Vahide Simsek

Impaired coronary flow reserve in patients with metabolic syndrome

BACKGROUND Metabolic syndrome (MetS) is a strong predictor of cardiovascular events. Coronary flow reserve (CFR), as determined by transthoracic echocardiography, is an indicator of microvascular function. In this study, we sought to determine whether CFR is impaired in patients with MetS without clinical coronary heart disease. METHODS Thirty-three patients with MetS (mean age, 67+/-8 years) and 35 age- and sex-matched controls were studied prospectively. Transthoracic two-dimensional and Doppler echocardiography was performed on all patients. Baseline and hyperemic (after dipyridamole infusion) coronary flow rates were measured using pulsed Doppler echocardiography. CFR was calculated as the ratio of hyperemic to baseline diastolic peak velocities. RESULTS There was no difference with regard to baseline systolic and diastolic coronary flow rates in patients with MetS compared with control subjects (19.9+/-3.1cm/s vs. 19.7+/-2.9cm/s, P>.05; and 27.7+/-4.2cm/s vs. 27.1+/-3.6cm/s, P>.05, respectively). Hyperemic diastolic flow and CFR were significantly lower in patients with MetS than in controls (61.7+/-9.4cm/s vs. 70.2+/-9.2cm/s, P<.0001; and 2.2+/-0.5 vs. 2.6+/-0.4, P=.001, respectively). In a logistic regression analysis that included age, sex, body mass index, hypertension, and dyslipidemia and MetS, MetS was the only predictor of a CFR<2.5 (P=.007, OR=6.1, 95% CI: 1.6-23.3). CONCLUSION In conclusion, CFR is impaired in patients with MetS suggesting that coronary microvascular dysfunction, an early finding of atherosclerosis, is present in this patient population. Metabolic syndrome is associated with a CFR<2.5.

Evaluation of coronary microvascular function in patients with end-stage renal disease, and renal allograft recipients.

BACKGROUND Approximately half of all deaths in patients with end-stage renal disease (ESRD) are due to cardiovascular diseases. Although renal transplant improves survival and quality of life in these patients, cardiovascular events significantly affect survival. We sought to evaluate coronary flow reserve (CFR), an indicator of coronary microvascular function, in patients with ESRD and in patients with a functioning kidney graft. METHODS Eighty-six patients (30 with ESRD, 30 with a functioning renal allograft, and 26 controls) free of coronary artery disease or diabetes mellitus were included. Transthoracic Doppler echocardiography was used to measure coronary peak flow velocities at baseline and after dipyridamole infusion. CFR was calculated as the ratio of hyperemic to baseline diastolic peak flow velocities and was compared among the groups. RESULTS The mean age of the study population was 36.1+/-7.3 years. No between-group differences were found regarding age, sex, or prevalences of traditional coronary risk factors other than hypertension. Compared with the renal transplant and control groups, the ESRD group had significantly lower mean CFR values. On multivariate regression analysis, serum levels of creatinine, age, and diastolic dysfunction were independent predictors of CFR. CONCLUSIONS CFR is impaired in patients with ESRD suggesting that coronary microvascular dysfunction, an early finding of atherosclerosis, is evident in these patients. Although associated with a decreased CFR compared with controls, renal transplant on the other hand seems to have a favorable effect on coronary microvascular function.

Coronary microvascular function in patients with isolated systolic and combined systolic/diastolic hypertension.

J Clin Hypertens (Greenwich). 2012;14:871–876. ©2012 Wiley Periodicals, Inc.

Comparison of Tissue Doppler Echocardiography Parameters in Patients With End-Stage Renal Disease and Renal Transplant Recipients

BACKGROUND Tissue Doppler echocardiography has been introduced as a useful tool to assess systolic myocardial function. In this study we sought to compare patients with end-stage renal disease (ESRD), with renal transplantations and control subjects with regard to tissue Doppler parameters. METHODS Thirty recipients with functional grafts of overall mean age 36 +/- 7 years included 24 men. An equal number of patients with ESRD of overall mean age 35 +/- 7 years included 20 men. A third cohort was comprised of 20 age- and gender matched control subjects. Tissue Doppler imaging from the septal and lateral mitral annulus of the left ventricle and free wall of the right ventricle was performed from a 4-chamber view. RESULTS Mean systolic and diastolic blood pressures were similar among the groups during imaging. Peak systolic velocity (S wave) at the septal annulus was similar in control subjects and recipients. S waves were significantly lower among ESRD patients compared with recipients (10.3 +/- 2.1 vs 12.0 +/- 2.5 cm/s, P = .04, respectively). Isovolumic contraction velocity of the septum and the right ventricular wall were significantly lower in ESRD patients than recipients or controls: 10.2 +/- 2.6 vs 12.5 +/- 2.8 vs 11.4 +/- 1.8 cm/s for septal wall (P = .008) and 13.9 +/- 3.6 vs 17.9 +/- 5.1 vs 16.8 +/- 5.8, for right ventricle (P = .01). CONCLUSION Systolic indices of tissue Doppler echocardiography in recipients demonstrated similar values as control subjects and increased values compared with ESRD patients. These results suggested improvement in systolic myocardial function following renal transplantation.