This study assessed the effect of
ischemia during
dobutamine stress echocardiography (DSE) on cardiac mortality in patients with
heart failure. We studied 528 patients (62 +/- 11 years of age, 402 men) who had
heart failure and previous
myocardial infarction or known
coronary artery disease and underwent DSE.
Ischemia was defined as new or worsening wall motion abnormalities or a biphasic response. End point during follow-up was
cardiac death. Mean ejection fraction was 35 +/- 12%.
Ischemia was detected in 407 patients (77%). During a mean follow-up of 3.2 +/- 2.4 years,
cardiac death occurred in 150 patients (28%).
Myocardial revascularization was performed within 4 months after DSE in 117 patients (29%) who had
ischemia. Annual rates of
cardiac death were 4.8% in patients who did not have
ischemia, 5.5% in those who had
ischemia and underwent revascularization within 4 months, and 11.8% in those who had
ischemia and were not revascularized (p <0.001 vs other groups). In a multivariate analysis model, independent predictors of
cardiac death were diabetes (RR 2, 95% confidence interval 1.4 to 2.9), male gender (RR 1.7, 95% confidence interval 1.2 to 3.1), low-dose wall motion score index (RR 1.4, 95% confidence interval 1.2 to 2.6), and
ischemia (RR 1.9, 95% confidence interval 1.3 to 3.2). Angina was not predictive of death. In patients who had
ischemia, revascularization within 4 months after DSE was associated with decreased risk of
cardiac death (RR 0.43, 95% confidence interval 0.3 to 0.8). In conclusion,
myocardial ischemia that is detected by DSE is associated with increased risk of
cardiac death among patients who have
heart failure, after adjustment for left ventricular function. Patients who had
ischemia and received revascularization within 4 months had a better survival than did patients who had
ischemia and did not receive revascularization. Angina had no effect on prognosis. Therefore, patients who do not have angina should not be considered a lower-risk population if they have inducible
ischemia.