Incremental prognostic value of thallium reinjection after stress-redistribution imaging in patients with previous myocardial infarction and left ventricular dysfunction.

Abstract

This study evaluated the incremental prognostic value of 201TI reinjection imaging over clinical, exercise and thallium stress-redistribution data in patients with previous myocardial infarction and left ventricular dysfunction. Thallium-201 reinjection after stress-redistribution SPECT was performed in 104 consecutive patients with a first Q-wave myocardial infarction (> 8 wk) and left ventricular ejection fraction < or = 40%. Follow-up data (mean 22 mo) were available for 98 patients; 16 patients underwent early revascularization procedures within 3 mo after exercise testing and were not considered for the analysis. During follow-up there were 13 hard events (cardiac death and myocardial infarction) and 11 soft events (coronary revascularization procedures > 3 mo after thallium imaging). With multivariate Cox regression analysis, the sum of defects at stress-redistribution imaging that were reversible or moderate irreversible after reinjection was a powerful predictor of subsequent events. The addition of thallium reinjection imaging data significantly improved the prognostic power of clinical, exercise and stress-redistribution data for the occurrence of hard events (p < 0.01). In patients with previous myocardial infarction and left ventricular dysfunction, thallium reinjection imaging provides incremental prognostic information over those obtained from conventional stress-redistribution imaging.