Does the ESC chronic coronary syndrome pre-test probability score assist coronary artery disease diagnosis in an advanced nurse practitioner led integrated community chest pain clinic?

Background The Advanced Nurse Practitioner (ANP) led integrated community chest pain clinic provides an alternative avenue to which GPs can refer patients with non-acute chest pain providing emergency dept. avoidance. The role of the ANP is to differentiate between a non-anginal versus anginal cause. In addition to taking a clinical history, physical assessment and ECG the ANP utilises the 2019 ESC guidelines for chronic coronary syndromes pre-test-probability (PTP) score, to judge if invasive investigation is required. Purpose ANP assessment of chest pain in a community clinic is unique in the Irish healthcare setting. The aim was to assess if angina characteristics & allocated ESC PTP were predictive of coronary artery disease (CAD) diagnosis in a community chest pain cohort. Method A retrospective audit of 144 patients assessed by the ANP in the ICCPC and subsequently referred for coronary angiography was performed. Final diagnosis of was analysed by i. anginal characteristic, ii. ESC PTP, iii. age and sex. Approval was given by the department of quality, safety and risk management. Results The average combined age was 61 years in n=92 Male, and n=51 Female patients. Coronary Artery Disease was diagnosed in 92% (n= 132) of those referred for angiography; obstructive CAD in 38% (n=55) and non-obstructive CAD (NOCAD) in 54% (n=77). The ANP allocated the angina characteristic ‘typical’ in 31% (n=45) cases and 58% (n=26) were diagnosed with obstructive CAD, average PTP of 20%, and 38% (n=17) were diagnoses with NOCAD. In those with ‘typical’ symptoms only two cases resulted in normal coronary arteries. Conversely 34% (n=49) were allocated ‘non-anginal’ symptoms, in whom 28% (n=14) obstructive CAD was detected; 12 cases had an intermediate to high PTP due to age and clinical likelihood. The majority of referrals (57%) were ‘high’ PTP of CAD (≤16%-52%), average 22%. The average PTP was 27% (High) in those diagnosed with CAD versus a PTP of 11% (Intermediate) in those with normal coronaries (n=12). The new category of ‘dyspnoea’ was allocated to 14% (n=20) and resulted in diagnosis of NOCAD (n=12) and (n=5) CAD. Those with dyspnoea as a presenting symptom of CAD were all male with high PTP. Conclusion Pre-test-probability and age are highly correlated, rising with age and defined by sex. The main variable is the ‘angina’ characteristic allocated by the ANP. In this community-based cohort, ‘typical’ symptom allocation by the ANP resulted in a higher PTP and subsequent CAD diagnosis. Clinical suspicion in the ‘low-intermediate risk’ can be further adjusted using the clinical likelihood ratio. The value of the PTP score in predicting CAD is as useful as the ‘angina’ characteristic and clinical likelihood allocated, requiring expert health history taking. This retrospective analysis of coronary angiogram results in this community cohort evidences that the ANP is skilled in utilising the ESC PTP score to assist in the diagnosis of CAD.