Descriptive analysis of long-term survival after aortic valve replacement for dialysis patients: importance of renal pathologies and age

OBJECTIVES

This study analyzed the long-term survival of dialysis patients undergoing AVR using the Japanese National Clinical Database with additional survival data.

METHODS

De-novo AVR for dialysis-dependent patients between 2010 and 2012 who were registered in the Japan Cardiovascular Surgery Database were included. Concomitant aortic surgery and transcatheter aortic valve replacement were excluded. An additional questionnaire was sent to each hospital regarding the underlying kidney disease, the duration of dialysis initiation to the surgery, and clinical outcomes. The Kaplan-Meier survival curve was descriptively shown for all cohorts and each renal pathology. Furthermore, we compared the incidence of bioprosthetic valve failure in patients who were < 65 years old (group Y) and ≧65 years old (group O).

RESULTS

Of these 1529 patients, diabetic nephropathy was 517, chronic glomerulonephritis was 437, and renal sclerosis was 210, regarding renal pathology. 1, 3, and 5-year survival in each pathology was 78.4%, 58.6%, 45.9% in diabetic nephritis, 78.8%, 68.4%, 58.2% in chronic glomerulonephritis, 79.0%, 67.8%, 52.1% in renal sclerosis, and 74.4%, 62.6%, 49.2% in others. Active infectious endocarditis was more prevalent in group Y (O 2.7% vs. Y 9.6%). The incidence of bioprosthetic valve failure requiring re-hospitalization was too small to analyze. 1, 3, and 5-year survival was 76.0%, 63.4%, 49.2% in group O and 74.3%, 64.2%, and 47.7% in group Y.

CONCLUSIONS

Long-term survival of AVR for dialysis-dependent was higher in patients with chronic glomerulonephritis and lower in patients with diabetic nephritis than in other pathologies.

In-hospital outcomes after SAVR or TAVI in patients with severe aortic stenosis

There were no data comparing the in-hospital outcomes after transcatheter aortic valve implantation (TAVI) with those after surgical aortic valve replacement (SAVR) in Japan. Among consecutive patients with severe AS between April 2018 and December 2020 in the CURRENT AS Registry-2, we identified 1714 patients who underwent aortic valve replacement (TAVI group: 1134 patients, and SAVR group: 580 patients). Patients in the TAVI group were much older (84.4 versus 73.6 years, P < 0.001) and more often had comorbidities than those in the SAVR group. In-hospital death rate was numerically lower in the TAVI group than in the SAVR group (0.6% versus 2.2%). After excluding patients with dialysis, in-hospital death rate was very low and comparable in the TAVI and SAVR groups (0.6% versus 0.8%). The rates of major bleeding and new-onset atrial fibrillation during index hospitalization were higher after SAVR than after TAVI (72% versus 20%, and 26% versus 4.6%, respectively), while the rate of pacemaker implantation was higher after TAVI than after SAVR (8.1% versus 2.4%). Regarding the echocardiographic data at discharge, the prevalence of patient-prosthesis mismatch was lower in the TAVI group than in the SAVR group (moderate: 9.0% versus 26%, and severe: 2.6% versus 4.8%). In this real-world data in Japan, TAVI compared with SAVR was chosen in much older patients with more comorbidities with severe AS. In-hospital death rate was numerically lower in the TAVI group than in the SAVR group.

Validation study of EuroSCORE II for dialysis patients: A single-center study in Japan

BACKGROUND

The European System for Cardiac Operative Risk Evaluation (EuroSCORE) II is a predictive model for in-hospital mortality after cardiac surgery. Although it has good performance among the general population undergoing cardiac surgery, it has not been validated among dialysis patients, who have a higher rate of mortality after cardiac surgery. This study aimed to evaluate the performance of the model in predicting in-hospital mortality in maintenance dialysis patients undergoing cardiac surgery.

METHODS

This retrospective, single-center study included adult patients on maintenance dialysis who underwent open cardiac surgery at our institution. Calibration performance of EuroSCORE II for in-hospital death was determined based on the comparison between expected and observed mortalities for low- (EuroSCORE II <4 %), intermediate- (4-8 %), and high-risk (>8 %) groups. The area under receiver operating characteristic curve (AUROC) was investigated to determine the model's discrimination performance.

RESULTS

A total of 163 patients (male, 73.6 %; median age, 70 years; median dialysis vintage, 9 years; median EuroSCORE II, 3.3 %) were included. The mortality rate was 9.2 %. The observed mortality rates (vs. mean expected mortality) rates were 2.1 % (vs. 2.4 %), 7.5 % (vs. 5.5 %), and 34.5 % (vs. 21.1 %) in the low-, intermediate-, and high-risk groups, respectively. Its AUROC was 0.825 (95 % confidence interval, 0.711-0.940).

CONCLUSIONS

Although EuroSCORE II model adequately estimated in-hospital mortality in the low-and intermediate-risk groups (EuroSCORE II <8 %), it underestimated in-hospital mortality in the high-risk group (EuroSCORE II >8 %) among maintenance dialysis patients. The discrimination performance of the model for in-hospital death was good among maintenance dialysis patients.

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.

Association between Serum Phosphate Levels and the Development of Aortic Stenosis in Patients Undergoing Hemodialysis

We aimed to investigate the factors associated with the development of aortic stenosis (AS) in patients undergoing hemodialysis (HD), and to elucidate the prognosis of HD patients with AS. Patients on HD that had also undergone echocardiography at Nagasaki Renal Center between July 2011 and June 2012 were included. Patients with AS at the time of inclusion were excluded. The diagnosis of AS was based on an annual routine or additional echocardiography. The patients were followed up until June 2021. The association between patient background and AS was also evaluated. Of the 302 patients (mean age, 67.4 ± 13.3 years; male, 58%; median dialysis history, 4.7 years), 60 developed AS and 10 underwent aortic valve replacement. A Cox proportional hazards model revealed that age (hazard ratio (HR), 1.07; 95% confidential interval (CI), 1.04–1.10; p < 0.001) and serum phosphate levels (HR, 1.40; 95%CI, 1.16–1.67, p < 0.001) were independent risk factors for developing AS. Incidentally, there was no significant mortality difference between patients with AS and those without (p = 0.53). Serum phosphate levels are a risk factor for developing AS and should be controlled. Annual echocardiography may contribute to the early detection of AS and improves the prognosis of patients undergoing HD.

One-year outcomes of the pivotal clinical trial of a balloon-expandable transcatheter aortic valve implantation in Japanese dialysis patients

BACKGROUND

Dialysis patients with aortic stenosis are generally considered as being at extreme or high surgical risk. Herein, the first clinical trial was conducted to investigate clinical safety and effectiveness of transcatheter aortic valve replacement (TAVR) using the balloon-expandable transcatheter aortic valve (SAPIEN 3, Edwards Lifesciences, Irvine, CA, USA) in Japanese dialysis patients.

METHODS

The clinical trial is a single arm, prospective, open, non-randomized, Japanese multicenter study. The primary purpose of this trial is to evaluate the efficacy and safety of TAVR using SAPIEN 3 in 28 Japanese dialysis patients.

RESULTS

Mean age was 79.2 years and 67.9% were male (Mean STS score was 14.3%). Transfemoral and transapical approaches were performed in 25 (89.3%) and 3 patients (10.7%), respectively. All bioprostheses were successfully implanted. Median intensive care unit stay and hospital stay after TAVR were 1.4 days and 6.3 days, respectively. In-hospital mortality was 3.6% and freedom from all-cause mortality at 1 year was 89.3%. Disabling stroke and life-threatening bleeding at 1 year was 7.7% and 8.5%, respectively. There was no structural valve deterioration during follow-up. New York Heart Association functional status, six-minute walk test, and EuroQOL visual analogue scale score significantly improved through 1 year compared with baseline.

CONCLUSIONS

TAVR using SAPIEN 3 is safe and effective for the treatment of Japanese dialysis patients with symptomatic severe aortic valve stenosis.

A computational strategy for metabolic network construction based on the overlapping ratio: Study of patients' metabolic responses to different dialysis patterns

BACKGROUND

Uremia is a worldwide epidemic disease and poses a serious threat to human health. Both maintenance hemodialysis (HD) and maintenance high flux hemodialysis (HFD) are common treatments for uremia and are generally used in clinical applications. In-depth exploration of patients' metabolic responses to different dialysis patterns can facilitate the understanding of pathological alterations associated with uremia and the effects of different dialysis methods on uremia, which may be used for future personalized therapy. However, due to variations of multiple factors (i.e., genetic, epigenetic and environment) in the process of disease treatments, identification of the similarities and differences in plasma metabolite changes in uremic patients in response to HD and HFD remains challenging.

METHODS

In this study, a computational strategy for metabolic network construction based on the overlapping ratio (MNC-OR) was proposed for disease treatment effect research. In MNC-OR, the overlapping ratio was introduced to measure metabolic reactions and to construct metabolic networks for analysis of different treatment options. Then, MNC-OR was employed to analyze HD-pattern-dependent changes in plasma metabolites to explore the pathological alterations associated with uremia and the effectiveness of different dialysis patterns (i.e., HD and HFD) on uremia. Based on the networks constructed by MNC-OR, two network analysis techniques, namely, similarity analysis and difference analysis of network topology, were used to find the similarity and differences in metabolic signals in patients under treatment with either HD or HFD, which can facilitate the understanding of pathological alterations associated with uremia and provide the guidance for personalized dialysis therapy.

RESULTS

Similarity analysis of network topology suggested that abnormal energy metabolism, gut metabolism and pyrimidine metabolism might occur in uremic patients, and maintenance of both HFD and HD therapies have beneficial effects on uremia. Then, difference analysis of network topology was employed to extract the crucial information related to HD-pattern-dependent changes in plasma metabolites. Experimental results indicated that the amino acid metabolism was closer to the normal status in HFD-treated patients; however, in HD-treated patients, the ability of antioxidation showed greater reduction, and the protein O-GlcNAcylation level was higher. Our findings demonstrate the potential of MNC-OR for explaining the metabolic similarities and differences of patients in response to different dialysis methods, thereby contributing to the guidance of personalized dialysis therapy.