Department of Clinical Medicine

BACKGROUND: Clinical outcomes following coronary computed tomography-derived fractional flow reserve (FFRCT) testing in clinical practice are unknown.

OBJECTIVES: The study sought to assess real-world clinical outcomes following a diagnostic strategy including first-line coronary computed tomography angiography (CTA) with selective FFRCT testing.

METHODS: The study reviewed the results of 3,674 consecutive patients with stable chest pain evaluated with CTA and FFRCT testing to guide downstream management in patients with intermediate stenosis (30% to 70%). The composite endpoint (all-cause death, myocardial infarction, hospitalization for unstable angina, and unplanned revascularization) was determined in 4 patient groups: 1) CTA stenosis <30%, optimal medical treatment (OMT), and no additional testing; 2) FFRCT >0.80, OMT, no additional testing; 3) FFRCT ≤0.80, OMT, no additional testing; and 4) FFRCT ≤0.80, OMT, and referral to invasive coronary angiography. Patients were followed for a median of 24 (range: 8 to 41) months.

RESULTS: FFRCT was available in 677 patients, and the test result was negative (>0.80) in 410 (61%) patients. In 75% of the patients with FFRCT >0.80, maximum coronary stenosis was ≥50%. The cumulative incidence proportion (95% confidence interval [CI]) of the composite endpoint at the end of follow-up was comparable in groups 1 (2.8%; 95% CI: 1.4% to 4.9%) and 2 (3.9%; 95% CI: 2.0% to 6.9%) (p = 0.58) but was higher (when compared with group 1) in groups 3 (9.4%; p = 0.04) and 4 (6.6%; p = 0.08). Risk of myocardial infarction was lower in group 4 (1.3%) than in group 3 (8%; p < 0.001).

CONCLUSIONS: In patients with intermediate-range coronary stenosis, FFRCT is effective in differentiating patients who do not require further diagnostic testing or intervention (FFRCT >0.80) from higher-risk patients (FFRCT ≤0.80) in whom further testing with invasive coronary angiography and possibly intervention may be needed. Further studies assessing the risk and optimal management strategy in patients undergoing first-line CTA with selective FFRCT testing are needed.