The FDA is reminding healthcare providers that pump thrombosis, strokes and bleeding events are complications that can result from using implantable left ventricular assist devices on certain heart failure patients. Currently, Thoratec and HeartWare are the only companies marketing such devices in the U.S.

While acknowledging that LVADs are life-sustaining devices whose benefits can outweigh their risks, the agency says in a safety communication that providers should conduct a thorough clinical evaluation when considering these devices for patients. It encourages them to return explanted devices to help manufacturers determine why adverse events occur.

Adverse Events

Specifically, the FDA highlights an increased rate of thrombosis events in patients implanted with Thoratec’s HeartMate II LVAD, which is approved as a bridge-to-transplant therapy for those at risk of imminent death from nonreversible left ventricular heart failure and awaiting a transplant. It also is approved as a destination therapy for end-stage patients who are ineligible for a transplant.

The agency cites the analysis of scientific literature showing that the HeartMate II’s thrombosis rate was as high as 8.4 percent of implanted devices at three months and 6 percent at six months. Those numbers are higher than those seen in clinical studies — 1.6 percent in the BTT trial, and 3.8 percent in the DT trial.

With HeartWare’s HVAD, which only has the BTT indication, the FDA says there is an increased stroke risk in patients implanted with the device for the DT. “Investigators reported 28.7 percent of HVAD patients experienced one or more strokes over two years, compared to 12.1 percent among patients implanted with the control device (HeartMate II).”

That information comes from clinical trial results intended to demonstrate the safety and effectiveness of the device in the DT indication.

In addition, there have been reports of patients experiencing bleeding complications after being implanted with both the HeartWare and Thoratec devices. The agency says it the cause of the bleeding isn’t understood, adding that modification to the blood thinning therapy to lower the risks of thrombosis and stroke could be a factor.

Last month, St. Jude Medical offered to buy Thoratec in an all-cash transaction valued at about $3.4 billion (IDDM, July 24). The HeartMate II was touted as making Thoratec as an attractive acquisition target. Medtronic, Abbott and Johnson & Johnson were mentioned as potential suitors that could woo Thoratec away from St. Jude during a 30-day “go-shop” period.

At least one analyst group doesn’t think the FDA’s announcement will have an impact on the deal. The information isn’t new, according to a Wells Fargo communication. “We do, however, believe that it highlights the need for new and better devices with improved adverse event profiles like [Thoratec’s] HeartMate 3 and [HeartWare’s] MVAD,” according to the group.

Neither company responded for a request for comment by press time. — Elizabeth Hollis