Incremental prognostic value of post-stress left ventricular ejection fraction and volume by gated myocardial perfusion single photon emission computed tomography

Background - The incremental prognostic value of post-stress left ventricular ejection fraction (EF) and volume over perfusion has not been investigated. Methods and Results - We identified 1680 consecutive patients who underwent rest T1-201/stress Tc-99m sestamibi gated single photon emission computed tomography (SPECT) and who were followed-up for 569 ± days. Receiver-operator characteristics analysis defined an EF<45%, an end- systolic volume (ESV) >70 mL, and-an end-diastolic volume > 120 mL as optimal thresholds, yielding moderate sensitivity and high specificity in the prediction of cardiac death. Patients with an EF≥45% had mortality rates < 1%/year, despite severe perfusion abnormalities, whereas patients with an EF<45% had high mortality rates, even with only mild/moderate perfusion abnormalities (9.2%/year; P<0.00001). Similarly, an ESV≤70 mL was related to a low cardiac death rate (<1.2%/year), even for patients with severe perfusion abnormalities, whereas patients with an ESV>70 mL and only mild/moderate perfusion abnormalities had high death rates (8.2%/year; P<0.00001). Patients with an EF<45% and an ESV≤70 mL had low cardiac death rates (1.7%/year); those with an EF<45% but an ESV>70 mL had high death rates (7.9%/year; P<0.02). Multivariate cox proportional hazards regression showed that perfusion variables and ESV were independent predictors of overall coronary events, whereas EF and ESV demonstrated incremental prognostic values over prescan and perfusion information in predicting cardiac death and cardiac death or myocardial infarction. Conclusions - Post-stress EF and ESV by gated-SPECT have incremental prognostic values over prescan and perfusion information in predicting cardiac death, and they provide clinically useful risk stratification.