MedicalResearch.com Interview with:
Neeraj Shah, MD, MPH
Department of Cardiology
Lehigh Valley Health Network
Medical Research: What is the background for this study? What are the main findings?
Dr. Shah: Congestive heart failure (CHF) affects 5.8 million Americans, with prevalence as high as 10% in individuals aged 65 years or more. There are long wait times for heart transplants. Left ventricular assist devices (LVADs) have been shown to significantly improve outcomes in end stage CHF patients. In the current situation of limited donor hearts, the utilization of LVAD technology is likely to increase over time. Moreover, the LVAD technology has improved considerably over time. The first generation devices were bulky and pulsatile in nature and of limited durability, whereas the second and third generation devices are smaller, longer lasting and exhibit “continuous flow”. The United States Food and Drug Administration (FDA) approved continuous flow devices in 2008. Presently, continuous flow devices account for over 95% of LVAD implants. Our aim was to examine the trends in utilization, in-hospital mortality, procedure related complications and cost of care after LVAD implantation from 2005 to 2011, and to study any differences in the pulsatile flow era from 2005-2007, compared to continuous flow era from 2008-2011. We used the Nationwide Inpatient Sample (NIS), which the largest all-payer US national hospitalization database, for our study. We identified LVAD implants using International Classification of Disease, 9th edition (ICD-9) procedure code 37.66. NIS data showed that there were 2,038 LVAD implantations from 2005 to 2011. LVAD utilization increased from 127 procedures in 2005 to 506 procedures in 2011, with a sharp increase after the year 2008 (from 149 procedures in 2007 to 257 procedures in 2008). In-hospital mortality associated with LVAD implantation decreased considerably from 47.2% in 2005 to 12.7% in 2011 (p<0.001), with a sharp decline in mortality after the year 2008 (from 38.9% in 2007 to 19.5% in 2008). Average length of stay (LOS) decreased from 44 days in the pulsatile-flow era to 36 days in the continuous-flow era. Cost of hospitalization increased from $194,380 in 2005 to $234,808 in 2011 but remained steady from 2008 to 2011. There was a trend of increased incidence of major bleeding and thromboembolism and decreased incidence of infectious and iatrogenic cardiac complications in the continuous-flow era. Thus, there has been a considerable increase in utilization of LVADs and decline in in-hospital mortality and LOS after LVAD implantation. These changes strongly coincide with US FDA approval of continuous flow devices in 2008.
Medical Research: What should clinicians and patients take away from your report?
Dr. Shah: Outcomes after LVAD implantation have improved considerably over time. A significant driver of improved outcomes is improved LVAD technology and introduction of continuous flow devices.
Other factors that contribute to improved outcomes are increasing experience with these devices, better patient selection and improved surgical and postoperative care over time. With the increasing congestive heart failure prevalence and limited availability of donor hearts for end stage CHF patients, the utilization of LVAD technology is only going to increase. Hence it is important for patients and clinicians to be aware of the current LVAD technology of continuous flow devices. Clinicians should bear in mind that although continuous flow devices have far better outcomes compared to the older pulsatile flow devices, due to their inherent continuous flow nature, there is a higher incidence of blood clots forming in these devices resulting in a higher incidence of thromboembolic complications and a higher bleeding rate with these devices, due to the use of blood thinners such as aspirin plus warfarin to reduce the risk of blood clot formation.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Shah: It is clear from our study that continuous flow LVADs have far better outcomes compared to the older first generation pulsatile flow devices. Although the in-hospital mortality after LVAD implantation has continued to decrease over time, it still remains high at 12.7% in 2011. Moreover, these continuous flow devices do have a higher incidence of bleeding and thromboembolic complications. Further research to continually improve LVAD technology is therefore warranted. It would be interesting to see if introduction of some degree of pulsatility in the current continuous flow devices would significantly lower the bleeding and thrombosis rates. Since the use of LVADs is only likely to increase in the coming years, it is important to perform more research to improve this technology.
National Trends in Utilization, Mortality, Complications, and Cost of Care After Left Ventricular Assist Device Implantation From 2005 to 2011
Shah, Neeraj et al. The Annals of Thoracic Surgery
Neeraj Shah, MD, MPH (2015). ER Visits For Hypertension Common and Increasing