The diagnosis and prognosis of coronary microvascular disease using PET/CT

This study aimed to evaluate the diagnostic and prognostic value of 13N-NH3·H2O positron emission tomography combined with computed tomography (PET/CT) for non-obstructive coronary microvascular disease (CMVD).

A retrospective analysis was conducted on 70 patients with clinically suspected non-obstructive CMVD (35 males, 35 females) between March 2017 and August 2019. The average age of the patients was 53.32±7.82 years. The patients underwent 13N-NH3·H2O PET/CT and were divided into two groups based on diagnostic criteria: a CMVD group and a non-CMVD group. They were then followed up for 180-1,095 days. Data were analyzed using an χ2 test, the logistic regression model, the multiple linear regression model, the Kaplan-Meier method, the Cox proportional hazards regression model, and a receiver operating characteristic (ROC) curve.

(1) The incidence of cardiovascular family history and a high calcification score (11-400) was higher in the CMVD group than in the non-CMVD group (58.8% vs. 20.8% and 29.4% vs. 5.7%, respectively; P < 0.05 for all), stress myocardial blood flow (MBF) and coronary flow reserve (CFR) values were lower in the CMVD group than in the non-CMVD group (2.280±0.693 vs. 3.641±1.365 and 2.142±0.339 vs. 3.700±1.123, respectively), and calcification score was higher in the CMVD group than in the non-CMVD group (110.18±165.07 vs. 13.21±41.68, respectively; P < 0.05 for all). Gender and diabetes were risk factors for stress MBF reduction (β= 1.287 and β= -0.636, respectively), calcification score and hypertension were risk factors for CFR reduction (β= -0.004 and β= -0.654, respectively), and hypertension, family history, and calcification score were risk factors in the CMVD group (OR = 7.323, OR = 5.108, OR = 1.012, respectively; P < 0.05 for all). (2) The prognosis of patients with CFR < 2.5 was worse than that of patients with CFR≥2.5 (x2 value: 27.404, P < 0.001). The risk of adverse cardiovascular events in diabetic patients was also increased (β= 0.328, P < 0.001). When CFR was set to 2.595, the prognostic sensitivity was 94% and the specificity was 80%.

The technology of 13N-NH3·H2O PET/CT can be used for the diagnosis and prognosis of non-obstructive CMVD. Cardiovascular risk factors are related to the occurrence and prognosis of CMVD.