Katz frailty syndrom has no predictive value in low-risk patients undergoing transcatheter aortic valve implantation
Authors: Byczkowska K , Pawlak A , Gil R J 
Published: October 2021

Abstract

Background
Aortic stenosis is a disease of the elderly people, with multiple comorbidities and often with the frailty syndrome. Therefore, we decided that frailty as a clinical factor requires precise characterization in low-, intermediate– and high-risk patients as it may be a valuable supplement to the risk stratification in TAVI.

Purpose
The aim of our study was to evaluate the prognostic value of the Katz frailty scale in patients undergoing TAVI in relation to the risk of mortality assessed with the STS scale.

Methods
The study included 105 patients (mean age 82.36±4.5) with severe AS treated with TAVI at the Department of Cardiology of our clinical hospital. Each patient had laboratory tests, ECG, echocardiography and was assessed based on the STS scale and the Katz frailty scale. Study population was divided into groups: I with moderate and severe Katz frailty syndrome (≤4 pts) and II with mild Katz frailty syndrome (≥5 pts). Follow-up observations were carried out at 1 month and 1 year.

Results
In the study population 46% were men, the mean age was 82.36±4.5 years, the mean STS score was 7.03±4.24%, and the Katz frailty syndrome with the degree of ≤4 pts was found in 44,8%. There was a statistically significant reduction in Katz frailty score at 1 month and 1 year (n=40, 40%; n=21, 26%; p≤0,05, p≤0,05 respectively) compared to before TAVI. The greatest improvement was observed in the intermediate- and high-risk patients in 1-year follow up (p≤0,05, p≤0,05 respectively) (Tab.1). There was no significant change (p&gt;0.05) between 1-month and 1-year follow-up. 1-year all-causes mortality in patients with moderate and severe Katz frailty syndrome was 30% and with mild Katz frailty syndrome was 3% (p&lt;0,001). 1-month all-causes mortality after TAVI in high-risk patients was a significantly dependent on Katz frailty score (p&lt;0,05). And at the same time 1-year all-causes mortality after TAVI in high- and intermediate-risk patients was a significantly dependent on Katz frailty score (p&lt;0,05). This relationship was not demonstrated in the low-risk patients. Analysis using Cox's proportional hazards model confirmed a significant prognostic value for the Katz frailty syndrome before TAVI (p≤0.05). Patients with moderate to severe frailty on the Katz score (values ≤4) had a 13,68 times higher risk of death per year compared to the group with Katz frailty syndrome ≥5. Multivariate regression indicated that Katz frailty score and STS score were prognostically significant factors of cardiovascular death in patients undergoing TAVI (p&lt;0,01).

Conclusion
A significant correlation was demonstrated between survival and Katz frailty score. The Katz frailty score had a significant prognostic value, especially in intermediate- and high risk patients, but no in low-risk patients. Katz frailty score and STS risk score significantly correlated with the risk of death from cardiovascular causes in patients undergoing TAVI.

Funding Acknowledgement
Type of funding sources: None. Figure 1Table 1