A retrospective analysis of two studies involved the HeartWare left-ventricular assist device Medtronic (NYSE:MDT) acquired in 2016 showed that managing blood pressure reduced the severity of strokes in patients implanted with the HVAD pump.
The analysis, of “destination therapy” patients who are not candidates for a heart transplant, took data from the Endurance and Endurance Supplemental studies. Results were presented this week at the annual meeting of the International Society for Heart & Lung Transplantation in London, Medtronic said.
The 465-patient Endurance Supplemental study compared 308 patients implanted with the HeartWare HVAD and 157 patients implanted with arch-rival Thoratec‘s HeartMate II device; the HVAD-treated cohort was also managed with a pre-specified blood pressure strategy to try to cut the stroke rates seen in earlier trials.
Endurance Supplemental’s primary endpoint was the rate of transient ischemic attack or stroke with 24-week residual deficit at 12 months. Secondary endpoints included a composite of freedom from death, disabling stroke and device replacement or urgent transplantation and a comparison of stroke or transient ischemic attack between the HVAD-treated cohorts in Endurance Supplemental and the original Endurance trial.
Although Endurance Supplemental missed the primary endpoint, with a 14.7% stroke rate for the HVAD cohort and 12.1% for the HeartMate II group, HVAD patients a 76.1% rate of freedom from the secondary endpoint’s adverse events compared with 66.9% for the control arm. Stroke rates were 24.2% lower for the HVAD cohort in the second trial compared with Endurance and hemorrhagic cerebrovascular accident was reduced by 50.5%.
Today Fridley, Minn.-based Medtronic said the two-year rate of freedom from disabling stroke for the HVAD group was 91%. Patients with the HeartWare device who had a stroke of any severity showed a lower rate of stroke-related mortality than patients implanted with HeartMate II, at 17% compared with 27%, respectively, the company said.
And there was a 23% reduction in total strokes, a 36% reduction in disabling strokes and a 39% reduction in stroke-related mortality in the HVAD arm of Endurance Supplemental, compared with the same arm in Endurance.
“This analysis shows that stroke severity is an important determinant of outcomes, and the use of the HVAD system with a guidelines-based blood pressure management strategy can, in addition to reducing overall stroke rates, reduce the occurrence of disabling stroke and improve survival in patients who experience strokes,” Dr. Jeffrey Teuteberg, of Stanford University, said in prepared remarks. “We also found that patients with a stroke in the HVAD cohort had better survival than those who received the control device. These results reinforce the importance of blood pressure management with the HVAD for end-stage heart failure patients.”
Medtronic said it’s also running a pair of real-world studies on the HVAD device, a 300-patient post-approval review of destination therapy patients called DT PAS and Apogee, which is designed to examine best practices in blood pressure management, anticoagulation/anti-platelet therapy and implant procedure in a DT PAS subset.
“Medtronic aims to advance the field of mechanical circulatory support and, consequently, the overall management of heart failure patients who can benefit from the therapy,” added cardiac rhythm & heart failure CMO Dr. Rob Kowal. “Continuing to define and drive best practices that reduce pump-related adverse events in a real-world setting is central to this patient-first strategy.”
Medtronic paid $1.1 billion in August 2016 for HeartWare, after cross-town rival St. Jude Medical paid $3 billion for Thoratec in October 2015; Abbott (NYSE:ABT) paid $25 billion for St. Jude in January 2017.