Clinical outcomes for continuous-flow left ventricular assist device patients stratified by pre-operative INTERMACS classification

Abstract

Background: Risk stratification for mechanical circulatory support (MCS) has emerged as an important tool in patient selection and outcomes assessment. Most studies examining risk stratification have been limited to pulsatile devices. We use the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) to stratify patients with continuous-flow devices and assess outcomes in less severe, but functionally impaired, heart failure patients.

Methods: This study included 101 bridge-to-transplant and destination-therapy patients at 3 centers. Three groups were studied: Group 1, cardiogenic shock (INTERMACS Profile 1); Group 2, inotrope-dependent (INTERMACS Profile 2 or 3); and Group 3, ambulatory advanced heart failure (INTERMACS Profiles 4 to 7). The outcomes of interest were actuarial survival, survival to discharge and length of stay.

Results: Survival at 36 months was better in Group 3 than in Group 1 (95.8% vs 51.1%, p = 0.011), but not between Groups 2 and 3 (68.8 vs 95.8%, p = 0.065). Lengths of stay for Groups 1 to 3 were 44, 41 and 17 days: Groups 1 vs 3, p < 0.001; Groups 2 vs 3, p < 0.001; and Groups 1 vs 2, p = 0.62. Lengths of stay for survivors were 49, 39 and 14 for the 3 groups: Groups 1 vs 3, p < 0.001; Groups 2 vs 3, p < 0.001; and Groups 1 vs 2, p = 0.28.

Conclusion: INTERMACS classification is a useful metric for risk-stratifying candidates for MCS. Less acutely ill but functionally impaired heart failure patients receiving continuous-flow LVADs had longer short- and long-term survival and shorter lengths of stay compared with patients who were more acutely ill.