Screening of Pulmonary Hypertension in Methamphetamine Abusers

Methamphetamine is a potent central nervous system stimulant originally prescribed for individuals with neuropsychiatric diseases. Owing to its highly addictive nature, illicit use has emerged as a major public health problem worldwide. It causes methamphetamine use disorders and also affects cardiovascular (CV) system. PAH is one of those CV complications and is devastating and often life-threatening. In a subsequent retrospective cohort, patients with idiopathic PAH were found to have a much higher prevalence of prior use of methamphetamine and/or its related compounds, compared with patients with chronic thromboembolic pulmonary hypertension or pulmonary hypertension due to a known associated condition. Although current international guidelines recognize methamphetamines as a "likely" cause of drug-induced PAH, almost nothing is known about its prevalence and incidence amongst methamphetamine users. Besides, since patients with PAH often remain asymptomatic in the early phase, the diagnosis is often made late in the course of the disease, when most small pulmonary arteries have been obliterated, rendering therapy ineffective. Although the prognosis of patients with methamphetamine-associated PAH appears to be much worse than for those with idiopathic PAH, international guidelines and expert consensus have not considered screening for PAH in asymptomatic methamphetamine users. This study will apply a current guideline-recommended PAH screening algorithm for systemic sclerosis to a large cohort of unselected methamphetamine users in Hong Kong. The study objectives include: 1) to describe the prevalence of PAH among methamphetamine users using a current guidelines-recommended screening algorithm for PAH in systemic sclerosis; 2) to identify independent risk factors for PAH in methamphetamine users; and 3) to develop a prediction model for PAH in methamphetamine users.