Left Ventricular Outflow Tract Obstruction Associated with Chronic Ventricular Assist Device Support

Abstract

Favorable long-term patient outcome after insertion of a left ventricular assist device (LVAD) as a bridge to recovery or destination therapy for the treatment of end-stage cardiomyopathy is adversely affected by pathophysiologic changes affecting the heart. Alterations in the native aortic valve apparatus, specifically aortic valve cusp fusion, is an example of such a phenomenon and may especially affect patients in cases of bridge to recovery, a rare but reported event. A retrospective review of the last 33 LVAD placements at our institution was conducted, including reviews of operative reports and pathologic examinations of the native hearts. Seven hearts were found to have varying degrees of aortic valve cusp fusion after chronic LVAD support (63-1, 339 days). Five of these patients had native aortic valves, and two had bioprosthetic valves. The left ventricular outflow tracts in two patients were surgically occluded at the time of LVAD insertion. Aortic valve cusp fusion occurs in roughly 25% of patients on chronic LVAD support. This phenomenon may prove to be clinically significant by creating a potential source of emboli and infection. In addition, in the case of myocardial recovery, left ventricular outflow tract obstruction could limit parallel flow and produce suprasystemic ventricular pressures that in turn would elevate left ventricular end diastolic pressures. The latter may contribute to further myocardial injury, ultimately limiting the ability of an otherwise recovered heart to be weaned from LVAD support.

Less Frequent Opening of the Aortic Valve and a Continuous Flow Pump Are Risk Factors for Postoperative Onset of Aortic Insufficiency in Patients With a Left Ventricular Assist Device

“…On the other hand, no AI has been reported in cases of fusion of all 3 commissures. 19, 20 Consistent with the previous reports, 8,9,11,12 we found that less frequent opening of the native aortic valve correlated with the development of more severe AI. No opening of an aortic valve indicates that the ascending aortic pressure exceeds left ventricular pressure throughout the cardiac cycle.…”

Is Native Aortic Valve Commissural Fusion in Patients With Long-term Left Ventricular Assist Devices Associated With Clinically Important Aortic Insufficiency?

“…3 Baradarian and colleagues reported a similar finding. 4 Acquired aortic valve commissural fusion was detected in 17 of 33 patients undergoing long-term left ventricular mechanical assist with a HeartMate device at our own institution; 4 of these patients had fusion at 2 commissures, and 13 had fusion at 1 commissure. 5 The clinical implications of acquired commissural fusion are not well described or understood.…”

Aortic valve closure associated with HeartMate left ventricular device support: Technical considerations and long-term results

“…Our group and others observed that bioprosthetic valves will normally close completely from fibrosis, but there is a risk of thromboembolism. 9,13 Therefore, we now recommend that pre-existing bioprosthetic valves be removed and the outflow tract closed with a pericardial patch at the time of LVAD implant. If the bioprosthetic valve cannot be easily removed, early anticoagulation may be successful for avoiding embolization.…”

“…However, successful aortic valve closure at the time of LVAD implant has been reported without untoward effects. 8,9 Also, patients who develop aortic insufficiency and concurrent LVAD failure can have the aortic outlet closed safely during LVAD exchange, with a reasonable long-term outcome. 10 In this report, we present our single-center experience with aortic valve closure and LVAD insertion or replacement in patients with incompetent native or prosthetic aortic valves.…”