Methamphetamine Induced Transient Dynamic Pulmonary Artery Hypertension

Abstract

Introduction Methamphetamine has been identified as a risk factor for the development of pulmonary hypertension (PH), though the mechanism remains unclear. We present a case of reversible, symptomatic PH in a patient consuming methamphetamine. Case Presentation A 35-year-old male smoker with a history of hypertension and active methamphetamine abuse presented to the emergency department with progressive dyspnea on exertion for 8 months, with worsening symptoms over the preceding week. He took no medications at home. At presentation, he was hypertensive (218/140 mm Hg) and tachycardic. Physical examination was unremarkable. He was found to be in acute hypoxic respiratory failure, requiring oxygen supplementation via a venturi mask. Labwork at presentation was notable for elevated nt-pro bnp (1572 pg/mL), hypoxia with respiratory alkalosis on arterial blood gas (pH: 7.49;pCO2: 30 mm Hg;pO2: 54.4 mm Hg), and amphetamines on urine toxicology. Respiratory viral panel, including testing for SARS-CoV-2, was negative. Chest imaging, including radiography and computed tomography (CT) with angiography demonstrated no acute pathology. Aggressive control of blood pressure was instituted with lisinopril, hydrochlorothiazide, and amlodipine, along with diuresis and non-invasive ventilatory support. Transthoracic echocardiography with bubble study was notable for right ventricular enlargement and systolic dysfunction, with enlarged right atrium, bidirectional shunt at the atrial level, and high pulmonary artery systolic pressure (83 mm Hg). Rheumatoid factor, anti-double stranded DNA, HIV testing, and serum protein electrophoresis were negative. One week following admission, his respiratory failure improved, and a right heart catheterization was performed, which demonstrated a mean pulmonary artery pressure of 27 mmg Hg, with normal pulmonary capillary wedge pressure (11 mm Hg) and pulmonary vascular resistance (2.5 Woods Units). Transesophageal echocardiography showed normal right ventricular size and function with a moderate right-to-left shunt through a patent foramen ovale. Discussion Methamphetamine is a sympathomimetic amine which can cause adrenergic stimulation by displacing neurotransmitters such as norepinephrine, epinephrine, and serotonin from cytoplasmic vesicles of pre-synaptic neurons. Methamphetamines are associated with a range of pulmonary complications, including PH, pulmonary hemorrhage, and edema. We present a case of transient dynamic PH in the setting of methamphetamine use, which caused severe hypoxic respiratory failure, and abated with cessation of amphetamines and aggressive control of hypertension. Methamphetamine is classified as a “likely” risk factor for PH.(1) Studies have demonstrated worse prognosis in patients with meth-PH compared to idiopathic PH.(2,3) PH should be considered as a differential when encountering respiratory failure in patients who use methamphetamines.