Heart Pump Protocol Makes a Dent in Cardiogenic Shock Mortality

Hospitals participating in the National Cardiogenic Shock Initiative (NCSI) produced favorable survival rates for the challenging population of acute MI patients with cardiogenic shock, investigators announced.

Adoption of a standardized treatment protocol -- featuring early use of Impella mechanical circulatory support (MCS), percutaneous coronary intervention (PCI), and right heart catheterization to assess left and right ventricular function -- resulted in most people surviving in the short term, the odds particularly good for those in stage C and D shock:

• 71% survival to discharge (79% for stage C/D vs 54% for stage E, P<0.01)
• 68% survival to 30 days (77% vs 49%, P<0.01)
• 53% survival to 1 year (62% vs 31%, P<0.01)

Importantly, survival in the NCSI was at least numerically better than what was seen in prior cardiogenic shock studies -- and in a cohort who were sicker than any comparable study population to boot, said Babar Basir, DO, of Henry Ford Health System in Detroit, reporting at this year's virtual scientific sessions of the Society for Cardiovascular Angiography and Interventions (SCAI).

"It's a breath of fresh air to see some movement in the positive direction in treating a disease where we've had stagnant mortality over the past 20 years," Basir said during an SCAI press conference.

Ultimately, with this study, Basir and colleagues were able to reproduce earlier successes with the protocol, originating in Detroit, in a larger study.

"If implemented across the country, the NCSI protocol could save up to 20,000 lives a year," said principal investigator William O'Neill, MD, also of Henry Ford, in a press release.

Greater adoption of this protocol, along with more refined escalation strategies, including use of right ventricular MCS, could take survival rates over 80%, Basir suggested, noting that such a strategy will be tested in the upcoming RECOVER IV trial.

During the SCAI session, Ron Waksman, MD, of MedStar Washington Hospital Center in Washington, D.C., cautioned that investigators needed a concurrent control group and that they should perform a comparison of Impella against other MCS devices.

For the single-arm study, the NCSI group included 406 patients enrolled nationwide in 2016-2020. All participants presented with acute MI with cardiogenic shock to one of 80 participating hospitals (48 community hospitals and 32 academic centers).

The cohort averaged 63.7 years of age, and women accounted for a quarter of the group. White patients made up 69% of the study population.

Notably, more than a quarter of people were in stage E shock, making them a group that would have been historically unlikely to be recruited in a trial.

Operators largely opted for the Impella CP instead of the Impella 2.5 MCS device, and tended to insert the MCS before PCI rather than the other way around. Femoral access was preferred.

The NCSI algorithm calls for a door-to-support time goal of <90 minutes, encompassing identification of cardiogenic shock and cath lab activation to MCS insertion.

Basir's group achieved a median door-to-support time of 78 minutes in ST-segment elevation MI (and a door-to-balloon time of 81 minutes).

Basir acknowledged that 1-year mortality continued to be high for NCSI participants. He suggested greater optimization of guideline-directed medical therapy and consideration of early advanced heart failure follow-up. Novel therapies to reduce heart failure risk may also help patients in the long run, he added.

Comment