Diagnostic performance of angiography-based fractional flow reserve by patient and lesion characteristics: FAST-FFR substudy

BACKGROUND: A large, prospective, multicentre trial recently showed that fractional flow reserve (FFR) derived from coronary angiography (FFR(angio)) has an accuracy of 92% compared with conventional guidewire-based FFR (FFR(wire)); however, little is known about whether specific patient/lesion characteristics affect the diagnostic performance. AIMS: The primary goal of the present study was to investigate whether specific patient or lesion characteristics such as high body mass index (BMI), presentation with an acute coronary syndrome, or lesion location affect the diagnostic performance of FFR(angio) in patients enrolled in the FAST-FFR study. METHODS: FFR(angio) was measured in a blinded fashion in 301 patients (319 vessels) who were undergoing FFR(wire) assessment. Using an FFR(wire) ≤0.80 as a reference, the diagnostic performance of FFR(angio) was compared in pre-specified subgroups. RESULTS: The mean FFR(wire) and FFR(angio) were 0.81±0.13 and 0.80±0.12. Overall, FFR(angio) had a sensitivity of 93.5% and specificity of 91.2% for predicting FFR(wire). Patient characteristics including age, sex, clinical presentation, body mass index, and diabetes did not affect sensitivity or specificity (p>0.05 for all). Similarly, lesion characteristics including calcification and tortuosity did not affect sensitivity or specificity (p>0.05 for all), nor did lesion location (proximal, middle, versus distal). Sensitivity was equally high across all target vessels, while specificity was highest in the LAD and lower (~85%) in the RCA and LCx (p