Patients with acute coronary syndrome and nonobstructive coronary artery disease in the real world are markedly undertreated.

OBJECTIVES

We assessed the clinical profile of patients with acute coronary syndrome (ACS) and nonobstructive coronary artery disease (CAD) in a real world setting, focusing on pattern of care and on prognosis.

METHODS

Each nonobstructive CAD (<50% stenosis in any epicardial coronary artery) patient was matched with an obstructive CAD patient; adjusted estimates of prescription of guideline-recommended drugs at discharge and of long-term prognosis were evaluated.

RESULTS

Among 2995 consecutive ACS patients who underwent coronary angiography, 125 (4.2%) had nonobstructive CAD. Nonobstructive CAD patients had significantly lower odds of receiving aspirin [odds ratio (OR) 0.31, 95% confidence interval (CI): 0.14-0.68], thienopyridines (OR 0.01, 95% CI: 0.00-0.07), statins (OR 0.31, 95% CI: 0.17-0.58), beta-blockers (OR 0.32, 95% CI: 0.17-0.63) and angiotensin converting enzyme-inhibitors /angiotensin receptor blockers (OR 0.36, 95% CI: 0.17-0.91) compared with matched patients. During a 3-year follow-up, nonobstructive CAD patients had significantly fewer cardiovascular deaths and myocardial infarctions but numerically more episodes of unstable angina.

CONCLUSIONS

The prevalence of nonobstructive CAD appears lower (4.2%) compared with published data. After extensive adjustment, patients with nonobstructive CAD were significantly less likely to be treated with guideline-recommended therapy, including aspirin and statins. Multicenter prospective studies targeting this specific population and the potential benefit of guideline-recommended therapies appear warranted.