Prognostic value of stress-gated Tc-99m Sestamibi SPECT after acute myocardial infarction

Stress-gated technetium-99m (Tc-99 m) sestamibi single-photon emission comp uted tomography (SPECT) is used to risk stratify patients after acute myoca rdial infarction (AMI). In clinical practice, results of this test are used primarily to identify patients with myocardial ischemia for intervention. The value of this test to risk stratify patients with AMI not at high ische mic risk has not been addressed. More than 1-year follow-vp was undertaken in 124 patients who underwent predischarge gated Tc-99m sestamibi SPECT stu dies and who did not undergo subsequent revascularization, Clinical variabl es and test-derived variables were evaluated to predict cardiac death, recu rrent AMI, and hospitalization for unstable angina, congestive heart failur e, or coronary revascularization. Independent predictors by multivariate an alysis for cardiac death or recurrent AMI were a history of prior AMI (rela tive risk [RR] = 5.32, confidence interval [Cl] 2.17 to 12.96), a low exerc ise capacity (RR = 6.84, Cl 1.99 to 23.48), and left ventricular (LV) eject ion fraction (EF) <40% (RR = 2.63, CI 1.04 to 6.38). The incidence of cardi ac death or recurrent AMI was 29.8% in patients with a low exercise capacit y versus 4.5% in those with good exercise capacity and 38.1% in patients wi th LVEF <40% versus 9.4% in those with LVEF >40%. Independent predictors of cardiac death, AMI, or hospitalizatian for unstable angina, congestive hea rt failure, or revascularization were a history of prior AMI (RR = 2.24, Cl 1.11 to 4.50) and LVEF <40% (RR = 3.13, Cl 1.64 to 5.95). Among patients f ollowed after AMI without revascularization Tc-99m sestamibi SPECT can iden tify ct high-risk subset. The strongest independent predictors ore poor exe rcise capacity and LVEF <40%. (C) 2001 by Excerpta Medica, Inc.