Coronary Reaccess And Risk Of Coronary Obstruction During Aortic Valve Reintervention In Patients Receiving TAVR

Objective:As clinical trials have demonstrated the safety and effectiveness of transcatheter aortic valve replacement(TAVR)across all surgical risk categories,TAVR indications are expanding into lower risk and younger aortic stenosis AS patients.These patients with longer life expectancy have a higher cumulative risk of coronary events and thus there will be an increasing need for repeating coronary angiography and intervention after index TAVR.However,coronary reaccess after TAVR may be technically challenging due to interference by the transcatheter heart valve(THV).Also,these patients endure a higher risk of structural valve failure of THVs which eventually leads to valve reintervention.Thus there will be an increasing need for redo TAVR whose feasibility is mainly determined by the risk of coronary artery obstruction due to sinus of Valsalva sequestration.Recently,several post-TAVR MSCT(multislice computed tomography)studies tried to characterize the coronary reaccess after TAVR and the risk of coronary obstruction during redo TAVR.These studies all only focused on tricuspid aortic valve(TAV)stenosis,although there is a higher proportion of bicuspid aortic valve(BAV)stenosis in the lower risk and younger population.In consideration of the difference in aortic root anatomical features and geometric interaction with THV,the results of previous studies cannot be directly extrapolated to BAV stenosis patients receiving TAVR.Hence,it is important to clarify these two issues in these patients.We retrospectively enrolled BAV and TAV stenosis patients who underwent TAVR using Venus A which was a self-expanding supra-annular design THV in a single center over 6 years.Then we conducted CT-based simulation studies and tried to characterize and compare the coronary reaccess and the risk of coronary obstruction during redo TAVR after TAVR in BAV versus TAV stenosis.Methods:We enrolled 80 type-0 BAV,76 type-1 BAV,and 132 TAV stenosis who successfully underwent TAVR using Venus A in a large center from January 2014 to December 2019.Post-TAVR CT images were analyzed using Fluoro CT software.Coronary reaccess was defined as difficult if the coronary ostium was below the skirt or in front of the commissural posts or front of the bulky native leaflets,and was defined as complex if the catheter cannot cross opening diamond cell and coronary ostium coaxially.The optimal fluoroscopic viewing angle for coronary reaccess was defined as the intersection between the optimal projection curves of the optimal opening diamond cell for catheter engagement and the THV short-axis plane(double S curve method).Redo TAVR was considered at high risk of coronary obstruction due to sinus sequestration if 1)when coronary ostia to THV inflow distance<STJ to THV inflow distance<commissure height,STJ to THV distance<2mm,or THV to the aortic wall at commissure level<2mm;or 2)when coronary ostia to THV inflow distance<commissure height<STJ to THV inflow distance,STJ to THV distance<2mm and STJ to THV commissure<2mm.The degree of overlap between coronary ostium and the nearest THV commissure was defined in 4 categories:no overlap(angle 45.1°to 60.0°),mild overlap(angle30.1°to 45.0°),moderate overlap(angle 15.1°to 30.0°),severe overlap(angle 0°to15.0°).BASILICA(Bioprosthetic or native aortic scallop intentional laceration to prevent coronary artery obstruction)was not feasible to reduce the risk of coronary obstruction during redo TAVR if coronary ostium to THV commissure angle was less than 30°(23 mm THV)or 36°(THV size≥26 mm).Results:(1)The incidence of THV-related difficult left coronary reaccess was 21.2%,and the interferences by commissure triangles were the most common(17.7%).The independent predictors for THV-related difficult left coronary reaccess included left coronary ostium-THV commissure angle(OR=0.79,95%CI 0.74-0.85),left THV implanted depth(OR=0.62,95%CI 0.52-0.75),left coronary ostium height(OR=0.74,95%CI 0.63-0.88)and using 26mm THV(OR=6.84,95%CI 1.65-28.40)or29/32 mm THV(OR=11.30,95%CI 2.05-62.44).Compared with type-0 BAV group,the incidence of THV-related difficult left coronary reaccess in TAV group(OR=2.37,95%CI 1.12-4.97)and type-1 BAV group(OR=2.02,95%CI 0.87-4.70)was significantly higher or tended to