CHEST Guidelines-Idiopathic Pulmonary Arterial Hypertension in Asia

Idiopathic Pulmonary Arterial Hypertension in Asia

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The letter to the editor in the April 2015 issue of CHEST discusses a pioneering long-term study on idiopathic pulmonary arterial hypertension (IPAH) outcomes in an Asian cohort, focusing on patients from the National University Heart Centre of Singapore. Conducted from 2001 to 2013, the study examines survival rates and therapeutic responses in an Asian context where access to pulmonary vasodilators is often limited due to economic constraints.<br /><br />The study involved 55 patients with a mean age of 50 years, primarily female (80%), and analyzed survival using the Kaplan-Meier method, comparing it against predictions from National Institutes of Health (NIH) and Pulmonary Hypertension Connection (PHC) registries. Results demonstrated notably higher survival rates, with 96.0% at one year dropping to 64.8% by the ninth year, surpassing NIH and PHC predictions. Treatment consisted of calcium channel blockers and gradually increased doses of vasodilators based on patient response over regular reviews.<br /><br />Despite many participants being categorized in World Health Organization functional class I/II, they exhibited advanced disease characteristics similar to class III populations elsewhere, marked by elevated natriuretic peptide levels and reduced six-minute walk distances. The study concludes that initiating therapy at doses lower than typically recommended could be beneficial for Asians, who, due to differences in body mass and drug metabolism—affected by genetic polymorphisms—may respond adequately to smaller dosages.<br /><br />The authors, Drs. Genevieve M. Y. Tan, Edgar L. Tay, Bee-Choo Tai, and James W. L. Yip, suggest that this low-dose strategy is cost-effective and could greatly benefit patients in developing Asian countries by leading to better survival rates while mitigating economic barriers. They advocate for funding and support for such approaches from healthcare agencies.

Keywords

idiopathic pulmonary arterial hypertension

Asian cohort

survival rates

Kaplan-Meier method

vasodilators

calcium channel blockers

genetic polymorphisms

cost-effective treatment

National University Heart Centre Singapore

World Health Organization functional class