Smaller LV dimensions may increase risk of death for HeartMate 3 LVAD patients
Patients undergoing treatment with Abbott’s HeartMate 3 left ventricular device (LVAD) may face an increased risk of death if they have especially small left ventricular dimensions, according to new findings published in JACC: Heart Failure.[1] This include short-term deaths from stroke and bleeding events as well deaths associated with heart failure symptoms.
“Durable LVAD therapy markedly improves outcomes in patients with advanced heart failure who are poorly responsive to medical therapy,” wrote first author Ezequiel J. Molina, MD, a cardiothoracic surgeon with the Piedmont Heart Institute in Atlanta, and colleagues. “Results from the MOMENTUM 3 randomized clinical trial have demonstrated that median survival exceeds five years following implantation of the HeartMate 3 LVAD irrespective of therapeutic goal of therapy (including bridging to transplant or lifelong therapy). However, the life-prolonging benefits of this therapy may be modified by specific baseline patient characteristics.”
Molina et al. explored data from nearly 2,000 patients from MOMENTUM 3, noting that 108 patients presented with a left ventricular end-diastolic diameter (LVEDD) smaller than 55 mm. Those patients were slightly older than other LVAD patients and they were much more likely to be women. In addition, ischemic cardiomyopathy was seen in 60.2% of patients with a smaller LVEDD compared to just 42.6% of all other patients.
Overall, the group found, patients with a smaller LVEDD faced a significantly higher risk of death during the implant procedure (14.8% vs. 5.7%) as well as a significantly lower risk of still being alive two years later (63.3% vs. 81.8%). Also, deaths from hemocompatibility-related adverse events such as stroke and bleeding events were seen in 2.8% of patients with a smaller LVEDD compared to 0.6% of all other patients. Death from right heart failure, meanwhile, was more common in patients with a smaller LVEDD both in the first 30 days (7.4% vs. 2%) and after 30 days 12% vs. 4.8%).
“Although an infrequent occurrence, a smaller LVEDD, characterized as <55 mm, is a significant risk factor for early mortality following HeartMate 3 LVAD implantation,” the authors wrote. “The early mortality is associated with increased hemocompatibility-related adverse events and heart failure–related deaths.”
Rehospitalization due to a low-flow alarm was also significantly more common in patients with a smaller LVEDD (17.4% vs. 8.3%). All other reasons for rehospitalization, however, were comparable between the two groups.
“We found that pump speeds and pump flows were lower in the smaller LV size group during the follow-up period,” the authors added. “In addition, larger LV size patients demonstrated decreasing LVEDD measurements, but smaller LV size patients did not show a further decrease in dimensions. It is possible that patients with smaller LV dimension at baseline did not tolerate higher pump speeds after LVAD implantation compared with patients with larger LV size, which could have resulted in lesser remodeling or the absence of such signifies no greater opportunity for reverse remodeling.”
Molina and colleagues did emphasize that patients with smaller left ventricular dimensions can still receive a HeartMate 3 LVAD if medically necessary. This does not necessarily mean it is to be avoided altogether, they said, and any treatment decisions should still be made by reflecting on the expected mortality if they did not receive an LVAD.
“Emerging surgical strategies using left atrial cannulation may represent a partial solution to the anatomical and physiologic limitations imposed by a small ventricular size but require proper investigation,” they wrote. “The successful use of a left atrium-to-aorta durable LVAD configuration has been reported in patients with restrictive cardiomyopathy including hypertrophic cardiomyopathy and amyloid heart disease. The advantages of these innovative surgical approaches deserve further study.”
Click here to read the full analysis in JACC: Heart Failure, an American College of Cardiology journal.
Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.