Abstract 12776: Non-ST-segment Elevation Acute Coronary Syndromes Patients without Angiographically Detected Obstructive Coronary Artery Disease are Low-risk but Not No-risk: A Meta-analysis of 8 Trials of 37,101 Patients
Background: Characteristics and outcomes of patients (pts) with non-ST-segment elevation acute coronary syndromes (NSTE ACS) but without angiographic evidence of obstructive coronary artery disease (CAD) are poorly defined. Imaging and histopathology show that extent of luminal obstruction does not reliably reflect atheromatous disease in the vascular wall. Further, ACS may result from erosion or rupture (+/− vasospasm) of angiographically trivial lesions that provoke thrombus formation and fragment distally.
Methods: To elucidate characteristics and outcomes of NSTE ACS pts with non-obstructive CAD (<50% stenosis in any artery), we performed a meta-analysis of 8 randomized trials (n=37,101 pts: GUSTO IIb, PURSUIT, PARAGON A, PARAGON B, SYNERGY, PRISM, PRISM-PLUS, EARLY ACS). The odds ratio (OR) for each trial was adjusted for age, enrolling myocardial infarction (MI), prior percutaneous coronary intervention, prior MI, sex, weight, diabetes, systolic blood pressure.
Results: Overall, 10.4% of pts had non-obstructive CAD (28.7% single vessel; 26.1% double vessel; 34.9% triple vessel). Those without significant disease (n=3685) were younger (median 62.0 vs 65.7 yrs), more often female (54.7 vs 29.4%) and had less diabetes (15.7 vs 26.3%), smoking (24.1 vs 27.1%), prior MI (15.9 vs 31.7%) than those with CAD. 41.1% (vs 63.3%) of pts with no CAD had elevated cardiac markers on presentation, and 40.3% (vs 52.9%) had ECG changes. By 30 days, 0.6% died (vs 2.8%), 1.7% had MI (vs 11.7%), and 2.8% had death, MI, or recurrent ischemia prompting urgent revascularization (RI; vs 18.7%). Adjusted OR (95% confidence intervals) for death/MI/RI (obstructive vs non-obstructive CAD) are in the figure.
Conclusions: Patients with angiographically non-obstructive CAD have a low, but important, rate of death, MI, and recurrent ischemia within 30 days of presentation and warrant attention to secondary prevention measures.
- © 2010 by American Heart Association, Inc.