Excessively increased pulmonary artery systolic pressure during exercise in adults with a history of extreme premature birth is unresponsive to sildenafil (1175.8)

Abstract

Extreme preterm birth results in abnormal alveologenesis and pulmonary vasculogenesis. Abnormal pulmonary vasculature may be unable to accommodate increased cardiac output during exercise, thereby resulting in an abnormally increased pulmonary artery systolic pressure (PASP) and exercise‐induced pulmonary hemorrhage (EIPH) in adult with a history of extreme preterm birth (PRE). We hypothesized that 1) PRE would have increased PASP during exercise thereby causing EIPH and 2) oral sildenafil would reduce PASP thereby preventing EIPH. PRE (n = 2) performed exercise at 80% of max power output to exhaustion on a cycle ergometer 60 mins after 100 mg sildenafil (p.o.) and, on a separate day, without sildenafil. Age and sex matched full term controls (CON; n = 2) exercised at the same workload and for the same time as PRE. PASP was measured via ultrasonography at rest and within the last minute of exercise. Induced sputum samples were collected post‐exercise and analyzed for cellular constituents. PASP was not different at rest between groups. During exercise, PASP was greater in PRE (54 Torr) vs CONT (48 Torr) without drug, and was unchanged in PRE (59 Torr) but decreased in CONT (41 Torr), with sildenafil. There was no evidence of EIPH in either group. These data suggest that excessive PASP during exercise in PRE may be the result of abnormal pulmonary vascular architecture, which cannot be ameliorated by oral sildenafil.Grant Funding Source: Supported by AHA Scientist Development Grant and OHSU Early Clinical Investigator Grant