Value of Myocardial Viability Estimation Using Dobutamine Stress Echocardiography in Assessing Risk Preoperatively Before Noncardiac Vascular Surgery in Patients With Left Ventricular Ejection Fraction <35%
Patients with heart failure (HF) scheduled for vascular surgery have an increased risk of adverse postoperative outcome, and stratification usually depends on dichotomous risk factors. A quantitative prognostic model for patients with HF was developed using wall motion patterns during dobutamine stress echocardiography (DSE). A total of 295 consecutive patients (mean age 67 ± 12 years) with ejection fraction ≤35% were studied. During DSE, wall motion patterns of dysfunctional segments were scored as scar, ischemia, or sustained improvement. Cardiac death and myocardial infarction were noted perioperatively and during 5 years of follow-up. Of 4,572 dysfunctional segments; 1,783 (39%) had ischemia, 1,280 (28%) had sustained improvement, and 1,509 (33%) had scar. In 212 patients, ≥1 ischemic segment was present; 83 had only sustained improvement. Perioperative and late cardiac event rates were 20% and 30%, respectively. Using multivariate analysis, number of ischemic segments was associated with perioperative cardiac events (odds ratio per segment 1.6, 95% confidence interval 1.05 to 1.8), whereas number of segments with sustained improvement was associated with improved outcome (odds ratio per segment 0.2, 95% confidence interval 0.04 to 0.7). Multivariate independent predictors of late cardiac events were age and ischemia. Sustained improvement was associated with improved survival. In conclusion, DSE provides accurate risk stratification of patients with HF undergoing vascular surgery.