Ejection fraction by radionuclide ventriculography and contrast left ventriculogram: tale of two techniques

Objectives. We assessed the abilities of two methods to measure ejection fraction (EF)—radionuclide ventriculography (RVG) and contrast left ventriculography (Cath-EFa) to predict cardiovascular events. Background. Both RVG and Cath-EF are commonly used methods to measure left ventricular performance and assess prognosis. Their comparative abilities to predict clinical events have not been reported. Methods. Both RVG EF and Cath-EF were measured within 16 days of myocardial infarction (MI) in 688 patients. The results were divided into terciles. Prognosis by terciles was assessed for each technique. multivariate analysis was performed to determine which EF measurement was better predictor of prognosis. Results. Average RVG–EF was 32% ± 7, while Cath-EF was 42% ± 10. Both RVG and Cath-EF were poorly correlated (R = 0.42). Event rate declined across terciles with increasing EF for both techniques (events in lowest to highest tercile of Cath-EF 40.7%, 25.9%, 11.6%, p < 0.001; and RVG-EF 39.9%, 26.1%, 15.6%, p < 0.001). There was concordance of terciles in 303 of 688 patients (44%). When patients in the highest RVG terciles were in the highest Cath-EF tercile, the event rate was 7%. However, when patients in the highest RVG terciles were in the lowest Cath-EF tercile, the event rate was 19%. Both Cath-EF (p < 0.001) and RVG-EF (p < 0.001) were independent predictors of cardiovascular events. Conclusions. Ejection fraction measured by RVG or during catheterization is valuable tool in the risk stratification of postinfarct patients. When disagreement is present between clinical impression and measurement by either method, the use of an alternative measurement is warranted and complementary.