Coronary Computed Tomography Angiography Alone Versus Confirmatory Functional Testing for Guiding Treatment Strategy for Patients With Intermediate Coronary Artery Stenosis

• We compare 2 strategies for intermediate stenosis detected on coronary CTA.
• CTA-alone–based 1-step strategy causes invasive catheterization and intervention.
• Functional testing in addition to coronary CTA stops unnecessary revascularization.
• Functional testing in addition to coronary CTA improves clinical outcomes.
• Two-Step strategy with functional testing might be more proper management strategy.

Intermediate coronary artery stenosis (≥50% and <90%) on coronary computed tomography angiography (CTA) is usually considered as a significant lesion. However, anatomical diagnosis is not well correlated with the functional significance of myocardial ischemia. We investigated whether functional testing in addition to coronary CTA improves outcomes of patients with intermediate stenosis, compared with the 1-step CTA-alone–based strategy. From 2006 to 2011, we consecutively enrolled 335 patients with chest pain with intermediate stenosis detected by an initially performed coronary CTA. Of these, 159 patients followed the 1-step strategy, whereas 176 followed the 2-step strategy with confirmatory functional tests. One-year follow-up data were obtained for all patients. The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, and repeated or delayed revascularization (major adverse cardiac event) within a year. Baseline clinical parameters were comparable between patients of the 2 different strategies. The rate of invasive catheterization or percutaneous intervention was 75.5% in the 1-step group and 35.2% in the 2-step group (p <0.001). Consequently, more patients in the 2-step group were medically treated without unnecessary revascularization compared with patients in the 1-step group (71.0% vs 40.9%, p <0.001). Only 2.5% of the patients who received medical treatment in the 2-step group finally received delayed revascularization, whereas 14% in the 1-step group did. Overall, the primary end point occurred in 11.3% in the 1-step group and 4.0% in the 2-step group (p = 0.011). In conclusion, confirmatory functional testing reduces invasive catheterization and coronary intervention and improves clinical outcomes in patients with intermediate stenosis on coronary CTA.