Prognostic impact of post-procedural low-molecular-weight heparin in high-bleeding risk patients undergoing pci for acute myocardial infarction
S Q Qin, Z Zhang, R X Guo, Z K Xue, X Shao, H Zhang, X Liu, T Liu, K ChenAbstract
Background
Patients with Acute Myocardial Infarction (AMI) who present with High Bleeding Risk (HBR) criteria are often underrepresented in randomized trials. The optimal antithrombotic strategy post-Percutaneous Coronary Intervention (PCI) in this vulnerable population remains a clinical dilemma, balancing ischemic protection against bleeding complications. Real-world data regarding the use of Low-Molecular-Weight Heparin (LMWH) in this specific subset is limited.
Purpose
To evaluate the association between the use of post-PCI LMWH and 30-day clinical outcomes in AMI patients with HBR undergoing PCI.
Methods
We conducted a retrospective cohort study utilizing a large-scale institutional database. From an initial cohort of 163,472 AMI patients, we consecutively enrolled those meeting HBR criteria (defined as age >65 years, anemia, prior stroke, prior intracranial hemorrhage, CKD, or thrombocytopenia) who underwent PCI. Key exclusion criteria included malignancy, specific high-risk arrhythmias (ventricular tachycardia/fibrillation, sinus arrest), Killip class III-IV, use of alternative anticoagulants (bivalirudin, fondaparinux), or oral anticoagulants.The primary endpoint was 30-day all-cause mortality. The secondary endpoint was 30-day BARC type 3 bleeding. Multivariable Cox proportional hazards regression analysis was performed to adjust for potential confounders and estimate treatment effects.
Results
A total of 33,686 patients met the inclusion criteria, of whom 30,294 (89.9%) received post-PCI LMWH and 3,392 (10.1%) did not. The 30-day all-cause mortality was significantly lower in the LMWH group compared to the no-LMWH group (0.7% vs. 1.7%, p < 0.001). After multivariable adjustment, LMWH use was independently associated with a significant reduction in 30-day mortality (Adjusted HR: 0.565; 95% CI: 0.400–0.797; p=0.001). The incidence of BARC type 3 bleeding was numerically similar between groups (LMWH: 31 [0.10%] vs. no-LMWH: 4 [0.12%]; p=1.0), with no significant difference in the adjusted analysis (HR: 0.845; 95% CI: 0.273–2.617; p=0.771).Kaplan-Meier analysis confirmed a significant reduction in 30-day all-cause mortality in the LMWH group (log-rank p<0.001, Figure 1). Subgroup analyses consistently demonstrated a protective effect of LMWH across various HBR categories(Figure 2).
Conclusion
In this real-world cohort of AMI patients with HBR undergoing PCI, the use of post-procedural LMWH was associated with a significantly lower risk of 30-day all-cause mortality without a significant increase in major bleeding events. These findings suggest a favorable net clinical benefit for LMWH in this high-risk population, warranting further validation in prospective randomized trials.Kaplan-Meier curves