be higher.The aforementioned predictor,left coronary ostium height(12.9±2.5 mm vs.13.2±3.7 vs.15.4±3.7 mm,P.overall<0.001)was significantly higher in type-0 BAV group than other groups,although left THV implantation depth(10.2±3.9 mm vs.9.9±3.4 mm vs.8.9±3.5 mm,P.overall=0.027)was significantly shallower in this group.In addition,the proportion of using23 mm THV also tended to be more in type-0 BAV group(15.2%vs.14.3%vs.23.3%,P.overall=0.224).The incidence of THV-related difficult right coronary reaccess was 17.7%,and interferences by commissure triangles were the most common(12.2%).The independent predictors for THV-related difficult right coronary reaccess included right coronary ostium-THV commissure angle(OR=0.84,95%CI 0.80-0.89),THV implant depth(OR=0.60,95%CI 0.50-0.71)and right coronary ostium height(OR=0.81,95%CI 0.71-0.92).Compared with type-0 BAV group,the incidence of THV-related difficult right coronary reaccess in TAV group(OR=1.30,95%CI 0.61-2.78)and type-1 BAV group(OR=1.83,95%CI 0.80-4.18)seemed to be similar.(2)The incidence of difficult left and right coronary reaccess related to bulky native leaflet was 3.5%and 2.1%,respectively.Meanwhile,the incidence of THV-related complex left and right coronary reaccess were 5.9%and 17.0%,respectively;and the left coronary ostium was significantly larger than right coronary ostium(area:17.3±0.2 mm~2 vs.15.2±0.2 mm~2,P<0.001;circumference:23.6±0.6 mm vs.18.5±0.5 mm,P<0.001).There were no significant differences in the incidence of these two kinds of coronary reaccess among groups.(3)Post-TAVR MSCT can be used to calculate the theoretical optimal fluoroscopic viewing angle for coronary reaccess.There were significant differences in the theoretical optimal fluoroscopic viewing angle for left coronary reaccess for type-0 BAV,type-1 BAV and TAV after TAVR(median:LAO 27.9°vs.LAO 17.9°vs.LAO 28.0°,P.overall<0.001;CRA 21.6°vs.CRA 1.7°vs.CRA 16.8°,P.overall<0.001),the proportion of these fluoroscopic viewing angles within the practical range was lower in type-0 BAV group(77.9%vs.94.3%vs.89.4%,P.overall=0.006).In addition,there were also significant differences in the theoretical optimal fluoroscopic viewing angle for right coronary reaccess among groups(median:LAO 36.6°vs.LAO66.3°vs.LAO 62.5°,P.overall<0.001;CRA 29.6°vs.CRA 37.7°vs.CRA 36.9°,P.overall<0.001),the proportion of these fluoroscopic viewing angles within the practical range was higher in type-0 BAV group(36.0%vs.5.7%vs.12.9%,P.overall<0.001).(4)The estimated incidence of coronary reaccess in the study population at 5-year follow-up was 15.8%(95%CI:7.3%-32.0%).After a median follow-up of 19.4 months,there were a total of 17 coronary engagements.The failure rates of catheter engagement of the THV-related difficult and complex coronary reaccess were 80.0%,and 33.3%,respectively.For easy coronary reaccess,all coronary engagements were successful,but the rates of selective engagement were higher for left coronary ostium than that for right coronary ostium.(5)The incidence of CT-identified high risk of left coronary obstruction during redo TAVR was 36.1%.The independent predictors included STJ perimeter drived diameter(OR=0.82,95%CI 0.74-0.91),left STJ height(OR=0.61,95%CI 0.52-0.70),using 26mm THV(OR=5.65,95%CI 2.24-14.28)or 29/32 mm THV(OR=6.72,95%CI 2.18-20.74)and left THV implantation depth(OR=0.72,95%CI 0.64-0.81).The incidence of CT-identified high risk of left coronary obstruction in TAV group(OR=2.60,95%CI 1.40-4.81)and type-1 BAV group(OR=2.49,95%CI 1.24-5.01)were significantly higher than that in type-0 BAV group.The above-mentioned independent predictors,STJ perimeter derived diameter(29.9±3.7 mm vs.30.6±4.2mm vs.31.6±5.0 mm,P.overall=0.015)and the left STJ height(16.4±2.9 mm vs.16.9±3.6 mm vs.19.9±5.0 mm,P.overall<0.001)were significantly greater in type-0 BAV group than others,although left THV implantation depth(10.2±3.9 mm vs.9.9±3.4 mm vs.8.9±3.5 mm,P.overall=0.027)in this group was significantly smaller than others.The incidence of CT-identified high risk of righ coronary obstruction during redo TAVR was 27.8%.The independent predictors included STJ perimeter derived diameter(OR=0.75,95%CI 0.66-0.85),right STJ height(OR=0.73,95%CI 0.64-0.82),using 26 mm THV(OR=4.92,95%CI 1.93-12.53)or 29/32 mm THV(OR=7.54,95%CI 2.35-24.17)and right THV implantation depth(OR=0.81,95%CI 0.74-0.90).The incidence of CT-identified high risk of righ coronary obstruction in TAV group(OR=1.97,95%CI 1.02-3.80)and type-1 BAV group(OR=2.14,95%CI 1.02-4.48)were significantly higher that in type-0 BAV group.The aforementioned independent predictors,STJ perimeter derived diameter(29.9±3.7 mm vs.30.6±4.2mm vs.31.6±5.0 mm,P.overall=0.015)and right STJ height(17.1±3.3 mm vs.17.4±3.8 mm vs.19.5±4.8 mm,P.overall<0.001)in type-0 BAV group were significantly greater than others,although right THV implantation depth(9.6±3.7 mm vs.8.6±3.9 mm vs.7.9±3.8 mm,P.overall=0.005)in this group was significantly smaller than others.