Prognostic Impact of Residual Anatomic Disease Burden After Functionally Complete Revascularization

Background: Prognostic impact of residual anatomic disease burden after functionally complete percutaneous coronary intervention (PCI), defined by post-PCI fractional flow reserve (FFR) >0.80 would be a clinically relevant question. The current study evaluated clinical outcomes at 2 years according to residual Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery (SYNTAX) score (RSS) in patients who underwent functionally complete revascularization. Methods: A total of 1910 patients (2095 revascularized vessels) with post-PCI FFR >0.80 were selected from the International Post-PCI FFR Registry. RSS was defined as the SYNTAX score recalculated after PCI, SYNTAX revascularization index was calculated as 100×(1-RSS/pre-PCI SYNTAX score), and post-PCI FFR was measured after completion of PCI. The primary outcome was target vessel failure (TVF; a composite of cardiac death, target vessel-related myocardial infarction, and clinically driven target vessel revascularization) at 2 years, and risk of TVF was compared according to tertile classification of RSS (0, 1-5, and >5) and post-PCI FFR (≥0.94, 0.87-0.93, and ≤0.86). Results: After PCI, SYNTAX score was changed from 10.0 (Q1-Q3, 7.0-16.0) to 0.0 (Q1-Q3, 0.0-5.0) and FFR changed from 0.70±0.12 to 0.90±0.05. TVF at 2 years occurred in 4.9%, and patients with TVF showed higher pre-PCI SYNTAX score and lower post-PCI FFR than those without. However, there were no significant differences in SYNTAX revascularization index and RSS. The risk of TVF was not different according to tertile of RSS (log-rank P=0.851). Conversely, risk of TVF was different according to tertile of post-PCI FFR (log-rank P=0.009). Multivariable model showed the risk of TVF was significantly associated with post-PCI FFR (hazard ratio, 1.091 [95% CI, 1.032-1.153]; P=0.002) but not with RSS (hazard ratio, 0.969 [95% CI, 0.898-1.045]; P=0.417). Conclusions: Among patients who underwent functionally complete revascularization, residual anatomic disease burden assessed by RSS was not related with occurrence of TVF at 2 years. These results support the importance of functionally complete revascularization rather than angiographic complete revascularization. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT04012281.