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.