Combining body mass index with waist circumference to assess coronary microvascular function in patients with non-obstructive coronary artery disease

Background: Coronary microvascular dysfunction (CMD) may precede clinically overt coronary artery disease (CAD). Overall and central obesity (CO) are major risk factors for CAD. This study sought to investigate the subclinical significance of body adiposity patterns based on the CMD risk.

Methods: A total of 128 patients with non-obstructive CAD were prospectively enrolled. Patients were categorized into 4 anthropometric groups: normal weight and non-CO (NWNCO, n = 41), normal weight and CO (NWCO, n = 20), excess weight and non-CO (EWNCO, n = 26), and excess weight and CO (EWCO, n = 41). Patients underwent rest/stress electrocardiography-gated ¹³N-ammonia positron emission tomography to measure absolute myocardial blood flow (MBF), myocardial flow reserve (MFR), hemodynamic parameters, and cardiac function.

Results: Resting MBF did not differ between groups (P = .36). Compared with the NWNCO group, hyperemic MBF and MFR were significantly lower in the NWCO and EWCO groups. Notably, patients with NWCO presented the lowest hyperemic MBF and MFR and the highest incidence of CMD. Waist circumference was an independent risk factor for CMD (OR 1.05, 95% CI 1.01 to 1.10, P = .02).

Conclusion: In patients with non-obstructive CAD, CO may be associated with an increased risk of CMD to better fit the study findings which did not assess management or monitoring of MBF and MFR.