Prognostic implications of stress Tc-99m tetrofosmin myocardial perfusion imaging in patients with left ventricular hypertrophy

BACKGROUND: Left ventricular hypertrophy (LVH) is associated with an increased risk of cardiac death. Data on the prognostic value of myocardial perfusion imaging (MPI) in patients with LVH are limited. The aim of this study is to assess the independent value of stress technetium 99m tetrofosmin MPI in predicting the long-term mortality rate in patients with LVH.

METHODS AND RESULTS: We studied 177 patients (mean age, 59 +/- 12 years; 134 men) with LVH by electrocardiographic criteria who underwent dobutamine or exercise stress Tc-99m tetrofosmin MPI. Endpoints during follow-up were cardiac and all-cause death and hard cardiac events. A normal scan was detected in 42 patients (24%). Myocardial perfusion abnormalities were fixed in 59 patients (33%) and reversible in 76 (43%). Perfusion abnormalities were observed in a single-vessel distribution in 79 patients and in a multivessel distribution in 56. During a mean follow-up period of 5.5 +/- 2 years, 60 patients (34%) died. Death was considered cardiac in 42 patients (24%). Nonfatal myocardial infarction occurred in 10 patients (6%). The annual mortality rate was 1.4% in patients with normal perfusion, 3.2% in those with perfusion abnormalities in a single-vessel distribution, and 8% in those with a multivessel distribution. In a multivariate analysis independent predictors of death were age (risk ratio [RR], 1.05; 95% confidence interval [CI], 1.02-1.07), male gender (RR, 1.9; 95% CI, 1.1-3.6), hypercholesterolemia (RR, 1.7; 95% CI, 1.0-2.9), and abnormal perfusion (RR, 2.7; 95% CI, 1.5-4.8).

CONCLUSION: In patients referred for stress MPI, LVH is associated with a high mortality rate, with approximately one third of patients dying over a period of 5 years. Stress Tc-99m tetrofosmin MPI provides independent information for predicting death in these patients.