Autograft Dimensions after Ross Procedure in Children and Young Adults: MRI Based Modelling of Long-Term Results Allows Risk Stratification

Background: MRI data on how pulmonary autograft dimensions change over time after Ross procedure and their impact on autograft function from congenital cohorts are limited. This study aimed to assess long-term MRI data on autograft/aortic dimensions, to furthermore model the relationship between autograft/aortic dimensions and potential reinterventions and to provide an age-dependent prediction model for autograft dimensions after Ross procedure.

Methods: Between 02/2003 and 12/2022, all patients below the age of 40 at the time of Ross procedure and at least one postoperative MRI were included. Each postoperative MRI visit was assigned as a case with its specific baseline and outcome characteristics. Autograft/aortic dimensions were assessed at the level of aortic annulus (AV), sinus of Valsalva (SV), ST-junction (STJ) and ascending aorta (AA), converted into z-scores and modeled over time. Cox proportional hazard regression was used to assess hazard ratios for autograft reinterventions.

Results: A total of 76 of 307 Ross patients had 132 postoperative MRI. Median age at Ross procedure was 13.6 years (IQR 5.2–30.0) and median follow-up time was 7.9 years (IQR 4.2–12.1). Observed autograft dimensions revealed out-of-proportional growth with a great variability across different age groups. The combination of age at the time of Ross procedure and the time after Ross procedure was predictive for increases in z-scores across SV, STJ and AA (RMSE (R2) 2.07 (0.32), 2.54 (0.4), 3.24 (0.27) overall model´s p < 0.001). AV dimension was neither influenced by patients age at the time of Ross procedure nor by time after Ross procedure. During follow-up, 15 autograft-related reinterventions were performed. Autograft aneurysm was the most common indication for reintervention (11/15; 73.3%). Each SV z-score rise of one led to an 57% higher risk of autograft reintervention (HR 1.57, 95% CI 1.21–2.04, p = 0.001) and was associated with higher severity of aortic regurgitation (AR).

Conclusion: The age at which the Ross procedure is performed and the time elapsed since the procedure are predictive of increased z-scores over time in specific aortic dimensions (SV, STJ, and AA), but not affecting the AV dimension. During the follow-up period, individuals with higher SV z-scores face a higher likelihood of needing autograft reintervention, and increased z-scores are also linked to more severe autograft regurgitation. These findings highlight the utility of model-based estimates in guiding feasible long-term MRI surveillance after the Ross procedure, aiding clinicians in identifying potential autograft dilation early, for more personalized and preemptive healthcare interventions.

Publication History

Article published online:
13 February 2024