Assessing and modifying cardiovascular risk in people who present to a chest pain clinic with non‐cardiac causes

Managing patients with acute chest pain should include opportunistic discussion of strategies for preventing coronary artery disease

Chest pain is a frequent symptom in patients presenting to emergency departments. Assessing blood troponins is critical for rapid diagnosis,1 and guidelines clearly outline therapeutic strategies for patients diagnosed with acute myocardial infarction.2 However, evidence for guiding further management when myocardial infarction has been excluded — that is, for most people who present with chest pain — is less definite. As the risk of myocardial infarction or death within 12 months for such patients is 2–9%,1 accurate risk estimation and further preventive treatment are important. The 2020 European Society of Cardiology guidelines for non‐ST‐elevation myocardial infarction recommend non‐invasive cardiac imaging in patients without acute coronary syndrome only when coronary artery disease is nevertheless suspected.3 Further evaluation is often undertaken in chest pain clinics.

A carefully designed randomised trial by Black and colleagues, published in this issue of the MJA, examined whether cardiovascular risk can be modified in patients who presented to a chest pain clinic with non‐cardiac causes of chest pain.4 The authors recruited 189 patients at the rapid access chest pain clinic of the Royal Hobart Hospital who did not have cardiac disease, but a 5‐year risk of cardiovascular events, estimated with the National Vascular Disease Prevention Alliance absolute risk calculator (http://www.cvdcheck.org.au), of at least 8%. Although cardiovascular risk assessment algorithms could be improved, their use is superior to considering individual risk factors in isolation.5 Australian guidelines recommend lifestyle advice for all people over 45 years of age, and pharmacotherapy for those with estimated 5‐year cardiovascular risk of 15% or more, or 10–15% if the patient has other high risk features.6

In the intervention described by Black and his co‐authors, doctors discussed and managed individual risk factors in the context of informing patients about their absolute cardiovascular risk score, and initiated pharmacotherapy if indicated; nurses trained in cardiac rehabilitation educated and counselled patients about lifestyle factors. Patients were also strongly encouraged to follow up these discussions with their general practitioners. Doctors may have discussed risk factors with participants randomised to usual care while assessing their chest pain, but did not provide them with absolute risk scores or initiate other education or counselling.4

The primary outcome of the trial was change in estimated 5‐year risk at least 12 months after assessment. After mean follow‐up of 37.4 months (standard deviation [SD], 12.3 months) — noteworthy because of the relatively long duration — the mean estimated 5‐year risk score for the intervention group was significantly lower than at baseline (10.7%; SD, 5.0% v 13.1%; SD, 4.4%); improvements in risk factors, including smoking, low‐density lipoprotein cholesterol level and systolic blood pressure, were also noted. Mean risk in the control arm was similar at follow‐up and baseline (13.1%; SD, 6.3% v 12.8%; SD, 4.3%), and risk factor changes were not significantly different from those in the intervention group. Physical activity improved in both study arms, and lipid‐lowering and anti‐hypertensive medication use increased in the intervention group (but was not statistically significant).4 The ideal end‐point — numbers of major cardiovascular events — was not examined, as it would have required a much larger trial.

It is difficult to determine the relative importance of the various components of any intervention. However, the findings of Black and colleagues underscore the value of estimating absolute risk in patients with acute chest pain, and the complementary roles of lifestyle changes and drug therapy in reducing cardiovascular risk. The increase in physical activity in both trial groups attests to the fact that presenting to hospital with chest pain can motivate people to adjust their lifestyle, with benefits that do not depend on drug therapy.7

Discontinuation of recommended therapies is common among patients with any chronic disease, and adherence to evidence‐based therapies must be encouraged to optimise outcomes. Adherence to statin therapy is much higher among patients who have had acute coronary syndromes or have chronic coronary artery disease than among patients without diagnosed coronary disease.8 The study by Black and colleagues not only illustrates the importance of seizing the opportunity to intervene when the motivation of a patient without coronary disease is heightened, but also the important role that nurses can play. Further, their trial has implications beyond the context of coronary artery disease. How best to implement flexible systems of care that support patients after leaving hospital, as they transition to and continue care in the community, is challenging, but successful models have been developed in Australia.9

Cardiac causes of pain had been excluded in the patients in the trial by Black and his colleagues. However, imaging techniques — including coronary computed tomographic angiography and coronary artery calcium scoring — could become increasingly important for follow‐up assessment of people in whom coronary artery disease is suspected, subject to their cost‐effectiveness being established.10,11 A recent article in the MJA discussed the role of coronary calcium scoring for improving risk stratification in patients initially judged to be at intermediate risk.12 It has also been reported that showing people images of their coronary artery calcium may motivate them to adhere to treatment.13

Management of patients who present with acute chest pain should maximise the opportunistic discussion of the preventable nature of coronary artery disease and, if appropriate, include selective further investigation. Together with estimates of future risk, presenting patients with images can motivate change.