Direct comparison of Takotsubo cardiomyopathy between Japan and USA: 3-year follow-up study.

Objective: Takotsubo cardiomyopathy (TC) mimics myocardial infarction and is well defined and known to not only Japan but also western countries. However, whether or not there are differences in the characteristics of TC between Japan and USA remains unknown.

Patients: Data for patients who had undergone urgent left heart catheterization for suspected acute coronary syndrome were retrospectively retrieved from Keio University School of Medicine (KUSM) database in Japan and Lahey Clinic Medical Center (LCMC) database in USA between 2002 and 2007.

Results: During the study period, 626 coronary angiographies were performed in KUSM and 1,880 coronary angiographies were performed in LCMC. Twelve patients in Japan and 34 patients in USA met the inclusion criteria. Mean age of patients in Japan was 75 years where 92% were women, compared to 67 years and 94% women in USA. Although the prevalence of hypertension, dyslipidemia and diabetes mellitus were similar between Japan and USA, there was a trend towards fewer patients in Japan displaying a history of coronary revascularization. Surprisingly, a family history of premature coronary artery disease (CAD) was present in 21% of USA patients, whereas no patients were present in Japan. There were no differences in the incidence of readmission for heart failure, cardiac death and TC recurrence during the follow-up period.

Conclusion: Patients with TC in Japan have fewer prior overt CAD and fewer family history of premature CAD, but no significant differences were found in the long-term prognosis and the recurrence rate between patients in Japan and USA.