Long term risk of cardiovascular disease in patients presenting to primary care with undiagnosed chest pain: an electronic health records study

Conference:

SAPC ASM 2021 - virtual

Talk Code:

P1.11.6

Presenter:

Kelvin Jordan

Co-authors:

Trishna Rathod-Mistry, James Bailey, Ying Chen, Lorna Clarson, Spiros Denaxas, Richard Hayward, Harry Hemingway, Mamas Mamas, Danielle van der Windt

Author institutions:

Keele University, University College London, Xi'an Jiaotong - Liverpool University

Problem

2% of adults present in primary care with chest pain symptoms annually. Most will not receive a specific diagnosis (“unattributed” chest pain). The aim was to assess if there is an increased long term (10-year) risk of coronary heart disease and stroke in patients with new unattributed chest pain in primary care compared to those recorded with a non-coronary cause of chest pain, and determine whether investigations and interventions are targeted at those most at risk.

Approach

We used the CPRD Aurum database containing electronic health records from general practices in England linked to admitted patient hospitalisations from the Hospital Episode Statistics database. The study population was patients aged 18 and over with a new primary care record of chest pain with cause unattributed or non-coronary cause, between 2002 and 2018, and no record of cardiovascular disease up to six months (diagnostic window) afterwards. Outcomes were cardiovascular (coronary and stroke) events starting from end of the six-month diagnostic window.

Flexible parametric survival analyses were used to compare risk of a cardiovascular event by type of chest pain, adjusted for covariates. Covariates included risk factors in the QRISK3 general population cardiovascular risk algorithm, alternative explanations for chest pain, and other comorbidities predictive of cardiovascular disease. Analyses were repeated for coronary, acute myocardial infarction, and stroke outcomes separately.

We determined the prevalence of cardiac diagnostic investigations and lipid-lowering prescriptions during the six month diagnostic window in patients rated as elevated risk (≥10%) using the QRISK3 algorithm.

Findings

There were 375,240 patients with unattributed chest pain and 245,329 with non-coronary chest pain. Median follow-up was 6 years.

11% (193/10,000 person-years) of the unattributed chest pain group and 9% (144/10,000) of the non-coronary chest pain group had a cardiovascular outcome. There was an increased risk of cardiovascular events for patients with unattributed chest pain compared to non-coronary chest pain, highest in the first year after index date (hazard ratio 1.25; 95% CI 1.21, 1.29), but remaining after 10 years (1.09; 1.06, 1.13). Patterns were similar when restricted to coronary outcomes. Patients with unattributed chest pain had a consistently increased risk of myocardial infarction over time, but no increased risk of a stroke.

38% of patients with unattributed chest pain and at high risk received an investigation and 30% were prescribed lipid-lowering medication.

Consequences

Patients presenting to primary care with unattributed chest pain are at increased risk of cardiovascular events. Many do not receive an investigation or intervention, and primary prevention to reduce future cardiovascular events is sub-optimal, even in those at higher risk. This is particularly relevant given the high incidence of patients with unattributed chest pain in primary care.

Submitted by:

Kelvin Jordan

Funding acknowledgement:

Study funded by the British Heart Foundation, reference PG/19/46/34307. KJ also supported by matched funding awarded to the NIHR Applied Research Collaboration (West Midlands). This study is based in part on data from the Clinical Practice Research Datalink obtained under licence from the UK Medicines and Healthcare products Regulatory Agency. The data is provided by patients and collected by the NHS as part of their care and support. The Office for National Statistics (ONS) is the provider of the ONS data contained within the linked CPRD data used for this study. ONS Data and Hospital Episode Statistics (HES) Data: copyright © (2020), re-used with the permission of The Health and Social Care Information Centre; all rights reserved. The interpretation and conclusions contained in this study are those of the authors alone and not necessarily the views of The British Heart Foundation, the NHS, the NIHR or the Department of Health and Social Care.