When No VAD is the Right VAD: Medical Management of Critically Ill Infants Awaiting Heart Transplantation.

PURPOSE: Infants listed for heart transplant (HTx) are at high risk for waitlist (WL) mortality. While WL mortality for children has decreased overall in the current era of increased VAD use, outcomes for small infants supported by VAD remain suboptimal. We evaluated survival and morbidity in a cohort of critically ill infants listed for HTx and managed without VAD support.

METHODS: Critically ill infants (defined as age <1 year and requiring mechanical ventilation and/or ≥2 inotropes) listed for HTx between 2008 and 2019 were identified in an institutional database. VAD support was not offered for infant patients according to institutional protocol during the study period. Survival outcomes as well as WL morbidity were analyzed and risk factors for non-survival were evaluated.

RESULTS: Thirty-two critically ill infants were listed 1A for HTx during the study period, 66% with congenital heart disease. Mean age and weight at listing were 2.8 (±2) months and 4.4 (±1.3) kg, with the majority (69%) weighing <5 kg. At listing, 31 patients (97%) were mechanically ventilated, 32 (100%) on ≥1 inotrope, 13 (41%) on ≥2 inotropes, and 8 (25%) under neuromuscular blockade. Five patients (16%) were supported by ECMO after listing. Mean WL duration was 73 (±65) days. The most common WL complication was infection, with 38 infections in 26 patients (7 blood stream, 7 urinary tract, 23 trachea, 1 wound). Two patients (6%) suffered a stroke, both on ECMO. Renal function improved from listing to HTx, death, or delisting (eGFR 72 vs 93 ml/min/1.73m2 , p <0.01), while nutritional status was unchanged (weight for length percentile 34 vs 49, p>0.1). A favorable outcome was observed in 27 patients (84%) (26 HTx and 1 de-listed due to recovery of left ventricular function). Five patients (16%) died, including 3/5 patients supported with ECMO. Among patients who received a HTx, 24 (92%) survived to 1 year, with median post-HTx length of stay of 43 days. Two patients required tracheostomy post-HTx. Higher peak vasoactive-inotropic score (27 vs 16, p<0.05) and ECMO support (RR 5.4, CI 1.5-19.5) were associated with waitlist mortality.

CONCLUSION: A strategy incorporating a high threshold for mechanical circulatory support and acceptance of prolonged mechanical ventilation and neuromuscular blockade can achieve good short-term survival and morbidity outcomes for critically ill infants listed for HTx.