Correlation Between Aortic Valve Calcification And New Silent Cerebral Infarction After Transcatheter Aortic Valve Replacement

Part 1: Incidence and risk factors of new silent cerebral infarction after Transcatheter Aortic Valve ReplacementObjectives:This part aimed to study the incidence,distribution and risk factors of new silent cerebral infarction on brain diffusion weighted magnetic resonance imaging(DW-MRI)in patients undergoing transcatheter aortic valve replacement(TAVR).Methods:From December 2016 to December 2019,patients with symptomatic severe aortic stenosis(AS)and / or aortic regurgitation(AR)who received TAVR in the cardiovascular department of the Second Affiliated Hospital of Zhejiang University School of medicine and had completed postoperative MRI data were recruited consecutively.Patients were included in the study according to the screening criteria,and then,divided into two groups according to whether there were new silent cerebral infarction.The incidence of new silent cerebral infarction after TAVR in our center was analyzed,and the clinical basic data,preoperative imaging examination results and operation differences between the two groups were compared.Results:A total of 217 patients were included in this study,171(78.8%)of them had new silent cerebral infarction after TAVR detected by DW-MRI before discharge.There was statistically significant difference of the number of new silent cerebral infarction among the different blood supply area of cerebral arteries(ACA vs ACA/MCA vs MCA vs MCA/PCA vs PCA vs VA/BA,0.8±1.4 vs 0.9±1.4 vs 1.4±2.0 vs 0.1±0.5 vs 1.0±1.8 vs1.1±1.5,P<0.001).There was statistically significant difference in the volume(mm3)of new silent cerebral infarction among the blood supply area of each cerebral artery branch(ACA vs ACA/MCA vs MCA vs MCA/PCA vs PCA vs VA/BA,55.5±109.7 vs74.0±148.2 vs 729.4±7679.4 vs 9.7±36.9 vs 176.3±1185.3 vs 255.5±884.2,P<0.001).There was no significant difference in the number of new silent cerebral infarction between the two cerebral hemispheres(left hemisphere vs right hemisphere,2.9±3.2 vs2.5±2.7,P=0.31).More,we found that the aortic valve area was smaller(P=0.02),maximum flow velocity was faster(P=0.02)and mean gradient was higher(P=0.03)in the group with new silent cerebral infarction,compared with it that of the group without new silent cerebral infarction.Apart from the max diameter of annulus(P=0.04),the results of preoperative CTA showed no significant difference between the two groups,especially,in the degree(P = 0.68)and distribution(P = 0.58)of aortic valve calcification.Conclusion:The new silent cerebral infarction after TAVR detected by DW-MRI had two characteristics including high incidence and different distribution among the blood supply area of different cerebral arteries.The aortic valve area,maximum flow velocity,mean gradient measured by echocardiography and max diameter of annulus measured by CTA had a certain predictive effect on the occurrence of new silent cerebral infarction.There was no significant difference in the degree(P=0.68)and distribution(P=0.58)of aortic valve calcification between groups with or without new silent cerebral infarction after TAVR.Part 2: Correlation between Aortic Valve Calcification and New Silent Cerebral Infarction after Transcatheter Aortic Valve ReplacementObjectives:Current studies show interests in whether aortic valve calcification(AVC)affects the occurrence of new silent cerebral infarction after TAVR and its mechanism.The objective of this part is to explore the correlation between the AVC assessed by CTA and the distribution and volume of new silent cerebral infarction after TAVR.Methods:From December 2016 to December 2019,patients with symptomatic severe aortic stenosis and / or aortic regurgitation who received TAVR in the cardiovascular department of the Second Affiliated Hospital of Zhejiang University school of medicine and had completed postoperative MRI data were included consecutively.Patients were selected for inclusion in the study according to the screening criteria,and then patients were divided into groups according to the degree or distribution of aortic valve calcification.After comparing the number,volume and distribution of new silent cerebral infarction after TAVR,Kruskal-Wallis H test,Spearman’s analysis and linear regression were used to analyze the correlation.Results:We respectively analyzed 217 and 205 patients according to different grouping by the grade and distribution of AVC.By compared among different groups,in groups according to the grade of aortic valve calcification we found that the number,volume and distribution of new silent cerebral infarction after TAVR were not statistically significant different.When the distribution of aortic valve calcification was asymmetric,the number and volume of new silent cerebral infarction after TAVR in MCA blood supply areas(P=0.03;P=0.02,respectively)was statistically significant different.Then according to Spearman’s correlation analysis,AVC grade positively correlated with number of new silent cerebral infarction in right hemisphere(R=0.16,P=0.02),number of new silent cerebral infarction in MCA blood supply areas(R=0.14,P=0.045)and volume of new silent cerebral infarction in MCA blood supply areas(R=0.15,P=0.03).AVC distribution was correlated with number and volume of new silent cerebral infarction in MCA blood supply areas(R=0.18,P=0.01;R=0.17,P=0.02,respectively).According to linear regression,the effect of AVC grade on number of new silent cerebral infarction in right hemisphere and MCA blood supply areas has statistically significance(F=4.208,R2=0.02,adjusted R2=0.02,P=0.04;F=4.192,R2=0.02,adjusted R2=0.02,P=0.04,respectively).But the effect of AVC grade on volume of new silent cerebral infarction in MCA blood supply areas has no statistically significance(F=0.86,R2=0.004,adjusted R2=-0.001,P=0.34).The effect of AVC distribution on number of new silent cerebral infarction in MCA blood supply areas has statistically significance(F=6.84,R2=0.03,adjusted R2=0.03,P=0.01),but the effect on volume of new silent cerebral infarction in MCA blood supply areas has no statistically significance(F=0.04,R2=0.000,adjusted R2=-0.005,P=0.85).The number(2.0±1.5)of new silent cerebral infarction was lower in pure AR patients compared with all enrolled patients(P=0.47).Conclusion:In this part of study,we found that the degree and distribution of aortic valve calcification had limited correlation with new silent cerebral infarction after TAVR.The number of new silent cerebral infarction after TAVR in patients with AR alone was less than that in all enrolled patients,which proposed a new exploration direction for the mechanism of new silent cerebral infarction after TAVR.