Prognostic utility of Tc-tetrofosmin dipyridamole stress studies in patients with end-stage renal disease (ESRD) on chronic dialysis

Abstract

Background: Patients with end-stage renal disease (ESRD) have a higher prevalence of and mortality from coronary artery disease (CAD) than the general population. The prognostic utility of SPECT Technetium-tetrofosmin dipyridamole stress myocardial perfusion imaging (MPI) in this population is unknown. Previous studies have also cast doubts on the efficacy of dipyridamole-stress in this scenario. Methods: A consecutive series of 226 patients with ESRD on chronic dialysis underwent dipyridamole stress Tc-99m tetrofosmin SPECT imaging over 3.6 years (Jan 2000 Aug 2003) at the National University Hospital, Singapore. This represents 9% of all patients in Singapore (population 4 million) on chronic dialysis. Uniform methods of data collection and standardized epidemiologic methods for follow-up were employed. Follow-up was complete in 99% of patients at 2 years. Results: The average age was 58 years (range 20 80 years), 120 were male. 138 patients (61%) had diabetes, 193 (85%) hypertension. 176 patients had normal scans. None of these patients with normal scans underwent angiography within 3 months of the index MPI study. At 1.97 years of follow-up, 2 (1%) patients with normal scans had experienced a cardiac event (myocardial infarction / cardiac death), and a total of 21 patients had died (12%). No patients had undergone revascularization. The annualized cardiac event rate was 0.5%. 52 patients had abnormal scans. Of these, 5 patients underwent angiography within 3 months of imaging, 3 then had bypass surgery and 1 angioplasty. 2 patients sustained non-fatal MI. 11 patients died over the follow-up period, of which 2 were due to myocardial infarction. The cardiac event rate (cardiac death/MI/revascularization) in patients with abnormal scans was 15% (annualized rate 8%). Conclusions: 1)The negative predictive value of a normal Tc-tetrofosmin dipyridamole stress test was high and conferred good cardiac prognosis in this population. 2)Dipyridamole-stress is an effective modality in stratifying cardiac risk in patients with ESRD on chronic dialysis.