National assessment of early β-blocker therapy in patients with acute myocardial infarction in China, 2001-2011: The China Patient-centered Evaluative Assessment of Cardiac Events (PEACE)-Retrospective AMI Study

Background: Since 2007, clinical practice guidelines have recommended β-blocker therapy early in the course of acute myocardial infarction (AMI) for patients who are not at high risk for complications. Our objective was to perform a national quality assessment of early β-blocker use during hospitalization for AMI over the past decade in China.

Methods: We conducted medical record review of a nationally representative sample of patients admitted to Chinese hospitals with AMI and studied those without absolute contraindications to β-blocker therapy in 2001, 2006, and 2011. We evaluated the use, type, and dose of β-blockers within the first 24 hours of admission over time and identified predictors of not using this treatment both in ideal candidates and in those with risk factors for cardiogenic shock.

Results: Among 14,241 patients with AMI (representing 43,165 patients in 2001, 106,167 patients in 2006, and 221,874 patients in 2011 in China, respectively), 45.1% had no contraindications to early β-blocker therapy; 21.1% had risk factors for cardiogenic shock but no absolute contraindication. β-blocker use in ideal patients was 54.3% in 2001, 67.8% in 2006, and 61.8% in 2011 (P = .28 for trend). Predictors of nontreatment were older age, lower systolic blood pressure, lower heart rate, absence of chest discomfort, and admission to a nonteaching hospital. Use in patients with risk factors for cardiogenic shock was 42.6% in 2001, 59.5% in 2006, and 52.9% in 2011 (P = .31 for trend). Metoprolol was used most frequently (91.5%), but dosages were often below those recommended in guidelines.

Conclusions: The use of early β-blocker therapy for patients with AMI in China is suboptimal, with underuse in patients who could benefit and substantial use among those who might be harmed. Patterns of use have not changed over time, thus creating an important target of efforts to improve quality of care for AMI.