Diffusely impaired myocardial perfusion in patients with suspected coronary artery disease: Clinical utility of relative perfusion.

BACKGROUND

In patients with suspected coronary artery disease (CAD), diffusely impaired hyperaemic myocardial blood flow (MBF) may indicate a multivessel epicardial CAD but also impaired coronary microcirculation. We assessed whether relative hyperaemic MBF-that is, the ratio of the lowest to the highest regional hyperaemic MBF-predicts obstructive CAD in patients with diffusely impaired hyperaemic MBF.

METHODS

We studied 874 patients who underwent coronary computed tomography angiography and [15O]H2O myocardial perfusion imaging with positron emission tomography at Kuopio University Hospital, Finland, in 2017-2023. The final analyses included 64 patients who had diffusely impaired hyperaemic MBF and were subsequently referred to invasive coronary angiography (ICA).

RESULTS

In ICA, 34/64 (53%) patients had obstructive CAD. Compared to patients with non-obstructive CAD, those with obstructive CAD had lower relative hyperaemic MBF: 66% (95% CI 62-69%) versus 52% (95% CI 47-57%), respectively (p < 0.001). When relative hyperaemic MBF was used to predict the presence of obstructive CAD in ICA, the receiver operating characteristic analysis showed an area under the curve of 0.778 (95% CI 0.666-0.891). In binary logistic regression analysis, relative hyperaemic MBF independently predicted obstructive CAD (OR = 0.92 [95% CI 0.86-0.97], p = 0.004).

CONCLUSION

Obstructive CAD is more likely in patients with lower relative hyperaemic MBF. Consequently, relative hyperaemic MBF may have clinical utility in patients with suspected CAD and diffusely impaired hyperaemic MBF.