Acute kidney injury and in-hospital outcomes after transcatheter aortic valve replacement in patients without chronic kidney disease: insights from the national inpatient sample

BACKGROUND

Acute kidney injury (AKI) complicates transcatheter aortic valve replacement (TAVR), leading to higher mortality. The incidence and effects of AKI on clinical outcomes in patients undergoing TAVR without chronic kidney disease (CKD) are unclear. We aimed to determine the association between AKI and in-hospital outcomes in patients with TAVR using propensity score matching (PSM).

METHODS

Using International Classification of Diseases-10th Revision codes, we queried the National Inpatient Sample for TAVR performed between 2016 and 2021. Patients were divided into two groups according to perioperative AKI development. Patients with CKD or on permanent hemodialysis at baseline were excluded. We conducted 1:1 PSM to assemble a cohort of patients with similar baseline characteristics. Multivariate logistic regression was used to assess the association between AKI and in-hospital outcomes. Sensitivity analysis was conducted to evaluate the robustness of our inferences.

RESULTS

Of 47,372 unweighted patient admissions for TAVR, 1617 (3.41%) had a concomitant diagnosis of AKI. The incidence of AKI decreased from 4.82 to 3.18% from 2016 to 2021 (P-trend < 0.01). Before PSM, patients with AKI had a significantly higher rate of in-hospital mortality compared with those without AKI (6.12% vs. 0.48%, respectively; odds ratio [OR] 8.59, 95% confidence interval [CI] 6.32-11.68). Using the PSM algorithm, 1579 well-matched patients were included in each group. After PSM, an association was observed between patients with TAVR and concomitant AKI and a higher risk of in-hospital mortality (6.21% vs. 1.08%, respectively; OR 5.96; 95% CI 3.54-10.04). In subgroup analyses stratified according to age (≤ 80 and > 80 years), sex (male/female), and hypertension status, consistent associations were observed between AKI and the risk of in-hospital mortality. AKI patients were at higher risk for acute myocardial infarction (OR 1.78, 95% CI 1.35-2.34), major bleeding (OR 1.62, 95% CI 1.13-2.33), blood transfusion (OR 1.65, 95% CI 1.28-2.11), and cardiogenic shock (OR 3.73, 95% CI 2.77-5.01). No significant betweengroup differences were observed in stroke (P = 0.12).

CONCLUSION

AKI was a strong predictor of in-hospital mortality in patients undergoing TAVR without CKD and was associated with higher post-procedure complication rates.

Perioperative Changes in Plasma Nitrite and IL-6 Levels Predict Postoperative Atrial Fibrillation (POAF) and Acute Kidney Injury (AKI) after Cardiac Surgery

Background: Postoperative atrial fibrillation (POAF) and acute kidney injury (AKI) are common yet significant complications after cardiac surgery, with incidences of up to 40% for each. Here, we assessed plasma nitrite and serum interleukin-6 (IL-6) levels before and after cardiac surgery to quantify the extent to which oxidative stress and inflammation contribute to POAF and AKI occurrence. Methods: We prospectively enrolled 206 cardiac surgical patients. Plasma nitrite and serum IL-6 levels were determined preoperatively and at 24 h, 48 h and 72 h postoperatively. The patients had continuous EKG monitoring for occurrence of POAF, while daily serum creatinine was measured for determination of stage 1 + AKI. Results: Postoperatively, 78 (38%) patients experienced AF, and 47 (23%) patients experienced stage 1 + AKI. POAF analysis: Age, ACE-inhibitor use, valve surgery and percent change in baseline plasma nitrite at 24 h postoperatively were associated with POAF in multiple logistic regression analysis. The inclusion of this new biomarker significantly improved the POAF prediction model (AUC 0.77 for clinical risk factors alone, to AUC 0.81). AKI analysis: A history of diabetes mellitus was associated with AKI in multiple logistic regression analysis, and the addition of preoperative IL-6 levels improved the prediction model for AKI occurrence (AUC 0.69 to AUC 0.74). Conclusions: We previously observed selective upregulation of NADPH oxidase isoform 4 (NOX4) in patients with AF, a critical causal role of NOX4 for AF in zebrafish and a robust inhibitory effect of nitric oxide (NO) on NOX4. Our data innovatively demonstrate that a reduction in circulating nitrite levels, likely implicative of elevated NOX4-mediated oxidative stress, independently associates with POAF and improves POAF prediction, whereas the inclusion of circulating IL-6 levels improves the prediction model for AKI. Therefore, therapeutic strategies to mitigate these pathophysiological sequalae of surgical stress may reduce the incidence of severe postoperative complications of POAF and AKI.

Factors Associated With Acute Kidney Injury in Patients Undergoing Transcatheter Aortic Valve Implantation: A Systematic Review and Meta-Analysis

The aim of this meta-analysis is to assess the effect of different independent predictors on acute kidney injury (AKI) after transcatheter aortic valve implantation (TAVI). This meta-analysis adhered to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A comprehensive database search was conducted using PubMed, Web of Science, and Scopus for the period from January 1, 2015, to August 15, 2023. The following key terms were employed: "transcatheter aortic valve implantation" OR "transcatheter aortic valve replacement" AND "acute kidney injury" OR "acute renal failure." Our search was limited to studies published exclusively in the English language. The statistical analysis was conducted using RevMan version 5.4.1 (The Cochrane Collaboration). Estimates were presented as odds ratio (OR) with 95% confidence interval (CI) for categorical variables, while continuous variables were reported as mean difference (MD) with 95% CI. A total of 19 studies met the selection criteria and were included in the meta-analysis. The pooled incidence of AKI was reported as 20% (95% CI: 18-20%). Factors significantly associated with post-TAVI AKI encompass hypertension, chronic kidney disease (CKD), low estimated glomerular filtration rate (eGFR), high baseline creatinine levels, peripheral vascular disease (PVD), Society of Thoracic Surgeons (STS) score, European System for Cardiac Operative Risk Evaluation (EUROscore) II, and the transfemoral surgical approach.

