Abstract 15758: Peak Oxygen Consumption Does Not Depend on Aortic Valve Opening During Exercise in Patients with a Continuous Flow Left Ventricular Assist Device
Introduction: Patients with heart failure and a continuous flow left ventricular assist device (LVAD) have an increased incidence of aortic insufficiency. Closing the aortic valve (AV) at the time of surgery to prevent aortic insufficiency may limit exercise capacity. Our hypothesis was to evaluate whether AV opening during exercise is a predictor of peak oxygen consumption (pVO2) in patients with an LVAD.
Methods: We performed a cardiopulmonary exercise test in 29 patients with an LVAD. An echocardiogram was performed before and immediately after the test to assess significant AV opening of more than 50% immediately after cessation of exercise. We evaluated if percent predicted pVO2 (%pVO2) was associated with AV opening in the 21 patients who reached a respiratory exchange ratio (RER) > 1.
Results: Mean age was 57±13 years, 73% males, 53% non-ischemic cardiomyopathy, median left ventricular ejection fraction of 18%. The LVAD had been implanted a median of 9 months before the test and median LVAD speed was 8800 revolutions per minute. In the 21 patients who reached an RER > 1, significant AV opening immediately after exercise was seen in 48% of patients. Exercise capacity (%pVO2) did not differ between these patients and those who did not open the aortic valve (see figure). There was no difference between the groups regarding etiology of cardiomyopathy, time since LVAD implant, LVAD speed, right ventricular dysfunction, aortic insufficiency or hemoglobin.
Conclusions: In patients with heart failure and an LVAD, opening of the AV during exercise is not associated with increased %pVO2. Closing the AV in these patients should not impact their exercise capacity.
- © 2011 by American Heart Association, Inc.