Acute coronary syndromes without chest pain, an underdiagnosed and undertreated high-risk group - Insights from the Global Registry of Acute Coronary Events

Study objectives: The clinical manifestations of acute coronary syndromes (ACSs) vary, and patients present frequently with symptoms other than chest pain. In this analysis, a large contemporary database has been accessed to define the frequency, clinical characteristics, and outcomes of patients presenting without chest pain across different diagnostic categories of ACS. Design and setting: The Global Registry of Acute Coronary Events is a multinational, prospective, observational study involving 14 countries. Patients: Patients presenting to the hospital with a suspected ACS were stratified according to whether their predominant presenting symptoms included chest pain (ie, typical) or did not (ie, atypical). Demographics, medical history, hospital management, and outcomes were compared. Measurements and results: Of the 20,881 patients in this analysis, 1,763 (8.4%) presented without chest pain, 23.8% of whom were not initially recognized as having an ACS. They were less likely to receive effective cardiac medications, and experienced greater hospital morbidity and mortality (13% vs 4.3%, respectively; p < 0.0001) than did patients with typical symptoms. After adjusting for potentially confounding variables, increased hospital mortality rates were noted in patients with dominant presenting symptoms of presyncope/syncope (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.4 to 2.9), nausea or vomiting (OR, 1.6; 95% CI, 1.1 to 2.4), and dyspnea (OR, 1.4; 95% CI, 1.1 to 1.9), and in those with painless presentations of unstable angina (OR, 2.2; 95% CI, 1.4 to 3.5) and ST-segment elevation myocardial infarction (OR, 1.7; 95% CI, 1.2 to 2.2). Conclusion: Patients with ACSs who present without chest pain are frequently misdiagnosed and undertreated. With the exception of diaphoresis, each dominant presenting symptom independently identifies a population that is at increased risk of dying. These patients experience greater morbidity and a higher mortality across the spectrum of ACSs.