Long-Term Response to Calcium Channel Blockers in Idiopathic Pulmonary Arterial Hypertension

BACKGROUND: Characteristics of patients with idiopathic pulmonary arterial hypertension (IPAH) who benefit from long-term calcium channel blockers (CCB) are unknown. METHODS AND RESULTS: Acute pulmonary vasodilator testing with epoprostenol or nitric oxide was performed in 557 IPAH patients. Acute responders, defined by a fall in both mean pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) >20%, received long-term oral CCB. Patients who benefit from long-term CCB were defined as those being in New York Heart Association (NYHA) functional class I or II after at least 1 year on CCB monotherapy. Among the 70 patients who displayed acute pulmonary vasoreactivity (12.6%; 95% CI, 9.8% to 15.3%)…