Trends and Outcomes of Intra-Aortic Balloon Pump and Mechanical Circulatory Support in Cardiogenic Shock Patients Undergoing Coronary Artery Bypass Grafting: An STS ACSD Analysis

K. R.. An¹, L. Harik², M. Rahouma², T. Caldonazo², R. Habib³, N. K.. Dhingra¹, T. M.. Yau¹, V. Rao¹, K. Takeda⁴, Y. Naka², M. F.L.. Gaudino^2
1University of Toronto, Toronto, Ontario ²Weill Cornell Medicine, new york, New York ³The Society of Thoracic Surgeons, CHICAGO, Illinois ⁴Columbia University Medical Center, New York, New York

Purpose: The landscape surrounding the use of temporary mechanical circulatory support (tMCS) in acute myocardial infarction and cardiogenic shock (AMI-CS) has shifted in recent years. This study aims to describe the trends and outcomes of tMCS in patients with AMI-CS undergoing coronary artery bypass grafting (CABG).

Methods: We identified all patients with AMI-CS undergoing CABG in the Society of Thoracic Surgeons Adult Cardiac Surgery Database from July 2011 to December 2022. Peri-operative use of IABP, ECMO, and catheter-based tMCS were examined using descriptive statistics and trends analyses. AMI-CS was defined as cardiogenic shock and non-ST elevation MI or ST elevation MI occurring within 7 days before CABG. Outcomes included 30-day mortality, permanent stroke, re-operation, ICU re-admission, post-operative dialysis, post-operative atrial fibrillation, sepsis, and pneumonia.

Results: In total, 34,015 patients with AMI-CS underwent CABG during the study period. The annual volume of AMI-CS patients undergoing CABG remained stable, ranging from 2,905 in 2012 to 2,646 in 2022. Pre-operatively, IABP was used in 23,812 (70%) patients, catheter-based tMCS in 2,237 (6.5%), ECMO in 173 (0.5%), and multiple devices in 520 (1.5%). 7,273 (21.4%) patients did not receive any pre-operative circulatory support. Of these patients, 1,818 (25.0%) required intra- or post-operative IABP, 282 (3.9%) required intra- or post-operative tMCS, and 355 (4.9%) required intra- or post-operative ECMO. Use of pre-operative IABP decreased from 2163 (74.5%) in 2012 to 1708 (64.6%) in 2022. Conversely, the use of pre-operative tMCS increased from 50 (1.7%) in 2012 to 298 (11.3%) in 2022. Pre-operative usage of ECMO or multiple devices remained uncommon but increased over time (p-trend 0.004 for ECMO and p-trend < 0.001 for multiple devices). Overall, 30-day mortality was 20.9%, which decreased over time (p for trend < 0.001). The rate of permanent stroke was 4.9%, post-operative dialysis was 10.4%, and re-operation was 9.2%. With regards to timing of device use, IABP and tMCS were most used pre-operatively rather than intra- or post-operatively, while ECMO was most used intra- or post-operatively.

Conclusion: Overall mortality in AMI-CS patients undergoing CABG has decreased over time while the annual volume of cases remains stable. IABP remains the most common method of circulatory support in AMI-CS patients undergoing CABG although its usage is declining over time in favor of tMCS devices.

Identify the source of the funding for this research project: This project was funded by Weill Cornell Medicine institutional funds.