Prognostic value of stress 99mTc-tetrofosmin myocardial perfusion imaging in predicting all-cause mortality: a 6-year follow-up study.

Purpose: The aim of this study was to ascertain whether stress myocardial perfusion imaging can independently predict long-term mortality.

Methods: We studied 1,386 patients with known or suspected coronary artery disease by means of stress 99mTc-tetrofosmin myocardial perfusion tomography. The end point during follow-up was death from any cause. Mortality rates were compared with that in a reference population using calculated age- and gender-specific data in the general population.

Results: Mean age was 60+/-11 years. There were 608 (44%) women. Perfusion abnormalities were fixed in 416 (30%) patients and reversible in 445 (32%) patients. During a mean follow-up of 6+/-1.9 years, 290 (21%) patients died. The annual mortality was 1.7% in patients with normal perfusion and 5.2% in patients with abnormal perfusion. Patients with multivessel distribution of perfusion abnormalities had the highest annual mortality (6.2%). The annual mortality in the reference population was 3.2%. In a multivariate analysis model, predictors of death were age [risk ratio (RR)=1.06, 95% CI 1.04-1.07], male gender (RR=2, CI 1.6-2.6), history of heart failure (RR=2.3, CI 1.8-3.1), diabetes mellitus (RR=2.1, CI 1.6-2.7), smoking (RR=1.8, CI 1.4-2.3), reversible perfusion defects (RR=1.8, CI 1.4-2.5) and fixed perfusion defects (RR=1.7, CI 1.3-2.1).

Conclusion: Myocardial perfusion abnormalities on stress 99mTc-tetrofosmin tomography are independently associated with long-term risk of death. The extent of perfusion abnormalities is a major determinant of mortality. The presence of normal perfusion is associated with a lower mortality compared with the general population.