Comparison of bleeding complications and one-year survival of low molecular weight heparin versus unfractioned heparin for acute myocardial infarction in elderly patients. the FAST-MI registry

Background: There are limited data on the safety and efficacy of low molecular weight heparin (LMWH) in elderly patients with acute myocardial infarction (AMI). Methods: We aimed to compare LMWH with unfractioned heparin (UFH) in the management of AMI in elderly patients. FAST-MI is a nationwide registry carried out over a 1-month period in 2005, including consecutive patients with AMI admitted to intensive care unit < 48 h from symptom onset in 223 participating centers. We assessed the impact of LMWH on bleeding, the need for blood transfusion and one-year survival in elderly patients (≥ 75 years). Results: 963 patients treated with heparin were included (mean age 82 ± 5 years; 51% women; 42.5% ST-elevation myocardial infarction). Major bleeding (2.4% vs. 6.1%, P = 0.004) and blood transfusions (4.6% vs. 9.7%, P = 0.002) were significantly less frequent with LMWH compared with the UFH, a difference that persisted after multivariate adjustment (OR = 0.41, 95% CI: 0.20-0.83 and OR = 0.49, 95% CI: 0.28-0.85, respectively). One-year survival and stroke and reinfarction-free survival were also significantly higher with LMWH compared with UFH (OR = 0.66, 95% CI: 0.50-0.85 and OR = 0.71, 95% CI: 0.56-0.91, respectively). In two cohorts of patients matched on a propensity score for getting LMWH and with similar baseline characteristics (328 patients per group), major bleeding and transfusion were significantly lower while one-year survival was significantly higher in patients receiving LMWH. Conclusions: The present data show that in elderly patients admitted for AMI, use of LMWH is associated with less bleeding, less need for transfusion, and higher survival, compared with the use of UFH.