A new non-invasive detector for coronary microvascular dysfunction: exercise stress high-frequency QRS electrocardiogram.

Background: This study aimed to evaluate the diagnostic value of the exercise stress high-frequency QRS (HFQRS) electrocardiogram in coronary microvascular dysfunction.

Methods: We consecutively enrolled patients aged 20 years or older with chest pain between January 2022 and January 2024, all of them underwent HFQRS analysis and coronary angiography. The sensitivity, specificity, and positive predictive value of HFQRS for predicting coronary microcirculatory dysfunction were calculated using coronary angiography-based microvascular resistance (caIMR) ≥25.1 as the gold standard for determining coronary microcirculatory dysfunction. We used the area under the ROC curve (AUC) to evaluate the predictive accuracy of HFQRS and the diagnostic value of exercise HFQRS for coronary microvascular dysfunction (CMVD).

Results: A total of 139 patients were included. We found a moderate correlation between the caIMR values and the number of positive HFQRS leads. (R = 0.757, P < .001). Multifactorial logistic regression analysis showed that the number of positive leads on the HFQRS was an independent predictor of caIMR (9.17, CI 1.02-82.73, P = .048). The area under the ROC curve for the prediction of caIMR by the number of positive HFQRS leads was 0.81 (95% CI 0.73-0.89). The sensitivity, specificity, negative predictive value, and positive predictive value of HFQRS for the prediction of coronary microcirculatory dysfunction were 0.686, 0.971, 0.986, and 0.500, respectively.

Conclusions: Our study found that exercise HFQRS is an important predictor of coronary microvascular disease, that there is a correlation between the number of positive exercise HFQRS leads and CMVD, and that exercise stress HFQRS is a noninvasive and reliable indicator for the diagnosis of CMVD.