Introduction and objectives: To investigate the clinical characteristics and treatment of acute coronary syndromes (ACS), and to determine the effects of an early invasive strategy (EIS) in non-ST-elevation ACS (NSTEACS) and of primary percutaneous coronary intervention (PCI) in ST-elevation ACS (STEACS).
Methods: Data were collected prospectively for 9 months during 2004-2005 from 50 hospitals, which were randomly selected according to the level of care provided. In addition, follow-up data on mortality and readmission for ACS were collected for 6 months. The adjusted effects of different reperfusion strategies were analyzed.
Results: After checking data quality, the analysis included data from 32 hospitals, which covered 7923 coronary events (4431 [56%] STEACS, 3034 [38%] NSTEACS and 458 [6%] unclassified ACS) in 7251 patients. Compared with previous studies, the use of primary PCI in STEACS had increased markedly (from 10.7% to 36.8% of patients undergoing reperfusion), as had the use of EIS in NSTEACS (from 11.1% to 19.6%). Overall in-hospital mortality was 5.7% (95% confidence interval [CI], 5.1%-6.2%); for STEACS it was 7.6% (95% CI, 6.7%-8.7%), for NSTEACS 3.9% (95% CI, 3.3%-4.6%), and for unclassified ACS 8.8% (95% CI, 6.2%-12.2%). In the population as a whole, there was no association between prognosis (i.e., 6-month mortality) and EIS in NSTEACS (hazard ratio [HR]=0.94; 95% CI, 0.66-1.3) or between prognosis and primary PCI in STEACS (HR=1; 95% CI, 0.7-1.5). Findings for mortality and rehospitalization for ACS at 6 months were similar.
Conclusions: Data for 2004-2005 demonstrated a marked increase in the use of invasive procedures. However, the procedures employed were poorly matched to the patients' baseline risk.