Intramyocardial coronary artery course and risk of major adverse cardiac events: a nationwide CT coronary angiography study
E Olivecrona, D E Erlinge, E O Ostenfeld, A H Hakansson, S Z Zwackman, F B Bohm, H L Lofmark, T J Jernberg, K F Feldt, L D Desta, G B bergstrom, E F Fagman, E Z Zelleroth, H M Markstad, M A M Aladdin MohammadAbstract
Background
The clinical use of coronary computed tomography angiography (CCTA) has increased substantially over the past decade. As a consequence, a marked rise in the detection of incidental findings such as intramural coronary arteries (IMC) are being reported. The outcome of patients with intramural coronary arteries has not been extensively studied.
Purpose
The aim of the study is to study the prognostic impact of intramual coronary arteries.
Methods
All patients undergoing CCTA are prospectively registered in the SWEDEHEART registry which captures the presence of an intramyocardial coronary artery course in the proximal and middle left anterior descending artery as an optional variable. We included consecutive patients referred for evaluation of suspected myocardial ischemia between January 2016 and August 2025 and excluded patients with a history of myocardial infarction, coronary artery bypass grafting, percutaneous coronary intervention, or anomalous coronary arteries, in addition to patients with obstructive coronary artery disease on CCTA. Outcomes in patients with and without an IMC were evaluated using Kaplan–Meier estimates and Cox proportional hazards regression models. The primary endpoint was major adverse cardiovascular events (MACE), defined as a composite of all-cause mortality, myocardial infarction requiring revascularization, or any coronary revascularization within five years of the index CCTA. Secondary endpoints comprised the individual components of the primary endpoint.
Results
A total of 11,762 patients were included, of whom 3,473 (29.5%) had an IMC. Patients with an IMC were more frequently male (47.8% vs 44.6%) and had a slightly lower mean body mass index (27.2 vs 27.5 kg/m²). There were no clinically relevant differences in age (55.7 vs 56.2 years) or in the prevalence of diabetes, hyperlipidemia, hypertension, or smoking between groups. Atypical chest pain was the predominant presenting symptom (80.0%), with only minor between-group differences despite statistical significance (p < 0.001). An Agatston score of 0 was more common among patients with IMC (61.9%) compared with those without IMC (57.6%)p < 0.001. No significant differences were observed between patients with and without IMC in 5-year risk of MACE (4.0% vs 3.7%; adjusted hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.72–1.21) , all-cause mortality (adjusted HR 0.91, 95% CI 0.64–1.28), myocardial infarction (adjusted HR 1.46, 95% CI 0.68–3.13) or any coronary revascularization (adjusted HR 0.92, 95% CI 0.67–1.43). The degree of encasement (partial or full) was not associated with outcome and several subgroup analyses showed consistent results.
Conclusion
We found no association between IMC and risk of MACE or its components. These findings support the notion that the presence of intramural segments can be regarded as a benign finding.Abstract figure