Introduction Chest pain is a common presentation in primary care with many patients recorded with non-cardiac chest pain (NCCP), i.e. chest pain either unattributed to a cause or recorded with a non-cardiac reason. The relative prevalence of potential causes of NCCP in these patients and how these are related to risk of future cardiovascular disease (CVD) remains unclear. The aims of this study were to: (i) identify the recorded prevalence of comorbidities potentially linked to chest pain in patients with NCCP in primary care; and (ii) determine the incidence of future CVD in those with NCCP.

Methods A cohort study was conducted between 2002-2015 using the Consultations in Primary Care Archive (CiPCA) database of pseudonymised primary care data. Patients aged >18 years with no prior CVD presenting with NCCP (index date) were included. Recorded comorbidities (osteoarthritis [OA]; lower back pain [LBP]; depression/anxiety; respiratory; reflux; and cancer) were identified between 24 months prior to and 6 months after the index date of NCCP. NCCP was categorised into those recorded with a non-cardiac cause at index date, unattributed chest pain with no comorbidity, and unattributed chest pain with comorbidity. Variation in patient characteristics were investigated. Incidence rates (IRs) of CVD events per 1,000 person years were calculated by NCCP category and stratified by time windows from the index date to CVD.

Results In total, 20,996 patients presented with NCCP with 9,000 (43%) recorded with a non-cardiac cause at index date, 5,993 (28%) unattributed no comorbidity, and 6,003 (29%) unattributed with comorbidity. The non-cardiac cause NCCP group were younger (44.1 versus 44.3 and 49.3 years) with a lower proportion of men (41.6% versus 42.4% and 54.1%) compared to the unattributed no comorbidity and unattributed with comorbidity groups, respectively. The most common comorbidity was respiratory (35%) followed by depression/anxiety (33%), reflux (15%), LBP (8%), OA (6%) and cancer (3%) in the unattributed with comorbidity group. The unattributed with comorbidity group had the highest incidence of CVD (IR 16.3, 95% confidence interval [CI] 15.0-17.6) vs. non-cardiac cause NCCP (IR 8.8, 95% CI 8.1-9.6) and unattributed no comorbidity groups (IR 11.7, 95% CI 10.7-12.8). The highest incidence of CVD occurred between 6-12 months after the index date (IR 45.0, 95% CI 32.7-61.8). Patients in the unattributed with comorbidity group with OA (IR 29.2, 95% CI 23.4-36.4) and cancer (IR 29.2, 95% CI 20.0-42.6) had the highest incidence of CVD, reflecting their older age.

Conclusions Depression and respiratory symptoms may be the most common reasons for NCCP in primary care. A higher incidence of CVD was observed for patients with unattributed NCCP and comorbidity, and in the first 6-12 months after presentation to primary care. This study highlights the importance of following up patients with unattributed chest pain symptoms.

Conflict of Interest N/A