Impella device

PROTECT II Trial
The trial was discontinued early due to futility. A press release from the manufacturer Abiomed stated the following:

"Abiomed announced completion of the PROTECT II study based on a futility determination at the planned interim analysis regarding the primary end-point, which the company views as likely to be due to unanticipated confounding variables related to the use of rotational atherectomy² in the study. The decision to end the study followed the recommendation of the Data Safety Monitoring Board. The study was designed to measure major adverse events at 30 days in high risk percutaneous coronary intervention (PCI) patients randomized to receive hemodynamic support during the procedure with the Impella versus intra-aortic balloon (IAB)."

Summary and Conclusion of Protect II:


 * For the entire study population, Impella(R) significantly reduced out of hospital major adverse events (MAE) by 52% compared to IAB for the duration of the 90 day monitoring (p=0.02, N= 302).
 * There was an overall positive trend in the majority (88%, n=267) of patients in the study at the interim analysis, in which Impella reduced the major adverse event rate by 26% over the IAB (Impella 32% MAE vs. IAB 43% MAE, p=0.11).
 * Impella provided a 47% reduction in major adverse events over IAB in a subgroup that represents 70% of the protocol study population (Impella 23% MAE vs. IAB 43% MAE, p=0.009). An analysis of a “PROTECT” score will be presented at the upcoming ACC in April.
 * When using atherectomy, Impella significantly reduced repeat revascularization (p=0.02).
 * The data revealed confounding variables in the treatment between the two arms with the most significant differences related to two times more frequent use (p=0.04) and two times the number of passes per use (p=0.003) of rotational atherectomy in the Impella arm compared to the IAB arm, accounting for 12% (n=38) of total PROTECT II patients at the interim. Use of atherectomy during PCI has been previously shown to increase CK-MB release (heart enzyme) following PCI, triggering an endpoint in PROTECT II.

“Atherectomy was an unanticipated variable which resulted from the operators’ decision to ‘do more with Impella.’ Our investigators had unblinded knowledge of the treatment arm after randomization,” said William O’Neill, M.D., University of Miami and Principal Investigator of the PROTECT II study. “It is interesting that operators felt that they could do more complex interventions once randomized to Impella and this in and of itself is an important finding.”