Predictors of early and mid-term mortality after microaxial flow pump–supported high-risk pci: the role of baseline LVEF in a large multicenter real-world cohort

Background Microaxial flow pump-supported high-risk percutaneous coronary intervention (pHRPCI) has emerged as a revascularization strategy for patients with complex coronary artery disease who are not suitable candidates for surgery. However, the prognostic impact of baseline left ventricular ejection fraction (LVEF) in contemporary pHRPCI practice remains uncertain. Purpose To investigate the association between baseline LVEF, procedural complexity, and clinical outcomes in a large multicenter real-world pHRPCI cohort. Methods This multicenter observational study included patients undergoing pHRPCI at 22 Polish centers and one major German center (n=467). Patients were stratified by baseline LVEF ≤40% (n=324) and >40% (n=143). Baseline characteristics, procedural parameters, and clinical outcomes were analyzed. Multivariable Cox regression analyses identified independent predictors of 30-day and 1-year mortality. Results The cohort represented a highly complex pHRPCI population with extensive coronary disease and high clinical risk. Patients with LVEF ≤40% had a significantly higher baseline risk profile despite being younger, including higher EuroScore II (median 5.8% vs. 3.6%, p<0.001), higher rate of chronic kidney disease (49.1% vs. 34.3%, p=0.003), and more advanced heart failure symptoms (NYHA III/IV: 65.0% vs. 35.2%, p<0.001). Overall, coronary complexity was substantial, with a median SYNTAX score of 36 (IQR 25–46) and left main disease in 78.4%. Procedurally, extensive multivessel PCI was performed with a median of 3 treated vessels (IQR 2–3). A residual SYNTAX score ≤8 was achieved in 54.9% without differences between LVEF groups. Procedure-related complications reflected the high-risk nature of the population, with BARC 3–5 bleeding in 23.8% (20.9% vs. 30.2%, p=0.033) and access-site complications in 25.8% (22.6% vs. 32.9%, p=0.019), both significantly lower in patients with LVEF <40%. LVEF <40% was associated with higher early mortality (30-day mortality: 13.0% vs. 4.9%, p=0.009) and independently predicted early death in multivariable analysis (HR 3.11, 95% CI 1.35–7.18, p=0.008). In contrast, 1-year mortality was primarily driven by comorbidities including atrial fibrillation (HR 1.79, 95% CI 1.18–2.72, p=0.006), diabetes mellitus (HR 1.75, 95% CI 1.16–2.63, p=0.007), dialysis dependency (HR 2.13, 95% CI 1.01–4.52, p=0.048), and surgical risk assessed by EuroScore II (HR 1.02, 95% CI 1.00–1.04, p=0.039). In contrast, baseline LVEF was not independently associated with mid-term outcomes. Conclusion In a large contemporary multicenter real-world pHRPCI cohort, LVEF <40% identifies patients at increased early procedural risk but does not independently determine mid-term prognosis. These findings suggest that the comorbidity burden, rather than ventricular function alone, drives outcomes after pHRPCI and may inform patient selection and risk stratification in complex high-risk PCI.30-day and 1-year survivalFor image description, please refer to the figure legend and surrounding text.