Impact on stable chest pain pathways of CT fractional flow reserve

Abstract

Objectives To evaluate the impact of introducing CT fractional flow reserve (FFR CT) on stable chest pain pathways, concordance with National Institute for Health and Care Excellence (NICE) chest pain guidelines, resource usage and revascularisation of patients from a tertiary UK cardiac centre rapid access chest pain clinic (RACPC). Methods Single-centre before and after study comparing data from electronic records and Strategic Tracing Service of all RACPC patients attending between 1 July 2017 and 31 December 2017, and 1 August 2018 and 31 January 2019. Results Two hundred and sixty-eight and 287 patients (overall mean age 62 years, range 26-89 years, 48.3% male), were eligible for first-line CT coronary angiography (CTCA) pre-FFR CT and post-FFR CT, respectively. First-line CTCA use per NICE Guideline CG95 increased (50.6% pre-FFR CT vs 75.7% post-FFR CT, p<0.001). More patients reached pathway endpoint (revascularisation or assumed medical management) after one investigation (74.9% pre-FFR CT vs 84.9% post-FFR CT, p=0.005). There were fewer stress (22.8% pre-FFR CT vs 7.7% post-FFR CT, p<0.001) and rest (10.4% pre-FFR CT vs 4.2% post-FFR CT, p=0.007) myocardial perfusion scans and diagnostic-only angiograms (25.5% vs 13.7%, p<0.001). Despite fewer invasive procedures (29.3% pre-FFR CT vs 17.6% post-FFR CT, p=0.002), revascularisation rates remained similar (10.4% pre-FFR CT vs 8.8% post-FFR CT, p=0.561). Avoiding invasive investigations reduced inpatient admissions (39.0% pre-FFR CT vs 24.3% post-FFR CT, p<0.001). Time to revascularisation was unchanged (153.5 days pre-FFR CT vs 142.0 post-FFR CT, p=0.925). Unplanned hospital attendances, emergency admissions and adverse events were similar. Conclusions FFR CT adoption was associated with greater compliance with NICE guidelines, reduced invasive diagnostic angiography, planned admissions and needing more than one test to reach a pathway endpoint.