Differential prognostic significance of peri-infarction versus remote myocardial ischemia on stress technetium-99m sestamibi tomography in patients with healed myocardial infarction

Peri-infarction and remote myocardial ischemia involve different myocardial substrates, but their differential clinical implications have not been previously studied. We assessed the differential prognostic significance of peri-infarction and remote ischemia during long-term follow-up in patients with healed myocardial infarction. We studied 345 patients (59 ± 12 years old; 282 men) with previous myocardial infarction who demonstrated reversible perfusion abnormalities on exercise or dobutamine stress technetium-99m sestamibi tomography. Follow-up events for 5.5 ± 2.6 years were 60 deaths (17%; 40 cardiac deaths) and 25 reinfarctions (7%). Reversible perfusion abnormalities were detected in the remote region in 129 patients (37%), the peri-infarction region in 142 patients (41%), and in both regions in 74 patients (21%). The annual rates of cardiac death in these groups were 1.2%, 2.8%, and 2.9%, respectively (p <0.01). The annual rates of reinfarction were 1%, 1.5%, and 0.9%, respectively (p = NS). In a multivariate analysis model, independent predictors of cardiac death were history of heart failure (risk ratio [RR] 2.8, 95% confidence interval [95% CI] 1.2 to 7), diabetes mellitus (RR 4.1, 95% CI 1.9 to 8.9), summed score at rest (RR 1.4, 95% CI 1.1 to 3.1), and peri-infarction ischemia (RR 2.6, 95% CI 1.1 to 6.1). Predictors of reinfarction were age (RR 1.03, 95% CI 1.01 to 1.07) and diabetes mellitus (RR 3.3, 95% CI 1.2 to 9.1). Peri-infarction ischemia assessed by stress technetium-99m sestamibi tomography is associated with a greater risk of cardiac death than is remote ischemia. The risk of reinfarction is not related to the location of ischemia.