Quantitative flow ratio-Meta-analysis and systematic review.

INTRODUCTION: Despite of the wide evidence of use fractional flow reserve (FFR), isolated angiography evaluation is still the main tool to indicate percutaneous coronary intervention. Quantitative flow ratio (QFR) is a new functional index to assess functional significance. Recently, few studies have showed the capacity of QFR to predict significance stenosis. The aim of this research has been to describe the evidence of QFR in this clinical setting, to analyze the global diagnosis accuracy of QFR versus FFR and to compare the difference in feasibility between retrospective and prospective analysis. METHODS AND RESULTS: Systematic review of literature was performed. Eligible studies for the meta-analysis were considered those directly evaluating de QFR versus FFR. Pooled values of diagnosis test and summary receiver operator curve were calculated. Main causes of not-perform QFR analysis according to study design were also evaluated. Sixteen studies were included. Good correlation and agreement were showed. Global sensibility, specificity, PPV, and NPV were 0.84, 0.89, 0.80, and 0.92, respectively. Then, 18% of evaluated vessels could not be analyzed. Significant differences were found in the percentage of discarded vessels and the cause of nonperformed analysis between retrospective or prospective analysis. CONCLUSIONS: Excellent correlation and agreement between QFR and FFR was demonstrated. QFR assessment could be improved by its prospective analysis with a dedicated protocol.

Impact of renin-angiotensin system inhibitors on outcomes after surgical or transcatheter aortic valve replacement. A meta-analysis.

INTRODUCTION AND OBJECTIVES: To determine whether renin-angiotensin system inhibitor (RASi) prescription is associated with better outcomes after transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR). METHODS: All comparative studies of RASi vs no RASi prescription in patients undergoing TAVI/SAVR were gathered from PubMed, Web of Science, and Google Scholar through August, 2019. We extracted hazard ratios (HRs) with their confidence intervals (CIs) for mortality from each study and combined study-specific estimates using inverse variance-weighted averages of logarithmic HRs in the random effects model. RESULTS: We identified 6 eligible studies with a total of 21 390 patients (TAVI: 17 846; SAVR: 3544) and included them in the present meta-analysis. The 6 studies were observational comparative studies (including 3 propensity score matched and 3 cohort studies) of RASi vs no RASi prescription. The analysis demonstrated that RASi prescription was associated with significantly lower mortality in the whole group of patients undergoing aortic valve intervention (HR, 0.64; 95%CI, 0.47-0.88; P <.001). However, subgroup analysis suggested differences according to the selected therapy, with TAVI showing better mortality rates in the RASi group (HR, 0.67; 95%CI, 0.49-0.93) but not in the SAVR group (HR, 0.61; 95%CI, 0.29-1.30). No funnel plot asymmetry was identified, suggesting minimum publication bias. Sensitivity analyses sequentially eliminating dissimilar studies did not substantially alter the primary result favoring RASI prescription. CONCLUSIONS: These findings suggest a mortality benefit of RASi in patients with AS treated with aortic valve replacement that might be particularly relevant following TAVI. Future randomized studies are warranted to confirm this relevant finding.