Background: American and European guidelines recommended using Diamond-Forrester risk model (DFRM) to assess stable chest pain by classifying the nature of the chest pain, and then apply a risk model to predict the probability of obstructive coronary artery disease (CAD), although this has been criticised for overestimating the risk of CAD.
Purpose: To study the performance of chest pain typicality in diagnosing CAD in contemporary studies which assessed DFRM.
Methods: We performed a systematic literature search on studies published on MEDLINE and EMBASE until Nov 2016. Searched terms were “Diamond Forrester” and “coronary artery disease”. Overlapping studies and review articles were excluded. Data on the nature of chest pain and presence of CAD was independently extracted by both authors. Crude relative risks (RR) of CAD were calculated by comparing “typical angina” and “atypical angina” respectively to “non-anginal chest pain” or “pain free” as the reference, and not taking into account demographics or cardiovascular risk factors.
Results: 10 studies (n=31,528) were eligible for analysis (mean age 59±10, 54% male). Compared to the original DFRM (NEJM, 1979), more recent studies tended to use cohorts that had more patients with “atypical angina” and “non-anginal chest pain”. Positive diagnoses of CAD also varied significantly (9–88%) in those with “typical angina”. (Table 1) Strikingly those with “atypical chest pain” had similar crude RR of CAD 1.1 (range 0.5–1.9) compared to non-anginal pain.
Conclusions: Many of the contemporary studies assessing the DFRM constitute a lower risk cohort and we opine that classification of the nature of chest pain in several of them was very different to that used in the DFRM, which might explain why DFRM overestimates CAD risk in the contemporary studies.