New data show improved outcomes, better survival rates and lower costs with the use of continuous flow mechanical circulatory support devices in patients awaiting heart transplants. Research will be presented this week during symposia at the International Society for Heart and Lung Transplantation (ISHLT) 30th Annual Meeting and Scientific Session at the Hilton Chicago.
Ventricular Assist Devices (VADs), or heart pumps, are used to partially or completely replace the function of a failing heart by restoring normal blood flow to a person whose heart has been weakened by heart disease. In the past, these devices delivered blood in a pulsatile manner, which simulated a beating heart. The newest devices deliver blood in a continuous flow, which studies show is improving patient outcomes.
VADs Show Improvement as a Bridge to Transplant
While the previous generation of VADs was often associated with significant complications at the time of implant, research shows that the new continuous flow devices do not increase risk after heart transplantation. A study presented today by Jose Nativi, MD, University Medical Center, Salt Lake City, UT (Abstract 257 – Determinants of Survival in Patients Bridged to Heart Transplantation with Continuous-Flow Versus Pulsatile-Flow Ventricular Assist Devices) includes a detailed evaluation of the ISHLT Registry specifically reviewing the nearly 2,000 patients who underwent mechanical circulatory support between 2000 and 2008 as a bridge to transplant. The data showed an improvement in the overall post-transplant survival in patients transplanted in the more recent years 2004 – 2008.
Currently more than one-third of all patients undergoing heart transplants are being supported with an LVAD, according to the Cardiac Transplant Research Database. Therefore, Dr. Nativi's study, which shows similar post-transplant survival in patients bridged with LVADs, between 2004 and 2008, and those not requiring LVAD support, is of particular importance.
Continuous Flow Technology Outperforms Pulsatile Flow Technology
Improved overall outcomes for patients with continuous flow devices are approximately 30 percent higher than those obtained with previous generation pulsatile devices. This is according to INTERMACS data of over 1000 patients enrolled between June 2006 and March 2009 at 88 institutions. Joseph Rogers, MD, Duke University Medical Center, Durham, NC, (Abstract 66 – Destination Therapy: Improving Outcomes with Continuous Flow LVADs) presented findings this week that show an 88 percent one-year survival for those patients that received a continuous flow LVAD.
"The continuous flow devices are smaller, simpler and are proving to be more durable," said Dr. Rogers. "We believe that in the future there will be little need for pulsatile pumps."
Continuous Flow Devices Studied as Destination Therapy
Mark Slaughter, MD, University of Louisville, Louisville, KY, on behalf of the investigators for the Heart Mate II LVAD Destination Therapy will present findings this week from a study that compared outcomes with a continuous flow Heart Mate II mechanical circulatory support device and showed an improved median survival of 2.8 years. This was substantially improved compared to previous clinical trials with mechanical circulatory support and showed outcomes over the short term that are comparable to that obtained with heart transplant. (Abstract 265 – Quality of Life in Patients Supported 2 Years with a Continuous Flow Left Ventricular Assist Device as Destination Therapy)
"This is encouraging when you consider the critical shortage of potential hearts for transplant," said Dr. Slaughter. "Approximately 3,000 heart transplants are performed worldwide every year, while there are ten times as many candidates for transplantation. We hope the improved LVAD technology will help to fill this gap."
Dr. Slaughter will also present findings from a recent report showing a 50 percent reduction in cost of the initial implant of LVADs over the past 10 years (Abstract 262 – Changing Costs of Mechanical Circulatory Support: Impact of Era and Device). Data shows baseline characteristics of the patients receiving devices have not changed, which suggests that this economic improvement is largely related to improved surgical techniques, peri-operative management and may also be a reflection of the new continuous flow device technology.
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