Association between silent cerebral embolism and cognitive alterations following transcatheter aortic valve replacement in bicuspid versus tricuspid aortic valve patients

Abstract

Abstract Background Silent cerebral ischemic lesions (SCILs) is a common magnetic resonance imaging (MRI) finding in severe aortic stenosis patients post - transcatheter aortic valve replacement (TAVR). We evaluated the association between SCILs and cognitive alterations in patients with bicuspid aortic valve (BAV) versus tricuspid aortic valve (TAV) post-TAVR. Methods This study enrolled 100 consecutive TAVR (45 with BAV and 55 TAV). DW-MRI and neurocognitive evaluation (MoCA score) were performed at baseline, discharge, and 1- and 12-month post-discharge. Results Ninety-two out of the 100 patients (92%) exhibited cognitive dysfunction at baseline. Post-TAVR, overall cognitive function significantly improved, the average MOCA score increased from 18.69±6.74 to 22.18±6.30. During the 1-year follow-up, 54 patients demonstrated improved cognitive function, and the number of patients with moderate-to-severe cognitive dysfunction (MoCA score < 18) significantly decreased from 32 to 16. Prevalence of SCILs was 14% and 72% at baseline and discharge, respectively. New SCILs were observed in 60 patients at discharge, distributed across all vascular territories, averaging 4 lesions with a total volume of 215.4±195.4mm3. Although no significant correlation existed between total volume of new SCILs and cognitive changes post-TAVR (R=-0.133, p=0.206), patients with SCILs still displayed significant cognitive improvement (MoCA score from 18.4±6.6 to 22.0±7.1), whereas patients who developed large SCILs (lesion diameter >9) showed less improvement compared to those with small or median SCILs (number of patients who had cognitive improvement: 32 vs. 52, p<0.05). Cognitive function improvement post-TAVR did not significantly differ between BAV and TAV patients, MoCA scores were comparable (BAV group, n=45, from 18.63±6.68 to 21.88±6.80 vs. TAV group, n=55, from 18.73±6.81 to 22.42±5.80; p>0.05). DW-MRI revealed more new SCILs in BAV patients post-TAVR compare to TAV patients (235 lesions vs. 150 lesions, respectively). In BAV patients, SCILs primarily manifested in small and medium sizes (224 lesions), despite more severe calcification (valvular calcium volume 956.5±644.0 mm vs. 634.4±508.0 mm3; p=0.028). The number of large lesions was similar in the two groups (11 in BAV group and 10 in TAV group). Conclusion TAVR demonstrates positive effects on improving cognitive function in aortic stenosis patients, despite common occurrence of SCILs in both BAV and TAV patients. Cognitive function post-TAVR was comparable between BAV and TAV patients. The cognitive improvement from TAVR may be less impacted by small- and medium-sized SCILs, while severe SCILs might impede or diminish the cognitive benefits of TAVR.table