Increases in early discharge following acute coronary syndrome hospitalisations and associated clinical outcomes in New Zealand between 2006 and 2015: ANZACS-QI-43 study.

Background: International guidelines recommend early discharge for uncomplicated acute coronary syndrome (ACS) patients within 3 days; however, there is a paucity of contemporary literature regarding the safety of this strategy.

Aims: To report the trends in the proportion of ACS hospitalisations discharged within 3 days and their outcomes in New Zealand.

Methods: ACS hospitalisations 2006-2015 using national routinely collected data were categorised by length of stay (LOS) into ≤3, 4-5 and >5 days, excluding deaths during the index admission. Trend analysis of death, cardiovascular and bleeding events and their composites (net adverse clinical events) at 30-day and 1-year post-discharge were performed using generalised linear mixed regression models adjusting for covariates by LOS subgroups.

Results: Among 130 037 ACS hospitalisations, LOS ≤ 3 days increased from 32% in 2006 to 44% in 2016. This trend was observed for all demographics, ACS subtypes and management strategies. Event rates at 30 days and 1 year were the lowest for the LOS ≤3 days subgroup (all-cause mortality 1.6% and 9.1% respectively). Thirty-day and 1-year all-cause mortality rates were unchanged over time for this subgroup (adjusted odds ratio (95% confidence interval) of 1.011 (0.985-1.038) and 0.991 (0.979-1.003)), while net adverse clinical event rates significantly decreased (0.962 (0.950-0.973) and 0.972 (0.964-0.980) respectively).

Conclusion: There was a substantial increase in early discharge post-ACS over 10 years. These patients were associated with reduction in adverse clinical events up to 1 year and no increase in all-cause mortality. These findings from a comprehensive national register suggest that guideline recommendations on early discharge after uncomplicated ACS are safe and appropriate.