Myocardial bridging is associated with focal coronary artery spasm in ANOCA
F W Adriaansen, C Crooijmans, B Yosofi, J G Meeder, A C Dimitriu-Leen, T P van de Hoef, M A M Beijk, P DammanAbstract
Background
Myocardial bridging is a congenital coronary artery anomaly in which an epicardial segment that courses through the myocardium results in angiographically visible systolic compression of the tunnelled segment. Although generally considered a benign anatomical variant, previous literature suggests that myocardial bridging may be associated with angina and coronary vasomotor dysfunction (CVDys), which can be assessed using a coronary function test (CFT).
Purpose
This study assessed the prevalence of CVDys and the individual endotypes epicardial or microvascular spasm and coronary microvascular dysfunction (CMD) in patients with angina an non-obstructive coronary artery disease (ANOCA) with and without angiographic myocardial bridging. In addition, physiological measurements obtained during CFT were assessed.
Methods
Data were obtained from the NetherLands registry of invasive Coronary vasomotor Function Testing (NL-CFT), a Dutch multicentre registry on coronary function testing. Patients who underwent clinically indicated CFT, including coronary angiography, spasm provocation testing, and assessment of coronary microvasculature using bolus thermodilution or Doppler measurements, between December 2020 and December 2025 were included. Diagnostic yield and physiological measurements were compared between patients with and without myocardial bridging. Among patients with epicardial spasm, spasm phenotype (focal versus diffuse) was evaluated.
Results
1699 patients were included, 18.2% were men, and the mean age was 60.0 ± 9.9 years. Myocardial bridging was present in 9.8% of the patients, mostly located mid left anterior descending artery (LAD) (72.9%). Epicardial spasm was more prevalent in the group with myocardial bridging (42.9% versus 35.0%, p=0.04), while microvascular spasm was diagnosed less often (19.0% versus 26.6%, p=0.04). The overall prevalence of spasm was comparable (68.1% versus 65.7%, p=0.5). When focusing on patients diagnosed with epicardial spasm, focal spasm was more prevalent in those with myocardial bridging (29.2% versus 16.7%, p=0.01). There were no differences in the prevalence of CMD (37.3% versus 38.0%, p=0.9) or its subtypes between patients with and without myocardial bridging. Physiological assessment was also comparable (RFR 0.93 versus 0.93, p=0.08; FFR 0.90 versus 0.91, p=0.1; CFR 3.8 versus 3.9, p=0.6). The Seattle Angina Questionnaire (SAQ) summary scores at baseline and 1-year follow-up were slightly lower in patients with myocardial bridging, but these differences were not statistically significant (baseline 50.0 versus 51.9, p=0.3; 1-year 57.6 versus 59.3, p=0.5).
Conclusion
Focal epicardial spasm was more prevalent in patients with myocardial bridging, whereas microvascular spasm was more frequently observed in those without bridging.