Predictors of intra-aortic balloon pump hemodynamic failure in non-acute myocardial infarction cardiogenic shock

Abstract

Objectives: To characterize patient profile and hemodynamic profile of those undergoing intra-aortic balloon pump (IABP) for cardiogenic shock and define predictors of hemodynamic failure of IABP support.

Background: Clinical characteristics of IABP support in cardiogenic shock not related to acute myocardial infarction (AMI) remain poorly characterized.

Methods: We retrospectively studied a cohort of 74 patients from 2010 to 2015 who underwent IABP insertion for cardiogenic shock complicating acute decompensated heart failure not due to AMI.

Results: In the overall cohort, which consisted primarily of patients with chronic systolic heart failure (89%), IABP significantly augmented cardiac index and lowered systemic vascular resistance (P<.05). Despite this improvement, 28% of these patients died (24%) or require urgent escalation in mechanical circulatory support (MCS) (4%). Multivariable regression revealed that baseline left ventricular cardiac power index (LVCPI), a measure of LV power output derived from cardiac index and mean arterial pressure (P=.01), and history of ischemic cardiomyopathy (P=.003) were significantly associated with the composite adverse-event endpoint of death or urgent MCS escalation. An IABP Failure risk score using baseline LVCPI <0.28 W/m2 and ischemic history predicted 28-day adverse events with excellent discrimination.

Conclusion: Despite hemodynamic improvements with IABP support, patients with non-AMI cardiogenic shock still suffer poor outcomes. Patients with ischemic cardiomyopathy and low LVPCI fared significantly worse. These patients may warrant closer observation or earlier consideration of more advanced hemodynamic support.

Copyright © 2017 Elsevier Inc. All rights reserved.

Figures

Figure 1. Flow Diagram of Retrospective Patient Review

Over 5 years, 474 intra-aortic balloon pumps (IABP) were placed, of which 74 were placed for non-AMI cardiogenic shock. Of these 74, 18 died despite IABP support while 3 required urgent escalation to an advanced MCS. Of those who survived, 15 did so free of advanced therapies, 25 required LVAD, and 4 required OHT. CAB, coronary artery bypass; SBP, systolic blood pressure; PA, pulmonary artery.

Figure 2. Overall Hemodynamic Trends

Hemodynamic parameters were obtained just prior to IABP insertion (0 hours) as well as 12, 24, and 48 hours after insertion. Mean ± standard deviation at each time point is noted; time points were compared by one-way repeated measures analysis of variance. * significant difference versus 0 hour time point (P

Figure 3. LVCPI Trend by Adverse Outcome Status

Mean ± standard deviation at each time point is noted; time points were compared by two-way repeated measures analysis of variance. * significant difference versus 0 hour time point (P

Figure 4. Probability of Adverse Events based on LVCPI

(A) Hazard function was plotted of probability of adverse event (with 95% confidence interval) versus left ventricular cardiac power index (LVCPI). Adverse events were inversely related to LVCPI at time of IABP insertion. (B) Hazard function plot stratified by history of ischemic cardiomyopathy (ICM) versus non-ischemic cardiomyopathy (NICM). ICM history led to significantly higher probability of adverse events over a wide range of LVCPI when compared to NICM.

Figure 5. Adverse Events as Predicted by IABP Failure Risk Score

An IABP Failure Risk Score was generated for each patient at time of IABP insertion, with 1 point for a history of ischemic cardiomyopathy and 1 point for LVCPI2 (score range from 0 to 2 points). A score of 0 powerfully predicted success of IABP support, while a score of 2 predicted poor outcomes with IABP support (log rank P=0.005).