Intervention increased deaths from cardiovascular causes compared with standard care

NEW ORLEANS (March 29, 2026) — The first randomized trial to compare standard percutaneous coronary intervention (PCI), also known as coronary angioplasty, with PCI accompanied by the use of a temporary, miniaturized pump to support the heart in patients with both severe coronary heart disease and moderate to severe heart failure found no significant difference between the two approaches. However, at two years, patients who received the heart pump had almost double the risk of dying of a cardiovascular event compared with those who received standard care. The research was presented at the American College of Cardiology’s Annual Scientific Session (ACC.26).

“We found no evidence that use of the temporary pump protected the heart during the angioplasty procedure,” said Divaka Perera, MD, professor of cardiology at King’s College London in the United Kingdom and first author of the study. “Our findings strongly suggest that we shouldn’t be using this device routinely without more evidence of benefit.”

Severe impairment of the heart’s main pumping chamber, the left ventricle, reduces the heart’s ability to pump blood to the body’s other organs and tissues and puts the patient at risk for life-threatening complications such as cardiac arrest. To temporarily reduce the heart’s workload, a tiny mechanical pump may be inserted through the femoral artery into the heart, a technique known as left-ventricular (LV) unloading. However, LV unloading can have adverse effects, Perera said, including the risk of injury to blood vessels by causing them to bleed, tear or become blocked.

Over the past decade, Perera said, cardiologists have increasingly used LV unloading when performing a PCI, a minimally invasive procedure to restore blood flow to the heart in patients with moderate to severe coronary artery disease. It involves placing a tiny balloon inside a partially blocked coronary artery and inserting a small, wire-mesh tube called a stent to keep the artery from becoming blocked again.

“The expectation was that using the pump would protect both the patient and their heart, but this expectation was not based on evidence from randomized trials,” Perera said.

The BCIS-3 trial was designed to determine whether LV unloading reduced the risk of life-threatening complications and improved outcomes for patients with both extensive coronary artery disease and severe impairment of the left ventricle who were undergoing PCI. The trial enrolled 300 patients (average age 73 years, about 83% men, 85% White) at 21 sites in the UK. Half of the patients were randomly assigned to receive PCI with LV unloading and the other half to PCI alone (standard care).

Seventy-five percent of the patients had been admitted with acute coronary syndrome, which means they either had a heart attack or intense chest pain indicating they were at high risk of a further heart attack. They also had extensive coronary disease, defined as blockages of at least 70% in at least two coronary arteries or a blockage of at least 50% in the main coronary artery. Due to severe left ventricular impairment, patients’ hearts were, on average, pumping out just 27% of the blood in the left ventricle with each contraction. A healthy heart pumps out 50% to 70%.

The study’s primary endpoint was a composite of death from any cause, disabling stroke, heart attack, hospitalization for cardiovascular causes and any heart injury occurring during the patient’s treatment. Secondary endpoints included the individual components of the primary endpoint plus an assessment by independent doctors that the angioplasty successfully opened all the narrowed or blocked arteries as intended. Patients were followed for an average of approximately two years.

To analyze the study findings, Perera and his colleagues looked at pairs of patients (one from each arm of the study) and determined for each pair whether the outcome was better with LV unloading or with standard care. They found that it was better with standard care in 43% of the comparisons and better with LV unloading in 36.6%—a difference that was not statistically significant—while in 20.4% of pairs there was no difference.

When the investigators looked at the secondary outcome of death alone, however, they found that, compared with patients who received standard care, those who received LV unloading had about a 50% elevated risk of dying from any cause (32.6% vs. 23.4% for standard care) and an absolute increase of 12.2 percentage points in the risk of dying from a heart-related condition (26.7% vs. 14.5% for standard care).

Patients who received LV unloading had a higher rate of heart injuries during and after treatment than those who received standard care, Perera said.

“This was surprising because the whole premise of LV unloading was that it protects the heart,” he said. “But we found that patients assigned to LV unloading had more damage to the left ventricle than those assigned to standard care.”

Rates of bleeding and other blood-vessel injuries were low in both groups of patients, he said, ruling this out as a possible cause of the higher death rate among patients who received LV unloading. No differences were seen between the two groups of patients for other secondary endpoints such as heart attacks, disabling strokes and hospitalizations for heart failure.

Although the higher death rate among patients who received LV unloading is a secondary outcome of the study, it’s a strong signal that the treatment is doing harm, Perera said.

There were some limitations to the study, including that participants were predominantly male and the study was performed entirely in the UK, making the findings potentially less generalizable to women or to health care systems in other countries. In addition, patients with cardiogenic shock (a life-threatening medical emergency characterized by low blood pressure, low blood oxygen and inability of the heart to meet the body’s need for blood) were excluded from the study. Follow-up studies are needed to try to understand the causes of the higher rates of death and blood-vessel injury among patients who received LV unloading, Perera said. He and his colleagues are also currently working on a cost-benefit analysis of LV unloading compared with standard care, which they expect to present later this year, he said.

The study was funded by the UK’s National Institute for Health & Care Research.

The study was simultaneously published online in the New England Journal of Medicine at the time of publication.

Perera will present the study, “Controlled Trial of High-Risk Coronary Intervention with Percutaneous Left Ventricular Unloading (CHIP-BCIS3)” on Sunday, March 29, at 8:30 a.m. CT / 13:30 UTC in the Main Tent, Great Hall.

ACC.26 will take place March 28-30, 2026, in New Orleans, bringing together cardiologists and cardiovascular specialists from around the world to share the newest discoveries in treatment and prevention. Follow @ACCinTouch, @ACCMediaCenter and #ACC26 for the latest news from the meeting.
The American College of Cardiology (ACC) is the global leader in transforming cardiovascular care and improving heart health for all. As the preeminent source of professional medical education for the entire cardiovascular care team since 1949, ACC credentials cardiovascular professionals in over 140 countries who meet stringent qualifications and leads in the formation of health policy, standards and guidelines. Through its world-renowned family of JACC Journals, NCDR registries, ACC Accreditation Services, global network of Member Sections, CardioSmart.org patient resources and more, the College is committed to ensuring a world where science, knowledge and innovation optimize patient care and outcomes. Learn more at ACC.org.

The American College of Cardiology (ACC) is the global leader in transforming cardiovascular care and improving heart health for all. As the preeminent source of professional medical education for the entire cardiovascular care team since 1949, ACC credentials cardiovascular professionals in over 140 countries who meet stringent qualifications and leads in the formation of health policy, standards and guidelines. Through its world-renowned family of JACC Journals, NCDR registries, ACC Accreditation Services, global network of Member Sections, CardioSmart.org patient resources and more, the College is committed to ensuring a world where science, knowledge and innovation optimize patient care and outcomes. Learn more at ACC.org.

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