Cardiac disease in dialysis patients in a Jamaican hospital: echocardiographic findings that predict mortality.

The aim of the study was to assess, by echocardiography, the cardiac abnormalities in a group of patients with chronic renal failure and to determine the cardiovascular predictors of mortality. The study comprised forty-five patients from the Renal Unit, University Hospital of the West Indies, Kingston, Jamaica, and was undertaken between October 1, 1998 and July 31, 2000. All echocardiography was done by a single operator. The parameters assessed were systolic dysfunction, diastolic dysfunction, ejection fraction, regional wall motion abnormalities and valvular disease. Left ventricular cavity size, septal and posterior wall thickness were measured and left ventricular mass calculated. Demographic data were obtained directly from each patient by interview. The patients were mainly of African/mixed-African origin. Their mean age was 43.2 +/- 16.0 years. The average body mass index was 23.7 +/- 6.9. Twenty-eight (60.9%) patients were male and seventeen (39.1%) female. Hypertension, chronic glomerulonephritis and diabetes mellitus were the leading causes of chronic renal failure. Blood pressure was controlled at a mean value of 145/90 mm Hg pre-dialysis and 140/90 mm Hg postdialysis. The mean duration of renal failure was 2.8 years. Echocardiographic M-mode and two dimensional apical, four chamber view measurements indicated that mean left ventricular internal diameter (LVID) diastole was 55.7 +/- 7.9 mm (normal 38-56 mm) and LVID systole was 38.9 +/- 9.8 mm (normal 24-45 mm); the mean thickness of the chamber walls was 10.3 +/- 2.8 mm and 10.6 +/- 2.4 mm for the interventricular septum (normal 6-11 mm) and left ventricular posterior wall (normal 6-11 mm) respectively. Diastolic dysfunction was seen in 15 (34%) patients and systolic dysfunction in 12 (23%) patients who had ejection fractions less than 50%. The mean left ventricular ejection fraction was 56.3% +/- 16% (normal 65-85%), mean stroke volume was 82.9 +/- 27.2 mls (normal 51-96 ml). After 21 months enrolment in the study, Kaplan Meier analysis revealed a two-year mortality of 28.3%. Cox regression analysis indicated that a history of smoking current or past, low haemoglobin level, high aorta flow velocities, severity of mitral regurgitation and a negative association with serum creatinine were independent predictors of mortality. The correction of anaemia and control of other factors that impact negatively on cardiac function in dialysis patients is vital to enhance survival.