Cardiac Function in an African Dialysis Population with a Low Prevalence of Pre-Existing Cardiovascular Disease

Abstract

Cardiac dysfunction is highly prevalent in dialysis patients in the developed world, and is a major cause of morbidity and mortality. The relative impact of pre-existing cardiac disease and dialysis/uremia on cardiovascular morbidity are not clear. We conducted a retrospective, cross-sectional analysis of cardiac function and mortality in 202 incident and prevalent dialysis patients over an 18-month period in a population with a low prevalence of cardiovascular disease at dialysis initiation. Systolic dysfunction was defined as an ejection fraction (EF) of <50%. Left ventricular hypertrophy (LVH) was determined by echocardiography or electrocardiogram. Clinical data was collected by chart review. Ninety-nine percent of patients were black, with a mean age of 41.7 +/- 10.1 years, and median follow up 28 months (range 1-216 months). Echocardiograms were available in 132 patients. Seventy-seven patients received hemodialysis, and 55 received peritoneal dialysis. Mean EF was 63.2 +/- 11.1. EF was not lower in patients with greater duration of dialysis, although LVH tended to increase (not statistically significant). In 39 patients who died during the study period, cardiac function was not different from survivors, and no patient died of ischemic heart disease or heart failure. In conclusion, in a population of patients with a low prevalence of cardiovascular disease at dialysis initiation, cardiac function appears preserved over time, and cardiac morbidity and mortality are low. This finding suggests that dialysis and uremia per se, in the absence of pre-existing cardiac disease, may not be major contributors to cardiovascular morbidity.

Stroke and its correlates among patients on maintenance hemodialysis in Cameroon

“…Patients undergoing maintenance hemodialysis in Africa are somewhat younger than those dialyzed in developed countries and they have a relatively low prevalence of pre-existing cardiovascular disease. 5 Several studies have tried to explain the reason behind the increased incidence of stroke in the ESKD population. Vascular imaging studies have documented a high prevalence of carotid artery atherosclerosis 17,18 in dialysis patients compared to patients with normal kidney function, consistent with the well-established association between kidney failure and generalized atherosclerotic vascular disease.…”

“…This lower rate might be related to differences in study design and methods, as many previous studies included patients with prior stroke and those on peritoneal dialysis. Patients undergoing maintenance hemodialysis in Africa are somewhat younger than those dialyzed in developed countries and they have a relatively low prevalence of pre‐existing cardiovascular disease 5 …”

“…Most presently available data regarding the association between chronic kidney disease and cardiovascular disease originates from studies performed outside of Africa 3,4 . Several studies have indicated that uremia per se may not be a major contributor to cardiovascular morbidity in Africa 5 and that among dialysis patients, black Africans have fewer cardiovascular events compared to other ethnicities. Patients with ESKD experience markedly advanced atherosclerotic disease of the cerebral vasculature 6–10 .…”