Association of renal insufficiency with eccentric left ventricular hypertrophy in patients with renal artery stenosis

Abstract

Introduction: Observational studies have consistently demonstrated high cardiovascular event rates in patients with renal artery stenosis (RAS) that present with renal insufficiency. However, no study has yet established in this population a clear linkage between renal insufficiency and changes in cardiac structure. Hypothesis: Left ventricle hypertrophy (LVH) is an independent risk factor for increased cardiac morbidity and mortality. Thus, the current study was undertaken to 1) evaluate the prevalence of LVH in this population and describe the patterns of hypertrophy, and 2) determine whether renal insufficiency or other baseline factors influence the frequency or pattern of LVH. Methods: The population is a cohort of 78 patients out of 244 patients undergoing stenting for renal artery stenosis, who had an echocardiogram prior to the intervention. LVH was determined in all the patients and categorized into normal, concentric hypertrophy and eccentric hypertrophy using left ventricular mass index (LVMI) using the criteria of Devereux (LVMI >134 g/m2 for men and >110g/m2 for women), and relative wall thickness (RWT) was calculated as the 2 X posterior to end diastolic diameter ratio (a value of 0.44 was taken as the partition value to distinguish between LVH phenotypes). Baseline clinical characteristics and the indications for renal stenting were compared to the left ventricular geometry. Results: The baseline clinical characteristics of the patients who had echocardiogram (n = 78) were similar (p = NS) to the patients who did not have an echocardiogram (n = 166). The mean left ventricular mass index (LVMI) in the 78 patients was 117±40 g/m2 and 38% of the patients had LVH. Among the 30 patients with LVH, 13 (43%) had concentric hypertrophy and 17 (57%) had eccentric hypertrophy. Patients with eccentric hypertrophy were more likely to have renal insufficiency (53% vs 19%, 23%, p = 0.02) and heart failure as the indication for renal artery stenting (47% vs 16%, 23%, p = 0.04). Conclusions: In patients with renal artery stenosis undergoing stenting, there is a high prevalence of LVH (38%), which is consistent with previously published studies. The current study demonstrating a strong association of chronic renal insufficiency with eccentric hypertrophy might be a major factor that contributes to the increased morbidity and mortality in patients with renal artery stenosis presenting with renal insufficiency.