A smaller, centrifugal-flow left ventricular assist device that lies entirely within the pericardial space was found noninferior to the HeartMate II axial-flow device in patients with advanced heart failure who weren’t eligible for heart transplant, according to a report published online Feb. 2 in the New England Journal of Medicine.
The two LVADs were compared in(A Clinical Trial to Evaluate the HeartWare Ventricular Assist System), a prospective, randomized trial in 445 patients who were treated at 48 U.S. sites and followed for 2 years. The study participants had an LV ejection fraction of 25% or less and high prevalences of abnormal renal function and dependence on intravenous inotropic support, said , of Duke University, Durham, N.C., and his associates.
The study participants were randomly assigned to receive the HeartWare, an investigational centrifugal-flow LVAD (297 patients) or the standard axial-flow HeartMate II LVAD (148 patients). In the intention-to-treat analysis, the primary endpoint – a composite of survival free from disabling stroke and no removal of the device for malfunction or failure – was 55.4% with the new device and 59.1% in the control group. The results were similar in the per-protocol and the as-treated analyses, demonstrating that the new device was noninferior but not superior to the axial-flow LVAD, the investigators said (N Engl J Med. 2017 Feb 2. doi: 10.1056/NEJMoa1602954).
There were significantly more cases of device malfunction or failure requiring urgent surgery in the control group than in the centrifugal-flow group (16.2% vs 8.8%), but significantly more cases of stroke (29.7% vs 12.1%), sepsis, and right heart failure. Rates of major bleeding, cardiac arrhythmia, renal dysfunction, and infection were similar between the two study groups. Overall survival* also was not significantly different (60.2% with the new LVAD and 67.6% in the control group).
Both study groups showed significant and comparable improvement after LVAD implantation. Functional status improved to New York Heart Association class I or II in roughly 80% of patients. Mean 6-minute walk distance improved from 100.2 to 199.4 meters with the new device and from 91.9 to 190.1 meters in the control group, a change that was noted within 3 months of surgery and persisted through the end of follow-up. Similarly, mean scores on the Kansas City Cardiomyopathy Questionnaire improved by 25.8 points and 25.3 points, respectively, and mean scores on the European Quality of Life 5 Dimensions scale improved by 22.5 points and 25.5 points, respectively.
This trial was sponsored by HeartWare, which was also involved in data management and analysis. Dr. Rogers reported having no relevant financial disclosures; his associates reported ties to HeartWare (Medtronic), Thoratec (St. Jude Medical), Novartis, and GE HealthCare.
*Correction 2/2/17: An earlier version of this article misidentified survival rates as mortality rates.