AIM To investigate the influencing factors of coronary microcirculation resistance (IMR) in patients with ejection fraction preserved heart failure (HFpEF).

METHODS 239 HFpEF patients admitted to our hospital between September 2018 and March 2021 were selected as the study subjects. They were divided into two groups based on their IMR values: a normal IMR group (n=151) and an elevated IMR group (n=88). The influencing factors of IMR elevation in HFpEF patients were analyzed, and a logistic regression model was constructed to analyze the model’s efficacy and stability.

RESULTS The proportion of diabetes patients in the IMR elevated group was significantly higher than that in the IMR normal group (P<0.01), the proportion of general exercise intensity was higher than that in the IMR normal group, and the proportion of medium and high exercise intensity was lower than that in the IMR normal group (P<0.01). Hs CRP, IL-8, TNF in patients with elevated IMR-α、 HbA1c and BNP were significantly higher in the IMR normal group, while HDL-C levels were significantly lower in the IMR normal group (both P<0.01). The results of multivariate logistic regression analysis showed that hs CRP and TNF-α Level is a risk factor for increased IMR; Exercise intensity and HDL-C are protective factors for increased IMR. The exercise intensity has the highest C-index on both the training and validation sets, with values of 0.757 and 0.768, respectively. Exercise intensity, hs CRP, TNF-α The C index of the model composed of four factors including HDL-C level was 0.886 and 0.898 in the training and validation sets, respectively, which were higher than other models. The highest Jordan index of the model is 0.746, with a corresponding sensitivity of 87.8%, specificity of 86.8%, and accuracy of 87.3%. The stability of the prediction model was verified through cross validation, and the results showed that the parameters of the training and validation sets were very close.

CONCLUSION Exercise intensity, hs CRP, IL-8, TNF-α、 The levels of HbA1c, BNP, and HDL-C have a significant impact on non stenosis IMR in HFpEF patients; Hs CRP and TNF-α Level is a risk factor for IMR elevation, while exercise intensity and HDL-C are protective factors for IMR elevation; Based on exercise intensity, HDL-C, TNF-α The logistic regression model constructed at the hs CRP level predicts the probability of an increase in IMR, with good predictive performance and stability.