Improved clinical outcome after acute myocardial infarction in hospitals participating in a Swedish quality improvement initiative.

BACKGROUND: The Swedish quality improvement initiative Quality Improvement in Coronary Care previously demonstrated significant improvements in caregiver adherence to national guidelines for acute myocardial infarction. The associated impact on 1-year clinical outcome is presented here. METHODS AND
RESULTS: During the baseline period July 2001 to June 2002, 6878 consecutive acute myocardial infarction patients <80 years were included at the 19 intervention and 19 control hospitals and followed for a mean of 12 months. During the postintervention period of May 2003 to April 2004, 6484 patients were included and followed in the same way. From baseline to postintervention, improvements in mortality and cardiovascular readmission rates (events per 100 patient-years) were significant in the intervention group (-2.82, 95% CI -5.26 to -0.39; -9.31, 95% CI -15.48 to -3.14, respectively). However, in the control hospitals, there were no significant improvements (0.04, 95% CI -2.40 to 2.47; -4.93, 95% CI -11.10 to 1.24, respectively). Bleedings in the control group increased in incidence (0.92, 95% CI 0.41 to 1.43), whereas the incidence remained unchanged in the intervention group (0.07, 95% CI -0.44 to 0.58). When the difference of changes between the study groups were evaluated, the results still were in favor of the intervention group, albeit significant only for bleeding complications (mortality: -2.70, 95% CI -6.37 to 0.97; cardiovascular readmissions: -6.85, 95% CI -16.62 to 2.93; bleeding complications: -0.82, 95% CI -1.66 to 0.01).
CONCLUSIONS: With a systematic quality improvement initiative aiming to increase the adherence to acute myocardial infarction guidelines, it is possible to achieve long-term positive effects on clinical outcome.