Impact of integrating heart rate response with perfusion imaging on the prognostic value of regadenoson SPECT myocardial perfusion imaging in patients with end-stage renal disease.

BACKGROUND: We investigated whether integrating heart rate response (HRR) to regadenoson with myocardial perfusion imaging (MPI) analysis can enhance risk prediction in end-stage renal disease (ESRD) patients.

METHODS AND RESULTS: We prospectively followed 303 ESRD patients after regadenoson stress MPI for a mean of 35 months. Normal HRR to regadenoson was defined as ≥28% increase from baseline. Normal MPI was defined as a summed stress score ≤3 and left ventricular ejection fraction ≥50%. The study cohort was divided in four groups based on various combinations of normal/abnormal HRR and MPI. There was a step-wise increase in the risk of primary endpoint of all-cause death and the composite secondary endpoint of cardiac death or myocardial infarction; patients with Normal MPI/Normal HRR had the lowest event rates and those with Abnormal MPI/Abnormal HRR had the highest, whereas subjects with Abnormal MPI/Normal HRR and Normal MPI/Abnormal HRR had intermediate event rates. This pattern was maintained after adjusting for important clinical covariates.

CONCLUSION: In ESRD patients, integrating HRR to vasodilator stress with MPI interpretation improves risk stratification. Normal HRR/Normal MPI identify truly low-risk group, whereas abnormal MPI or abnormal HRR portrays elevated risk.