Diltiazem reduces pulmonary arterial pressures in recurrent pulmonary hypertension associated with pulmonary hypoplasia

Background/Purpose: Recurrent pulmonary hypertension in the neonatal population is an unusual event with dire consequences. Pulmonary hypertension seen in association with pulmonary hypoplasia may be refractory to conventional medical management. The effect of the calcium channel antagonist diltiazem was studied in five patients with severe pulmonary hypertension. Methods: A retrospective review of the hospital records was performed to determine the efficacy of diltiazem for refractory pulmonary hypertension. All five patients experienced and did not respond to maximal conventional therapy, which included inhaled nitric oxide, intravenous nitrates, and extracorporeal membrane oxygenation (ECMO). Right ventricular pressures were determined by transthoracic echocardiograms and were used to document improvement in the pressure gradients. Statistical analyses were performed using a paired Student's t test. A P value of less than .05 was considered significant. Results: Diltiazem significantly reduced the right ventricular systolic pressure (RVSP) from 82 ± 8.4 mm Hg to 58.4 ± 7 mm Hg (P = .008). Two patients died; one had a large ventricular septal defect, and the other suffered multisystem organ failure secondary to sepsis. The surviving patients were weaned off diltiazem and did not experience recurrent pulmonary hypertension. Conclusions: In cases of pulmonary hypoplasia with recurrent pulmonary hypertension, diltiazem may be considered as a therapy. A multicenter prospective trial is advocated.