Consequences of aortic insufficiency during long-term axial continuous-flow left ventricular assist device support

Abstract

Background: Although left ventricular assist device (LVAD) management strategies are undertaken to reduce the development of aortic insufficiency (AI), the effect of AI on patient morbidity and mortality is not known.

Methods: Patients undergoing HeartMate II (Thoratec, Pleasanton, CA) implant were prospectively monitored with serial echocardiograms. Kaplan-Meier methods and log-rank testing were used to estimate and compare mortality and freedom from moderate or worser right ventricular hypokinesis (RVHK), moderate or worse mitral regurgitation (MR), and hemolysis according to AI severity. Mixed modelling was used to examine for correlates of AI development in the pre-operative and post-operative setting and to investigate the effect of AI on post-operative MR and RVHK.

Results: There were 930 echocardiograms completed in 166 patients. During 291 person-years of follow-up, mild-moderate or worse AI developed in 70 (0.38 persons per year [PPY]), moderate or worse AI in 36 (0.17 PPY), moderate-severe AI in 11 (0.039 PPY), and severe AI in 2 (0.0069 PPY). Overall 2-year survival and 2-year survival after onset of moderate or worse AI was 87% ± 6.2% and 65% ± 11%, respectively, compared with 76% ± 5.1% and 76% ± 5.1%, respectively, in those with less AI (p = 0.57). Patients with moderate AI were not more likely to develop MR, hemolysis events, or worsening RVHK, but patients with pre-existing RVHK appeared to be less tolerant of AI. Three of 35 deaths were directly attributed to AI. No reoperations were performed solely for AI.

Conclusions: AI is common after LVAD implant but did not affect survival in this cohort. Except in those with significant RV dysfunction, this calls into question need for echocardiogram-guided device settings to ensure aortic valve opening.

Keywords: aortic insufficiency; continuous-flow LVAD; left ventricular assist device; mitral regurgitation; morbidity and mortality; right ventricular hypokinesis.