Guideline Adherence After ST-Segment Elevation Versus Non-ST Segment Elevation Myocardial Infarction

Abstract

Clinical guidelines recommend similar medical therapy for patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation MI (NSTEMI). Using the Get with the Guidelines-Coronary Artery Disease registry (GWTG-CAD), we analyzed data including 72 352 patients (48 966, NSTEMI; 23 386, STEMI) from 237 US sites between May 1, 2006 and March 21, 2010. Performance and quality measures were compared between NSTEMI and STEMI patients. NSTEMI patients were older and had a higher rate of medical comorbidities compared with STEMI patients, including prior coronary artery disease (38.5% versus 24.7%; P<0.0001), heart failure (17.5% versus 6.2%; P<0.0001), hypertension (70.8% versus 59.1%; P<0.0001) and diabetes mellitus (34.9 versus 23.3%; P<0.0001). Adjusting for confounding variables, STEMI patients were more likely to receive aspirin within 24 hours 98.5% versus 97.1% (adjusted odds ratio [AOR], 1.63; 95% confidence interval [CI], 1.32-2.02), be discharged on aspirin 98.5% versus 97.3% (AOR, 1.33; 95% CI, 1.19-1.49), β-blockers 98.2% versus 96.9% (AOR, 1.48; 95% CI, 1.35-1.63), or lipid-lowering medication for low-density lipoprotein level >100 mg/dL 96.8% versus 91.0% (AOR, 1.85; 95% CI, 1.61-2.13). STEMI patients were also more likely to receive β-blockers within 24 hours of hospital arrival 93.9% versus 90.8% (AOR, 1.57; 95% CI, 1.37-1.79) and the following discharge medications: angiotensin-converting enzyme inhibitors or angiotensin receptor blocking agents 85.3% versus 77.4% (AOR, 1.62; 95% CI, 1.51-1.75), clopidogrel 85.6% versus 67.0% (AOR, 2.42; 95% CI, 2.23-2.61) or lipid-lowering medications 94.8% versus 88.0% (AOR, 1.71; 95% CI, 1.56-1.86). Among hospitals participating in GWTG-CAD, adherence with guideline-based medical therapy was high for patients with both STEMI and NSTEMI. Yet, there is still room for further improvement, particularly in the care of NSTEMI patients.