Meta-analysis of prognostic implications of dyspnea versus chest pain in patients referred for stress testing.

Previous studies have suggested that patients with dyspnea referred for stress testing have high mortality. However, it is not clear whether this is explained by high rates of ischemia. The aim of the present study was to evaluate the incidence of ischemia in patients with dyspnea compared with patients with chest pain referred for stress testing and assess the outcomes of such patients. We systematically searched the electronic databases, MEDLINE, PubMed, EMBASE, and the Cochrane Library, until December 2012 to identify studies of patients with known or suspected coronary artery disease undergoing stress testing. We extracted data on group-specific incidence of stress-induced ischemia and all-cause mortality. In our analyses, we identified and included 6 studies that evaluated a total of 5,753 patients with dyspnea and 24,491 patients with chest pain as the clinical indication for stress testing. There was no statistically significant difference in the incidence of ischemia on stress imaging in patients with dyspnea compared with patients with chest pain (37.4% vs 30.2%, odds ratio 1.43, 95% confidence interval 0.99 to 2.06, p = 0.06). However, during the follow-up period, patients with dyspnea had higher all-cause mortality rates compared with patients with chest pain (annual mortality 4.9% vs 2.3%), with odds ratio of 2.57 (95% confidence interval 1.75 to 3.76, p <0.001). In conclusion, in patients undergoing stress testing, those evaluated for dyspnea had a significant increase in all-cause mortality but did not have higher rates of ischemia compared with patients presenting with chest pain. Clinicians evaluating patients with self-reported dyspnea should be aware that these patients represent a high-risk group with increased risk of mortality.