CVD is a major cause of death in persons with stage 4–5 chronic kidney disease, or CKD (estimated glomerular filtration rate lower than 30 mL/min/1.73 m2), accounting for approximately 40% of deaths in international registries of such patients. However, only limited data exist on the risk factors predicting these complications in these individuals, according to Ahmad Farshid, BMBS, and colleagues.
Dr. Farshid, of the cardiology unit at Canberra Hospital in Garran, Australia, and his team sought to determine the role of clinical and echocardiographic parameters in predicting mortality and cardiovascular complications in persons with advanced CKD. Their four-year prospective observational study included 153 consecutive patients of the renal outpatient clinic of a public tertiary referral hospital. All participants were adults (mean age 65.6 years; 57.5% male) with stage 4-5 CKD; 38% were already receiving dialysis and 78% of the dialysis group was on hemodialysis. Twenty percent of patients had a history of myocardial infarction and 46% had diabetes. Patients who were unable or unwilling to return for regular follow-up or who were at high risk of death from any cause within six months of enrollment were excluded from the study.
The majority of patients (85%) had some degree of diastolic dysfunction, with grade 2 or higher diastolic dysfunction present in 35%. Compared with those not on dialysis, patients on dialysis had a higher incidence of left ventricular dysfunction and troponin T elevation.
Over a mean follow-up of 2.6 years, mortality was 24% in the non-dialysis group and 31.6% in the dialysis group. On multivariate analysis, clinical predictors of death included diastolic dysfunction, a history of myocardial infarction, age older than 75 years, and elevated troponin T, the researchers reported in BMC Nephrology (2013;14:280).
Detection of significant diastolic dysfunction and elevated troponin T levels can be early markers of myocardial disease and increased risk in advanced CKD. “However,” they cautioned, “the optimal management of these patients is not well defined.”