Safety, Feasibility, and Impact of Enalapril on Cardiorespiratory Physiology and Health in Preterm Infants with Systemic Hypertension and Left Ventricular Diastolic Dysfunction

Abstract

Neonatal hypertension has been increasingly recognized in premature infants with bronchopulmonary dysplasia (BPD); of note, a sub-population of these infants may have impaired left ventricular (LV) diastolic function, warranting timely treatment to minimize long term repercussions. In this case series, enalapril, an angiotensin-converting enzyme (ACE) inhibitor, was started in neonates with systemic hypertension and echocardiography signs of LV diastolic dysfunction. A total of 11 patients were included with birth weight of 785 ± 239 grams and gestational age of 25.3 (24, 26.1) weeks. Blood pressure improvement was noticed within 2 weeks of treatment. Improvement in LV diastolic function indices were observed with a reduction in Isovolumic Relaxation Time (IVRT) from 63.1 ± 7.2 to 50.9 ± 7.4 msec and improvement in the left atrium size indexed to aorta (LA:Ao) from1.73 (1.43, 1.88) to 1.23 (1.07, 1.29). Neonatal systemic hypertension is often underappreciated in ex-preterm infants and may be associated with important maladaptive cardiac changes with long term implications. It is biologically plausible that identifying and treating LV diastolic dysfunction in neonates with systemic hypertension may have a positive modulator effect on cardiovascular health in childhood and beyond.

Cardiopulmonary physiological effects of diuretic therapy in preterm infants with chronic pulmonary hypertension

“…Recent data has also indicated that inferior LV function, in particular diastolic function, may contribute to the pathophysiology of cPH in BPD, through chronic elevation of LV end diastolic pressure and subsequently left atrial and pulmonary venous pressure. (29,30) By reducing systemic afterload, diuretic therapy may also improve LV end diastolic pressure and its contributory effects on pulmonary venous pressure in cPH pathophysiology and pulmonary edema. Our ndings of reduction in DBP and signi cant improvement in LV MPI, a marker of global function, in association with improvement in PVR markers after treatment lend support to this hypothesis.…”