Cardio-Splenic Relationship in Patients Receiving Trans-Catheter Aortic Valve Replacement

The spleen seems to be a significant buffer of the effective circulating blood volume by changing its size dramatically according to hemodynamics. The cardio-splenic relationship has been recently proposed in the literature regarding heart failure cohorts, and the splenic size has been proposed as a prognostic factor in these cohorts. However, the clinical implication of the splenic size in patients receiving trans-catheter aortic valve replacement (TAVR) remains unknown.

Patients who underwent TAVR at our institute between 2015 and 2022 were eligible. Of these, the patients whose abdominal computed tomography imaging was obtained before TAVR were included. The volume of the spleen was measured in all the participants. The prognostic impact of the indexed splenic volume (SVI) on the 2-year cardiac death or heart failure readmissions was evaluated.

A total of 343 patients (86 years, 98 males) were included. The median value of the peak velocity at the aortic valve was 4.4 (4.0, 4.8) m/s and the median SVI was 65.5 (48.9, 86.9) mL/m². A lower SVI tended to be associated with a lower cardiac output, whereas a higher SVI was associated with a higher plasma volume. The SVI was independently associated with the 2-year cardiac death or heart failure readmission after TAVR with a hazard ratio of 1.09 (95% confidence interval 1.01-1.18, p = 0.041), adjusted for potential confounders. A calculated cutoff of SVI was 70.2 mL/m², which significantly stratified the cumulative incidence of the primary outcome (10% versus 4%, p = 0.033).

A high baseline SVI, which was associated with systemic congestion, was associated with a higher incidence of cardiac death or heart failure readmission after TAVR. Further studies are warranted to clarify the detailed cardio-splenic relationship and implication of measuring the SVI in this cohort.