Hearing impairment following surgically repaired congenital heart disease in children: a prospective study

Objectives To determine the prevalence of sensorineural hearing loss (SNHL) in children who underwent congenital cardiac surgery (CCS) by using a pre- and postoperative hearing test, a conventional audiometry, an extended high-frequency audiometry (HFA) or auditory steady-state response (ASSR), and distortion-product otoacoustic emissions (DPOAE). Study design This prospective study enrolled children with CCS in Siriraj Hospital, Thailand, between 2019 and 2023. Conventional audiometry including HFA or ASSR and DPOAE were performed pre- and postoperatively. The patients with bilateral abnormal hearing loss or an incomplete examination were excluded. Collected data included: demographics, cardiac surgery and ototoxic medication. Prevalence of SNHL by conventional audiometry and subclinical hearing impairment by HFA or DPOAE were ascertained, and risks were analysed. Results Ninety-eight patients were eligible for the study. The median age (IQR) was 5.3 (1.5-9.6) years. Fifteen patients (15.3%) had univentricular hearts. The preoperative audiologic test was performed 1 day prior to the CCS. The postoperative test was performed at a median of 4.4 (IQR: 2.7-8.0) months postoperatively. Preoperative unilateral hearing impairments were reported in 17 patients (17.3%). Postoperatively, four patients (4.1%) showed significantly abnormal audiogram (> 25 dB) or 15 dB shift at 250-8000 Hz consistent to a new SNHL. Subclinical hearing impairment by HFA was affected in 10 patients (10.2%). Thirty-three patients (33.6%) had abnormal DPOAE exclusively. Therefore, new SNHL, including subclinical hearing loss, revealed a prevalence of ototoxicity up to 47.9%. Age <1 year at surgery was the independent risk of postoperative SNHL (adjusted OR 18.5, 95% CI 1.2 to 293.8, p=0.04). Conclusion Routine post-CCS audiological surveillance especially CCS in infancy is recommended for early recognition and timely management based on the 43.8% subclinical and the 4.1% SNHL that was found in this study.