Hemodynamic Support and Complete Revascularization

Jeffrey Moses, MD, discusses Protected PCI, complete revascularization, and strategies for determining when to use hemodynamic support. He gave this presentation at the 2021 virtual Cardiovascular Research Technologies (CRT) annual meeting.

Looking at data from the PROTECT series of trials, Dr. Moses highlights results showing that Impella® support reduces not only in-hospital major adverse cardiovascular and cerebrovascular (MACCE) events—death, stroke, myocardial infarction, and repeat revascularization—but post-discharge MACCE events to 90 days.  “When you’re treating these patients, obviously the procedure is safer with less hemodynamic disturbances, and giving you much more latitude, but the post-discharge reduction was also quite striking and actually more profound than even the in-house reduction,” Dr. Moses notes. “There’s a payback for the support that you use even after a hospital discharge.”

“If you look at the reduction in MACCE between the balloon pump arm and the Impella arm, it was exclusively in those who had a major reduction in ischemia,” Dr. Moses explains. “So, the impact of your revascularization is more profound if you do support, in this case with Impella versus IABP, and a more complete job of revascularization.”

Dr. Moses also looks at the relationship between SYNTAX score and prognosis. “It’s only those with a residual SYNTAX score above 8 that actually have an adverse prognosis,” he states. “If you get the SYNTAX score down to below 8 it doesn’t matter what your original SYNTAX score was. So, in reality, this high SYNTAX score, adverse outcomes, was driven predominantly by the incompleteness of revascularization and not by the initial anatomy itself.” He emphasizes that multiple meta-analyses reinforce this with tens of thousands of patients showing that complete revascularization is associated with reduced morbidity and mortality.

Dr. Moses discusses the goals of hemodynamic support and how various strategies meet the goals of maintaining organ perfusion (cardiac power output) and protecting the heart with reduced oxygen demand and increased oxygen supply. Balloon pumps, he explains, do little to meet these goals, and extracorporeal membrane oxygenation (ECMO), while improving CPO, increases oxygen demand and reduces oxygen supply, and thus does not provide myocardial protection.

Impella, however, increases blood pressure and flow to improve cardiac power output (CPO) and provide unloading that increases oxygen supply and reduces demand by reducing left ventricular end-diastolic pressure (LVEDP). “So that gives you the sweet spot, in terms of protecting the heart and allows it to tolerate the ischemic insults or any potential complications during the procedure.”

Dr. Moses reviews data demonstrating that Impella support reduced acute kidney injury (AKI) compared to a historic matched control group and virtually eliminated severe AKI. “So, it’s not just protecting the heart. It’s protecting the kidneys,” he emphasizes.

Regarding complete revascularization, Dr. Moses states, “With the access that we have, why not do everything?” asking, why risk a second access in these complex patients?

Dr. Moses concludes with his strategy for considering hemodynamic support, which entails 4 questions.

1. Is the patient hemodynamically unstable? If yes, consider support. If no, go to question 2.
2. Does the patient have the reserve to sustain even a brief ischemic insult? If no, consider support. If yes, go to question 3.
3. Is the patient at risk for complete interruption of a blood supply that will lead to hemodynamic collapse? If yes, consider support. If no, go to question 4.
4. Is the patient at risk for prolonged ischemic insult limiting the ability to completely revascularize the patient or subjecting the ventricle to stunning? If yes, consider support. If no, bilateral access/right heart cath.