Objectives

Patients with chronic hemodialysis due to end-stage renal disease (ESRD) or severely impaired kidney function (CKD) constitute a relevant share of patients undergoing transcatheter aortic valve implantation (TAVI) in current practice. However, due to exclusion of these patients from most randomized controlled trials, data on specific challenges and outcomes remain limited. We aimed to characterize this patient population, evaluate clinical results and assess the significance of calcification patterns.

Methods

This retrospective single-centre analysis evaluated 2,712 TAVI procedures (2012-2019). Patients were stratified into three groups according to baseline kidney function: GFR <30 ml/min/1,73m² (CKD; n=210), end-stage renal disease requiring chronic hemodialysis (ESRD; n=119) and control (CTRL; n=2,383). Calcification patterns were assessed from contrast-enhanced multidetector computed tomography in a quantitative (valvular calcification) and semi-quantitative (vascular calcification) fashion. Outcomes were evaluated in accordance with the Valve Academic Research Consortium (VARC-2) definitions.

Results

Patients with ESRD were younger (75.1 vs. 83.4 (CKD) and 81.0 (CTRL) years, p<0.001) and severely impaired left-ventricular function was more frequent compared to CKD and CTRL (19.8% vs. 12.7% and 10.4%, p<0.01). Predicted operative risk was elevated in both ESRD and CKD groups (STS score 8.4% and 7.6% vs. 3.9%, p<0.001). While calcification of the aortic valve and left ventricular outflow tract were similar, patients with ESRD were more affected by severe vascular calcifications (49.1% vs. 33.9% and 29.0%, p<0.01). TAVI was performed with similar procedural characteristics and hemodynamic results. Rates for myocardial infarction (1.3%), major strokes (2.0%), and access site complications (6.0%) were similar among the groups. Disabling/life-threatening bleeding was similar early (<24h after TAVI: 3.4% vs. 3.9% vs. 3.1%, p=0.82) but higher in ESRD and CKD patients after the acute phase (>24h after TAVI: 5.0% and 5.3% vs. 1.6%, p<0.01). Mid-term 3-year survival was impaired in patients with ESRD and CKD compared to CTRL (33.3% and 35.3% vs. 65.4%, p<0.001) and multivariate analysis identified ESRD (HR 1.62 [95% CI 1.19-2.21]) and CKD (HR 1.79 [95% CI 1.37-2.34]), among other comorbidities, as independent predictors for 3-year but not early 30-day mortality. In contrast, vascular calcifications were found to be associated with 30-day (HR 1.54 [95% CI 1.07-2.22]) and 3-year mortality (HR 1.30 [95% CI 1.08-1.56]). 

Conclusion

Patients with ESRD on chronic hemodialysis and CKD constitute a particularly vulnerable patient group with extensive vascular calcifications. Regardless, immediate periprocedural results were similar to patients with preserved renal function, yielding TAVI a particularly valuable treatment option in these patients. Impaired mid-term survival likely reflects the underlying renal disease. Interestingly, vascular calcifications were additionally found to be strongly associated with increased mortality. Longer follow-up is now required to evaluate the longevity and rule out early prosthetic degeneration in patients with ESRD.