TCT Feature: Impella may help thwart CV events in sicker patients

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SAN FRANCISCO—Patients with extensive coronary artery disease (CAD) and a reduced left ventricular function who undergo PCI benefit from extensive revascularization. Additionally, patients who undergo extensive revascularization with the Impella device see substantially reduced 90-day event rates when compared with intra-aortic balloon pumps, Jeffrey J. Popma, MD, director of interventional cardiology at Beth Israel Deaconess Medical Center in Boston, said during a Nov. 8 presentation at the 23rd annual Transcatheter Cardiovascular Therapeutics (TCT) conference.

Popma, who centered his talk around the previously presented PROTECT II trial results, evaluated the value of left ventricular support devices (Impella, Abiomed) versus intra-aortic balloon pump (IABP) in patients at an extremely high risk of coronary intervention. Additionally, the objective was to characterize the complexity of patients enrolled in PROTECT II based on the extent of CAD at the time of PCI.

During the study, Popma and colleagues assessed whether there were treatment differences with the Impella device that were related to the extent of revascularization performed. Ischemia zone scores were calculated using an 11-point scoring system, Popma told Cardiovascular Business.

Popma said that high risk was defined as two different types of risk set—the clinical risk set and the complexity of a patient’s coronary anatomy. “How complex were the blockages?

“This study looked at patents that had worst clinical risk and worst anatomic risk (a much more complex patient population) and asked a fundamental question: Is the Impella device preferred or not?" Popma offered.

The study population included 427 patients with either a LVEF of less than 30 percent or three vessel diseases, or who had a LVEF of less than 35 percent in a single main artery. Of the 448 patients, 211 were randomized to receive an IABP and 216 were randomized to receive the Impella device. Of those who received an IABP device, 54 received limited revascularization and 145 received extensive revascularization. For those who received an Impella device, 65 patients underwent limited revascularization while 133 patients received extensive revascularization.

“What we wanted to look at specifically was to determine how much work the investigators did as part of a PCI procedure,” Popma said. “Did they go in and simply put a single stent in a single vessel and say that was their revascularization procedure? Or did the investigators work hard and try to provide ventricular support in all three of the arteries?”

The extent of revascularization was analyzed. “Some patients had minimal revascularization and some patients had extensive revascularization where there where several stents placed in multiple arteries,” Popma noted.

“What we asked was, was the amount of repair of the vessels similar in patients who had a balloon pump compared with those who received the Impella device?” Popma and colleagues found that the revascularization was the same in both groups.

“There were the same number of lesions, the same SYNTAX scores, the same ischemia zone scores and the same changes in both SYNTAX and ischemia zone scores,” Popma said.

Popma said it matters how hard the investigators work to do their repair. “The more work you do, the more benefit you see,” he explained. In fact, major adverse event rates were substantially lower in patients who received extensive revascularization compared to those who received limited revascularization, 41 percent versus 56 percent.

“The bottom line was that if you are only going to do a little bit of work [limited revascularization], you don’t need something fancy like an Impella device,” Popma noted. “The balloon pump works just fine because the doctors are in an out so quickly, the patient never has a chance to get sick."

However, for patients with multiple blockages in multiple vessels who must undergo longer procedures that are more than two hours long, the Impella device can reduce the 90-day event rate by 30 to 47 percent, Popma offered

What does this mean for doctors?

“When faced with patients who have a very complex disease, doctors should work as hard as they can to fix as much as they can because this is what lowers the event rates," Popma offered.

As far as costs go, Popma said that because the event rates are reduced, the Impella devices seem to be a more cost-effective therapy that works as well as, or a little bit better than dialysis, Popma