Diagnostic quality (feasibility and utility) of cardiac CT imaging in pediatric patients on mechanical circulatory support.

BACKGROUND

Pediatric patients on ventricular assist devices (VAD) and Venoarterial extracorporeal membrane oxygenation (VA-ECMO) increasingly undergo cardiac computed tomography (CT) for device assessment, complication evaluation, and transplant planning. Imaging this population is challenged by metallic device components, contrast timing in altered hemodynamics, need for sedation, and small patient size. The diagnostic quality and utility of cardiac CT in pediatric patients on mechanical support have not been systematically described.

METHODS

We retrospectively reviewed electrocardiogram (ECG)-gated cardiac CT studies performed in pediatric patients (<18 years) on VAD or VA-ECMO support at our institution from January 2022 to November 2025. Two pediatric cardiac imaging experts independently scored diagnostic image quality on a 4-point scale (1 = fully diagnostic, 2 = mildly degraded, 3 = significantly degraded, 4 = non-diagnostic). Adverse events, clinically relevant findings, and post-scan management changes were collected.

RESULTS

Twenty-four ECG-gated cardiac CT studies were performed in 17 patients (median age 1.5 years, interquartile range [IQR] 0.8-2.7; median weight 11.2 kg, IQR 8.0-13.9). Twenty-one studies (87.5%) were performed on VAD support and 3 (12.5%) on VA-ECMO. Berlin Heart EXCOR was the predominant device (76.2% of VAD studies). Fourteen studies were done for cause and ten for routine pre-transplant sizing. All 24 studies (100%) were rated as diagnostic by both reviewers. Mean image quality scores were 1.21 ± 0.51 for Reviewer 1 and 1.54 ± 0.59 for Reviewer 2; the two reviewers agreed within one point on every study. Clinically relevant findings were identified in 8 studies (33.3% overall and 57.1% of for cause scans), including thrombus (n = 2), cannula obstruction (n = 4), and other (n = 2). Cardiac CT directly contributed to a change in management in 9 studies (37.5% overall), including anticoagulation modification, surgical or catheter-based intervention, and VAD parameter adjustment. One adverse event occurred (4.2%): transient hypotension requiring epinephrine in an ECMO patient during scan-related flow reduction.

CONCLUSION

ECG-gated cardiac CT provides diagnostic-quality imaging in 100% of pediatric patients on VAD or VA-ECMO at our center. The technique frequently revealed clinically relevant findings and informed management decisions, with a low rate of adverse events.