Background  To evaluate the association between hypertension and coronary microvascular function evaluated by cadmium zinc telluride single-photon emission computed tomography (CZT-SPECT) in angina patients.

Methods A total of 259 consecutive patients with angina pectoris and epicardial coronary artery stenosis ＜50% admitted between April 2023 and September 2024 were enrolled. They were divided into a hypertension group (125 cases) and a non-hypertension group (134 cases). Resting myocardial blood flow (rMBF), stress myocardial blood flow (sMBF), and coronary flow reserve (CFR) were measured by CZT-SPECT. Pearson correlation analysis and multivariate logistic regression analysis were performed to explore the influencing factors of reduced CFR.

Results Compared with the non-hypertension group, sMBF and CFR in all three coronary arteries were significantly decreased in the hypertension group (all P＜0.01). Correlation analysis revealed negative correlations of systolic blood pressure with sMBF and total CFR (r = –0.34 and –0.35, respectively, both P＜0.01). Interventricular septal thickness at end-diastole (IVSTd) and left ventricular posterior wall thickness at end-diastole (LVPWTd) were also negatively correlated with total CFR (r = –0.41 and –0.32, respectively, both P＜0.01). Multivariate logistic regression analysis demonstrated that systolic blood pressure (OR = 1.031, 95%CI: 1.014 to 1.048, P＜0.01), IVSTd (OR = 1.564, 95%CI: 1.271 to 1.923, P＜0.01), and LVPWTd (OR = 1.421, 95%CI: 1.158 to 1.742, P＜0.01) were independent influencing factors for reduced CFR.

Conclusions Hypertension is closely related to impaired coronary microvascular function, mainly manifested as decreased sMBF and CFR. Systolic blood pressure level and left ventricular structural remodeling may play important roles in this process.