Benefit of percutaneous heart pumps murky despite skyrocketing use

The use of percutaneous ventricular assist devices (PVADs) has grown by leaps and bounds in recent years, but a study published online March 30 in JAMA Internal Medicine casts doubt on their overall benefit, given the high costs and mortality rates.

Rohan Khera, MD, of the University of Iowa Hospitals and Clinics in Iowa City, and colleagues compared trends and outcomes for PVADs and intra-aortic balloon pumps (IABP) between 2007 and 2012 using the National Inpatient Sample and administrative coding data. They pointed out that two PVAD devices—the Impella pump (Abiomed) and TandemHeart (CardiacAssist)—had recently received 510(k) clearance from the FDA. PVADs offer up to 5 L per minute of cardiac output compared with the IABP’s 0.5 L per minute.

In the six-year study period, use of PVADs increased 30-fold, from 4.6 discharges per million in 2007 to 138 per million in 2012, with patients with cardiogenic shock having the greatest increase. Use of IABPs dropped from 1,738 per million in 2008 to 1,608 per million in 2012. The number of hospitals implanting PVADs jumped from 72 in 2007 to 477 in 2011.

Over time, patients implanted with PVADs tended to get older with more comorbidities. In the overall PVAD population, 45.4 percent had cardiogenic shock. The overall mortality rate for PVAD recipients was 28.8 percent with relatively little change between 2007 (29.6 percent) and 2012 (31 percent). PVAD patients with cardiogenic shock had the highest mortality rate of all subgroups, at 47.5 percent.

Overall mean costs were much higher with PVADs: $85,580 vs. $55,168 for IABPs. PVAD patients with cardiogenic shock had the highest cost, at $113,695. In a propensity score-matched analysis, PVADs were associated with a higher in-hospital mortality compared with IABPs (odds ratio 1.23).

“[I]t is still possible that PVAD recipients in our study were sicker compared with IABP recipients because of unmeasured confounders (eg, severity of underlying illness, comorbidities, or high-risk coronary anatomy),” Khera et al wrote. “Nevertheless, our findings highlight the uncertainty regarding the clinical benefit of PVAD implantation in contemporary practice.”

Based on their results, they recommended a randomized clinical trial be conducted. The Impella’s PROTECT II trial had been powered to assess clinical endpoints but it was stopped prematurely due to futility. They added that the findings also raise questions about the effectiveness of the FDA’s less stringent 510(k) pathway for approval. The Institute of Medicine has called for shuttering that process.