Abstract Body (Do not enter title and authors here): Background: The use of temporary mechanical circulatory support (tMCS) devices in cardiogenic shock has sharply risen; however, there are limited data depicting the current rates of device related complications and associated downstream clinical ramifications.

Methods: The Critical Care Cardiology Trials Network is an international multicenter research network of advanced cardiac intensive care units (CICUs). Between 2017-2024 participating CICUs captured all consecutive admissions with cardiogenic shock during annual minimum 2-month collection periods. This analysis focused on cases managed with non-ECMO tMCS. We conducted Wilcoxon rank-sum tests for continuous variables, chi-squared test for categorical variables, and a multi-variable linear mixed-effect regression model.

Results: Among 2,015 admissions with cardiogenic shock and tMCS, 103 (5.1%) developed an MCS-related complication with substantial variation across device types (2.8% to 10.9%, Fig A). Limb ischemia (28.9%) and access site bleeding (22.9%) were the most common tMCS-related complications. Admissions with a tMCS related complication were slightly younger (61 v. 63 years) and more likely female (34% v. 27%). Cases with tMCS-related complications had higher shock severity reflected by more SCAI D shock (43.7% versus 35.1%) and number of vasoactive medications (3 v. 2). Admissions with an MCS complication had higher rates of mechanical ventilation (68.9% v. 59.1%) and renal replacement therapy (33.0% v. 17.6%) with longer ICU length of stay (9.2 v. 6.6 days). In-hospital mortality was higher among cases with complications (46.6% v. 31.6%; Fig B); complications were associated with a higher mortality even after adjustment (OR 1.63; 95% CI: 1.00 – 2.67; p = 0.05).

Conclusions: The rates of MCS related complications vary notably by access site and specific modality; complications were associated with longer ICU stays and high mortality rates.