Twenty-year trends in incidence and 1-year mortality in Swedish patients hospitalised with non-AMI chest pain. Data from 1987-2006 from the Swedish hospital and death registries

OBJECTIVE: To study trends for 20 years in incidence and 1-year mortality in hospitalised patients who received a diagnosis of either angina or unexplained chest pain (UCP) in Sweden. DESIGN AND SETTING: Register study of all patients aged 25-84 years identified from the Swedish National Hospital Discharge Register who were hospitalised with a first-time diagnosis of UCP or angina pectoris during 1987 to 2006. PARTICIPANTS: A total of 378 454 patients, 235 855 with UCP and 142 599 with angina. MAIN OUTCOME MEASURES: 1-Year mortality and standardised mortality ratios (SMRs). RESULTS: From the period 1987-1991 to 2002-2006, the observed 1-year mortality rate in men and women with UCP aged 25-74 years decreased from 2.19% to 1.45% and from 1.85% to 0.91%, respectively. SMRs decreased from 1.67 (95% CI 1.39 to 1.95) and 1.63 (1.27 to 2.00) to 1.09 (0.96 to 1.23) and 0.88 (0.75 to 1.00). Corresponding decreases in 1-year mortality for a discharge diagnosis of angina were from 6.50% to 2.49% in men and from 4.80% to 1.68% in women, with SMRs decreasing from 2.69 (2.33-3.05) and 2.59 (2.06-3.12) to 1.09 (0.93-1.25) and 1.05 (0.81-1.29), respectively. Similar changes occurred in patients aged 75-84 years. Only men with UCP aged 75-84 years still retained a slightly increased mortality (SMR 1.14 (1.01-1.28)). CONCLUSIONS: The prognosis of patients admitted with chest pain in which acute myocardial infarction has been ruled out has improved for the past 20 years, such that the 1-year mortality of these patients is now similar to that in the general population.