(6)In the study population,BASILICA may be feasible to reduce the risk of left and right coronary obstruction in 13.9%and 11.5%,respectively.Particularly,the incidence that BASILICA may be not feasible to reduce the risk of left and right coronary obstruction was significantly lower in type-0 BAV group than that in others(5.8%vs.25.7%vs.31.1%,P.overall<0.001;8.1%vs.21.4%vs.18.9%,P.overall=0.045).Compared with other groups,the proportion that BASILICA may be not feasible in patients at high risk of coronary obstruction was also significantly lower in type-0 BAV group or the proportion had a lower trend(26.3%vs.62.1%vs.73.2%,P.overall=0.001;43.8%vs.65.2%vs.61.0%,P.overall=0.374).(7)If the commissural alignment strategy is successfully applied,the moderate/severe coronary ostium-THV commissure overlap will be reduced by 81.9%,however,the reduction in type-0 BAV group is significantly lower than that in others(55.1%vs.91.5%vs.90.6%,P.overall<0.001).The proportion of remaining moderate/severe overlap between one coronary ostium and THV commissure is 19.4%,which was significantly higher in type-0 BAVgroup than others(40.7%vs.10.0%vs.10.6%,P.overall<0.001).Conclusion:Post-TAVR CT analysis suggested that the interference by THV or native valve leaflets may result in a considerable proportion of difficult or complex coronary reaccess after TAVR with self-expanding supra-annular THV.Independent predictors of THV-related difficult coronary reaccess included coronary ostium to THV commissure angle,THV implantation depth,coronary ostium height,and using larger size THV.The lower incidence of THV-related difficult left coronary reaccess in type-0 BAV may be explained by the differences in aortic root anatomical features and geometric interaction with THV.Additionally,post-TAVR CT analysis may be able to clarify the interferences of coronary reaccess and provide the optimal fluoroscopic viewing angles,which may be helpful to plan and guide coronary angiography or PCI after TAVR.CT-based simulation study indicated that nearly 50%of patients may encounter a high risk of coronary obstruction during redo TAVR after first TAVR with the self-expanding supra-annular THV.Independent predictors included STJ diameter and height,first THV implantation depth,and using a larger size THV in the first TAVR.The lower incidence of CT-identified high risk of coronary obstruction during redo TAVR in type-0 BAV may be explained by the differences in aortic root anatomical features and geometric interaction with THV.Due to the significant overlap between coronary ostium and THV commissure,more than 60%of coronary ostia at high risk of obstruction may not be able to use BASILICA to facilitate redo TAVR,and the proportion is relatively low after TAVR in type-0 BAV.Commissural alignment can reduce the overlap between coronary ostia and THV commissure,thereby optimizing coronary reaccess after TAVR and facilitating BASILICA to reduce the risk of coronary obstruction during Redo TAVR.However,the effect of this strategy is limited during TAVR in type-0 BAV due to the differences in coronary ostia distribution.To iterate and update THV designs,including reducing the inner skirt and commissure posts,enlarging the open cell at coronary ostia level,allowing commissural alignment,and improving the durability of THV leaflets,may help optimize the coronary reaccess after TAVR and/or facilitate redo TAVR by reducing the risk of coronary obstruction.Particularly,the cumulative risk of coronary events and the THV failure should be measured during the first TAVR decision,and the impact of aortic root anatomical features on the coronary reaccess after TAVR and the risk of coronary obstruction during redo TAVR should be carefully considered.