5001Hemodynamic profile and outcome from mechanical circulatory support in cardiogenic shock due to end-stage heart failure vs acute myocardial infarction

Abstract

Background: There are little data on the cardiogenic shock (CS) phenotype based on aetiology. With greater chronicity, we hypothesised that there will be significant differences between patients with acute myocardial infarction (AMI) and end-stage heart failure (ESHF) with different outcomes from percutaneous mechanical circulatory support (pMCS). Method: Single-centre study consecutive patients with AMI or ESHF who underwent pMCS (extracorporeal life support (ECLS) and/or Impella). CS was defined as cardiac index <2.2L/min/m2, hypotension and evidence of hypoperfusion requiring inotropes. ESHF was defined as pre-existing HF >1 month duration. Hemoglobin oxygen dissociation (P50) was measured in mixed venous blood by the Severinghaus method. Results: 45 patients (22 AMI, 23 ESHF) were included (Age: 44±5 vs 43±7 years, males: 68% vs 48%, cardiac arrest: 27% vs 13%, IABP: 68% vs 44%, inotrope score: 26±3 vs 24±2, mean BP: 58±3 vs 56±3mmHg, all P=NS). Patients with AMI had higher lactate: 7.2±0.6 vs 5.9±0.3, LVEF: 27%±2 vs 12±2 and tricuspid annular plane systolic excursion: 18±1 vs 13±1mm (p<0.001). Pulmonary hemodynamics in AMI vs ESHF: right atrial: 9.9±0.9 vs 19.0±1.7, systolic pulmonary artery (PA): 43.1±1.9 vs 58.3±5.3, mean PA: 34.2±1.3 vs 42.7±3.8, PA occlusion pressure: 26.5±0.9 vs 30.3±2.3, pulmonary vascular resistance: 179±18.6 vs 290±51 dyn.s/cm5) and pulmonary capacitance: 2.18±0.28 vs 1.47±0.22ml/mmHg [figure, top] (all p<0.01). Cardiac output: was comparable 3.49±0.19 vs 3.45±0.18L/min (p=0.751). O2 delivery was higher in AMI due to higher hemoglobin (136±3 vs 109±5 g/L, p<0.01). ESHF patients compensated by extracting more oxygen, which is facilitated by higher P50 (4.12±0.08 vs 3.60±0.05kPa, p<0.01). pMCS for AMI patients: ECLS=13, ECLS+Impella=4, Impella=5 vs patients with ESHF: ECLS=17, ECLS+Impella=3, Impella only=3, p=0.672. ESHF patients with CS had poorer outcomes from pMCS compared to patients with AMI (1-year survival 35% vs 64%, p=0.037, figure, bottom) Conclusion: CS due to ESHF is associated with greater biventricular dysfunction, pulmonary vascular abnormalities, lower O2 delivery compensated by lower O2 affinity. Outcomes from pMCS are worse in ESHF compared to AMI. (Figure Presented).