Outcomes among non-ST-segment elevation acute coronary syndromes patients with no angiographically obstructive coronary artery disease: observations from 37,101 patients

Abstract

Aims: Limited data exist concerning outcomes of patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) with no angiographically obstructive coronary artery disease (non-obstructive CAD). We assessed the frequency of clinical outcomes among patients with non-obstructive CAD compared with obstructive CAD.

Methods and results: We pooled data from eight NSTE ACS randomized clinical trials from 1994 to 2008, including 37,101 patients who underwent coronary angiography. The primary outcome was 30-day death or myocardial infarction (MI). Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for 30-day death or MI for non-obstructive versus obstructive CAD were generated for each trial. Summary ORs (95% CIs) across trials were generated using random effects models. Overall, 3550 patients (9.6%) had non-obstructive CAD. They were younger, more were female, and fewer had diabetes mellitus, previous MI or prior percutaneous coronary intervention than patients with obstructive CAD. Thirty-day death or MI was less frequent among patients with non-obstructive CAD (2.2%) versus obstructive CAD (13.3%) (OR(adj) 0.15; 95% CI, 0.11-0.20); 30-day death or spontaneous MI and six-month mortality were also less frequent among patients with non-obstructive CAD (OR(adj) 0.19 (0.14-0.25) and 0.37 (0.28-0.49), respectively).

Conclusion: Among patients with NSTE ACS, one in 10 had non-obstructive CAD. Death or MI occurred in 2.2% of these patients by 30 days. Compared with patients with obstructive CAD, the rate of major cardiac events was lower in patients with non-obstructive CAD but was not negligible, prompting the need to better understand management strategies for this group.

Trial registration: ClinicalTrials.gov NCT00089895.

Keywords: Acute coronary syndromes; angiography; atherosclerosis; coronary disease; infarction.

Conflict of interest statement

Conflict of interest: GMDF: consulting fees and lecture fees from Merck & Co., Inc. KAAF: research support from Sanofi-aventis, Bristol-Myers Squibb, Eli Lilly and Co., and Bayer Corporation. JAW: no relationships to disclose; RPG: consulting fees from Sanofi-aventis; lecture fees from Bristol-Myers Squibb and Sanofi-aventis; research grant support, advisory board, and honoraria from Merck/Schering-Plough, Inc.; and research support from Daiichi-Sankyo, Inc. PTr: advisory board for and receiving research funding from Merck & Co., Inc. HRR: no relationships to disclose. JSH: advisory board for Merck/Schering-Plough and Eli Lilly and Co. CMG: research support from Merck/Schering-Plough. PTh: research support from Schering-Plough (now Merck and Co., Inc.); serving on the advisory board for Sanofi-aventis, Bristol-Myers Squibb, AstraZeneca, and Boehringer Ingelheim; and receiving speaker fees from Schering-Plough, Sanofi-aventis, and AstraZeneca. RAH: research funding from Schering-Plough (now Merck and Co., Inc.) for the EARLY ACS trial. A complete listing of RAH’s relationships with industry is available at https://dcri.org/about-us/conflict-of-interest. FVW: research funding from Merck/Schering-Plough. HDW: research funding from Merck/Schering-Plough. RMC: research funding from Schering-Plough (now Merck and Co., Inc.) for the EARLY ACS trial. A complete listing of RMC’s relationships with industry is available at https://dcri.org/about-us/conflict-of-interest. LKN: research funding from Schering-Plough (now Merck & Co., Inc.) through Duke University for the EARLY ACS trial and from Merck and Co., Inc. in support of the analysis for this manuscript. A complete listing of LKN’s relationships with industry is available at https://dcri.org/about-us/conflict-of-interest.