Left ventricular hypertrophy contributes to Myocardial Ischemia in Non-obstructive Coronary Artery Disease (the MicroCAD study)

The underlying mechanisms causing myocardial ischemia in non-obstructive coronary artery disease (CAD) are still unclear. We explored whether left ventricular hypertrophy (LVH) was associated with myocardial ischemia in patients with stable angina and non-obstructive CAD. 132 patients (mean age 63 ± 8 years, 56% women) with stable angina and non-obstructive CAD diagnosed as 46.7 g/m2.7 in women and >49.2 g/m2.7 in men. Patients were grouped according to presence or absence of myocardial ischemia by myocardial contrast stress echocardiography. The number of LV segments with ischemia at peak stress was taken as a measure of the extent of myocardial ischemia. Myocardial ischemia was found in 52% of patients, with on average 5 ± 3 ischemic LV segments per patient. The group with myocardial ischemia had higher prevalence of LVH (23 vs. 10%, p = 0.035), while age, sex and prevalence of hypertension did not differ between groups (all p > 0.05). In multivariable regression analyses, LVH was associated with presence of myocardial ischemia (odds ratio 3.27, 95% confidence interval [1.11–9.60], p = 0.031), and larger extent of myocardial ischemia (β = 0.22, p = 0.012), independent of confounders including age, hypertension, obesity, hypercholesterolemia, calcium score and segment involvement score by CCTA. LVH was independently associated with both presence and extent of myocardial ischemia in patients with stable angina and non-obstructive CAD by CCTA. These results suggest LVH as an independent contributor to myocardial ischemia in non-obstructive CAD. Clinical trial registration number: ClinicalTrials.gov, identifier NCT018535271. •Myocardial ischemia was detected in 52% of patients with stable angina and non-obstructive CAD.•Presence of myocardial ischemia was associated with left ventricular hypertrophy independent of hypertension.•Left ventricular hypertrophy may be a potential treatment target in patients with stable angina and non-obstructive CAD.