n Western countries, -blockers have been frequently proved to be effective in the treatment of myocardial infarction (MI); for example, the BHAT ( -Blocker Heart Attack Trial) in 1982. 1 In that trial, 3,837 patients with MI were randomized into 2 groups, a propranolol group, consisting of 1,916 patients, and a placebo group of 1,921 patients and they were followed up for mean period of 25 months. The total mortality rate was 9.8% in the placebo group and 7.2% in the propranolol group, indicating that propranolol had an effect on improving the long-term prognosis following MI. Many similar clinical trials were also carried out at that time, and an overview by Yusuf et al concluded that -blockers reduced total mortality by 25% and they should be provided to the patient at discharge. 2 According to these findings, -blocker usage has substantially increased in Western countries. In Israel, for instance, the frequency of prescribed -blockers has increased from 17% (at 1981-1983) to 38% (at 1992-1994) and it is believed that the increased frequency has made an obvious contribution to the reduced mortality rates because of MI. 3 In Minneapolis and St Paul, Minnesota, USA, surveys of coronary heart disease were carried out at 5-year intervals, and changes in the treatment planning and their effects on the prognosis of MI were analyzed. According to these studies, the 3-year mortality rate among males admitted
Circulation Journal Vol.68, January 2004with acute MI was 28% in 1985, which decreased to 19% in 1995, with the concomitant increased frequency ofblocker administration from 54% to 72% and aspirin from 26% to 92%. 4 Among European patients with MI, the use of -blockers has exceeded 80% in Sweden and Finland since 1993. 5 On the basis of that abundant clinical experience, the guidelines for the treatment of acute MI at the European Secondary Prevention Study Group 5 and the ACC/AHA (American College of Cardiology/American Heart Association) Task Force on Practice Guidelines 6 recommended prescribing -blockers for patients discharged after MI for the purpose of secondary prevention of this disease.In contrast, clinical data on the use of -blockers for MI in Japan are rather limited, and available reports are also limited. 7-9 Consequently, -blocker usage for patients with MI is markedly lower in Japan than in Western countries. Ischemic heart disease certainly differs between Japanese and Caucasians in some aspects; for example, coronary vasospasm occurs 3 times more frequently in Japan than in Western countries. 10 Therefore, the useful effects of this drug should be evaluated on the basis of original evidence obtained in Japan. In this retrospective study, we evaluated the effect of -blockers on the clinical courses of MI patients treated at our hospital with and without -blockers.
Methods
SubjectsPatients who underwent outpatient or inpatient management for MI at the Department of Cardiology, Kinki University Hospital were retrospectively divided into 2 groups, those treated with -blockers and those treated wit...
