Fractional flow reserve derived from coronary computed tomography angiography: diagnostic performance in hypertensive and diabetic patients

Abstract

Aims: Fractional flow reserve (FFR) derived from coronary computed tomography (FFRCT) has high diagnostic performance in stable coronary artery disease (CAD). The diagnostic performance of FFRCT in patients with hypertension (HTN) and diabetes (DM), who are at risk of microvascular impairment, is not known.

Methods and results: We analysed the diagnostic performance of FFRCT, in patients (vessels) with DM (n = 16), HTN (n = 186), DM + HTN (n = 58) vs. controls (n = 107) with or with suspected CAD. Patients (vessels) were further divided according to left ventricular mass index (LVMI) tertiles. Reference standard was invasively measured FFR ≤0.80. Per-patient diagnostic accuracy (95% CI) in control patients was 71.7% (61.6-81.8) vs. 79.3 (74.0-85.0) (P = 0.12), 75.0% (47.6-92.7) (P = 0.52), and 75.9% (62.8-86.1) (P = 0.39) in patients with HTN, DM, and HTM + DM, respectively. There was no difference in discrimination of ischaemia by FFRCT between groups. On a per-vessel level, there was no significant difference in diagnostic performance or discrimination of ischaemia by FFRCT between groups. There was a decline in both per-patient and -vessel diagnostic specificity of FFRCT in the upper LVMI tertile when compared with lower tertiles; however, discrimination of ischaemia by FFRCT was unaltered across LVMI tertiles.

Conclusion: The diagnostic performance of FFRCT is independent of the presence of HTN and DM. FFRCT is a robust method in a broad stable CAD population, including patients at high risk for microvascular disease.

Keywords: angiography; coronary computed tomography; diabetes; fractional flow reserve; hypertension; microcirculation.