Among 295 adults undergoing congenital heart surgery at a single academic center (2018–2022, median age 30), the ACHD Anatomic and Physiologic (ACHD-AP) classification demonstrated meaningful perioperative predictive power. Patients in the most severe physiologic category faced 14% overall mortality versus 0% in the mildest tier (p=0.02). The ACHD-AP achieved an AUC of 0.711 for mortality — comparable to the purpose-built Adult Congenital Heart Surgery score (AUC 0.798) and superior to the PEACH score (AUC 0.575). Higher complexity scores in both anatomic and physiologic domains independently predicted prolonged hospital stays exceeding five days.
Adult congenital heart disease surgery occupies a uniquely challenging niche: patients survive childhood defects only to face reoperation with accumulated myocardial remodeling, arrhythmia burden, and pulmonary vascular disease. Dedicated risk tools for this population remain underdeveloped compared to acquired heart disease. The finding that a guideline-based classification — originally designed for disease staging, not surgical prediction — performs on par with operative risk scores is clinically meaningful, suggesting routine ACHD-AP documentation could double as perioperative stratification without additional scoring burden. However, several important limitations temper enthusiasm: the single-institution retrospective design, modest cohort of 295 patients with only 14 deaths, and non-significant anatomic complexity mortality trends (p>0.9) all limit generalizability. As a preprint not yet peer-reviewed, these results require independent prospective validation before influencing surgical consent or resource allocation decisions. Incrementally confirmatory rather than paradigm-shifting, but a useful foundation for multicenter studies.