Comparison of the Hemodynamic Response to Intra-Aortic Balloon Counterpulsation in Patients With Cardiogenic Shock Resulting from Acute Myocardial Infarction Versus Acute Decompensated Heart Failure

Abstract

The intra-aortic balloon pump (IABP) neither benefits nor harms patients with acute myocardial infarction (AMI) with cardiogenic shock (CS) but may stabilize those with chronic heart failure who decompensate into CS. We sought to compare its hemodynamic effects in these 2 populations. We performed a retrospective analysis of the hemodynamic effects of IABP for AMI or acute decompensated heart failure (ADHF) patients with hemodynamic evidence of CS. The primary outcome was cardiac output (CO) change following insertion. In total, 205 patients were treated for CS resulting from AMI (73; 35.6%) or ADHF (132; 64.4%). At baseline, both cohorts had significant hemodynamic compromise with mean arterial pressure 75.6 ± 12.3 mm Hg, CO 3.02 ± 0.84 L/min, and cardiac power index 0.26 ± 0.06 W/m²; these parameters were nearly identical between groups though ADHF-CS patients had a higher pre-IABP mean pulmonary artery (PA) pressure than AMI-CS patients. After IABP insertion, ADHF-CS patients had moderate CO augmentation whereas AMI-CS experienced almost no improvement (0.58 ± 0.79 L/min vs 0.12 ± 1.00 L/min; p = 0.0009). Intracardiac filling pressures were reduced by similar amounts in both cohorts. Systemic vascular resistance was reduced in patients with ADHF-CS but not in those with AMI-CS. In conclusion, following IABP insertion, ADHF-CS patients experience roughly a 5-fold greater CO augmentation compared with AMI-CS patients. Pre-IABP PA pressure differences and differential systemic vascular resistance reduction may explain these results and shed light on recent evidence supporting IABP use in ADHF-CS and curbing it in AMI-CS.

Figure 1:

Institutional Use of IABP. The study cohort was derived from an analysis of all IABP use in the CCU from January, 2011 to April, 2016. Patients with AMI or ADHF and hemodynamic evidence of CS prior to IABP insertion were included. CCU, Cardiac intensive Care Unit; HF, heart failure, CS, cardiogenic shock; AMI, acute myocardial infarction; HT, heart transplant; ADHF, acute decompensated heart failure.

Figure 2:

Institutional IABP Use by Year and Indication. The use of IABP for AMI decreased during the study period while its use for ADHF increased. ADHF, acute decompensated heart failure; CS, cardiogenic shock; AMI, acute myocardial infarction.

Figure 3:

Cardiac Output Change Following IABP insertion. The cardiac output change is displayed for each patient with AMI or ADHF. AMI, acute myocardial infarction; CS, cardiogenic shock; ADHF, acute decompensated heart failure.

Figure 4.

Patient Outcomes Following IABP Insertion for Cardiogenic Shock. Patient outcomes are displayed following A) AMI with CS and B) ADHF with CS according to the MCSDs used. AMI, acute myocardial infarction; CS, cardiogenic shock; MCSD, mechanical circulatory support device; pVAD, percutaneous ventricular assist device; ECMO, extracorporeal membrane oxygenation; HRT, heart replacement therapy BiVAD, biventricular assist device (short-term, surgically implanted).