Including The Influence Of RAP In The Analysis Of FFR In Long Lesions Of Coronary Artery With Intermediate Stenoses

Background: Fractional Flow Reserve (FFR) is an emerging technology that has beenwidely validated. Studies DEFER and FAME have increased physician consciousnessconcerning the clinical effectiveness of FFR in patients presenting with stable anginapectoris that have moderate coronary lesions. The utilization of FFR to guide PCI isreferenced in a class Ⅰ recently presented in published2014ESC-EACTS Guidelines onmyocardial revascularization. The initial characterization of FFR combined right atrialpressure into the computation of FFR as below; FFR Myo=Pd-Pv/Pa-Pv (where Pd isdistal pressure, Pv is venous pressure or right atrial pressure [RAP], Pa is the proximalarterial pressure).This equation was used in some but not all of the initial validationresearches that helped conclude the optimal FFR ischemic critical value. There has beenproof suggesting that negligence of RAP in the computation of FFR does not alter therelationship between FFR and PET concluded myocardial blood flow indices. However,this was in a chosen small population of low risk patients with a mean RAP of5mmHg.This brief and quick calculation (Pd/Pa) has nevertheless been used as a concluded index inclinical experiments, with significant non-invasive validation for ischemic critical value.It has been useful in prognoses as well.However, whether the inclusion of right atrialpressure would influence clinical decisions in real-world chosen catheter laboratory patientshas not been conclusively determined. Further research of the impact of routine inclusion ofright atrial pressure into the computation of FFR(FFRrap) in a real world elective PCIpopulation is needed.FFR is useful in the consideration of coronary lesion ischemia. However, the influenceof lesion length on FFR has not been sufficiently evaluated.Therefore, it is imperative to research the application value of Fractional flow reservein long lesions of coronary artery with intermediate stenoses and the influence of right atrial pressure.Objective:To study the value of FFR-guided clinical treatment decision for moderate stenoses ofcoronary lesions and whether right atrial pressure could affect the FFR of coronary.Method:From September2013to July2014,83Patients with at least one coronary arterymoderate stenoses (50％～70％) according to coronary arteriography(CAG) were selectedand randomly divided into3groups according to lesion length: A grouop：short lesiongroup(<20mm，n=42)，B grouop：long lesion group(20～35mm，n=27)，C grouop：verylong lesion group(≥36mm，n=14). Difference of FFR and FFRrap in3groups werecompared. When FFR was<0.75, the patients underwent PCI and optimal medical therapy;when FFR was>0.80, the optimal medical therapy was applied alone. When FFR was from0.75to0.80, the FFR was recalculated by RAP and the patients were revaluated by FFRrap:FFRrap<0.75, the patients underwent PCI; FFRrap≥0.75, the patients were treated withoptimal medical therapy. The major adverse cardiac events(MACE)，including cardiacdeath，nonfatal myocardial infarction，revascularization of target vessel once more andangina frequency，were followed up after FFR or FFRrap and PCI3moths respectively.Results:1.FFR and FFRrap in C group were less than those of A and B groups(F=2.524, p<0.05;F=1.656, p<0.05).2. FFR and FFRrap have no conspicuous significance of statistics in every grouprespectively; FFRrap calculated within right atrial pressure (0.73±0.11) was significantlylower than the tested-FFR in each group (A group：0.84±0.19vs0.78±0.14, p<0.05；Bgroup：0.75±0.14vs0.72±0.11, p<0.05；C group：0.67±0.11vs0.63±0.07, p<0.05).3. There was no significant difference of major adverse cardiac event (MACE)incidence between the drug therapy group and PCI group. The total rate of MACE was13.3%in our research.4. When FFR value is between0.75to0.80, FFR calculated within right atrial pressure,can more accurately determine the blood flow in the distal end of the lesion and guide thechoice of clinical therapeutic strategies. Conclusion:1.The longer of moderate coronary artery stenoses, the lower the value of FFR.2. FFR and FFRrap had diagnosis and treatment-evidence value for patients withcoronary artery moderate stenoses，Incorporation of RAP into the calculation of FFR(FFRrap) prominently alters FFR values， FFRrap is lower than FFR of simplifiedcalculation.3. When FFR is between0.75to0.80, FFRrap which recalculated with right atrialpressure can be more accurate to evaluate the distal blood flow of lesion and guide theclinical treatment strategies.