The clinical utility of FFRCT stratified by age

Background: CT coronary angiography (CTA) with Fractional Flow Reserve as determined by CT (FFRCT) is a safe alternative to invasive coronary angiography. A negative FFRCT has been shown to have low cardiac event rates compared to those with a positive FFRCT. However, the clinical utility of FFRCT according to age is not known.Methods: Patients' in the ADVANCE (Assessing Diagnostic Value of Non-invasive FFRCT in Coronary Care) registry, were stratified into those >= 65 or <65 years of age. The impact of FFRCT on clinical decision-making, as assessed by patient age, was determined by evaluating patient management using CTA results alone, followed by site investigators submitting a report on the treatment plan based upon the newly provided FFRCT data. Outcomes at 1-year post CTA were assessed, including major adverse cardiovascular events (myocardial infarction, all-cause mortality or unplanned hospitalization for ACS leading to revascularisation) and total revascularisation. Positive FFRCT was deemed to be <= 0.8.Results: FFRCT was calculated in 1849 (40.6%) subjects aged <65 and 2704 (59.4%) >= 65 years of age. Subjects >= 65 years were more likely to have anatomic obstructive disease on CTA (>= 50% stenosis), compared to those aged <65 (69.7% and 73.2% respectively, p = 0.008). There was a similar graded increase in recommended and actual revascularisation with either CABG or PCI, with declining FFRCT strata for subjects above and below the age of 65. MACE and revascularisation rates were not significantly different for those >= or <65, regardless of FFRCT positivity or stenosis severity <50% or >= 50%. With a negative FFRCT result, and anatomical stenosis >= 50%, those >= and <65 years of age, had similar rates of MACE (0.2% for both, p = 0.1) and revascularisation (8.7% and 10.4% respectively p = 0.4).Logistic regression analysis, with age as a continuous variable, and adjustment for Diamond Forrester Risk, baseline FFRCT and treatment (CABG, PCI, medical therapy), indicated a statistically significant, but small increase in the odds of a MACE event with increasing age (OR 1.04, 95% CI 1.006-1.08, p = 0.02). Amongst patients with a FFRCT > 0.80, there was no effect of age on the odds of revascularisation.Conclusion: The findings of this study point to a low risk of MACE events or need for revascularisation in those aged >= or <65 with a FFRCT>0.80, despite the higher incidence of anatomic obstructive CAD in those >= 65 years. The findings show the clinical usefulness and outcomes of FFRCT are largely constant regardless of age.