Impact of dialysis in patients undergoing bioprosthetic aortic valve replacement

Early structural valve deterioration of balloon expandable transcatheter aortic valve leaflets due to intrinsic and extrinsic nodular calcifications in a haemodialysis patient: a case report

Background

Several reports have shown that transcatheter aortic valves are comparable in durability to surgical aortic valves. However, early structural valve deterioration (SVD) is rarely reported to occur, especially in haemodialysis patients.

Case summary

We present a case of rapidly progressive bioprosthetic aortic valve stenosis in a patient with end-stage renal disease secondary to diabetic nephropathy in an 83-year-old female admitted due to progressive dyspnoea and orthopnoea. A 23 mm sized SAPIEN3 bioprosthetic aortic valve showed normal function for the first year after transcatheter aortic valve implantation (TAVI), but then rapidly developed stenosis and required acute hospitalization for heart failure a year and a half after surgery. Emergent surgical aortic valve replacement with a 19 mm On-X valve (CryoLife, Kennesaw, GA, USA) was performed. Pathological examination of the explanted SAPIEN 3 valve demonstrated severely degenerated bioprosthetic pericardial leaflets with severe intrinsic and extrinsic nodular calcifications, which could limit the leaflet motion.

Discussion

There is a lack of reports on the long-term procedural outcomes of TAVI in haemodialysis patients. The development of SVD in patients undergoing dialysis is multifactorial and has yet to be fully elucidated. In the presented case, the removed TAVI valve had severe extrinsic calcified nodules alongside a fibrin thrombus. Considering these pathological findings, antithrombotic therapy to prevent fibrin thrombus from adhering to the TAVI valve may be important to avoid early SVD.

Left atrial Thrombus formation after discontinuation of anticoagulation in patient with severe bioprosthetic mitral stenosis

BACKGROUND

Mitral valve stenosis can be a highly symptomatic condition with significant complications if left untreated. In such cases, mitral valve replacement with a bioprosthetic or mechanical valve may be a viable solution to prevent progressive disease. Current guidelines do not recommend continued anticoagulation beyond 6 months for patients who have undergone bioprosthetic valve replacement without a separate indication for anticoagulation. With this case discussion we aim to 1) Review the current indications for anticoagulation for bioprosthetic mitral valves in patients without atrial fibrillation and 2) Discuss the constellation of comorbidities that may affect the decision to begin anticoagulation therapy.

CASE PRESENTATION

We present a case describing a 55-year-old male with end-stage renal disease, coronary artery disease with coronary artery bypass graft surgery, and bioprosthetic mitral valve replacement 2 years prior with rapid degeneration of the replaced valve and on warfarin without a clear indication for anticoagulation. The patient was admitted for symptomatic, severe mitral stenosis and consideration of transcatheter mitral valve-in-valve replacement. During hospital admission, warfarin was discontinued and replaced with prophylactic anticoagulation. However, 8 days after warfarin cessation an intraoperative transesophageal echocardiography revealed a newly developed large left atrial thrombus leading to cancellation of the planned operation.

CONCLUSIONS

This patient developed a left atrial thrombus after discontinuing warfarin in the setting of rapidly deteriorating bioprosthetic valve stenosis and vascular comorbidities. The decision to discontinue warfarin was made in concordance with current guidelines, which do not indicate systemic anticoagulation post 3-6 months after bioprosthetic valve replacement without separate indication for anticoagulation. This case identifies the need to investigate rebound hypercoagulability and further risk stratify comorbidities which may independently increase the risk of clot formation in the setting of severe mitral valve stenosis.

A Case of Severe Aortic Stenosis after Aortic Valve Neocuspidization Using Autologous Pericardium (Ozaki Procedure)

A 56-year-old man with a history of left nephrectomy for Wilms' tumor on chronic hemodialysis underwent aortic valve neocuspidization using autologous pericardium (Ozaki procedure) for aortic stenosis (AS) due to a bicuspid aortic valve 6 years ago. The AS gradually progressed and a decrease in the left ventricular ejection fraction was observed. Because of this, we decided to perform reoperative aortic valve replacement using a mechanical valve. Intraoperative findings showed severe calcification at the site where the autologous pericardium was sutured to the annulus. However, the degeneration of the valve leaflets themselves was mild. While excellent mid-term results have been reported for the Ozaki procedure, the long-term results are still unclear. In this case, the annulus was severely calcified, which reduced the mobility of the leaflet. We report the first case of AS progression requiring reoperation in the long-term period after the Ozaki procedure.

Examination of Non-Infected Operatively-Excised Bioprostheses in the Aortic Valve Position to Determine the Reason for their Dysfunction

Described herein are findings in 55 non-infected bioprostheses that had been in the aortic valve position from 2 to 276 months (mean 107). The major purpose of this study was to illustrate the variable causes prompting excision of the bioprostheses. Fifty-three (96%) patients survived ≥ 30 days following the bioprosthetic excision and 50 (91%) patients lived ≥1 year postoperatively. The techniques used to explant the bioprostheses appear to vary considerably among the operating surgeons.

End-stage renal disease, calcification patterns and clinical outcomes after TAVI

BACKGROUND

Patients with chronic hemodialysis due to end-stage renal disease (ESRD) or severely impaired kidney function (CKD) constitute a relevant share of patients undergoing trans-catheter aortic valve implantation (TAVI). However, data on specific challenges and outcomes remain limited.

AIM

We aimed to characterize this patient population, evaluate clinical results and assess the significance of calcification patterns.

METHODS

This retrospective single-center analysis evaluated 2,712 TAVI procedures (2012-2019) according to baseline renal function: GFR < 30 ml/min/1.73m2 (CKD; n = 210), chronic hemodialysis (ESRD; n = 119) and control (CTRL; n = 2383). Valvular and vascular calcification patterns were assessed from contrast-enhanced multi-detector computed tomography. Outcomes were evaluated in accordance with the VARC-2 definitions.

RESULTS

Operative risk was higher in ESRD and CKD vs. CTRL (STS-score 8.4% and 7.6% vs. 3.9%, p < 0.001) and patients with ESRD had more severe vascular calcifications (49.1% vs. 33.9% and 29.0%, p < 0.01). Immediate procedural results were similar but non-procedure-related major/life-threatening bleeding was higher in ESRD and CKD (5.0% and 5.3% vs. 1.6%, p < 0.01). 3-year survival was impaired in patients with ESRD and CKD (33.3% and 35.3% vs. 65.4%, p < 0.001). Multivariable analysis identified ESRD (HR 1.60), CKD (HR 1.79) and vascular calcifications (HR 1.29) as predictors for 3-year and vascular calcifications (HR 1.51) for 30-day mortality.

CONCLUSION

Patients with ESRD and CKD constitute a vulnerable patient group with extensive vascular calcifications. Immediate procedural results were largely unaffected by renal impairment, yielding TAVI a particularly valuable treatment option in these high-risk operative patients. Mid-term survival was determined by underlying renal disease, cardiovascular comorbidities, and vascular calcifications as a novel risk marker.

Mid-term results of surgical aortic valve replacement with bioprostheses in hemodialysis patients

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HD patients underwent SAVR-BP for AS (hospital mortality, 8.8%; 5-year mortality, 42.1%).

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Preoperative risk factors for 5-year mortality: age, hyperlipidemia, LVDd, LVDs, and Japan SCORE.

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Postoperative risk factors for 5-year mortality: length of ICU stay, and albumin level at discharge.

Background

Limited studies have assessed the factors affecting prognosis in hemodialysis (HD) patients who undergo surgical aortic valve replacement with a bioprostheses (SAVR-BP). This study aimed to evaluate the outcomes of HD patients who had undergone SAVR-BP for aortic stenosis (AS) and identify the risk factors for mortality.

Methods

This retrospective study included 57 HD patients who had undergone SAVR-BP for AS between July 2009 and December 2020. Multivariate logistic regression was used to predict factors associated with mid-term outcomes and death or survival. Kaplan − Meier curves were also generated for mid-term survival.

Results

The in-hospital mortality rate was 8.8%, and the 5-year mortality rate was 42.1%. The independent predictors of 5-year mortality were preoperative age (hazard ratio [HR], 1.57; 95% confidence interval [CI], 1.175–2.083, p = 0.002), hyperlipidemia (HR, 0.02; 95% CI, 0.002–0.297, p = 0.004), left ventricular diastolic diameter (HR, 1.74; 95% CI, 1.142–2.649, p = 0.010), left ventricular systolic diameter (HR, 0.61; 95% CI, 0.392–0.939, p = 0.025), and Japan SCORE (HR, 1.28; 95% CI, 1.052–1.563, p = 0.014). The postoperative predictors included intensive care unit stay (HR, 1.11; 95% CI, 1.035–1.194, p = 0.004) and albumin level (HR, 0.38; 95% CI, 0.196–0.725, p = 0.003).

Conclusions

The 5-year prognosis of HD patients undergoing SAVR may be improved by early diagnosis (before the occurrence of LV hypertrophy/enlargement) and nutritional management with oral intake to alleviate postoperative hypoalbuminemia.

Registration number of clinical studies: UMIN000047410.