Effect of beta-blockers on the mortality of Japanese patients with myocardial infarction.

BACKGROUND: After a myocardial infarction, a higher prevalence of coronary vasospastic response has been reported in the Japanese population than in the Caucasian population. Beta-blockers may exacerbate coronary vasospasm. However, beta-blockers are given to Japanese patients after an acute myocardial infarction, though the mortality benefit is unknown. Thus, we investigated the mortality benefit of beta-blockers given to Japanese patients after an acute myocardial infarction. METHODS: We prospectively studied consecutive patients with a first myocardial infarction admitted to the coronary care unit of Kansai Medical University Hospital, Osaka, Japan from May 1994 through the end of 2001. Patients who died during hospitalization or who were referred for coronary artery bypass graft surgery were excluded. The association of beta-blocker use with mortality after discharge was assessed by a proportional hazards regression analysis. RESULTS: There were 546 patients and 400 (73.3%) patients were treated with beta-blockers at the time of discharge from hospital. During a mean follow-up of 2 years, 46 (8.4%) patients died. Beta-blocker therapy was associated with a reduced mortality after adjustment for age, gender, Q wave myocardial infarction, reperfusion therapy during acute phase, Killip functional class, serum creatinine level, cardiovascular risk factors, and medications (hazard ratio=0.51, 95% confidence interval=0.27 to 0.95). CONCLUSIONS: Contrary to the concern that beta-blocker therapy might induce coronary vasospasm and reduce survival, beta-blocker therapy improved survival after discharge in Japanese patients with a first myocardial infarction.

Communication network analysis in maternity hospital bulletin board system.

Recent changes in Japanese social environments consequently dropped total fertility rate, and poor interpersonal relationships in local communities have aggravated the environments for childbirth and child-rearing. Under such circumstances, we introduced a bulletin board system (BBS) to an official web-site of a maternity hospital to set up a community for its patients for communication regarding childbirth and the like. Based on the logs from BBS, we graphed types of communication among its users with to describe topologies. Additionally, we calculated degrees of centralization of entire networks and found the hospital role as the administrator becomes smaller as inter-user communication becomes more brisk. The analysis of contents of respective threads also revealed that main topics shifted from gestational matters to postnatal and child-rearing as communication became more brisk, which indicates those postnatal users are also strongly conscious with gestational and progestational contents and contribute to supporting the entire BBS.