Endothelial and Microvascular Functions in Patients With Myocardial Ischemia

Cardiovascular diseases (CVD) are responsible, throughout the world, for high mortality rates and cardiovascular morbidity. Endothelial dysfunction is the earliest marker of clinical atherosclerosis development. Human studies show that endothelial and microvascular dysfunction are independent predictors of ischemic cardiovascular events and long-term prognosis. The study´s objective is to evaluate the endothelial and peripheral microcirculation changes by venous occlusion plethysmography (VOP), nailfoldvideocapillaroscopy (NVC) and serum biomarkers in patients with myocardial ischemia detected by scintigraphy and normal coronarography.

A cross-sectional study was carried out with 50 participants: 25 with myocardial ischemia detected by scintigraphy and normal coronarography (Ischemic Patient - IP) and 25 healthy non-ischemic individuals (Control Group - CG). All of them were submitted to anamnesis, serum markers (Intercellular Cell Adhesion Molecule \[ICAM\], Vascular Cell Adhesion Molecule\[VCAM\], adiponectin, endothelin, LDL-oxidized and CRP-US), NVC and VOP. Exclusion criteria were: inflammatory diseases, cancer patients, recent traumas, Diabetes Mellitus, obese individuals with BMI\> 35 kg/m², uncontrolled hypertensive patients, and those with active infectious processes. In the NVC,capillary diameters were observed, as well as red blood cells velocity in the capillaries (RBCV, mm/s), maximum red blood cells after 1 minute ischemia (RBCVmax, mm/s) and time to reach maximal velocity (TRBCVmax) and, regarding VOP,the baseline blood flow (ml/min), post 5 minute ischemia flow and vascular resistance (mmHg/ml/min) were evaluated. Data were analyzed using Student's t-tests for independent or Mann-Whitney samples; χ2 or Fisher exact. The absolute and relative variations (delta) of plethysmography measurements versus baseline in each group were analyzed by the Wilcoxon signed-ranks test and compared between the groups by the Mann-Whitney test. For correction of confounding factors, age and BMI, it was used Covariance Analysis (ANCOVA).

Eligibility Criteria:
Inclusion Criteria:

The study population consisted of 50 patients of both sexes, stratified into two groups: patients with myocardial ischemia detected by scintigraphy (group IP, n = 25) and healthy individuals (CG group, n = 25). In the patients who underwent scintigraphy with tomographic sections and presented any type of image attenuation during the examination, they also underwent a complementary prone position technique. Patients without these characteristics scintigraphy methodologies were excluded from the study.

Exclusion Criteria:

Exclusion criteria were adopted: patients with type 1 or 2 Diabetes Mellitus, heart failure, myocardial infarction or brain stroke with less than three months of the event, chronic renal disease, users of hormonal or non-hormonal anti-inflammatory drugs, recent trauma (less than three months) autoimmune diseases, active infectious processes, presence of neoplasia, use of Aspirin (anti-inflammatory dose), obesity with BMI\>35 kg/m², uncontrolled hypertensive patients, resistant hypertensives, and non-compliance in the examinations or with the signature of the Consent Form.