The MBF change during mental stress in angina women with no obstructive coronary disease

Abstract Background Angina with no obstructive coronary artery disease (ANOCA) and mental stress-induced myocardial ischemia (MSIMI) are currently distinct and poorly understood conditions. The mechanism of MSIMI remains unclear and has attracted more attention. This study aimed to characterize the myocardial blood flow (MBF) changes associated with mental stress in patients with ANOCA. Methods This single-blind, parallel-group clinical trial enrolled 84 women with ANOCA aged 18-75 years old and 42 age-matched healthy women between June 2019 and April 2021. Participants completed standardized mental stress (Stroop test, public speaking, and mental arithmetic) and adenosine vasodilator stress tests. Myocardial perfusion defects and MBF changes were assessed by 13-NH3 Positron Emission Tomography. MSIMI was defined as a summed difference score(SDS)≥3. Results A significantly higher prevalence of MSIMI was observed in women with ANOCA than in controls (42.9% vs.2.4%, p0.001). Hemodynamic response to mental stress was also greater in ANOCA compared to controls but the global MBF change during mental stress test was similar between groups. Notably, a reduction in MBF early post mental stress was found to correlate with higher SDS and angina grading. It was also a significant independent indicator of MSIMI. Additionally, an overall MBF post to during mental stress difference ratio ofs-10%was associated with a 4-times higher risk of MSIMI; a difference ratio of s-10%in the right coronary artery was associated with a 28-times higher risk of MSIMI. Conclusions MSIMl is a common and neglected phenomenon in women with ANOCA .We found an early decline in MBF post mental stress that may have a critical role in the pathophysiology of MSIMI. Wider recognition of MSIMI and further research into the mechanisms and possible treatments could greatly improve outcomes, particularly in patients with ANOCA.Graphical abstract Table