up; 678 patients (65.8%) with improved LVEF (≥5 U change in LVEF), 288 patients (27.9%) with unchanged LVEF (−5 U ≤ change in LVEF <5 U) and 65 patients (6.3%) with worsened LVEF (<−5 U change in LVEF).

Results
During the median follow-up of 1067 [879–1226] days, patients improved LVEF had lower rate of HF hospitalization, compared with those with unchanged and worsened LVEF (2.1%, 8.0%, and 21.5%, respectively, P<0.0001). Recurrent atrial tachyarrhythmias were documented in 43.5%, 47.2% and 67.7%, respectively (P=0.0008).
Figure 1

Conclusion
Among patients with reduced LVEF undergoing AF ablation, patients with subsequently improved LVEF in association with maintained sinus rhythm had markedly lower risk of HF hospitalization during follow-up as compared with those with unchanged or worsened LVEF.
P5653Atrial fibrillation in arrhythmogenic right ventricular cardiomyopathy and its association with left atrial volume index
Authors: Baturova M A , Svensson A , Svendsen J H , Bundgaard H , Carlson J , Meurling C , Astrom Aneq M , Platonov P G 
Published: October 2019

Abstract

Background
Recent studies in arrhythmogenic right ventricular cardiomyopathy (ARVC) support atrial involvement in the disease progression and consider atrial fibrillation (AF) as one of the primary manifestations of ARVC. We aimed to assess clinical factors, components of 2010 Task Force criteria (TFC2010) and echocardiographic characteristics of atria associated with AF in the Scandinavian cohort of ARVC patients.

Methods
Study sample comprised of 106 definite ARVC patients by TFC2010 from three tertiary care centers participating in the Nordic ARVC Registry (33% females, median age at ARVC diagnosis 41 years [IQR 30–54 years]). No concomitant diseases were observed in 90 patients (85%) while 16 patients had one or more comorbidities: hypertension (n=6), diabetes mellitus (n=5), coronary artery disease (n=5) or congestive heart failure (n=9). AF was included in the registry protocol as a pre-specified clinical event and verified by processing of the electronic ECG databases which contains all ECG recordings from the involved hospitals catchment areas (earliest ECG from 1988). Left (LA) and right atrial (RA) dimensions were obtained by revisiting cardiac ultrasound examinations performed at the time of ARVC diagnosis. Association between AF and clinical characteristics was assessed using multivariable logistic regression analysis adjusted for age and gender.

Results
AF was diagnosed in 29 patients (27%) at a median age of 53 (IQR 38–63) years, 7 females (24%). Median time from ARVC diagnosis to AF onset was 8 (IQR 2–12) years. AF was univariately associated with right ventricular structural abnormalities meeting the definition of major imaging criterion by 2010TFC, ventricular tachycardia (VT) with superior axis (major criterion) and LA volume index. Significantly associated variables were included in a multivariate model, in which LA volume index (OR=1.07, 95% CI 1.01–1.14, p=0.021) and superior axis VT (OR=7.45, 95% CI 1.82–30.55, p=0.005) remained independently associated with AF. In receiver operating characteristic (ROC) curve analysis, LA volume index was significantly associated with AF (AUC=0.703, p=0.005) and with superior axis VT (AUC=0.703, p=0.021). AF was not associated with either RA volume index (univariate OR=1.03, 95% CI 0.99–1.06, p=0.203) or left ventricular ejection fraction (OR=0.97, 95% CI 0.92–1.03, p=0.299).

Conclusion
In patients with ARVC,AF is primarily associated with LA structural abnormalities without indication of RA involvement and is strongly associated with ventricular arrhythmias thus indicating parallel development of atrial and ventricular arrhythmic substrate.