Objective To assess the effect of surgical revascularisation on left ventricular (LV) systolic function in patients with viable and non-viable dysfunctional LV segments determined by low dose dobutamine stress echocardiography (DSE).

Design Prospective observational cohort study.

Setting Single tertiary care centre.

Patients Consecutive patients referred to surgical revascularisation (n=115).

Interventions DSE and surgical revascularisation.

Main outcome measures Functional recovery defined as increase in ejection fraction ≥5% 1 year after revascularisation in patients with and without viable myocardium (viability defined as improvement of contractility in ≥4 LV segments on DSE).

Results The mean age, ejection fraction and wall motion score index (WMSi) of patients were 59±9 years, 44±9% and 1.82±0.31, respectively. There was no difference between DSE positive and DSE negative patients for any of those parameters at baseline study (p>0.05 for all). After 12 months, the ejection fraction increased 11±1% in patients with viable myocardium vs 7±1% in patients without viable myocardium (p=0.002). Moreover, in patients with viable myocardium, the greatest increase of ejection fraction occurred 1 month after surgery (9±1%), whereas in those patients with negative DSE the ejection fraction increased more gradually (2±1% after 1 month, p=0.002 between groups for 1 month vs preoperative value), but still improved after 12 months follow-up (p<0.0001 in time for both groups).

Conclusions It appears that patients with LV dysfunction, but without viable myocardium, may also benefit from myocardial revascularisation. Functional recovery continuously occurs throughout the first year after surgical treatment.