Prognostic significance of thermodilution-derived coronary flow capacity in patients with deferred revascularisation

AIMS: The aim of this study was to investigate the prognostic value of thermodilution-derived coronary flow capacity (T-CFC) in patients with stable coronary artery disease and deferred revascularisation. METHODS AND RESULTS: We evaluated 308 lesions in 308 patients with deferred revascularisation, stratifying the cohort according to T-CFC. Ischaemic T-CFC was defined as a composite of mildly, moderately, and severely reduced T-CFC. Clinical outcomes were assessed by vessel-oriented composite endpoints (VOCE) and major adverse cardiac events (MACE). VOCE and MACE occurred in 19 and 28 patients, respectively. Ischaemic T-CFC was found in 88 lesions (28.6%). Kaplan-Meier analysis revealed that lesions with ischaemic T-CFC had a significantly higher risk of both VOCE and MACE. The net reclassification index and integrated discrimination improvement index were both significantly improved when ischaemic T-CFC was added to the clinical risk model (age, sex, prior stent implantation, and lesion length) for predicting VOCE and MACE. Furthermore, ischaemic T-CFC showed significant incremental predictive ability for VOCE and MACE when compared with the clinical risk model + fractional flow reserve ≤0.8, or with the clinical model + coronary flow reserve ≤2.0. CONCLUSIONS: T-CFC categorisation improved the risk stratification for both VOCE and MACE and showed incremental prognostic value in patients with deferred revascularisation.