Guided By FFR:The Stability Of Coronary Microcirculation Dilated By ATP And Ffr Repeatability

AIM:To discusse the stability of coronary microcirculation dilated by adenosine tri phosphate(ATP)and the repeatability of FFR measurement.Methods:We conducted a retrospective single-center study on 196 patients who rec eived FFR measurements using peripheral ATP intravenously at the heart center of Qingdao municipal hospital from 2016 to 2018.According to the 2016 consensus of experts on the clinical application of FFR,ATP pumping through the elbow vei n or femoral vein(140 g/ kg/min)is recommended.Starting from the injection of ATP,the pressure measurement was started after 15 cardiac cycles,lasting for 2 m inutes,the injection was suspended for 2 minutes,and the FFR was measured aga in(except for patients who could not tolerate this operation).The minimum FFR v alue(meanvalue of the minimum FFR value for 5 consecutive cycles),heart rate,aortic pressure(Pa),lesion distal pressure(Pb),and FFR curve shape after two AT P injections were recorded.Results:Three main FFR curves were observed,among which 59%(232/392)wer e“classic”representing stable curve,37%(145/392)were "hump",and 4%(15/392)were "irregular" representing unstable curve.According to the repeated shape of FFR curves,196 cases were divided into 5 groups:“both classic”,“both humped”,“b oth unusual”,“once classic,once humped”,“once unusual”,there was no statisti cal significance in age,gender,cardiovascular risk factors,symptoms,previous me dical history,medication history and other variables of patients in each group.The minimum FFR value of repeated measurement is highly linear correlated with mea surement for the first time(r2=0.964,squared ICC=0.97,P<0.001),by contrast,the aortic pressure(Pa)(r2=0.662,the ICC=0.79,P=0.042),distal coronary artery pres sure(Pd)(r2=0.824,ICC=0.89,P=0.010)and heart rate(r2=0.599,ICC=0.72,P=0.030)of repeated measurements are less correlated with the first time.Conclusions:Adenosine triphosphate(ATP),like adenosine triphosphate,can make the coronary microcirculation expand stably.When adenosine triphosphate was used as the vascular dilator for repeated FFR measurement,the heart rate,Pa and Pd v aried greatly,but the FFR value was highly correlated,indicating that FFR had go od repeatability.