Recruitment in out-patient clinic has been suspended due to COVID-19 pandemic

Methamphetamine is misuse if classified as a "likely" risk factor for pulmonary arterial hypertension (PAH). Nevertheless the actual prevalence of and a screening strategy for PAH in methamphetamine users have not been established. In this study, the prevalence of PAH will be investigated and its independent risk factors among methamphetamine users will be identified.

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.

Inclusion Criteria:

• >= 18 years at enrollment
• report of methamphetamine use in the last 2 years
• diagnosed as amphetamine dependent according to the Diagnostic and Statistical Manual of Mental Disorders (the 5th edition) (DSM-V)(13)
• voluntarily agree to participate by providing written informed consent

Exclusion Criteria:

• failed or refused to provide written informed consent

Reference:

13. Battle DE. Diagnostic and Statistical Manual of Mental Disorders (DSM). Codas 2013;25(2):191-2.

Participants with a history of methamphetamine use followed-up in the participating substance abuse clinic will be identified via the computerized database of the clinical management system.