Background and purpose: The risk of neurological damage following transcatheter aortic valve implantation (TAVI) vs. surgical aortic valve replacement (SAVR) in severe aortic stenosis patients deemed to be at intermediate surgical risk is unknown. In this target population, the degree of neurological damage was compared using brain diffusion-weighted magnetic resonance imaging (DW-MRI) and cognitive testing.
Methods: Forty-six consecutive patients undergoing TAVI (78.0 ± 8.3 years; STS score 4.4 ± 1.7) and 37 patients undergoing SAVR (78.9 ± 6.2 years, STS score 4.7 ± 1.7) were compared. DW-MRI was performed in 67 patients (40 in TAVI vs. 27 in SAVR group) within the first 15 days post-procedure. A cognitive assessment was performed at baseline and at 3 months follow-up. The occurrence of potential cognitive impairment post-intervention was determined using the reliable change index (RCI).
Results: Baseline characteristics were comparable in TAVI and SAVR groups except for the presence of severe calcified aorta, which occurred more frequently in the TAVI group [17 (37 %) vs. 0 (0 %), p < 0.001]. Three patients presented a clinical stroke: 1 (2.2 %) in TAVI group vs. 2 (5.4 %) in SAVR group, (p = 0.58). No differences were observed in the rate of acute ischemic cerebral lesions detected by DWI in patients undergoing TAVI vs. SAVR [18 (45 %) in TAVI vs. 11 (40.7 %) in SAVR, adjusted OR 0.95; 95 % CI 0.25-3.65; p = 0.94]. TAVI was associated with a lower number of DWI lesions (adjusted OR 0.54; 95 % IC 0.37-0.79; p = 0.02). An older age was a predictor of the occurrence of acute lesions (OR 1.13; 95 % CI 1.03-1.23; p = 0.01), and the use of vitamin-K antagonist therapy had a protective effect (OR 0.25; 95 % CI 0.07-0.92; p = 0.037) regardless the type of intervention. Overall no significant changes were observed in global cognitive scores post-intervention (p = 0.23). The RCI showed mild cognitive decline in nine patients undergoing TAVI (26.4 %) and in six patients in the SAVR group (30.0 %) (p = 0.96). There was no association between the number and total volume of lesions and the occurrence of cognitive decline (CC Spearman 0.031, p = 0.85 and -0.011, p = 0.97, respectively).
Conclusions: TAVI and SAVR were associated with a similar rate of acute silent ischemic cerebral lesions in intermediate risk patients. Although acute lesions occurred very frequently in both strategies, their cognitive impact was not clinically relevant.
Keywords: Cardiac valvular surgery; Catheterization; Magnetic resonance imaging; Stroke; Valves.