Outcomes of valve replacement with mechanical prosthesis versus bioprosthesis in dialysis patients: A 16-year multicenter experience

Readmission After Bioprosthetic vs Mechanical Mitral Valve Replacement in the United States

BACKGROUND

Choosing between a bioprosthetic and a mechanical mitral valve is an important decision for both patients and surgeons. We compared patient outcomes and readmission rates after bioprosthetic mitral valve replacement (Bio-MVR) vs mechanical mitral valve replacement (Mech-MVR).

METHODS

The Nationwide Readmissions Database was queried to identify 31 474 patients who underwent isolated MVR (22 998 Bio-MVR, 8476 Mech-MVR) between January 1, 2016, and December 31, 2018. Propensity score matching by age, sex, elective status, and comorbidities was used to compare outcomes between matched cohorts by prosthesis type. Freedom from readmission within the first calendar year was estimated by Kaplan-Meier analysis and compared between matched cohorts.

RESULTS

Bio-MVR patients were older (median age, 69 vs 57 years; P < .001) and had more comorbidities (median Elixhauser score, 14 vs 11; P < .001) compared with Mech-MVR patients. After propensity score matching (n = 15 549), Bio-MVR patients had similar operative mortality (3.5% vs 3.4%; P = .97) and costs ($50 958 vs $49 782; P = .16) but shorter lengths of stay (8 vs 9 days; P < .001) and fewer 30-day (16.0% vs 18.1%; P = .04) and 90-day (23.8% vs 26.8%; P = .01) readmissions compared with Mech-MVR patients. The difference in readmissions persisted at 1 year (P = .045). Readmission for bleeding or coagulopathy complications was less common with Bio-MVR (5.7% vs 10.1%; P < .001).

CONCLUSIONS

Readmission was more common after Mech-MVR than after Bio-MVR. Identifying and closely observing patients at high risk for bleeding complications may bridge the readmissions gap between Bio-MVR and Mech-MVR.

Long-term outcomes of mitral valve replacement in dialysis patients: evidence from a nationwide database

BACKGROUND

To compare the late outcomes between mechanical and bioprostheses after isolated mitral valve replacement (MVR) in dialysis-dependent patients.

METHODS

A nationwide propensity-matched retrospective cohort study was conducted involving dialysis patients who underwent primary mitral replacement between 2001 and 2018. Ten-year postoperative outcomes were compared between mitral bioprosthesis and mechanical prosthesis using the Cox proportional hazard model and restricted mean survival time (RMST).

RESULTS

The all-cause mortality was 20.8 and 13.0 events per 100 person-years, with a 10-year RMST of 7.40 and 7.31 years for bioprosthesis and mechanical prosthesis, respectively. Major bleeding was the most common adverse event for both bioprosthesis and mechanical prosthesis, with an incidence rate of 19.5 and 19.1 events per 100 person-years, respectively. The incidence of valve reoperation was higher among those who received bioprosthesis (0.55 events per 100 person-years). After 1:1 matching, the all-cause mortality was 15.45 and 14.54 events per 100 person-years for bioprosthesis and mechanical prosthesis, respectively. The RMST at 10 years was comparable between the two groups after matching (5.10 years for bioprosthesis vs. 4.59 years for mechanical prosthesis), with an RMST difference of -0.03. Further, no difference was observed in the incidence of major adverse valve-related events between bioprosthesis and mechanical valves. However, bioprosthesis was associated with a higher incidence of mitral valve reoperation among all major adverse events (RMST difference -0.24 years, 95% CI -0.48 to -0.01, P =0.047).

CONCLUSIONS

This study found no association between valve selection and long-term survival outcomes in dialysis patients after MVR. However, bioprosthetic valves may be associated with a slightly higher incidence of reoperation, while other valve-related adverse events, including major bleeding and stroke, were comparable between the two types of prostheses.

