Effect of Transcatheter Aortic Valve Implantation on the Immune Response Associated With Surgical Aortic Valve Replacement.

The immune response after transcatheter aortic valve implantation (TAVI) in comparison to that after surgical aortic valve replacement (SAVR) remains to be fully elucidated. In a 2-part study, we assessed laboratory data obtained before, immediately after, and 24 and 48 hours after SAVR (128 patients; age ≥80 [mean 82] years) or transfemoral TAVI (102 patients; age ≥80 [mean 86] years) performed for aortic stenosis. In-hospital mortalities were similar (3% vs 0%), but leukocyte counts and aspartate aminotransferase and creatine kinas concentrations were decreased immediately and 24 hours after surgery (all, p <0.001). We performed cytokine profiling in a SAVR group (11 patients; mean age, 77 years) and transfemoral TAVI group (12 patients; mean age, 84 years). By measuring normalized concentrations of 71 cytokines at 3 time points, we found a significant difference (defined as fold change >1.7 and p <0.05 [by Mann-Whitney U-test]) in 23 cytokines. The differentially expressed cytokines fell into 3 hierarchical clusters: cluster A (high increase after SAVR and suppressed increase after TAVI only immediately after surgery [CCL2, CCL4, and 2 others]), cluster B (high increase after SAVR and suppressed increase after TAVI at 2 time points [IL-1Ra, IL-6, IL-8, IL-10, and 5 others]), and cluster C (various patterns [TRAIL, CCL11, and 8 others]). Gene enrichment analysis identified multiple pathways associated with the inflammatory responses in SAVR and altered responses in TAVI, including cellular responses to tumor necrosis factor (p = 0.0035) and interleukin-1 (p = 0.0062). In conclusion, a robust inflammatory response follows SAVR, and a comparatively attenuated response follows TAVI.