Coexistence of coronary microvascular dysfunction and left ventricular hypertrophy can predict prognosis of patients with nonobstructive coronary arteries

Abstract Background Previous studies have reported that coronary microvascular dysfunction (CMD) and left ventricular hypertrophy (LVH) were associated with adverse cardiovascular events. The aim of this study was to determine the prognostic impact of coexistence of abnormal coronary flow reserve (CFR) and left ventricular mass index (LVMI). Methods and results This study included 297 patients who underwent intracoronary physiological assessment including CFR for suspected myocardial ischemia without significant stenosis in the epicardial coronary artery at our hospital from December 2019 to March 2023. Of 297 patients (female: n=89 [30%], age: 70±11 years), 93 (31%) had CMD (CFR<2.5) and 133 (45%) had LVH (LVMI>95 g/m2 for female and >115 g/m2 for male). We excluded patients with history of heart failure (HF). Patients were classified into 4 groups based on the cut-off values of CFR and LVMI: group 1 (no CMD nor LVH, n=109); group 2 (only LVH, n=95); group 3 (only CMD, n=55) and group 4 (both CMD and LVH, n=38). Patients of group 4 had a larger proportion of female (female 19%, 34%, 24% and 61% in group 1 to 4 respectively). There was no significant difference in left ventricular ejection fraction between patients of each groups. Clinical follow-up was performed for major adverse cardiovascular events (MACE) including cardiovascular death, myocardial infarction and hospitalization for new-onset HF. During a median follow-up of 753 days, the cumulative MACE-free survival rate at 2 year were 99.0%, 98.9%, 95.6% and 90.0% in groups 1 to 4. Group 4 showed significantly higher risk of MACE at 2 year compared with group 1 (hazard ratio [HR] 2.6; 95% confidence interval [CI] 1.3-5.3; p=0.009). Notably, Group 4 showed the highest incidence of hospitalization for new-onset HF than any other groups. Conclusion Patients with both CMD and LVH showed significantly higher risk for MACE and new onset of HF. The combined classification based on CFR and LVMI would identify the high-risk patients for MACE as well as new-onset HF.