Abstract Body (Do not enter title and authors here): Background
Recent DanGer-Shock trial demonstrated potential mortality benefit of microaxial flow pumps (mAFP) in select patients with acute myocardial infarction cardiogenic shock (AMI-CS). However, the clinical profile, hemodynamic response, and outcomes of mAFP use in non-acute myocardial infarction cardiogenic shock (nonAMI-CS) remain less well understood.
Methods
Patients treated for cardiogenic shock between 2016 to 2022 with mAFP support (Impella 2.5, CP, 5.0, or 5.5) were retrospectively identified. Those with pulmonary artery catheter derived hemodynamics before and after implantation were included. Baseline hemodynamics were defined as the last recordings prior to device placement; post-implant hemodynamics were defined as the median of recordings within 24 hours after placement. Treatment success was defined as survival to discharge without ECMO escalation. Wilcoxon rank-sum and Chi-square tests were used for comparisons.
Results
Of 110 patients included, 65 (59%) had AMI-CS and 45 (41%) had nonAMI-CS. Compared to AMI-CS, nonAMI-CS group had higher prevalence of chronic kidney disease, heart failure, atrial fibrillation, lower baseline ejection fraction and larger left ventricular diameter. High-capacity mAFP (Impella 5.0/5.5) were more frequently used in nonAMI-CS (29% vs. 5%, p<0.01) whereas AMI-CS received predominantly Impella CP (95%). The culprit vessels among AMI-CS patients were predominantly left-sided (51% LAD, 26% LCx, 12% left main, 9% RCA, 2% OM1).
Baseline hemodynamics were similar between groups. Post-implantation, AMI-CS patients showed greater reductions in CVP (-40% vs. -31%, p = 0.04) and mPAP (-27% vs. -17%, p=0.04), achieving lower absolute CVP (9 vs. 12 mmHg, p < 0.01) and mPAP (25 vs. 29 mmHg, p = 0.04). In contrast, nonAMI-CS patients had greater improvement in cardiac index (CI) (+29% vs. +5%, p<0.01) and achieved a higher post-implant CI (2.45 vs. 1.93 L/min/m², p < 0.01). Treatment success rates were not significantly different (52% AMI-CS vs. 36% nonAMI-CS, p=0.08).
Conclusion
NonAMI-CS patients received more high-capacity mAFP and showed greater improvement in CI, while AMI-CS patients experienced more pronounced decongestion without significant increase in CI and a trend toward higher treatment success. These findings highlight decongestion as a potential prognostic signal in this patient cohort.