Sailing between scylla and charybdis-anticoagulation dilemma in a patient with calciphylaxis and mechanical cardiac valve replacement: a case report and literature review

Calciphylaxis is a rare and life-threatening condition in patients with end-stage kidney disease (ESKD). In this case report, we reported a 72-year-old female who had undergone aortic and mitral mechanical valve replacement 22 years ago due to rheumatic aortic and mitral stenosis. Following the valve replacement, she initiated warfarin treatment. Five years ago, she received a diagnosis of uremia and has since been undergoing regular hemodialysis. Ten months prior to her current admission, she experienced excruciating pain and was diagnosed with calciphylaxis. Additionally, an electrocardiogram revealed atrial fibrillation, while echocardiography indicated that the aortic and mitral mechanical valves were appropriately positioned, with normal perivalvular surroundings and good valve leaflet activity. No noticeable thrombosis was observed in the left atrium or left atrial appendage. Color Doppler imaging showed moderate stenosis in the lower extremity arteries, with no venous thromboembolism present. Extensive eggshell-like calcification within the arterial media was detected. The patient was managed with regular hemodialysis, symptomatic treatments (including anticoagulation and analgesia), and sodium thiosulfate. Unfortunately, symptomatic management provided limited relief, and during the one-month follow-up period, the patient passed away due to septic shock. Currently, there is insufficient conclusive evidence regarding alternative influential anticoagulants or appropriate prosthetic valve selection. For individuals with ESKD receiving maintenance hemodialysis, early identification, diagnosis, and treatment of calciphylaxis are of paramount importance.

Transcatheter aortic valve implantation versus surgical aortic valve replacement in dialysis-dependent patients: a meta-analysis

OBJECTIVES

This meta-analysis aims to compare the clinical outcomes of transcatheter aortic valve implantation (TAVI) versus aortic valve replacement (AVR) for aortic stenosis in dialysis-dependent patients.

METHODS

Literature searches employed PubMed, Web of Science, Google Scholar and Embase to identify relevant studies. Bias-treated data were prioritized, isolated and pooled for analysis; raw data were utilized where bias-treated data were unavailable. Outcomes were analysed to assess for study data crossover.

RESULTS

Literature search identified 10 retrospective studies; following data source analysis, five studies were included. Upon pooling of bias-treated data, TAVI was significantly favoured in early mortality [odds ratio (OR), 0.42; 95% confidence interval (95% CI), 0.19-0.92; I2  = 92%; P  = 0.03], 1-year mortality (OR, 0.88; 95% CI 0.80-0.97; I2  = 0%; P  = 0.01), rates of stroke/cerebrovascular events (OR, 0.71; 95% CI 0.55-0.93; I2  = 0%; P  = 0.01) and blood transfusions (OR, 0.36; 95% CI 0.21-0.62; I2  = 86%; P  = 0.0002). Pooling demonstrated fewer new pacemaker implantations in the AVR group (OR, 3.33; 95% CI 1.94-5.73; I2  = 74%; P  ≤ 0.0001) and no difference in the rate of vascular complications (OR, 2.27; 95% CI 0.60-8.59; I2  = 83%; P  = 0.23). Analysis including raw data revealed the length of hospital stay to favour TAVI with a mean difference of -9.20 days (95% CI -15.58 to -2.82; I2  = 97%; P  = 0.005).

CONCLUSION

Bias-treated meta-analysis comparing surgical AVR and TAVI favoured TAVI in early mortality, 1-year mortality, rates of stroke/cerebrovascular events and blood transfusions. There was no difference in the rates of vascular complications; however, TAVI required more pacemaker implantations. Data pooling including raw data revealed that the length of hospital admission favours TAVI.

Mechanical vs Bioprosthetic Aortic Valve Replacement in Patients on Dialysis: Long-term Outcomes

BACKGROUND

Using the Japan National Clinical Database and additional data, this study is an analysis of long-term survival of dialysis-dependent patients who underwent aortic valve replacement (AVR).

