PROTECT II: Positive Outcomes Observed with Impella Device

SAN FRANCISCO, CALIF.—High-risk patients undergoing PCI, treatment with Impella 2.5 compared very favorably with the intra-aortic balloon-pump, according to trial results.

Researchers of the PROTECT II trial reported that there was a substantial learning curve associated with the Impella 2.5 device (Abiomed), although outcomes did improve over the trial’s duration. There was a trend toward improvement with 30-day outcomes for the population with Impella vs. intra-aortic balloon-pump (IABP; P=.10). At 90 days, with extensive revascularization, Impella was associated with significant reductions in major adverse events, MACCE and the composite of death, MI, stroke and revascularization.

“When angiographic information was analyzed, it became apparent that the more we intervened on coronary territories, the larger the improvement in 90-day outcome was for Impella treated patients,” William O’Neill, MD, trial researcher with the University of Miami Health System, Miami, Fla., told TCT Daily. “Thus, when high-risk PCI patients are being treated, if a quick single lesion needs treatment, little advantage occurred. Conversely, a large superiority for Impella support exists with complex multivessel interventions.”

Another clinical implication from the trial, he said, is that in current practice PCI can be performed with comparable safety to CABG in very ill, high-risk patients.

The prospective, multicenter trial was designed to examine 654 high-risk PCI patients who required prophylactic hemodynamic support. Those deemed eligible for the study had three-vessel disease and left ventricular ejection fraction no higher than 30%, or unprotected left main or last patent conduit and LVEF of no more than 35%.

Patients were randomly assigned to either Impella 2.5 or the intra-aortic balloon-pump (IABP), with the operator of the procedure determining the PCI approach. The primary endpoint was defined as a composite of 10 major adverse events at 30 days with follow-up conducted at 90 days.

Halfway through enrollment, the trial was halted after the Data Safety Monitoring Board recommended termination of the study due to the futility of the 30-day primary analysis. Upon receiving this recommendation, researchers had reached just over two-thirds of the planned enrollment (n=447).

Jeffrey J. Popma, MD, study co-author with Beth Israel Deaconess Medical Center and Harvard Medical School, said that the results show that even in a patient cohort he called “the sickest of the sick,” more work by the physician leads to better outcomes.

“Among patients who had more extensive revascularization, the 90-day clinical event rate was better than in those patients who had limited revascularization,” he said. “That gives an idea to clinicians who take on the very complex patients that the more work they can do, the better off the patient will be.”

Researchers observed no difference in outcomes or adverse events between Impella and IABP for patients who underwent limited revascularization. However, Popma said the Impella device was associated with improved outcomes in patients who had extensive revascularization.

“For patients who have this very complex coronary disease with reduced LVEF, there is a benefit to complete revascularization,” he said. “Secondly, if one is to do extensive revascularization, there is an advantage for the Impella device compared with the balloon pump. We want to fix as much as we can, and we can do that more safely with the Impella device.”