Microaxial Circulatory Support for Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis

Abstract

<h3>Purpose</h3> Microaxial circulatory support can facilitate percutaneous coronary intervention (PCI) in the setting of acute myocardial infarction with cardiogenic shock (AMICS). While proper timing of support is important, data are lacking to inform a standardized approach. We sought to pool existing evidence and compare outcomes of microaxial support based on its initiation before or after PCI. <h3>Methods</h3> Electronic search identified adult patients with AMICS undergoing PCI who received Impella 2.5, CP, or 5.0 support. Cohort-level data for 543 patients from 5 studies were extracted and analyzed. Patients were categorized as pre-PCI (Impella before PCI) or post-PCI (Impella after PCI) groups. Individual Kaplan-Meier survival curves were digitized and combined to analyze pooled survival. <h3>Results</h3> Mean patient age was 66 (95% CI: 58-74) years with 23% (17-30%) being female. Pre-PCI group had a higher incidence of previous stroke or transient ischemic attack [14% (6-28%) vs. 6% (3-14%), p = 0.02] and a trend toward higher incidence of diabetes [44% (22-69%) vs. 27% (13-48%), p = 0.08]. Mean left ventricular ejection fraction [pre-PCI: 29.5% (18.2-40.8%) vs. post-PCI: 32.3% (21.9-42.6%), p = 0.72] was similar between groups. Mean serum lactate was 6.5 (2.3-10.7) mmol/L in pre-PCI group and 5.7 (2.0-9.50) mmol/L in post-PCI group (p = 0.8). Pre-PCI group's incidence of cardiac arrest before Impella was 56% (4-98%) compared to 67% (8-98%) for post PCI-group (p = 0.76). Total duration of support was 1.6 (0-3.7) and 1.3 (0-3.3) days in pre-PCI and post-PCI groups, respectively (p = 0.87). 30-day mortality was lower in pre-PCI group [41% (34-49%) vs. 61% (42-77%), p < 0.01]. Pooled Kaplan-Meier analysis showed better early survival (log rank: p < 0.001) in pre-PCI group (Figure). <h3>Conclusion</h3> Timing of microaxial support initiation may reflect higher perceived risk in pre-PCI patients and higher acuity in post-PCI patients. Early survival appears to be better when microaxial support is initiated pre-PCI.