Hemodynamic and Lesion Characteristics Associated with Discordance between the Instantaneous Wave-Free Ratio and Fractional Flow Reserve.

BACKGROUND: The instantaneous wave-free ratio (iFR) is an invasive coronary physiological index that is not inferior to fractional flow reserve- (FFR-) guided revascularization. The indexes of iFR and FFR are similar and closely correlated, but there are a few key differences. Previous studies suggested that patient characteristics and lesion severity could induce discordance between iFR and FFR. This study aimed to clarify the hemodynamics and lesion characteristics that influence discordance between iFR and FFR. METHODS: In this retrospective study, we enrolled 225 patients (304 lesions) who underwent clinically indicated invasive coronary angiography and both iFR and FFR examinations between 2012 and 2017. We included only patients who underwent right heart catheterization and had blood pressure and heart rates recorded immediately prior to iFR and FFR. RESULTS: Discordance (iFR ≤0.89 and FFR >0.8 or iFR >0.89 and FFR ≤0.8) was observed in 80 lesions (26.3%). The heart rate, rate-pressure product, and cardiac index tended to be higher in the iFR ≤0.89 group than in the iFR >0.89 group. These trends were not seen between the FFR ≤0.8 group and FFR >0.8 group. A multivariate analysis showed that independent predictors of iFR ≤0.89 and FFR >0.8 discordance were female sex and higher rate-pressure product. iFR >0.89 and FFR ≤0.8 discordance was rare in hemodialysis patients. CONCLUSION: Even if iFR is functionally significant in intermediate stenosis, additional FFR evaluations should be considered for women, especially those with a high rate-pressure product, to avoid unnecessary percutaneous coronary intervention. If iFR is not functionally significant with intermediate stenosis in hemodialysis patients, then further FFR evaluations are unnecessary.

Long-term clinical outcomes after percutaneous coronary intervention to treat long lesions in hemodialysis patients in the era of second-generation drug-eluting stents.

BACKGROUND: There is little knowledge about clinical outcomes after the percutaneous coronary intervention (PCI) in hemodialysis patients with long lesions. The objective of the present study was to examine the long-term prognosis after PCI in hemodialysis patients in the second-generation drug-eluting stents (DES) era. METHODS: We retrospectively enrolled 270 consecutive hemodialysis patients who underwent PCI using second-generation DES from January 2010 to July 2015. We defined long lesions as the total stent length >30mm. In total, 96 hemodialysis patients (35.6%) underwent PCI for long lesions. The median follow-up period was 2.7 years. The endpoints of this study were cardiac death, target lesion revascularization (TLR), and major adverse cardiovascular events (MACE), including cardiac death, non-fatal myocardial infarction, non-fatal stroke, stent thrombosis, and TLR. RESULTS: The patients' baseline characteristics were similar between the long lesion and the non-long lesion groups, except for prior PCIs (long-lesion vs. non-long lesion=30.2% vs. 46.0%; p= 0.01). Kaplan-Meier analyses revealed that the incidence of cardiac death, TLR, and MACE were comparable between the two groups (long lesion vs. non-long lesion; 5.2% vs. 5.7%, log-rank p=0.84, 26.0% vs. 23.0%, log-rank p=0.29, and 43.8% vs. 40.2%; log-rank p=0.49, respectively). CONCLUSIONS: Clinical outcomes of PCI for long lesions in hemodialysis patients were similar to that of non-long lesions. Long-stenting in hemodialysis patients, who were considered high-risk subset of adverse cardiovascular events, might be acceptable in the second-generation DES era.