Clinical outcomes of adults with anomalous aortic origin of a coronary artery: 2-year data from the multicenter study on coronary anomalies in The Netherlands (MuSCAT)

Background The MuSCAT protocol established a pathway for risk stratification and treatment of patients with an anomalous coronary artery from the opposite sinus of Valsalva (AAOCA) (1). It demonstrated a high degree of discrepancy between non-invasive and invasive functional testing, altering the management for 20% of adults with high-risk AAOCA anatomy (2). Data on clinical outcomes of this risk stratification driven management strategy is lacking. Methods Consecutive AAOCA patients aged ≥16 years from five cardiology centers in the Netherlands who underwent non-invasive and invasive functional stress testing as part of the MuSCAT study and completed the two-year follow-up were included for analysis. Invasive assessment comprised of fractional flow reserve (FFR), instantaneous wave-free ratio (iFR) or resting full-cycle ratio (RFR); and intravascular ultrasound (IVUS) to assess the dynamic compression in rest and under pharmacological stress. The outcome measures were survival, adverse cardiac events (re-intervention, myocardial infarction, arrythmia) and the evolution of symptoms at follow-up. Results A total of 69 patients with two-year follow-up were analysed. The median age at AAOCA diagnosis was 52 years [43–59], and 52% were female. 91% of the patients had AAORCA, the systolic left ventricular function was preserved in 87% of patients. Cardiovascular risk factors were common - hypertension (44%), hypercholesterolemia (29%), and (history of) tobacco use (38%). Thoracic symptoms were reported in 65% of patients: typical angina (22%), atypical angina (23%) and non-specific chest pain (17%). Coronary artery disease (CAD) was present in 25% of patients of which 56% had CAD in the AAOCA. Invasive functional testing was positive in 20% of patients and dynamic compression with IVUS was significant in 14.5%. Sixteen (23% of total cohort) patients underwent surgical correction (93.8% AAORCA and 6.3% AAOLCA). At two-year follow-up, no cardiac deaths occurred in either treatment groups, one operated patient required percutaneous treatment for ostial restenosis and no patients had a myocardial infarction in the effluence territory of the AAOCA. Thoracic symptoms improved in both surgically (81% to 31%) and conservatively (57% to 32%) managed patients; however, surgery was not independently associated with symptom relief (OR 0.5, p=0.4). Conclusions In this cohort, patients with AAOCA demonstrated favourable mid-term prognosis and overall symptom improvement following comprehensive diagnostic evaluation and tailored management. Surgical intervention was not associated with superior symptomatic outcomes, suggesting that operative treatment may be best reserved for patients with documented ischemia or high-risk anatomical features, rather than broadly applied to symptomatic individuals (3). These findings may inform clinical decision-making and patient counselling regarding expected mid-term outcomes.