Clinical Geriatrics

American Heart Association Scientific Sessions 2009
November 14-18, 2009
Orlando, FL

______________________________

Investigational Left Ventricular Assist Device Prolongs Life in Advanced Heart Failure as Compared to FDA-Approved Pulsatile-Flow Device

Orlando, FL—A second-generation left ventricular assist device (LVAD) called HeartMate II achieved superior outcomes as compared to its predecessor, HeartMate XVE, in patients with advanced heart failure (HF) who were ineligible for heart transplantation. In the HeartMate II Destination Therapy Clinical Trial, 2-year survival was more than double for patients implanted with the HeartMate II continuous-flow device than in those who received the pulsatile-flow HeartMate XVE. The study was presented at a late-breaking session during the 2009 Scientific Sessions of the American Heart Association (AHA).

“Treatment with the continuous-flow device in patients with advanced heart failure significantly improved the probability of survival free from stroke and device failure at 2 years compared with a pulsatile device. Both LVAD devices significantly improved quality of life and functional capacity,” said Joseph G. Rogers, MD, Duke University Medical Center, Durham, NC. Both LVADs draw blood from the tip of the left ventricle and deliver it to the ascending aorta, and both are electrically driven. The continuous-flow device has the advantages of being smaller, quieter, and more durable. Both devices are capable of a flow rate up to 10 L/min. HeartMate II is Food and Drug Administration (FDA)–approved as bridge device for heart transplant, and it is investigational for the use studied in the Destination Therapy Clinical Trial. Only a small percentage of patients with advanced HF are candidates for heart transplant. Mechanical circulatory devices such as LVAD are now considered one of the few effective treatment options for these severely ill patients.

The multicenter, prospective, randomized Destination Therapy Clinical Trial was conducted at 38 centers in the United States. Patients with New York Heart Association (NYHA) class III or IV HF were randomized 2:1 to treatment with the HeartMate II device (n = 134) or to the FDA-approved pulsatile-flow device (n = 66). Two hundred patients were randomized between March 2005 and May 2007. Baseline characteristics of both groups were similar, with the exception of more women in the continuous-flow device group. All patients had left ventricular ejection fraction ≤ 25% and had a HF hospitalization within the previous 6 months. Patients were followed for at least 2 years or until death, transplantation, or device removal.

The primary composite end point (survival at 24 mo, free from disabling stroke or reoperation for device repair or replacement) was met by 46% of the continuous-flow group versus 11% of the pulsatile-flow group (P < 0.001). The continuous-flow device was also significantly superior to the pulsatile-flow device for reoperation to replace the device: 13 (10%) versus 24 (36%, P < 0.001); and for death at 2 years: 44 (33%) versus 27 (41%, P = 0.05). A similar percentage of patients in both groups sustained a disabling stroke: 15 (11%) versus 8 (12%). Both devices improved exercise capacity and quality of life. Of the 59 patients who had a pulsatile-flow LVAD, 20 had it replaced during the study period; 18 of them got a continuous-flow device; four other patients required device removal. In the 133 patients who had a continuous-flow LVAD, 12 required 13 pump replacements with a similar device; one additional patient required device removal due to a broken lead.

Adverse events were reduced in the group implanted with the continuous-flow device, with significant reductions in device-related infections, non-device–related infection, right HF, respiratory failure, renal failure, and cardiac arrhythmia as compared with the pulsatile-flow device.