Risk of conventional cardiac surgery among patients with severe left ventricular dysfunction in the era of mechanical circulatory support.

BACKGROUND

Despite suggestions that severe left ventricle dysfunction may warrant selection of durable mechanical circulatory support over conventional surgery, comparative studies are lacking due to incomplete characterization of patients at highest risk after conventional surgery. We sought to define subsets of patients with severe left ventricle dysfunction who are at greatest mortality risk following conventional cardiac surgery.

METHODS

We studied 892 patients aged ≥ 18 years who underwent conventional coronary or valve surgery from 1993 to 2014, with preoperative ejection fraction ≤ 25%. Exclusions were transcatheter interventions, major concomitant procedures, active endocarditis, and prior/concurrent durable mechanical circulatory support use. Logistic and Cox regression identified determinants of early and late mortality.

RESULTS

Median age was 70 years (interquartile range, 62-76 years), 46% (n = 411) had New York Heart Association (NYHA) functional class IV symptoms, and 16% (n = 142) had undergone prior surgery. Operative mortality was 7.5%. NYHA functional class IV (odds ratio [OR], 1.88; P = .033), prior cardiac surgery (OR, 2.13; P = .017), peripheral vascular disease (OR, 2.55; P = .001), emergency status (OR, 2.68; P = .024), and intra-aortic balloon pump use (OR, 4.95; P < .001) independently predicted operative death. Risk imparted by presence of both NYHA functional class IV symptoms and prior surgery was additive, with a 4-fold increase in early mortality risk (OR, 3.95; P = .003). Prior surgery increased the hazard of late death by 60% (P < .001). In patients without prior surgery, late mortality was greatest in those aged ≥ 70 years (hazard ratio, 1.86; P < .001), especially if NYHA functional class IV symptoms were concurrently present (hazard ratio, 2.25; P < .001). Surgery type (coronary artery bypass graft surgery, aortic valve surgery, or mitral valve surgery) did not predict long-term outcome.

CONCLUSIONS

In patients referred for conventional surgery with an ejection fraction ≤ 25%, prior cardiac surgery, and/or NYHA functional class IV symptoms-particularly in those aged ≥ 70 years-confer significant and sustained survival disadvantages. Such high-risk subsets may benefit from durable mechanical circulatory support consideration.