We investigated the influence of the extent of viability using low dose dobutamine wall motion score index (WMS) on the survival benefit of surgical revascularization (CABG) versus medical therapy. In the STICH trial, viability assessment was not helpful in determining the benefit of CABG. However, the extent of viable myocardium with contractile function was not assessed in the trial. Dobutamine echocardiography was performed in 250 patients with ischemic left ventricular dysfunction (125-medically treated, 125-CABG). The mean ejection fraction (EF) was 32% in both groups. WMS during low dose dobutamine infusion was used to classify patients into groups with extensive (WMS < 2.00), intermediate (WMS 2.00–2.49), and limited (WMS ≥ 2.50) viability. Survival free of cardiac death was assessed at 2 years and for the complete duration of follow-up. There were 44 (35.2%) and 67 (53.6%) cardiac deaths in the revascularized and medically treated patients respectively (follow-up of 5.7 ± 5.8 years). Revascularized and medically treated patients with extensive viability had similar 2-year survival (p = 0.567) but revascularized patients had improved long-term survival (p = 0.0001). In those with intermediate viability, revascularization improved both 2 year (p = 0.014) and long-term survival (p = 0.0001). In patients with limited viability, 2-year survival was worse in revascularized patients (p = 0.04) and long-term survival was similar (p = 0.25) in revascularized and medically treated groups. Patients with extensive and intermediate amounts of viability have improved survival with CABG but those with limited viability have poorer short-term outcome and no long-term benefit.
- Dobutamine stress echocardiography
- Ischemic cardiomyopathy
- Myocardial viability
- Surgical revascularization (CABG)
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine