Importance: The frequency of baseline renal impairment among high-risk and inoperable patients with severe aortic stenosis undergoing a transcatheter aortic valve replacement (TAVR) and the effect of TAVR on subsequent renal function are, to our knowledge, unknown.
Objective: To determine the effect of TAVR among patients with baseline renal impairment.
Design, setting, and participants: This substudy of patients with baseline renal impairment (estimated glomerular filtration rate [eGFR] ≤ 60 mL/min) and paired baseline and 30-day measures of renal function undergoing TAVR in the PARTNER 1 trial and continued access registries was conducted in 25 centers in the United States and Canada.
Main outcomes and measures: Patients were categorized with improved eGFR (30-day follow-up eGFR≥10% higher than baseline pre-TAVR), worsened eGFR (≥10% lower), or no change in renal function (neither). Baseline characteristics, 30-day to 1-year all-cause mortality, and repeat hospitalization were compared. Multivariable models were constructed to identify predictors of 1-year mortality and of improvement/worsening in eGFR.
Results: Of the 821 participants, 401 (48.8%) were women and the mean (SD) age for participants with improved, unchanged, or worsening eGFR was 84.90 (6.91) years, 84.37 (7.13) years, and 85.39 (6.40) years, respectively. The eGFR was 60 mL/min or lower among 821 patients (72%), of whom 345 (42%) improved, 196 (24%) worsened, and 280 (34%) had no change at 30 days. There were no differences in baseline age, body mass index, diabetes, chronic obstructive pulmonary disease, coronary artery disease, peripheral arterial disease, hypertension, pulmonary hypertension, renal or liver disease, New York Heart Association III/IV symptoms, transaortic gradient, left ventricular ejection fraction, or procedural characteristics. The group with improved eGFR had more women, nonsmokers, and a lower cardiac index. Those with worsening eGFR had a higher median Society of Thoracic Surgeons score and left ventricle mass. From 30 days to 1 year, those with improved eGFR had no difference in mortality or repeat hospitalization. Those with worsening eGFR had increased mortality (25.5% vs 19.1%, P = .07) but no significant increases in repeat hospitalization or dialysis. Predictors of improved eGFR were being female (odds ratio [OR], 1.38; 95% CI, 1.03-1.85; P = .03) and nonsmoking status (OR, 1.49; 95% CI, 1.11-1.01; P = .01); predictors of worsening eGFR were baseline left ventricle mass (OR, 1.00; 95% CI, 1.00-1.01; P = .01), smoking (OR, 1.51; 95% CI, 1.06-2.14; P = .02), and age (OR, 1.03; 95% CI, 1.00-1.05; P = .05); and predictors of 1-year mortality were baseline left ventricular ejection fraction (OR, 0.98; 95% CI, 0.97-0.99; P = .003), baseline eGFR (OR, 0.98; 95% CI, 0.96-0.99; P < .001), and worsening eGFR vs no change in eGFR (OR, 1.51; 95% CI, 1.02-2.24; P = .04).
Conclusions and relevance: Baseline renal impairment was frequent among patients who underwent TAVR. While improved eGFR did not improve 1-year outcomes, worsening eGFR was associated with increased mortality.
Trial registration: clinicaltrials.gov Identifier: NCT00530894.