Absence of chest pain and long-term mortality in patients with acute myocardial infarction.

Objective: Chest pain is the predominant symptom in patients with acute myocardial infarction (AMI). A lack of chest pain in patients with AMI is associated with higher in-hospital mortality, but whether this outcome is sustained throughout the first years after onset is unknown. Therefore, we aimed to investigate long-term mortality in patients hospitalised with AMI presenting with or without chest pain.

Methods: All AMI cases registered in the SWEDEHEART registry between 1996 and 2010 were included in the study. In total, we included 172 981 patients (33.5% women) with information on symptom presentation.

Results: Patients presenting without chest pain (12.7%) were older, more often women and had more comorbidities, prior medications and complications during hospitalisation than patients with chest pain. Short-term and long-term mortality rates were higher in patients without chest pain than in patients with chest pain: 30-day mortality, 945 versus 236/1000 person-years; 5-year mortality, 83 versus 21/1000 person-years in patients <65 years. In patients ≥65 years, 30-day mortality was 2294 versus 1140/1000 person-years; 5-year mortality, 259 versus 109/1000 person-years. In multivariable analysis, presenting without chest pain was associated with an overall 5-year HR of 1.85 (95% CI 1.81 to 1.89), with a stronger effect in younger compared with older patients, as well as in patients without prior AMI, heart failure, stroke, diabetes or hypertension.

Conclusion: Absence of chest pain in patients with AMI is associated with more complications and higher short-term and long-term mortality rates, particularly in younger patients, and in those without previous cardiovascular disease.