Impact on stable chest pain pathways of CT fractional flow reserve.

Objectives: To evaluate the impact of introducing CT fractional flow reserve (FFR) 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 and post-FFR, respectively. First-line CTCA use per NICE Guideline CG95 increased (50.6% pre-FFR vs 75.7% post-FFR, p<0.001). More patients reached pathway endpoint (revascularisation or assumed medical management) after one investigation (74.9% pre-FFR vs 84.9% post-FFR, p=0.005). There were fewer stress (22.8% pre-FFR vs 7.7% post-FFR, p<0.001) and rest (10.4% pre-FFR vs 4.2% post-FFR, 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 vs 17.6% post-FFR, p=0.002), revascularisation rates remained similar (10.4% pre-FFR vs 8.8% post-FFR, p=0.561). Avoiding invasive investigations reduced inpatient admissions (39.0% pre-FFR vs 24.3% post-FFR, p<0.001). Time to revascularisation was unchanged (153.5 days pre-FFR vs 142.0 post-FFR, p=0.925). Unplanned hospital attendances, emergency admissions and adverse events were similar.

Conclusions: FFR 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.