METHODS

Dialysis-dependent patients who underwent de novo AVR between 2010 and 2012 and who were registered in the database were included. Concomitant aortic surgery and transcatheter aortic valve replacement were excluded. Additional data on the underlying kidney disease, the duration of dialysis, and clinical outcomes were registered between October 29, 2019, and August 30, 2020. The primary outcome was all-cause mortality. The secondary outcomes were cerebral infarction, cerebral bleeding, gastrointestinal bleeding, and prosthetic valve failure.

RESULTS

After propensity score matching, 1016 cases (508 each in the bioprosthetic and mechanical valve groups) were matched. The median follow-up period was 3.29 years (interquartile range [IQR], 0.59 years, 6.25 years). The median survival time was 5.38 years (IQR, 1.20 and 9.26 years) in the mechanical valve group and 4.98 years (IQR, 1.69 and 9.62 years) in the bioprosthetic valve group. The Cox regression model showed no significant difference in long-term survival between the groups (mechanical valve: hazard ratio [HR], 0.895; 95% CI, 0.719-1.113; P = .318). The incidences of cerebral infarction and prosthetic valve failure requiring admission were similar between the groups. Cerebral bleeding (HR, 2.143; 95% CI, 1.125-4.080; P = .002) and gastrointestinal bleeding (HR, 2.071; 95% CI, 1.243-3.451; P = .0005) were more frequent in the mechanical valve group.

CONCLUSIONS

Long-term survival of dialysis-dependent patients was similar regardless of whether mechanical valves or bioprosthetic valves were implanted. The incidences of cerebral and gastrointestinal bleeding were 2-fold higher in the mechanical valve group.

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.

Prosthetic cardiac valves: history and review of cardiac prostheses clinically available in Japan

Recently developed prosthetic valves are reliable and essential for the treatment of valvular heart disease. The mechanical valve evolved remarkably following the introduction of pyrolite carbon material, which enabled the creation of a bileaflet form incorporated with a pivot mechanism. The improved durability of the biological valve is attributed mainly to the development of a tissue fixation process and anti-calcification treatments. However, optimal antithrombogenicity and durability have not yet been achieved for either prosthetic valve type. To select the most suitable prosthetic valve for each individual patient from among the many clinically available prosthetic valves, it is necessary to have a thorough understanding of the characteristics of each valve.

Surgical outcomes of minimally invasive aortic valve replacement via right mini-thoracotomy for hemodialysis patients

OBJECTIVES

Minimally invasive valve surgery has become increasingly accepted as an alternative to conventional median sternotomy in low-risk patients. However, there have been no reports regarding the outcomes of this procedure on high-risk hemodialysis patients. The purpose of this investigation was to assess the surgical outcomes of minimally invasive aortic valve replacement (AVR) via right mini-thoracotomy (MIAVR) in hemodialysis patients compared with those of conventional AVR (CAVR) via full sternotomy.

METHODS

Two hundred and seventy-four patients underwent isolated AVR for severe AS, and 42 hemodialysis patients were included in this study. MIAVR was performed in 17 cases and CAVR in 25 cases. We compared the short-term surgical outcome among the two groups.

RESULTS

There was no difference in the aortic cross-clamp or cardiopulmonary bypass time. However, the procedure time was significantly shorter in the MIAVR group. Patients in the MIAVR group had less bleeding and a smaller amount of transfused red blood cells. There were four hospital deaths (18.2%) in the CAVR group. For postoperative complications, there were 2 (9.1%) cerebrovascular incidents, 2 (9.1%) cases of respiratory failure, 1 (4.5%) re-exploration for bleeding in CAVR group. The postoperative ventilation time was significantly shorter in the MIAVR group. There was no difference in the length of postoperative intensive care unit stay or of postoperative hospital stay.

CONCLUSION

The surgical outcomes of MIAVR in hemodialysis patients were acceptable, with a low incidence of morbidity, reasonable lengths of hospital stay, and no mortality among the patients studied.

