(802) Determinants of Cardiac Index Improvement after Intra-Aortic Balloon Pump Insertion

PurposeThe hemodynamic effects and clinical efficacy of the intra-aortic balloon pump (IABP) are still not fully understood. Prior studies on the hemodynamic response to IABP have been limited to a one-time pre- vs post-IABP comparison or have focused on survival, without providing pathophysiological explanations. The aim of the current study was to longitudinally study the effect of the IABP and identify baseline parameters (before IABP insertion) that predict the change of cardiac index (CI) after IABP insertion (ΔCI)MethodsRetrospective analysis of all pts who received an IABP between Feb 2016 - Aug 2022 and had at least one CI assessment while on IABP support. Linear mixed effect regression models with backward stepwise selection and multivariate imputation by chained equations with a predictive mean matching were utilized to identify pre-IABP variables associated with post-IABP CI change over time.Results330 pts with 2,165 time-point CI assessments were included in the study. The mean age was 63±14 years and 210 (63.6%) were male. 226 patients (68.5%) were in CS, and 156 (47.3%) had an ACS at the time of IABP insertion. Pts on pressors or inotropes at the time of IABP insertion were 94 (28.5%) and 109 (33.0%), respectively. Median duration of IABP support was 2.9 [1.8 - 4.8] days. The univariable and final multivariable regression models with the variables analyzed are presented in the Table. Baseline pulmonary artery pulsatile index (PAPi, B=0.024, P<0.001) and history of diabetes (B=0.194, P=0.005) were associated with an increase post-IABP CI, while baseline CI (B=-0.766, P<0.001) and body surface area (BSA, B=-0.404, P=0.001) reduced the improvement of CI after IABP insertion. In the final model ΔCI = PAPi x 0.024 + 0.194 (if DM) - Baseline CI x 0.766 - BSA x 0.404 + Day on IABP x 0.073 + 2.68ConclusionIntact right ventricle function, diabetes, small body size, and low baseline CI are associated with a significant increase of CI after IABP insertion. Further prospective studies are warranted to validate these findings. The hemodynamic effects and clinical efficacy of the intra-aortic balloon pump (IABP) are still not fully understood. Prior studies on the hemodynamic response to IABP have been limited to a one-time pre- vs post-IABP comparison or have focused on survival, without providing pathophysiological explanations. The aim of the current study was to longitudinally study the effect of the IABP and identify baseline parameters (before IABP insertion) that predict the change of cardiac index (CI) after IABP insertion (ΔCI) Retrospective analysis of all pts who received an IABP between Feb 2016 - Aug 2022 and had at least one CI assessment while on IABP support. Linear mixed effect regression models with backward stepwise selection and multivariate imputation by chained equations with a predictive mean matching were utilized to identify pre-IABP variables associated with post-IABP CI change over time. 330 pts with 2,165 time-point CI assessments were included in the study. The mean age was 63±14 years and 210 (63.6%) were male. 226 patients (68.5%) were in CS, and 156 (47.3%) had an ACS at the time of IABP insertion. Pts on pressors or inotropes at the time of IABP insertion were 94 (28.5%) and 109 (33.0%), respectively. Median duration of IABP support was 2.9 [1.8 - 4.8] days. The univariable and final multivariable regression models with the variables analyzed are presented in the Table. Baseline pulmonary artery pulsatile index (PAPi, B=0.024, P<0.001) and history of diabetes (B=0.194, P=0.005) were associated with an increase post-IABP CI, while baseline CI (B=-0.766, P<0.001) and body surface area (BSA, B=-0.404, P=0.001) reduced the improvement of CI after IABP insertion. In the final model ΔCI = PAPi x 0.024 + 0.194 (if DM) - Baseline CI x 0.766 - BSA x 0.404 + Day on IABP x 0.073 + 2.68 Intact right ventricle function, diabetes, small body size, and low baseline CI are associated with a significant increase of CI after IABP insertion. Further prospective studies are warranted to validate these findings.