A left ventricular end-diastolic dimension less than 6.0 cm is associated with mortality after implantation of an axial-flow pump

Abstract

ObjectiveThe effects of having a lower left ventricular end-diastolic dimension before HeartMate II (Thoratec Corp, Pleasanton, Calif) left ventricular assist device implantation remain unclear. We analyzed our single-center data on HeartMate II implantation to determine whether having a lower left ventricular end-diastolic dimension preoperatively was associated with inferior outcomes. MethodsFrom November 2003 to March 2016, 393 patients with chronic heart failure underwent primary HeartMate II implantation. We compared the preoperative left ventricular end-diastolic dimension and associated survival outcomes of these patients to determine the left ventricular end-diastolic dimension cutoff for worse overall survival. Then, we compared the preoperative demographics, stroke rate, and mortality of patients with a left ventricular end-diastolic dimension above the cutoff for worse survival with those of patients with a left ventricular end-diastolic dimension below the cutoff. ResultsA Cox multivariate regression model showed that low left ventricular end-diastolic dimension was an independent predictor of mortality (hazard ratio, 1.49; P = .02). The Contal and O'Quigley method showed that overall survival postimplantation was decreased in patients with a left ventricular end-diastolic dimension less than 6.0 cm (n = 91). Kaplan–Meier analysis confirmed that the left ventricular end-diastolic dimension less than 6.0 cm group had lower overall survival than the left ventricular end-diastolic dimension 6.0 cm or greater group (P = .04). Furthermore, a competing-risk analysis showed that postoperative stroke was more common in the left ventricular end-diastolic dimension less than 6.0 cm group than in the left ventricular end-diastolic dimension 6.0 cm or greater group (P < .01). ConclusionsOverall survival was decreased and postoperative stroke was increased in HeartMate II recipients with a preoperative left ventricular end-diastolic dimension less than 6.0 cm. Future research should determine the left ventricular end-diastolic dimension cutoff values for safely implanting other support devices, and device designs should be improved to better accommodate the needs of patients with a limited left ventricle size.