Longitudinal Hemodynamics of Aortic Bioprosthetic Valve in Hemodialysis Patients

We examined the hemodynamic profile of bioprosthetic aortic valves in patients on hemodialysis (HD), longitudinally, and assess the incidence of adverse changes detected by echocardiography. Of 1,146 consecutive patients with severe aortic stenosis who underwent bioprosthetic aortic valve replacement (AVR), 148 patients had end-stage renal disease requiring HD. Each patient on HD was matched one-to-one with a non-HD patient on the basis of propensity scores. The mean follow-up period was 3.3 years for the HD group and 5.9 years for the non-HD group. Follow-up information was available for 95.2%. Postoperative trends of valve hemodynamics derived from linear mixed-effect models showed significant group vs time interactions between the two groups. Stable hemodynamics was consistently observed in the non-HD group, whereas the HD group showed a decrease of -0.06 cm²/y (95% confidence interval (CI), -0.10 to -0.02) in effective orifice area, an increase of 0.8 mm Hg/year (95% CI, 0.4-1.1) in mean pressure gradient, and an increase of 0.08 m/s/year (95%CI, 0.02-0.13) in peak velocity. Cumulative incidence function of SVD more than stage 2 was significantly higher in the HD group (13.1% vs 3.1% at 5 years, Gray test p = 0.01). In a multivariable Fine-Gray analysis, diabetes was independently associated with SVD more than stage 2 in the HD group (subhazard ratio, 1.91; 95% CI, 1.25-2.89; p = 0.02). Survival free-from stenotic-type SVD was significantly lower in HD patients undergoing bioprosthetic AVR. Diabetes was independently associated with postoperative stenotic-type SVD in HD patients.

Cohort study: "Outcomes of kidney transplantation in patients with prosthetic heart valves"

The number of kidney transplant candidates with prosthetic heart valves (PHVs) is increasing. Yet, outcomes of kidney transplantation in these patients are still unclear. This is the first report of post-transplant outcomes in patients with PHVs at time of kidney transplantation. We conducted a matched cohort study among recipients from the multicentric and prospective DIVAT cohort to compare the outcomes in patients with left-sided PHVs at time of transplantation and a group of recipients without PHV matched according to age, dialysis time, initial disease, pretransplant DSA, diabetes, and cardiovascular events. Of 23 018 patients, 92 patients with PHVs were included and compared to 276 patients without PHV. Delayed graft function and postoperative bleeding occurred more frequently in patients with PHVs. Kidney graft survival was similar between groups. 5-year overall survival was 68.5% in patients with PHV vs. 87.9% in patients without PHV [HR, 2.72 (1.57-4.70), P = 0.0004]. Deaths from infection, endocarditis, and bleeding were more frequent in patients with PHV. Mechanical valves, but not bioprosthetic valves, were independent risk factors for mortality [HR, 2.89 (1.68-4.97), P = 0.0001]. Patients with PHV have high mortality rates after kidney transplantation. These data suggest that mechanical valves, but not biological valves, increase risks of post-transplant mortality.

The results of aortic arch replacement using antegrade cerebral perfusion in haemodialysis patients: analysis of the Japan cardiovascular surgery database

OBJECTIVES

There have been limited data available regarding aortic arch replacement in dialysis patients. The purpose of this study was to examine real-world data and to determine the impact of preoperative dialysis status and other risks on surgical aortic arch replacement using the Japan Cardiovascular Surgery Database.

METHODS

A total of 5044 patients who underwent elective, isolated aortic arch replacement using antegrade cerebral perfusion during 2014-2017 were eligible for the study. Of these, 89 patients received haemodialysis preoperatively. The patients were divided into 6 groups according to their preoperative estimated glomerular filtration rate and dialysis status for comparison. Preoperative and postoperative data were examined using a multivariable regression model.

