Background: Right heart dysfunction confers significant morbidity and mortality after left ventricular assist device implantation and historically occurs in as many as a third of patients. It is unknown whether newer axial flow pumps have a different impact on postimplant right heart dysfunction. We compared the incidence of right heart dysfunction after implantation of the pulsatile HeartMate I (XVE) and the continuous flow HeartMate II left ventricular assist device.
Methods: We retrospectively reviewed patients who underwent HeartMate I or HeartMate II implantation between June 2000 and March 2007. Right heart dysfunction was defined as inotropic/vasodilator support for 14 or more consecutive days or the need for a right ventricular assist device, or both.
Results: Seventy-seven patients underwent HeartMate implantation; 43 received a HeartMate I and 34 received a HeartMate II, for a mean left ventricular assist device support time of 202 and 160 days, respectively. Operative mortality was lower for HeartMate II patients (28% versus 15%; p = 0.26). The HeartMate II patients had lower preoperative right ventricular stroke work index. Pulmonary vascular resistance index, right ventricular stroke work index, and pulmonary and right atrial pressures improved and were similar between groups postoperatively. Overall, right heart dysfunction developed in 35% of HeartMate I patients (15 of 43) and 41% of HeartMate II patients (14 of 34; p = 0.63). Fewer HeartMate II patients (2) than HeartMate I patients (5) required 7 or more days of epinephrine, whereas more HeartMate II patients (7) than HeartMate I patients (5) required 7 or more days of milrinone. Six HeartMate I and 3 HeartMate II patients required right ventricular assist device implantation for right heart failure. Survival was similar (p = 0.7) between groups at, respectively, 3 (63% versus 62%), 6 (58% versus 58%), and 12 months (49% versus 48%).
Conclusions: Right heart dysfunction is a persistent clinical problem after left ventricular assist device placement. We report the first study comparing the incidence of right heart dysfunction after HeartMate I versus HeartMate II implantation. Although the incidence of right heart dysfunction was similar, fewer HeartMate II patients required right ventricular assist device placement and fewer required pure inotropic support for right heart failure.