The impact of mildly elevated HbA1c level, and low levels of high-density lipoprotein cholesterol and hemoglobin on microvascular angina

Microvascular angina (MVA), resulting from coronary microvascular dysfunction (CMD), is increasingly recognized as a contributor to adverse cardiovascular outcomes. However, the clinical factors for MVA remain unclear. In this retrospective case-control study, we investigated the clinical factors of MVA in 92 patients with MVA and 391 age- and sex-matched control participants without chest pain or cardiovascular diseases. All patients underwent coronary angiography including an acetylcholine (ACh)-provocation test and a coronary flow reserve (CFR) measurement. MVA was diagnosed based on the Coronary Vasomotion Disorders International Study Group (COVADIS) criteria. Multivariate logistic regression analysis showed mildly elevated hemoglobin A1c (HbA1c) (i.e., prediabetes), low high-density lipoprotein cholesterol (HDL-C), and low hemoglobin (Hgb) levels as independent factors significantly associated with MVA. Mean corpuscular volume (MCV) was also significantly lower in MVA patients. No significant differences in clinical characteristics were found between microvascular spasm (MVS) and MVA without MVS. MVS was more common in women than in men. In conclusion, mildly elevated HbA1c level, and low levels of HDL-C and Hgb may serve as modifiable risk markers for MVA. The study findings may aid in the management of MVA.