Abstract 19655: AVR Elevation Predicts Early Revascularization but not Cardiac Events in Patients Undergoing Exercise Stress Myocardial Perfusion Imaging
Introduction: Lead AVR elevation has been associated with a high prevalence of multivessel disease in patients undergoing exercise stress. Myocardial perfusion imaging (MPI) may be falsely negative in multivessel disease due to balanced ischemia, leading to false reassurance. We sought to identify the prevalence of early revascularization and subsequent cardiac events in a cohort undergoing exercise stress SPECT MPI.
Methods: We analyzed clinical data and prospectively-collected events on a cohort of 587 consecutive patients referred for exercise SPECT MPI. Standard exercise protocols were used. AVR elevation was defined as ≥1mm in 3 consecutive beats. Follow-up was 98% complete with a median time of 3.75 years. Cardiac events included cardiac death and nonfatal myocardial infarction. Early revascularization rates were compared by chi-square analysis. The effect of AVR elevation on cardiac events was assessed using Cox proportional hazards analysis.
Results: The cohort had a median age of 60.0 years and 61.4% were male. Patients with AVR elevation had a higher prevalence of hypertension, dyslipidemia, and known CAD. Early revascularization was 10-fold higher in patients with AVR-elevation (8.3% versus 0.81%, p<0.001). In the 568 patients without early revascularization, there were 24 cardiac events (1.1%/year), of whom only 10 (41.7%) had AVR elevation on their initial stress test. AVR elevation was not a significant predictor of cardiac events by Cox analysis (Hazard Ratio 2.0 (95% CI 0.8-5.1), p=0.137).
Conclusion: AVR elevation on exercise electrocardiography strongly predicts early revascularization. However, there was a low cardiac event rate in the remaining patients, and events were not predicted by AVR elevation. This idicates a low risk of clinically significant false-negative SPECT in this subgroup.
- © 2012 by American Heart Association, Inc.