Impact of intra-aortic balloon pump diastolic augmentation on survival in patients with cardiogenic shock
Authors: Senman B , Van Diepen S , Alviar C L , Kittipibul V , Dahiya G , Pinsker B , Soneji S , Ratliff W , Hintze B , Kochar A , Dupont A , Katz J N 
Published: May 2024

Abstract

Funding Acknowledgements
Type of funding sources: Other. Main funding source(s): PI funded - Jason Katz, MD

Background
Temporary MCS devices are routinely used in pts with CS. The most commonly used temporary MCS device worldwide is the IABP, which increases DBP, enhances coronary perfusion, and improves cardiac output. No randomized controlled trial has demonstrated its superiority over standard care practices and observational data suggest heterogeneity in its hemodynamic effect. IABP response likely depends on optimizing several pt- and device-related factors, most notably the ability to augment DBP. Unfortunately, a notable gap exists in defining the association of augmented DBP (aDBP) with mortality, and none of the contemporary clinical trials have systematically assessed this concept.

Purpose
In a cohort of pts with CS, the goal was to investigate the association between aDBP and survival in those supported with an IABP.

Methods
In a retrospective analysis of prospectively collected data from pts with CS who underwent IABP placement at Duke from 1/2010-6/2021 we describe baseline characteristics and discharge outcomes stratified by aDBP. Pre-insertion DBP was measured immediately prior to IABP, while post-insertion aDBP was collected 2 hrs following device placement. Success was defined as survival to hospital discharge. Death prior to discharge, hospice care, or escalation to ECMO, Impella, durable LVAD, or heart transplant were all considered a non-successful result. A multivariate logistic regression model was created to assess the association of aDBP on outcome, adjusting for pre-IABP DBP, age, sex, race, history of MI and HF.

Results
514 CS pts were identified, of which 470 (91%) had available pre-insertion DBP and post-insertion aDBP. The modal age was 65-74 yrs, 75% were male, 54% were white, 85% had prior HF, and 34% had prior MI. Figure 1A shows the distribution of pre-insertion DBP (median 67 mmHg) and post-insertion aDBP (median 106 mmHg). Overall, 49% of pts had a successful outcome. There was a u-shaped relationship between aDBP and the likelihood of success; as an example, for a modeled pt (65-75yo male, pre-insertion DBP of 66 mmHg, no HF or MI), the predicted probability of a successful outcome increased from 10% to 65% as aDBP rose to 120 mmHg, followed by a subsequent decline (Figure 1B). The relationship between either absolute or relative change in aDBP over baseline, on the other hand, was no longer u-shaped, but rather linear. After multivariate adjustment, only aDBP was associated with success such that every 10mmHg increase in aDBP over baseline was associated with improved survival to hospital discharge (OR 1.12, p=0.03).

Conclusions
In a cohort of pts with CS managed with an IABP, we report for the first time that aDBP is associated with improved survival to hospital discharge. Future prospective and randomized analyses should aim to capture degree of augmentation when studying counterpulsation devices, and this may help to clarify the currently controversial role of the IABP in contemporary CS care.