BACKGROUND: The prognostic significance of the difference between poststress and at rest left ventricular ejection fraction (ÄLVEF) in patients sent for diagnostic myocardial perfusion study (MPS) is not well characterized. The purpose of this study was to prospectively evaluate the ability of ÄLVEF in further risk stratifying these patients in addition to the severity/extent of myocardial perfusion abnormalities expressed as the total perfusion deficit at stress (sTPD), according to the type of stress used.METHODS AND RESULTS: Two-day 99mTc-MIBI MPS after stress and rest were obtained for 507 patients subdivided according to the type of stress used, sTPD values, and ÄLVEF. Subsequent cardiac events were determined through a standardized questionnaire applied 1, 2, and 6 years after MPS. Independent of the type of stress used, the 6-year event rate with progressive perfusion and functional abnormalities combined was significant for total events, all-cause death, cardiac death, and revascularization but not for myocardial infarct. When ÄLVEF decreased by more than -10%, only those individuals with sTPD of 5% or less had increased 6-year total event rates [5.9% vs 15% for those submitted to treadmill test (P < 0.001) and 8.3% vs 19% when submitted to pharmacological stress (P = 0.001)]. An sTPD greater than 5% was the only variable predictive of total events when multivariate analysis was applied (P < 0.001 for treadmill exercise and P = 0.033 for dipyridamole).CONCLUSIONS: Estimation of ÄLVEF in addition to sTPD seems to improve risk stratification for future events when ÄLVEF decreases by more than -10% for those individuals with normal or near-normal myocardial perfusion (sTPD ? 5%). An sTPD greater than 5% was a better prognostic indicator of future events when compared with ÄLVEF for individuals with greater perfusion abnormality at stress.
Demography Dipyridamole