The Prognostic Value of Residual Coronary Stenoses After Functionally Complete Revascularization

Abstract

Background: The residual SYNTAX score (RSS) and SYNTAX revascularization index (SRI) quantitatively assess angiographic completeness of revascularization for patients with multivessel coronary artery disease. Whether residual angiographic disease remains of prognostic importance after "functionally" complete revascularization with fractional flow reserve (FFR) guidance is unknown.

Objectives: This study sought to investigate the prognostic value of the RSS and SRI after FFR-guided functionally complete revascularization.

Methods: From the FFR-guided percutaneous coronary intervention (PCI) cohort of the FAME (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation) trial, the RSS and SRI were calculated in 427 patients after functionally complete revascularization. The RSS was defined as the SYNTAX score (SS) recalculated after PCI. The SRI was calculated as: 100 × (1 - RSS/baseline SS) (%). We compared differences in 1- and 2-year outcomes among patients with RSS of 0, >0 to 4, >4 to 8, and >8, and with SRI of 100%, 50% to <100%, and 0 to <50%.

Results: The mean baseline SS, RSS, and SRI were 14.4 ± 7.2, 6.5 ± 5.8, and 55.1 ± 32.5%, respectively. Major adverse cardiac events (MACE) at 1 year occurred in 53 patients (12.4%). Patients with MACE had higher SS than those without (18.0 [interquartile range (IQR): 11.0 to 21.0] vs. 12.0 [IQR: 9.0 to 18.0], p = 0.001), but had similar RSS and SRI after PCI (RSS: 6.0 [IQR: 3.0 to 10.0] vs. 5.0 [IQR: 2.0 to 9.5], p = 0.51 and SRI: 60.0% [IQR: 40.9% to 78.9%] vs. 58.8% [IQR: 26.7% to 81.8%], p = 0.24, respectively). Kaplan-Meier analysis showed similar 1-year incidence of MACE with RSS/SRI stratifications (log-rank p = 0.55 and p = 0.54, respectively). Results were similar with 2-year outcome data analysis.

Conclusions: After functionally complete revascularization with FFR guidance, residual angiographic lesions that are not functionally significant do not reflect residual ischemia or predict a worse outcome, supporting functionally complete, rather than angiographically complete, revascularization. (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation [FAME]; NCT00267774).

Keywords: SYNTAX revascularization index; fractional flow reserve; multivessel revascularization; residual SYNTAX score.