Abstract 18036: Heart Rate Response to Adenosine is an Independent Predictor of Long-term Mortality in End Stage Renal Disease

Abstract

Introduction: We have shown that a blunted heart rate response to adenosine (HRR) is an independent predictor of poor outcome in all comers undergoing myocardial perfusion imaging (MPI). Patients with end stage renal disease (ESRD) are at exceptionally high risk. We hypothesized that HRR will be independently associated with mortality in this population.

Methods: We studied ESRD patients undergoing renal transplant evaluation at our institution between 2003-2007 who had adenosine MPI. All images were reprocessed using an automated program to determine the presence and extent of perfusion defects and measure left ventricular ejection fraction (EF). HRR was calculated as the % heart rate change from baseline during adenosine infusion. Mortality data was prospectively collected and verified against the social security death index database.

Results: The study population consisted of 792 ESRD patients (age 52.6 ± 0.4 yrs, 60% diabetes mellitus, 95% hypertension). During a mean follow-up of 5.1± 0.1 years, 281 (36%) patients died. The HRR was lower in patients who died than those who survived (19 ± 1 vs. 28 ± 1 %, p<0.001). There was a stepwise increase in mortality with decreasing HRR by tertiles (Fig). In univariate analysis, HRR (HR 0.979, p<0.001) and EF (HR 0.908, p<0.001) but not perfusion defect size (HR 1.003, p=0.5) were associated with mortality. In a multivariate model adjusting for age, gender, diabetes, hypertension, and perfusion both HRR (0.982, p<0.001) and EF (0.982, p<0.001) were independent risk predictors. A low HRR was associated with worse survival in patients with or without diabetes, perfusion defects or depressed EF (<50%).

Conclusions: HRR is a strong independent predictor of mortality in ESRD. A 1% drop in HRR provides similar prognostic data to 1% drop in EF. HRR possibly due to autonomic denervation provides valuable prognostic information in this high-risk population especially in the subset with normal perfusion pattern or normal EF.