An epidemiological study of pulmonary arterial hypertension in Japan

Aims: The aim of this study is to evaluate the clinical features and provide estimates of the prevalence of patients diagnosed for pulmonary arterial hypertension (PAH) in Japan. Methods: A nationwide epidemiological survey of PAH was performed using clinical personal records in 2012. Some 2299 patients with PAH were covered by public insurance (2012), according to the data from the Japan Intractable Diseases Information Center. The forms from 1377 patients (new: 389, recurrent: 988) were collected (2012). Results: The prevalence of PAH in Japan was estimated to be 15.6 per million. The male-female ratio was 1:2.17, showing a predominance of women with the disorder. The average age was 53.0±19.4 in 2012, older than the previous survey in 2004 (41.9 ± 19.5). The average age had been aging for 12.1 years in those 8 years. The ratio of elderly patients (older than 65 years) was 33.3% in 2012 and it was 18.3% in 2004. It increased remarkably. The average age of PAH at diagnosis (44.5 ± 23.6) in 2012 was aged than previous survey (38.1 ± 20.8) in 2006. Idiopathic and heritable PAH were the most common type of PAH (66.6%) and PAH associated with congenital heart disease (16.3%) and PAH associated with connective tissue diseases are common (11.1%).Most of the PAH analyzed cases were at a severity level of WHO class II or III. There were more patients who treated with combination therapy (58%) than monotherapy (42%). Conclusions: The average age of PAH patients aged rapidly in Japan.