Diastolic heart failure may be noted in paediatric patients with CHD, cardiomyopathy, or malignancies requiring chemotherapy, but the available data are scarce, and often derived from adult trials or based on theoretic or anecdotal evidence.

Data between 2016 and 2021 were obtained from Pediatric Health Information System database. Patients <18 years of age with isolated diastolic heart failure admitted to ICU at some point during admission were included. They were divided into patients with and without inpatient mortality. Patients’ demographics, comorbidities using ICD-10 codes, and pharmacologic interventions were also recorded. Univariate analysis was done in demographics, comorbidities, pharmacologic interventions, and mechanical interventions between admissions with and without mortality. Multivariable logistic regression was done for inpatient mortality and multivariable linear regression was done for total hospital length of stay in survivors.

Isolated diastolic heart failure comprised 0.5% of critically ill paediatric patients. A total of 121 (5%) experienced mortality among the 2,273 admissions in the final analyses. Milrinone and angiotensin converting enzyme inhibitor were found to be associated with decreased mortality. Increasing age and diuretics were associated with decreased total hospital length of stay in survivors.

In the cohort studied, isolated diastolic left heart failure has a 5% mortality. Several comorbidities and interventions are associated with increased mortality with milrinone and angiotensin converting enzyme inhibitors being associated with decreased risk of mortality. When only admissions with survival to discharge are considered, older age and diuretics are associated with lower total hospital length of stay.