Large Clinical Trial Finds Heart Support Pumps Increase Cardiovascular Death Risk During Complex Angioplasty Procedures

ACC.26 trial finds that temporary mechanical heart pumps fail to protect patients during angioplasty and nearly double the risk of cardiovascular death.

By: AXL Media

Published: Mar 30, 2026, 4:04 AM EDT

Source: Information for this report was sourced from American College of Cardiology

A Critical Reevaluation of Mechanical Heart Support in Cardiology

A longstanding assumption in interventional cardiology is being overturned by new evidence from a major clinical trial in the United Kingdom. For years, physicians have increasingly relied on miniaturized, temporary pumps to "unload" the left ventricle during complex angioplasty procedures, believing the mechanical assistance protected the heart muscle from the stress of surgery. However, the CHIP-BCIS3 trial, the first randomized study of its kind, found no evidence of such protection. Divaka Perera, a professor of cardiology at King's College London, stated that the findings strongly suggest these devices should no longer be used routinely without much clearer evidence of a tangible clinical benefit.

The Rise of Left-Ventricular Unloading Without Randomized Evidence

The practice of left-ventricular unloading involves inserting a tiny pump through the femoral artery to assist the heart's main chamber in circulating blood. This technique was widely adopted as a safety measure for patients with both severe coronary artery disease and moderate to severe heart failure. Until now, the expectation that these pumps would protect the patient was not based on rigorous randomized trials but on clinical intuition. The procedure is intended to reduce the heart's workload while surgeons place stents to open blocked arteries, but the new data suggests that the added complexity of the device may introduce more harm than the protection it was designed to provide.

Analyzing the Surprising Mortality Spike in the BCIS-3 Trial

The study followed 300 high-risk patients over a two-year period, comparing standard percutaneous coronary intervention against the same procedure supported by a mechanical pump. While the primary composite endpoints showed no statistical difference, the secondary analysis of mortality revealed a troubling trend. Patients assigned to the heart pump group experienced a 26.7% risk of dying from heart-related conditions, nearly double the 14.5% risk observed in the standard care group. This 12.2 percentage point increase in cardiovascular death provides a strong signal that the intervention may be detrimental to the very patients it was meant to save.