Prolonged QT interval is a predictor of cardiovascular mortality. It indicates delayed repolarization of ventricular myocardium and is considered a precursor of malignant cardiac arrhythmias and sudden cardiac death. Increased cardiovascular risk (CVR) in the presence of prolonged QT interval, corrected by heart rate (QTc), is attributed to ventricular electrical instability. Patients with chronic renal disease (CRD) usually die from sudden cardiac death before reaching the final stage, final chronic kidney disease (CRD stage V). We investigated whether patients with CRD stage III-V have prolonged QT interval, what are the possible causes of this extension, and whether in this patient population trimetazidine application may affect the reduction in QT prolongation. Our study showed one quarter of predialysis patients, mostly asymptomatic, to have QT prolongation, thus being at a higher risk of CV events. Introducing trimetazidine along with standard therapy can reduce the incidence of sudden cardiac death, and calculation of the QTc index would be a useful and economical method of screening and monitoring high risk patients.