Long-term outcomes of intermediate coronary stenosis in patients undergoing hemodialysis after deferred revascularization based on fractional flow reserve

Physiological Assessment with iFR prior to FFR Measurement in Left Main Disease

Despite guideline-based recommendation of the interchangeable use of instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) to guide revascularization decision-making, iFR/FFR could demonstrate different physiological or clinical outcomes in some specific patient or lesion subsets. Therefore, we sought to investigate the impact of difference between iFR and FFR-guided revascularization decision-making on clinical outcomes in patients with left main disease (LMD). In this international multicenter registry of LMD with physiological interrogation, we identified 275 patients in whom physiological assessment was performed with both iFR/FFR. Major adverse cardiovascular event (MACE) was defined as a composite of death, non-fatal myocardial infarction, and ischemia-driven target lesion revascularization. The receiver-operating characteristic analysis was performed for both iFR/FFR to predict MACE in respective patients in whom revascularization was deferred and performed. In 153 patients of revascularization deferral, MACE occurred in 17.0% patients. The optimal cut-off values of iFR and FFR to predict MACE were 0.88 (specificity:0.74; sensitivity:0.65) and 0.76 (specificity:0.81; sensitivity:0.46), respectively. The area under the curve (AUC) was significantly higher for iFR than FFR (0.74; 95%CI 0.62-0.85 vs. 0.62; 95%CI 0.48-0.75; p = 0.012). In 122 patients of coronary revascularization, MACE occurred in 13.1% patients. The optimal cut-off values of iFR and FFR were 0.92 (specificity:0.93; sensitivity:0.25) and 0.81 (specificity:0.047; sensitivity:1.00), respectively. The AUCs were not significantly different between iFR and FFR (0.57; 95%CI 0.40-0.73 vs. 0.46; 95%CI 0.31-0.61; p = 0.43). While neither baseline iFR nor FFR was predictive of MACE in patients in whom revascularization was performed, iFR-guided deferral seemed to be safer than FFR-guided deferral.

Prognostic Values of Fractional Flow Reserve Based on Clinical Outcomes in Patients on Chronic Hemodialysis

The fractional flow reserve (FFR) cut-off values of 0.75 or 0.8 have been widely used; however, whether they apply to patients on hemodialysis remains unknown. We aimed to investigate the cut-off value of FFR associated with clinical outcomes in patients on hemodialysis. Using the Japanese multicenter registry, we analyzed data of patients on hemodialysis with measured FFR between January 2010 and December 2016. Survival classification and regression tree analysis for the composite primary outcome of cardiovascular mortality, myocardial infarction, and target vessel revascularization revealed a threshold FFR of 0.83. Multivariate Cox regression analyses were performed for the clinical outcomes. Additionally, the primary outcome was analyzed using propensity score matching by dividing the patients into complete and incomplete revascularization groups according to the presence of residual lesions with an FFR of ≤0.83 after the intervention. Of the 212 included patients, 112 (52.8%) had lesions with an FFR of ≤0.83. After adjusting for confounders, an FFR of ≤0.83 was associated with a higher risk for the primary outcome (adjusted hazard ratio 2.01, 95% confidence interval 1.11 to 3.66, p = 0.021). Propensity score matching showed that complete revascularization for lesions with an FFR of ≤0.83 was associated with a reduced risk for the primary outcome compared with incomplete revascularization (hazard ratio 0.38, 95% confidence interval 0.20 to 0.71, log-rank p = 0.0016). In conclusion, an FFR of ≤0.83 was an independent predictor of clinical events in patients on hemodialysis. Furthermore, complete revascularization was associated with better clinical outcomes. Thus, this population may require a distinct FFR cut-off value.

Practical Application of Coronary Physiologic Assessment: Asia-Pacific Expert Consensus Document: Part 1

Coronary physiologic assessment is performed to measure coronary pressure, flow, and resistance or their surrogates to enable the selection of appropriate management strategy and its optimization for patients with coronary artery disease. The value of physiologic assessment is supported by a large body of evidence that has led to major recommendations in clinical practice guidelines. This expert consensus document aims to convey practical and balanced recommendations and future perspectives for coronary physiologic assessment for physicians and patients in the Asia-Pacific region based on updated information in the field that including both wire- and image-based physiologic assessment. This is Part 1 of the whole consensus document, which describes the general concept of coronary physiology, as well as practical information on the clinical application of physiologic indices and novel image-based physiologic assessment.