Anatomic and Functional Discordance Among Patients With Nonobstructive Coronary Disease
Journal of the American College of Cardiology
Background: Nonobstructive coronary artery disease (CAD) is associated with increased adverse cardiovascular (CV) events. However it is unclear if functional significance, as assessed by fractional flow reserve derived from computed tomography (FFRCT) < 0.80, further stratifies risk among patients with nonobstructive CAD, and what factors contribute to this anatomic-functional discordance (stenosis < 50% and FFRCT < 0.80). Methods: We evaluated patients in the ADVANCE (Assessing Diagnostic Value of Noninvasive FFRCT in Coronary Care) Registry who had exclusively nonobstructive CAD and stratified by FFRCT ≥ 0.80 in all coronary vessels (concordant) versus FFRCT < 0.80 in at least 1 vessel (discordant). Baseline patient demographics, coronary computed tomography angiography findings, downstream testing, and clinical outcomes were compared between groups. Results: Among 1,261 patients with nonobstructive CAD, 543 (43.1%) had FFRCT < 0.80 Patients in the discordant group were older, had more hypertension and hyperlipidemia, and significantly higher indexed left ventricular (LV) mass and significantly lower coronary volume-to-mass ratios when compared with patients in the concordant group (Table 1). Downstream noninvasive testing (stress echo, nuclear stress, and cardiac magnetic resonance imaging [MRI]) was more common among patients with discordance (all P < 0.05), but there were similar rates of positive noninvasive results. Invasive angiography was also more common among patients with discordance (P < 0.0001). Anatomic-functional discordance was associated with higher rates of cardiovascular (CV) hospitalization (15.1% vs 7.1%) and percutaneous coronary intervention (PCI) (5.9% vs 0.8%) (both P < 0.0001), but no significant difference in all-cause death (0.7% vs 0.3%). Conclusion: Anatomic-functional discordance was present in nearly one-half of patients with exclusively nonobstructive CAD. These patients had higher rates of CV risk factors and worse clinical outcomes than those with concordance. The findings of greater LV mass and lower coronary volume: mass ratio suggests that this discordance may be reflective of abnormal coronary physiology at lower thresholds of anatomical stenosis and a marker of increased risk for adverse CV events among patients with nonobstructive CAD.
Rymer J, Takagi H, Lowenstern A, Rabbat M, Fairbairn T, Chinnaiyan K, et al. TCT-86 Anatomic and functional discordance among patients with nonobstructive coronary disease. J Amer Coll Cardiol 2021 Nov 9;78(19S): B 36-7.