Background. Transcatheter aortic valve implantation (TAVI) has become the most common treatment for patients with severe aortic stenosis (AS) in Europe and North America. Since prosthetic valve durability is a key issue for younger patients with longer life expectancy, current European guidelines recommend transfemoral TAVI for patients with severe, symptomatic AS aged 75 years or older. However, this cut-off is based solely on coincidentally existing patient cohort mean age of randomized controlled trials and individual risk factors such as frailty and comorbidities might have a greater impact on outcomes after TAVI compared to age alone. 

Aims. This study aimed to validate the guideline-recommended age cut-off of 75 years compared to a comorbidity focused approach.

Methods. Using long-term prospective single-centre data, we analysed 4,278 patients with severe, symptomatic AS undergoing transfemoral TAVI between 2008 and 2022. Patients with concomitant mitral or tricuspid disease, valve-in-valve TAVI, concomitant valvular procedures, and asymptomatic patients were excluded. A multivariable Cox regression model was fitted to assess predictors of all-cause mortality after TAVI. Based on this model, a comorbid patient risk profile was defined as at least one prevalent comorbidity from the final model. Kaplan-Meier estimates were calculated for all-cause mortality after 3 years for young (<75 years) and elderly (≥75 years) patients, and comorbid and non-comorbid patients.

Results. A total of 1,620 patients undergoing transfemoral TAVI were included in the final analysis (<75 years: N=302 [18.6%], 70.8 [IQR 67.4-73.3] years; ≥75 years: N=1,318 [81.4%], 82.6 [IQR 79.5-85.6] years). In multivariable analysis, male gender (hazard ratio [HR] 1.37, 95%-confidence interval [CI] 1.06-1.77), atrial fibrillation (AF) (HR 1.78, 95%-CI 1.35-2.33), chronic obstructive pulmonary disease (COPD) (HR 1.44, 95%-CI 1.07-1.93) and chronic kidney disease (CKD) (eGFR<60ml/min/1.72m2)(HR 0.99, 95%-CI 0.98-0.99) were identified as predictors or comorbidities independently associated with all-cause mortality. Overall, 64% of patients were defined as comorbid by at least one risk factor emerging as an independent predictor: AF or COPD or CKD. While there was no difference in all-cause mortality 3 years after TAVI between patients younger and older than 75 years (27.5% vs. 23.9%, p=0.62) (Figure 1A), 3-year mortality rates were significantly higher in comorbid (30.4%) compared to non-comorbid subjects (14.5%, p<0.001) (Figure 1B). No difference was found comparing non-comorbid young to non-comorbid elderly patients (16.2% vs. 14.1%, p=0.69), but comorbid young patients showed significantly higher mortality at 3 years than non-comorbid elderly (34.0% vs. 14.1%, p<0.001) (Figure 1C). According to multivariable analysis including adjustment for age, a comorbid risk profile was independently associated with all-cause mortality after TAVI (HR 2.09, 95%-CI 1.49-2.93), whereas age was not predictive.

Conclusion. In a large all-comer TAVI patient cohort age was not predictive for mortality within a 3-year follow-up period. This finding was true for both, non-comorbid as well as comorbid TAVI patients. Thus, outcome of patients with AS currently undergoing transfemoral TAVI depends on patients’ risk profiles and comorbidities rather than age. Our findings do not confirm the guideline recommended binary age cut-off currently recommended for patients with severe symptomatic AS.