Association of Coronary Artery Dominance With Long-term Outcomes in Female Patients With Suspected Ischemia but Nonobstructive Coronary Artery Disease

Coronary artery dominance, referring to the arterial supply of the posterior descending artery (PDA), significantly impacts clinical outcomes in cardiac patients. Typically, the PDA originates from the right coronary artery in the right-dominant pattern, the most common form found in individuals. The less prevalent left-dominant type sees the PDA deriving from the left circumflex artery, and balanced dominance involves both the right coronary artery and left circumflex artery supplying the PDA. Notably, left coronary dominance has been found to be linked to adverse outcomes in patients with acute coronary syndrome who undergo percutaneous coronary interventions.1Khan A.R. Khan Luni F. Bavishi C. Khan S. Eltahawy E.A. Left dominant circulation increases mortality in acute coronary syndrome: A systematic review and meta-analysis of observational studies involving 255,718 patients.Catheter Cardiovasc Interv. 2016; 88: 201-208https://doi.org/10.1002/ccd.26281Crossref PubMed Scopus (8) Google Scholar Additionally, for patients referred for computed tomography angiography, a study found that a left-dominant system was an independent predictor of nonfatal myocardial infarction and all-cause mortality.2Veltman C.E. de Graaf F.R. Schuijf J.D. et al.Prognostic value of coronary vessel dominance in relation to significant coronary artery disease determined with non-invasive computed tomography coronary angiography.Eur Heart J. 2012; 33: 1367-1377https://doi.org/10.1093/eurheartj/ehs034Crossref PubMed Scopus (40) Google Scholar However, the clinical implications of coronary dominance in female patients with ischemia and nonobstructive coronary artery disease (INOCA) are poorly understood. To explore this, we conducted a study using data from female participants in the National Heart, Lung, and Blood Institute-sponsored Women’s Ischemia Syndrome Evaluation, examining the correlation between coronary dominance and major adverse cardiovascular events (MACE). We evaluated female participants enrolled between 1996 and 2000 in the National Heart, Lung, and Blood Institute-sponsored Women’s Ischemic Syndrome Evaluation study (NCT00000554) who were undergoing evaluation for suspected ischemia. Angiograms of these participants, displaying no obstructive coronary artery disease, were deemed suitable for determining coronary artery dominance. A core laboratory carried out both qualitative and quantitative angiographic studies, operating under blind conditions to ensure objectivity, remaining unaware of all patient characteristics, including sex and outcomes. Coronary dominance was determined by the coronary artery supplying the PDA: characterized as left, right, or balanced. Information on all-cause death at 8 years (mean) follow-up and MACE (all-cause mortality, nonfatal myocardial infarction, nonfatal stroke, heart failure hospitalization) at 5.4 years were analyzed. χ2 tests were used for categorical variables and Wilcoxon rank sum tests for continuous variables. Cox proportional hazard regression was used to explore the impact of coronary dominance on MACE, cardiovascular events, angina hospitalization, and overall survival. Angina hospitalization survival probability was analyzed by the Kaplan-Meier method. Among 569 female participants, there was no significant difference in mean age, race, body mass index, and overall comorbidities. Patients with left-dominant circulation did not show an increased risk for MACE (P = .7), cardiovascular events (P = .3), and overall mortality (P = .5). However, patients with left-dominant circulation had an increased rate of hospitalizations for angina. At the end of follow-up, 14/44 (32%) patients with left-dominant circulations vs 99/438 (23%) of patients with right-dominant circulations had angina hospitalizations (P = .041, respectively) (Figure 1A). There was no significant difference found when globally comparing left-dominant, right-dominant, and balanced-dominant systems to one another (P = .12) (Figure 1B). Although left coronary dominance has been linked with a poorer prognosis in obstructive coronary artery disease (CAD), there is a knowledge gap regarding its impact on clinical outcomes in female patients with suspected INOCA. This study illuminates a potential link between left-dominant circulation and a heightened risk of angina-related hospitalization among these women. Our work builds on 2 prior studies; one demonstrated that a left-dominant circulation, determined by computed tomography angiography, was an independent predictor of nonfatal myocardial infarction and all-cause mortality, whereas a preceding case-control study accentuated a notably higher prevalence of nonobstructive CAD in females with left dominance.2Veltman C.E. de Graaf F.R. Schuijf J.D. et al.Prognostic value of coronary vessel dominance in relation to significant coronary artery disease determined with non-invasive computed tomography coronary angiography.Eur Heart J. 2012; 33: 1367-1377https://doi.org/10.1093/eurheartj/ehs034Crossref PubMed Scopus (40) Google Scholar,3Makarovic Z. Makarovic S. Bilic-Curcic I. Sex-dependent association between coronary vessel dominance and cardiac syndrome X: a case-control study.BMC Cardiovasc Disord. 2014; 14: 142https://doi.org/10.1186/1471-2261-14-142Crossref PubMed Scopus (7) Google Scholar Our study advances this understanding by incorporating prognostic measures, suggesting that angina-related hospitalizations are more frequent in females with nonobstructive CAD with left-dominant circulations.