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

Objective: The 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. Methods: From 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. Results: A 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 0' 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). Conclusions: Overall 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.