Prognostic Value of Non-Obstructive and Obstructive Coronary Artery Disease Detected by Coronary Computed Tomography Angiography To Identify Cardiovascular Events
Background—The contribution of plaque extent to predict cardiovascular (CV) events among patients with non-obstructive and obstructive coronary artery disease (CAD) is not well defined. Our objective was to evaluate the prognostic value of plaque extent detected by coronary computed tomography (CTA).
Methods and Results—All consecutive patients without prior CAD referred for coronary CTA to evaluate for CAD were included. Exam findings were classified as normal, non-obstructive (<50% stenosis) or obstructive (≥50%). Based on the number of segments with disease, extent of CAD was classified as non-extensive (≤4 segments) or extensive (>4 segments). The cohort included 3242 patients followed for the primary outcome of cardiovascular (CV) death or myocardial infarction (MI) for a median of 3.6 (2.1 - 5.0) years. In a multivariable analysis, the presence of extensive non-obstructive CAD (HR 3.1, 95% confidence interval (CI):1.5-6.4); non-extensive obstructive (HR 3.0, 95%CI: 1.3-6.9) and extensive obstructive CAD (HR:3.9, 95%CI:2.2-7.2) were associated with an increased rate of events, while non-extensive non-obstructive CAD was not. The addition of plaque extent to a model that included clinical probability as well as the presence and severity of CAD improved risk prediction.
Conclusions—Among patients with non-obstructive CAD, those with extensive plaque experienced a higher rate CV death or MI, comparable to those who have non-extensive obstructive disease. Even among patients with obstructive CAD, greater extent of non-obstructive plaque was associated with higher event rate. Our findings suggest that regardless whether obstructive or non-obstructive disease is present, the extent of plaque detected by coronary CTA enhances risk assessment.
- Received August 20, 2013.
- Accepted February 5, 2014.