Prognostic value of demographic factors, pre-test probability scoring, exercise test diagnosis, and inability to exercise in patients with recent onset suspected cardiac chest pain.

AIMS

To assess the prognostic value of an inconclusive exercise test or inability to exercise in patients with recent onset suspected cardiac chest pain and to determine the independent predictors of events in these patients.

METHODS

This was an observational follow-up study of patients presenting to a rapid access chest pain clinic with a history of recent-onset suspected cardiac chest pain as referred by the family practitioner. The main outcome measure was a composite endpoint of death and acute coronary syndrome hospital admission.

RESULTS

The study cohort consisted of 1851 patients in whom a total of 147 events were recorded during a mean follow-up period of 4.1 ± 1.1 years. Those with events were significantly older (65.1 ± 12.5 years versus 56.4 ± 13.2 years, p < 0.001), had higher mean pre-test probability of coronary artery disease (CAD), and had higher prevalence of diabetes (18.4% vs. 13.6%, p < 0.001), hypertension (55.8% vs. 38.7%, p < 0.001), and smoking (36.7% vs. 25.4%, p = 0.03) than those without events. These patients were also more likely to have a positive exercise electrocardiogram (ECG) (15.6% vs. 8.6%, p < 0.001) or not have a diagnostic exercise test because of an inconclusive result or inability to exercise (60.5% vs. 28.6%, p < 0.001). Cox multivariate regression analysis showed that age (hazard ratio, HR 1.03, p < 0.001), pre-test probability of CAD (HR 1.08, p = 0.04), positive exercise ECG (HR 2.94, p < 0.001), and an inconclusive test or inability to exercise (HR 3.45, p < 0.001) were independent predictors of events.

CONCLUSIONS

In patients with recent onset suspected cardiac chest pain, not having a diagnostic exercise ECG because of an inconclusive test or inability to exercise is an independent predictor of events and has similar prognostic implications to a positive exercise ECG. In addition, pre-test probability estimation at baseline is a robust indicator of clinical outcome. Future models of care need to incorporate early and increased access to non-exercise cardiac imaging techniques in order to meet the needs of this high-risk subgroup of patients.