Elective unloading with a microaxial flow pump showed no material difference in outcomes versus standard care in severe left ventricular dysfunction

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The New England journal of medicine Published May 7, 2026 Medically reviewed May 12, 2026 Study authors: Perera Divaka, Ryan Matthew, Ezad Saad M, Khan Sohail Q, Webb Ian, O'Kane Peter D, Weerackody Roshan… PubMed ↗ NCT05003817 ↗ DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Consider that elective unloading with a microaxial flow pump showed no material difference versus standard care in severe LV dysfunction.

This randomized controlled trial evaluated elective unloading with a microaxial flow pump versus standard care in patients with severe left ventricular dysfunction and extensive coronary artery disease. The study population consisted of 300 individuals undergoing planned complex PCI. The primary outcome was a hierarchical composite including death from any cause, disabling stroke, spontaneous myocardial infarction, hospitalization for cardiovascular causes, or periprocedural myocardial injury, analyzed using a win ratio at a minimum of 12 months.

The main results indicated no material between-group difference for the hierarchical composite primary outcome. Specifically, 36.6% of pairwise comparisons favored the microaxial flow pump, while 43.0% favored standard care. The win ratio was 0.85 with a 95% CI of 0.63 to 1.15 and a P value of 0.30. For death from any cause, 47 patients occurred in the microaxial-flow-pump group versus 33 in the standard-care group, yielding a hazard ratio of 1.54 with a 95% CI of 0.99 to 2.41.

Safety and tolerability assessments found no material between-group difference in the risk of bleeding or vascular complications. The median follow-up duration was 22 months with an interquartile range of 16 to 30 months. The study was funded by the U.K. National Institute for Health and Care Research. Given the wide confidence intervals and lack of statistical significance, the findings suggest that elective unloading with a microaxial flow pump does not provide a clear benefit over standard care for this specific population in this setting.

Study Details

Study typeRct

Sample sizen = 300

EvidenceLevel 2

Follow-up12.0 mo

PublishedMay 2026

PMID41910380

TrialNCT05003817

View Original Abstract ↓

BACKGROUND: Complex percutaneous coronary intervention (PCI) in patients with severely impaired left ventricular function carries a high risk of death and complications. Whether percutaneous left ventricular unloading improves outcomes remains unclear. METHODS: We randomly assigned 300 patients with severe left ventricular dysfunction and extensive coronary artery disease in a 1:1 ratio to a strategy of elective unloading with a microaxial flow pump or to standard care during planned complex PCI. The primary outcome was a hierarchical composite that included death from any cause, disabling stroke, spontaneous myocardial infarction, hospitalization for cardiovascular causes, or periprocedural myocardial injury at a minimum of 12 months, as analyzed according to a win ratio. RESULTS: A total of 148 patients were assigned to receive a microaxial flow pump and 152 to receive standard care. At a median of 22 months (interquartile range, 16 to 30), 36.6% of pairwise comparisons favored the microaxial flow pump, and 43.0% favored standard care (win ratio, 0.85; 95% confidence interval [CI], 0.63 to 1.15; difference, -6.4 percentage points; P = 0.30). Death from any cause occurred in 47 patients in the microaxial-flow-pump group and 33 in the standard-care group (hazard ratio, 1.54; 95% CI, 0.99 to 2.41). There was no material between-group difference in the risk of bleeding or vascular complications. CONCLUSIONS: Among patients with severely impaired left ventricular function undergoing complex PCI, elective left ventricular unloading with a microaxial flow pump did not reduce the risk of major adverse clinical outcomes at a minimum of 12 months. (Funded by the U.K. National Institute for Health and Care Research; CHIP-BCIS3 ClinicalTrials.gov number, NCT05003817.).