Clinical Analysis of Impella® in High-Risk PCI

Alexandra Lansky, MD, discusses her propensity-adjusted population-based analysis of Impella in patients undergoing high-risk PCI from a large-scale claims dataset. She presented this data at the 2021 Transcatheter Cardiovascular Therapeutics (TCT) conference.

The intention of this analysis was to compare outcomes of mechanical support with Impella to intra-aortic balloon pump (IABP) support in a narrow population of patients undergoing high-risk PCI (HRPCI). Dr. Lansky states that this analysis is important in light of a recent publication from the Premier Healthcare Database that examined a very broad patient population (including patients with cardiogenic shock and ST-elevation myocardial infarction) during a wide timeframe, between 2004 and 2016, and showed worse outcomes with Impella compared to IABP. “So, we really wanted to look at this much narrower patient population and indication in a contemporary, real-world practice.”

Dr. Lansky’s analysis, which looked at patients from the Premier Healthcare Database in a narrower, more contemporary timeframe, between April 2016 and June 2019, used propensity adjustment to control baseline differences between treatment groups. “With propensity adjustment, essentially what we found was that in fact the use of Impella was associated with a survival benefit. There was reduction in complications, including AMI and cardiogenic shock. And we also showed there was actually no difference in outcomes in terms of bleeding complications, stroke, and acute kidney injury.”

“We know that there’s enormous challenges in looking at outcomes and comparing outcomes of one therapy versus the other in these datasets,” Dr. Lansky acknowledges. She explains that over time there are likely to be differences in types of patients as well as evolution in techniques.

“One of the questions that has come up in our analysis is that we didn’t show any differences in bleeding complication,” Dr. Lansky notes. While some people are questioning that, she emphasizes that the reality is that interventional techniques and large bore access techniques have evolved. “So, all these things absolutely change over time.”

Dr. Lansky’s advice to physicians is to be very critical when looking at claims datasets and comparative effectiveness and to be sure to look at how the patient population is defined. “My take home from working on this particular indication, which was very narrow, I do believe that there is benefit from Impella in this setting.”

“We shouldn’t be lumping everything together from a decade ago, a decade plus ago, even 2 decades to current day, cause it’s a completely different setting. It’s different patients. It’s different techniques, etc.” Dr. Lansky emphasizes that if we’re going to be using these kinds of datasets to look at outcomes, it is essential to be more focused and attempt, as best we can, to eliminate confounders. “And I think that’s what we tried to do in our particular analysis.”