All-Cause Mortality Following an Acute Coronary Syndrome: 12-Year Follow-Up of the Comprehensive 2002 New Zealand Acute Coronary Syndrome Audit

Background: To describe the long-term mortality of a complete national cohort of acute coronary syndrome (ACS) patients enrolled in 2002, to compare this with a national age, sex and Māori ethnicity matched population, and to assess the influence of baseline factors on the 12-year mortality.

Methods: We reviewed 721 patients with a discharge diagnosis of an ACS who were enrolled in the first New Zealand ACS audit group cohort over 14days in May 2002. We matched the cohort to the national mortality database using each patient's unique national identity number.

Results: Over a median follow-up of 12.7 years of 721 patients discharged with an ACS, overall mortality was 52%: ST-elevation myocardial infarction (STEMI) (58%), non-ST-elevation myocardial infarction (NSTEMI) (61%) and unstable angina pectoris (UAP) (42%) patients, p<0.0001. In an age-adjusted survival model, males had a 29% increased mortality rate compared to females with a hazard ratio of 1.29 (95% CI 1.04, 1.61, p=0.019). Over 12 years there were 339 (47%) deaths, compared to 284 (39%) deaths observed in the matched population. The standardised mortality ratio for patients admitted with an ACS in New Zealand is 1.3 (95% CI 1.2, 1.5) with eight patients per 100 not surviving to 12 years compared to this matched population.

Conclusions: The high mortality rate in this ACS cohort is a stark reminder of the prognostic implications of a presentation with an ACS. It emphasises the on-going need for optimal management of these patients throughout every stage of their initial treatment and subsequent on-going care.