Acute coronary syndromes without typical chest pain: the role of comorbidities

Background: Not all patients exhibit the classic symptoms of chest pain. Patients who present with acute coronary syndrome (ACS) without typical chest pain have a very high in-hospital mortality. Purpose: To investigate the impact of atypical symptoms on management and outcomes of ACS patients. Methods: Between 2010 and 2016, 11458 ACS patients were admitted at 57 hospitals included in the network of the ISACS-TC registry (ClinicalTrials.gov, NCT01218776). Of these patients 8.7% did not have typical chest pain at the initial evaluation. Results: More women (10.5%) than men (7.8%) exhibit ACS without typical presentation. ACS patients with atypical presentation were older (67.8±12.2 vs 62.9±12.1, p<0.001). Patients with comorbidities were not equally distributed: 38.7% were with typical presentation and 55.2% without typical presentation, (p<0.001). The probability of having ACS without typical presentation was greater as the number of comorbidities increased (OR: 1.64 for one comorbid; OR: 2.52 for two comorbidities; and OR: 4.57 for three or more comorbidities). Stepwise logistic analysis showed that the absence of ST elevation (OR 2.98), Killip class ≥2 (OR 2.12, history of stroke (OR 1.78), peripheral artery disease (OR 1.68), chronic kidney disease (OR 1. 56), diabetes mellitus (OR 1.36), age (OR 1.02 per year) were all independent predictors of ACS without typical presentation. Conversely smoking habit (OR 0.75) and hypercholesterolemia (OR 0.72) had protective effect (p<0.01). In-hospital mortality rate was much higher in patients without typical presentation than in patients with the typical presentation (15.5% versus 6.3%, p<0.001). The presence of atypical presentation increased the risk of death either in non ST segment elevation acute coronary syndrome (NSTE-ACS) (OR 2.57, 95% CI 1.91–3.47) or ST segment elevation myocardial infarction (STEMI) patients (OR 3.48, 95% CI 2.70–4.49). The presence of comorbidities was also independently associated with an increased risk of death, both in NSTE ACS (OR 2.24, 95% CI 1.70–2.93) and in STEMI (OR 2.22, 95% CI 1.56–2.63) patients. Conclusions: Patients with ACS who present without typical chest pain are at increased risk of dying. Atypical presentation is frequently found in patients with comorbidities. The unfavorable outcomes of ACS without chest pain may be partly attributable to concomitant diseases.