Effort-related pain and two or more episodes of pain in 24 hours are associated with poor outcomes in patients presenting with chest pain of uncertain origin, according to a study, from Spain, in the BMJ.

The authors of this prospective cohort study sought to evaluate the predictive value of five simple clinical characteristics of chest pain. A total of 789 patients, 65% men, mean age 63 years, presenting to the emergency department were studied. None of these patients had evidence of ischaemia on ECG and all had normal troponin levels. (One could argue that a normal troponin is very reassuring but previous studies by the lead author have shown that such patients can still be at risk of cardiac events.)

The following pain characteristics were recorded:

• effort-related pain

• pressing character

• radiation

• associated symptoms

• two or more episodes in 24 hours.

Risk factors and comorbidities were also recorded. The primary endpoint was a composite of death, myocardial infarction, readmission for unstable angina or revascularisation at 30-day follow-up and the secondary endpoint was the same composite at one-year follow-up. The results were adjusted for risk factors and comorbidities.

The pain characteristics significantly associated with the primary and secondary endpoints were:

• effort-related pain HR=2.1 (95% CI: 1.5-3.0, p=0.0001) for the primary endpoint and HR=1.8 (95% CI: 1.3-2.5, p=0.0003) for the secondary endpoint

• two or more episodes of pain in 24 hours HR=2.4 (95% CI: 1.7-3.5, p=0.0001) and HR=2.3 (95% CI: 1.7-3.2, p=0.0001).

Both characteristics retained their predictive value in women, patients with diabetes and individuals aged 70 years and over.

The authors concluded that in patients presenting to the emergency department with chest pain and without ECG evidence of ischaemia or a raised troponin, effort-related pain and two or more episodes of pain in 24 hours are the main characteristics to be considered for decision-making.

Patients presenting with chest pain can be a real challenge. Furthermore, an ECG is rarely helpful although often advocated in guidelines. Although this research comes from an acute settingI think the message carries some relevance for primary care physicians as they try to navigate a path through the potential minefield of chest pain.

Dr Peter Savill