Introduction The UK National Institute of Health and Care Excellence (NICE) updated chest pain guidelines in 2016 and recommended CT coronary angiography (CTCA) as the first line investigation for all patients presenting with new stable chest pain and removal of pre-test probability (PTP) risk score (RS) due to overestimation of coronary artery disease (CAD). This contrasts with European Society of Cardiology (ESC) guidelines, which recommend a PTPRS based approach based on age, gender and typicality of chest pain, guiding choice of diagnostic modality. In patients with intermediate PTP 15-50%, CT coronary angiography (CTCA) is the recommended modality of investigation, and functional tests if PTP 50-85%. No investigation is recommended if PTP <15%. The PTPRS was further updated in 2019 to adjust for lower prevalence of CAD from contemporary studies. We implemented the NICE 2016 guideline at our centre, and retrospectively analysed how an ESC 2019 PTPRS may have guided diagnostic modality and subsequent management.

Methods A retrospective search of our local radiology database from January 2017 to June 2018 was undertaken of all CTCA undertaken. CTCA reported CAD degree of stenosis as normal/minimal stenosis, mild (30-50%), moderate (50-70%), or severe (>70%) and retrospectively calculated ESC PTP scores from 2019 guidelines.

Results In total 652 patients underwent CTCA (mean age 55 yrs; IQR 48-63; 330 male).

There were no patients with PTP >85%. 2 patients had PTP 50-85%; 1 patient had moderate stenosis and 1 mild stenosis on CTCA. There were 267 patients with PTP 15-50%; 23 (9%) had severe stenosis and 35 (13%) moderate stenosis by CTCA. Finally, 379 patients had PTP <15%; 11 (3%) had severe stenosis and 18 (5%) moderate CTCA stenosis.

Conclusions The updated ESC guideline risk score has shown patients presenting to our chest pain clinic have an overall low PTP of CAD, and is predictive of coronary artery disease in this patient cohort.

A PTP led approach would have meant more than half our cohort underwent no investigation due to low PTP of <15%, however this is at risk of under diagnosis of CAD given 29 patients (8%) had moderate or severe CTCA stenosis. A NICE guided CTCA approach, ensured diagnosis and initiation of medical therapy, which has been demonstrated in SCOT-Heart (1) to have mortality benefit.

Reference

1. Investigators S-H, Newby DE, Adamson PD, Berry C, Boon NA, Dweck MR, et al. Coronary CT angiography and 5-year risk of myocardial infarction. N Engl J Med. 2018;379(10):924-33.

Conflict of Interest None