RESULTS

The overall surgical mortality rates of non-Chronic Kidney Disease (CKD) (estimated glomerular filtration rate >60 ml/min/1.73 m2), stage 3A, stage 3B, stage 4, stage 5 CKD and dialysis patients were 2.6%, 3.1%, 6.8%, 11.6%, 16.7% and 13.5%, respectively. After risk adjustment, dialysis was shown to be strongly associated with surgical mortality (odds ratio 4.39 and 95% confidence interval 2.22-8.72) and have a trend to be associated with postoperative stroke (odds ratio 2.02, 95% confidence interval 1.00-4.10, P = 0.051) when compared to the non-CKD group. As predictors of mortality, male sex, peripheral arterial disease, preoperative liver dysfunction and impaired left ventricular function were identified.

CONCLUSIONS

The Japanese nationwide database revealed the outcomes of aortic arch replacement in dialysis patients. Appropriate counselling and an alternative strategy should be considered for such patients with multiple risks for mortality.

In patients undergoing dialysis who require a valve replacement is a bioprosthetic valve superior to a mechanical prosthesis in terms of long-term survival and morbidity?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In [dialysis patients undergoing a valve replacement] is [a bioprosthetic valve superior to a mechanical prosthesis] for [long-term survival and morbidity]'. Altogether more than 501 papers were found using the reported search, of which five represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. There was limited high-quality evidence with all studies being retrospective. One meta-analysis and four cohort studies provided the evidence that there was no significant difference in long-term survival based on prosthesis type. However, the majority of studies demonstrated a significantly higher rate of valve-related complications including bleeding and thromboembolism, and readmission to hospital in the mechanical valve prosthesis group, likely related to the requirement for long-term anticoagulation. We conclude that overall long-term survival in dialysis-dependent patients is poor. While prosthesis type does not play a significant contributing role to long-term survival, bioprosthetic valves were associated with significantly fewer valve-related complications. Based on the available evidence, a bioprosthetic valve may be more suitable in this high-risk group of patients as it may avoid the complications associated with long-term anticoagulation without any reduction in long-term survival.

Mechanical or biological heart valve for dialysis-dependent patients? A meta-analysis

OBJECTIVE

The optimal selection of prosthetic heart valve for dialysis-dependent patients remains controversial. We investigated the comparative effectiveness and safety of mechanical prosthesis (MP) and bioprosthesis (BP) for these patients.

METHODS

After the systematic review, we included studies that involved patients on dialysis undergoing aortic valve replacement or mitral valve replacement (MVR) and reported comparative outcomes of MP and BP. Meta-analysis was performed using random-effects model. We conducted a subgroup analysis based on the valve position and postoperative international normalized ratio (INR), which was extracted from either tables or methods of each study. A meta-regression was used to examine the effects of study-level covariates.

RESULTS

We included 24 retrospective studies without randomized-controlled trials, involving 10,164 participants (MP = 6934, BP = 3230). Patients undergoing aortic valve replacement with MP exhibited a better long-term survival effectiveness (hazard ratio, 0.64; 95% confidence interval [CI], 0.47-0.86). Conversely, studies including MVR demonstrated little difference in survival (hazard ratio, 0.90; 95% CI, 0.73-1.12). A meta-regression revealed that age had little effect on long-term survival difference between MP and BP (β = -0.0135, P = .433). MP had a significantly greater bleeding risk than did BP when INR was above 2.5 (incidence rate ratio, 10.58; 95% CI, 2.02-55.41). However, when INR was below 2.5, bleeding events were comparable (incidence rate ratio, 1.73; 95% CI, 0.78-3.82). The structural valve deterioration rate was significantly lower in MP (risk ratio, 0.24; 95% CI, 0.14-0.44).

CONCLUSIONS

MP is a reasonable choice for dialysis-dependent patients without additional thromboembolic risk requiring aortic valve replacement, for its better long-term survival, durability, and noninferior bleeding risk compared with BP. Conversely, BP might be an appropriate selection for patients with MVR, given its similar survival rate and lower bleeding risk. Although our meta-regression demonstrates little influence of age on long-term survival difference between MP and BP, further studies stratifying patients based on age cut-off are mandatory.