Background:
As many as 62.4% of patients undergoing elective coronary angiography have no obstructive epicardial coronary artery disease (CAD). These patients have substantial morbidity and are inadequately characterized. Our aim was to identify the prevalence and predictors of the absence of epicardial obstructive CAD and to assess the clinical characteristics of this population.
Methods:
We conducted a retrospective analysis of consecutive patients undergoing index coronary angiography. Patients with known CAD, a history of myocardial infarction, or an emergent indication were excluded, as were those evaluated for transplantation or valvular/cardiac surgery. Obstructive CAD was defined as a stenosis ≥70% (≥50% left main). We performed multivariable logistic regression of clinical variables, peak troponin levels, and stress findings to identify predictors of the absence of obstructive epicardial CAD.
Results:
The study population included 935 patients with median age of 62 years and 10-year ASCVD risk score of 17.7%; 55.6% of the patients were male, 35.1% had diabetes, 77.3% had hypertension, and 67.8% had hyperlipidemia. No obstructive CAD was found in 442 patients (47.3%). Ten variables were independent predictors of the absence of obstructive CAD in a multivariable analysis (Table 1). In the 258 patients who underwent stress imaging, a negative stress ECG (OR 3.1 (1.6-6.0), p<0.001) and absence of ischemia on stress imaging (OR 3.6 (1.9-6.8), p<0.001) were additional independent predictors.
Conclusion:
Despite a cohort with substantial cardiac risk factors and an intermediate median ASCVD risk score, the prevalence of index angiograms without obstructive epicardial CAD was high. Traditional markers of disease were predictors, including positive troponin and stress imaging; however the model was only 78% predictive. Additional research is needed to better characterize patients referred for catheterization without obstructive CAD.
Ratio of lung to heart thallium-201 uptake on exercise and dipyridamole stress imaging in coronary artery disease. Implication of SPECT.
