Background: The Thai ACS registry is a multi-center, prospective registration that describes the epidemiology, management practices and in-hospital outcomes of patients with acute coronary syndromes.

Objective: Study the registry difference in hospital outcomes about cardiac death and length of stay between low molecular weight heparin (LMWH) and un-fractionated heparin (UFH).

Material and Method: This is an observational descriptive study. The authors collected data from the database of the Thai ACS registry.

Results: There were 233 of 3963 cases (5.9%) with cardiac death in the present study. Cardiac death in the non-ST elevated myocardial infraction (NSTEMI) group was larger than in the UA group (7.6% vs. 2.4%, p-value <0.001). The heparin group had more cardiac death than the LMWH group (9.3% vs. 5.2%, p-value <0.001). NSTEMI with heparin treatment had more cardiac deaths than LMWH treatment (11.8% vs. 6.8%, odd ratio 1.8). UA with heparin treatment had more cardiac deaths than LMWH treatment (4.0% vs. 2.0%, odd ratio 2.0). NSTEMI had a longer length of stay than UA (56.9% vs. 44.7%, p-value = 0.001). The heparin group had a longer stay than LMWH (58.8% vs. 51.7%, p-value <0.001).

Conclusion: Low molecular weight heparin had benefit over un-fractionated heparin in reduction of hospital mortality and length of stay in both unstable angina and non-ST elevation myocardial infarction.

Keywords: NSTEMI, UA, LMWH,UFH, ACS, Myocardial infraction, Unstable angina, Low molecular weight heparin, Un-fractionated heparin, Heparin, Acute coronary syndromes, Non-ST elevation myocardial infraction