D-SPECT-derived myocardial perfusion imaging and coronary blood flow reserve in the clinical diagnosis of hypertensive patients with INOCA

Long-term hypertension patients may experience structural changes in the myocardium, microvascular dysfunction, and myocardial ischemia, leading to a decrease in MBF and CFR, which exacerbates clinical symptoms and increases the incidence of MACE. This study aims to evaluate the characteristics of MPI and CFR, as well as their influencing factors, in hypertensive patients with LVH by utilizing a combination of D-SPECT with CAG or CTA. Materials and Methods This study is a retrospective analysis that selected patients with angina who visited Gansu Provincial People's Hospital from April 2023 to September 2024 and underwent D-SPECT, CAG, or coronary CTA. According to the 2024 ESC Guidelines for Hypertension Management, patients were categorized into non-hypertensive and hypertensive groups. The general data, laboratory indicators, echocardiographic parameters, and D-SPECT-related metrics of both groups were compared.Furthermore, based on the parameters obtained from echocardiography, a subgroup analysis was conducted for patients in the hypertension group to compare differences in MPI, MBF, and CFR between those with and without LVH. This study has received approval from the Ethics Committee of Gansu Provincial People's Hospital, with approval number: 2024 − 781. Result The SSS, SDS, TPD(s), and Extent(s) in the hypertension group were significantly higher than those in the control group ( P  < 0.05). Additionally, the sMBF and CFR of the LAD, LCX, and RCA coronary arteries were significantly lower in the hypertension group compared to the control group ( P  < 0.05). Subgroup analysis of hypertension revealed that patients with LVH exhibited a significantly lower CFR in the LAD, LCX, and RCA coronary arteries compared to those without LVH ( P  < 0.05). Notably, both LAD and LCX had a CFR below 2.5, with the lowest CFR observed specifically in the distribution area of the LAD. However, no significant statistical differences were found among subgroups regarding sMBF ( P  > 0.05).Through multivariate linear regression analysis, it was determined that SBP and IVS(D) are significant risk factors contributing to the reduction of CFR. Specifically, higher values of SBP and IVS(D) correlate with a lower CFR in coronary vessels. Furthermore, both sMBF and CFR demonstrate high sensitivity and specificity in disease diagnosis. The optimal cutoff values for diagnosing diseases were established through the maximum Youden index derived from the ROC curve; specifically, the optimal cutoff value for sMBF is 2.18, while that for CFR is 2.71. Conclusion The sMBF and CFR derived from D-SPECT demonstrate high sensitivity and specificity in disease diagnosis, making them reliable indicators for assessing coronary microcirculation in patients with hypertension. Furthermore, SBP and IVS(D) are identified as the primary risk factors contributing to the decline of CFR. Therefore, actively managing blood pressure and preventing the onset and progression of LVH is a crucial strategy for mitigating CMD.