RESUMO
BACKGROUND: Coronary slow flow phenomenon (CSFP) is a functional and structural disease that is diagnosed by coronary angiogram. OBJECTIVES: To evaluate the possible association between CSFP and small artery elasticity in an effort to understand the pathogenesis of CSFP. METHODS: The study population comprised 12 patients with normal coronary arteries and CSFP and 12 with normal coronary arteries without CSFP. We measured conjugated diene formation at 234 nm during low density lipoprotein (LDL) oxidation, as well as platelet aggregation. We estimated, noninvasively, arterial elasticity parameters. Mann-Whitney nonparametric test was used to compare differences between the groups. Data are presented as mean +/- standard deviation. RESULTS: Waist circumference was 99.2 +/- 8.8 cm and 114.9 +/- 10.5 cm in the normal flow and CSFP groups, respectively (P = 0.003). Four patients in the CSFP group and one in the normal flow group had type 2 diabetes. Area under the curve in the oral glucose tolerance test was 22% higher in the CSFP than in the normal group (P = 0.04). There was no difference in systolic and diastolic blood pressure, plasma concentrations of total cholesterol, triglycerides, high density lipoprotein, LDL and platelet aggregation parameters between the groups. Lag time required until initiation of LDL oxidation in the presence of CuSO4 was 17% longer (P = 0.02) and homocysteine fasting plasma concentration was 81% lower (P = 0.05) in the normal flow group. Large artery elasticity was the same in both groups. Small artery elasticity was 5 +/- 1.5 ml/mmHg x 100 in normal flow subjects and 6.1 +/- 1.9 ml/mmHg x 100 in the CSFP patients (P = 0.02). CONCLUSIONS: Patients with CSFP had more metabolic derangements. Arterial stiffness was not increased in CSFP.