Association between mid-term worsening renal function and mortality after transcatheter aortic valve replacement in patients with chronic kidney disease

INTRODUCTION

Chronic kidney disease (CKD), acute kidney injury (AKI) and worsening renal function at 30 days after transcatheter aortic valve replacement (TAVR) portend poor outcomes. We sought to evaluate the association between worsening renal function at 3-6 months and mortality among patients with baseline renal dysfunction undergoing TAVR.

METHODS

This is a retrospective study of patients with glomerular filtration rate (GFR) < 60 ml/min undergoing TAVR between June 2011 and March 2019 at the Regional Cardiac Catheterization Lab at Kaiser Permanente Los Angeles. Worsening renal function at 3-6 months post-TAVR was defined as: increase in serum creatinine >1.5 times compared to baseline, absolute increase of ≥0.3 mg/dl, or initiation of dialysis.

RESULTS

Of 683 patients reviewed, 176 were included in the analysis (median age 84 [IQR 79-88] years, 56% female). Of these, 27 (15.3%) had worsening renal function. AKI post-TAVR (OR 2.9, 95% CI 1.1-7.4, p = .03) and transfusion of ≥4 units red blood cells (OR 8.4, 95% CI 1.2-59, p = .03) were independent predictors of worsening renal function. Worsening renal function increased risk for mortality (HR 2.2, 95% CI 1.17-4.27, p = .015) at a median follow-up of 691 days. Those with improved/stable function with baseline GFR < 60 ml/min had comparable mortality risk to those with baseline GFR ≥ 60 ml/min (18% vs. 16.5%; HR 1.1, 95% CI 0.72-1.75, p = .62).

CONCLUSION

Among patients with baseline renal dysfunction, only 15% developed worsening renal function at 3-6 months after TAVR, which was associated with increased mortality. Predictors for worsening renal function include AKI and blood transfusions. Preventative measures peri-procedurally and continued monitoring post-discharge are warranted to improve outcomes.

Evolution of chronic kidney disease after surgical aortic valve replacement or transcatheter aortic valve implantation

BACKGROUND

Immediate improvement in kidney function has been reported after surgical aortic valve replacement or transcatheter aortic valve implantation. Long-term data, however, are not available.

AIM

To assess the evolution of kidney function in chronic kidney disease stage 3b-5, 1 year after surgical aortic valve replacement or transcatheter aortic valve implantation.

METHODS

All patients with chronic kidney disease stage 3b-5 undergoing surgical aortic valve replacement or transcatheter aortic valve implantation for aortic stenosis in a single centre were included. Kidney function was assessed 1 year postprocedure. Improvement or deterioration in estimated glomerular filtration rate was defined by an increase or decrease of 5mL/min/1.73 m², respectively.

RESULTS

Overall, 127 procedures were analysed (54 surgical aortic valve replacements and 73 transcatheter aortic valve implantations). Kidney function improved in 51% of patients at 1 year (45% of the surgical aortic valve replacement group versus 57% of the transcatheter aortic valve implantation group; P=0.21), and deteriorated in only 14% of patients at 1 year (18% of the surgical aortic valve replacement group versus 10% of the transcatheter aortic valve implantation group; P=0.22). Almost a quarter of patients (23%) had an improvement in estimated glomerular filtration rate of>15mL/min/1.73 m², and this was consistent at later follow-up. Few patients went onto chronic dialysis at 1 year (three after surgical aortic valve replacement and one after transcatheter aortic valve implantation). Acute kidney injury was an independent prognostic factor for long-term deterioration in kidney function (odds ratio 2.1, 95% confidence interval 1.4-3.6; P=0.006).

CONCLUSION

Aortic valve replacement, whether by surgical aortic valve replacement or transcatheter aortic valve implantation, improved estimated glomerular filtration rate at 1 year in more than half of patients with chronic kidney disease stage 3b-5.

Renal function in patients with mechanical prosthetic valves : Long-term effects of anticoagulation and over-anticoagulation with warfarin

BACKGROUND

Warfarin-related nephropathy (WRN) is a complication of warfarin over-anticoagulation that is associated with acute and/or chronic renal dysfunction and increased mortality. The long-term effects of warfarin on renal function has not been adequately studied in patients with a mechanical prosthetic valve (MPV).

AIM

To study the time-dependent effects of over-anticoagulation on renal function in patients with a MPV.

METHODS

A total of 193 patients who underwent MPV implantation and were followed up in this study were eligible for inclusion. Time above therapeutic international normalized ratio (INR) range (TATR) was calculated by dividing the number of INR measurements above target in a year by the total number of INR measurements within a year. Patients were divided into quartiles according to average TATR at 60 months.

RESULTS

At 60 months more patients within the 4th quartile had a ≥20% reduction in the estimated glomerular filtration rate (eGFR, 25.0%, p = 0.04) and chronic kidney disease (CKD, 33.0%, p = 0.07) compared to patients within the 1st quartile. High TATR remained a significant determinant for reduction in eGFR (odds ratio OR: 7.50, 95% confidence interval CI:1.55-36.32) and CKD (OR:5.15, 95% CI: 1.26-20.62) after adjusting for other variables. Longitudinal analysis revealed that the change in eGFR was related to the duration of warfarin use (p < 0.001) and the interaction between the duration of warfarin use and TATR (p = 0.03). Similar findings were observed in patients without CKD at baseline, but not in those with CKD before the index operation.

CONCLUSION

Anticoagulation over targeted INR values is associated with a steeper decline in eGFR and an increased frequency of CKD in patients with a MPV.

Association of frailty status with acute kidney injury and mortality after transcatheter aortic valve replacement: A systematic review and meta-analysis

Objective

Frailty is a common condition in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). The aim of this systematic review was to assess the impact of frailty status on acute kidney injury (AKI) and mortality after TAVR.

Methods

A systematic literature search was conducted using MEDLINE, EMBASE, and Cochrane databases from the inception through November 2016. The protocol for this study is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42016052350). Studies that reported odds ratios, relative risks or hazard ratios comparing the risk of AKI after TAVR in frail vs. non-frail patients were included. Mortality risk was evaluated among the studies that reported AKI-related outcomes. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

Results

Eight cohort studies with a total of 10,498 patients were identified and included in the meta-analysis. The pooled RR of AKI after TAVR among the frail patients was 1.19 (95% CI 0.97–1.46, I² = 0), compared with non-frail patients. When the meta-analysis was restricted only to studies with standardized AKI diagnosis according to Valve Academic Research Consortium (VARC)-2 criteria, the pooled RRs of AKI in frail patients was 1.16 (95% CI 0.91–1.47, I² = 0). Within the selected studies, frailty status was significantly associated with increased mortality (RR 2.01; 95% CI 1.44–2.80, I² = 58).

Conclusion

The findings from our study suggest no significant association between frailty status and AKI after TAVR. However, frailty status is associated with mortality after TAVR and may aid appropriate patient selection for TAVR.