Predictors of hemorrhagic events in patients with myocardial infarction complicated by cardiogenic shock undergoing dual antiplatelet therapy

Introduction

Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) is associated with considerable morbidity and mortality. Despite advancements in the management of these patients, bleeding complications remain prevalent and represent a critical challenge in this clinical context.

Objective

To evaluate the incidence, etiology, and predictors of hemorrhagic events in AMI-CS patients treated with dual antiplatelet therapy (DAPT).

Methods

A retrospective analysis was performed on 154 patients with AMI-CS admitted to a cardiac intensive care unit between January 2017 and October 2024. Baseline demographics, clinical characteristics, bleeding events, and transfusion requirements were collected. Major bleeding events were defined according to Bleeding Academic Research Consortium (BARC) criteria, class ≥3. Univariate logistic regression analysis was used to identify predictors of hemorrhagic events, including demographic, clinical, laboratory, and procedural variables.

Results

The cohort had a median age of 67 years, with 65.6% male. The most prevalent comorbidities included hypertension (74%), diabetes mellitus (44.2%), and dyslipidemia (63%).

Major bleeding events occurred in 29.2% of patients, with BARC3A (figure 1) and access-site hemorrhages (figure 2) accounting for 50.9% and 37.5%, respectively. Patients experiencing major bleeding events frequently required red blood cell transfusions, with 43.4% receiving more than four units - figure 3.

Independent predictors included lower minimum platelet count [(for each 1 × 10⁹/L decrease in platelet count, OR 0.986 (95% CI: 0.979–0.993; p < 0.001)], the use of mechanical circulatory support (OR: 5.517; 95%CI: 2.602-11.697 p<0.001) and renal replacement therapy (OR: 2.906; 95%CI:1.285-6.571 p=0.010). Antithrombotic therapy with glycoprotein IIb/IIIa inhibitors (OR: 6.729; 95%CI: 2.183-20.745 p<0.001) and anticoagulants (OR: 2.246; 95%CI: 1.049-4.806 p=0.037) were strongly associated with an increased risk of major bleeding. The choice of ticagrelor (29.9%) [vs clopidogrel (70.1%]) was not identified as a significant predictor of hemorrhagic events - figure 4.

Conclusion

Hemorrhagic events are common in AMI-CS patients on DAPT, influenced by preexisting conditions and procedural factors. Antithrombotic therapy with glycoprotein IIb/IIIa inhibitors and anticoagulants significantly increased risk, underscoring the need for tailored strategies to manage bleeding in this high-risk population.For image description, please refer to the figure legend and surrounding text.