Anatomical and functional concordance in assessing coronary artery disease complexity

Background Coronary artery disease (CAD) complexity can be assessed anatomically and by physiology. The contemporary use of coronary physiology allows for longitudinal functional evaluation for identifying diffuse disease. Purpose This study aimed to evaluate the agreement between anatomical and functional CAD complexity. Methods This prospective multicentre study included patients with at least one hemodynamically significant CAD confirmed by fractional flow reserve (FFR) ≤ 0.80 and scheduled for percutaneous coronary intervention (PCI). Pullback pressure gradient (PPG) was calculated using manual FFR pullbacks, and predominant focal and diffuse disease were categorized based on the median PPG value. The complexity of CAD was assessed using the SYNTAX score (SS). Completeness of revascularization (CR) was quantified by the residual SYNTAX score (rSS) and was defined as a post-PCI rSS of 0. Results Among 1004 enrolled patients, 820 underwent PCI, predominantly presenting stable angina (90%) and single-vessel disease (69%). The average age was 67.9 years, 75% were male, and 29% had diabetes. The mean SS was 11.9 ± 7.6, and the mean rSS was 2.3 ± 4.4. The mean FFR and PPG were 0.67 ± 0.12 and 0.64 ± 0.15. Patients with diffuse disease (PPG < 0.62) had higher SS (13.8 ± 7.9 vs 10.2 ± 6.9, p < 0.001) and rSS (2.5 ± 4.3 vs 2.0 ± 4.5, p = 0.018) compared to those with high PPG. CR rates were significantly lower in patients with low PPG compared to high PPG (28% vs 36%, p = 0.018). PPG was significantly correlated with SS (r = -0.29, 95% CI: -0.35 to -0.022, p < 0.001). PPG was independently associated with the SS (p < 0.001). Conclusions Anatomical disease complexity measured by the SYNTAX score is associated with functional diffuse disease defined by the PPG. Patients with focal disease (high PPG) achieved higher rates of complete revascularization compared to those with diffuse disease (low PPG).