Ayman El-Menyar, Mohammad Zubaid, Kadhim Sulaiman, Wael AlMahmeed, Rajvir Singh, Alawi A Alsheikh-Ali, Jassim Al Suwaidi

Background:
Patients with acute coronary syndrome (ACS) frequently present with typical chest pain; however a considerable proportion may present with atypical symptoms.

Objective:
The purpose of this study was to evaluate the prognostic value of different presenting symptoms in ACS patients.

Methods:
Over a 5-month period in 2007, 6704 consecutive patients presenting with ACS were enrolled and categorized into three groups according to their presenting symptom (typical chest pain, atypical chest pain, and dyspnea). Data were collected from a prospective, multicenter, multinational, observational study from 6 countries. The baseline characteristics, therapy, and in-hospital outcomes were analyzed and compared in the three groups.

Results:
In comparison to typical chest pain, patients with atypical pain or dyspnea were older and had more cardiovascular risk factors. These two groups were significantly less likely to receive evidence-based therapy and coronary angiography and suffered worse in-hospital outcomes. The mortality rates were 3%, 2.5%, and 6% in patients presenting with typical, atypical chest pain, and dyspnea, respectively. After adjustment for confounders, the absence of typical chest pain was associated with higher mortality rate (odds ratio 2.0, 95% confidence intervals 1.29-2.75).

Conclusions:
Across ACS, patients presenting without chest pain were frequently underestimated, less well treated with evidence-based therapy, and had worse in-hospital outcomes. Clinical presentation of ACS may provide additional prognostic impact particularly in high-risk populations.