Transcatheter Aortic Valve Replacement in Elderly Patients: Opportunities and Challenges

Over the past two decades, the rapid evolution of transcatheter aortic valve replacement (TAVR) has revolutionized the management of severe aortic stenosis (AS) in the elderly. The prevalence of comorbidities in elderly AS patients presents a considerable challenge to the effectiveness and prognosis of patients after TAVR. In this article, we aim to summarize some of the clinical aspects of the current use of TAVR in elderly patients and attempt to highlight the challenges and issues that need further consideration.

Transcatheter Aortic Valve Replacement-Associated Acute Kidney Injury: An Update

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is a relatively novel minimally invasive procedure for the treatment of symptomatic patients with severe aortic stenosis. Although it has been proven effective in improving mortality and quality of life, TAVR is associated with serious complications, such as acute kidney injury (AKI).

SUMMARY

TAVR-associated AKI is likely due to several factors such as sustained hypotension, transapical approach, volume of contrast use, and baseline low GFR. This narrative review aims to present an overview of the latest literature and evidence regarding the definition of TAVR-associated AKI, its risk factors, and its impact on morbidity and mortality. The review used a systematic search strategy with multiple health-focused databases (Medline, EMBASE) and identified 8 clinical trials and 27 observational studies concerning TAVR-associated AKI. Results showed that TAVR-associated AKI is linked to several modifiable and nonmodifiable risk factors and is associated with higher mortality. A variety of diagnostic imaging modalities have the potential to identify patients at high risk for development of TAVR-AKI; however, there are no existing consensus recommendations regarding their use as of this time. The implications of these findings highlight the importance of identifying high-risk patients for which preventive measures may play a crucial role, and should be maximized.

KEY MESSAGE

This study reviews the current understanding of TAVR-associated AKI including its pathophysiology, risk factors, diagnostic modalities, and preventative management for patients.

The effect of preoperative statins on postoperative mortality, renal, and neurological complications in patients undergoing cardiac surgeries: a retrospective cohort study

BACKGROUND

Cardiac surgery is performed worldwide to treat severe cases of cardiovascular diseases. Statins have shown controversial effects on complications after cardiac surgeries. We aimed to investigate the effect of preoperative statin therapy on the frequency of postoperative mortality, renal, and neurological complications.

METHODS

In a retrospective cohort study, the database of patients operated on in two hospitals in southern Iran during 2008-2019 was used to compare preoperative statin use with no use on the composite outcome of mortality, renal, and neurological complications as well as on each component of the composite, separately. Effects of low dose (<40 mg simvastatin equivalence) vs. high dose (≥40 mg) statins were also evaluated. Confounders that could affect the outcomes were considered in the logistic regression model, and multiple imputation techniques were used to categorize patients with unknown statin dose use as either high or low-dose users.

RESULTS

Of total 7329 patients, 17.6% of statin users and 17% of non-statin users developed the composite outcome (P=0.51). Statin use had no statistically significant association with the composite outcome (aRR 1.01 [95% CI: 0.88-1.16]). There was no significant association with mortality [aRR: 0.75 (95% CI: 0.34-1.69)], neurological [aRR: 1.25 (95% CI: 0.77-2.12)], or renal complications [aRR: 1.03 (95% CI 0.90-1.19)] after surgery. Neither low nor high doses had any statistically significant effect on the composite or any of its components.

CONCLUSIONS

In this large study, preoperative statin use, either high dose or low dose, did not affect short-term postoperative mortality, neurological, or renal complications.

In-hospital outcomes following percutaneous versus surgical intervention in the treatment of aortic stenosis and concomitant coronary artery disease

INTRODUCTION AND OBJECTIVES

Concomitant coronary artery disease (CAD) is prevalent among aortic stenosis patients; however the optimal therapeutic strategy remains debated. We investigated periprocedural outcomes among patients undergoing transcatheter aortic valve implantation with percutaneous coronary intervention (TAVI/PCI) vs surgical aortic valve replacement with coronary artery bypass grafting (SAVR/CABG) for aortic stenosis with CAD.

METHODS

Using discharge data from the Spanish National Health System, we identified 6194 patients (5217 SAVR/CABG and 977 TAVI/PCI) between 2016 and 2019. Propensity score matching was adjusted for baseline characteristics. The primary outcome was in-hospital all-cause mortality. Secondary outcomes were in-hospital complications and 30-day cardiovascular readmission.

RESULTS

Matching resulted in 774 pairs. In-hospital all-cause mortality was more common in the SAVR/CABG group (3.4% vs 9.4%, P <.001) as was periprocedural stroke (0.9% vs 2.2%; P=.004), acute kidney injury (4.3% vs 16.0%, P <.001), blood transfusion (9.6% vs 21.1%, P <.001), and hospital-acquired pneumonia (0.1% vs 1.7%, P=.001). Permanent pacemaker implantation was higher for matched TAVI/PCI (12.0% vs 5.7%, P <.001). Lower volume centers (< 130 procedures/y) had higher in-hospital all-cause mortality for both procedures: TAVI/PCI (3.6% vs 2.9%, P <.001) and SAVR/CABG (8.3 vs 6.8%, P <.001). Thirty-day cardiovascular readmission did not differ between groups.

CONCLUSIONS

In this large contemporary nationwide study, percutaneous management of aortic stenosis and CAD with TAVI/PCI had lower in-hospital mortality and morbidity than surgical intervention. Higher volume centers had less in-hospital mortality in both groups. Dedicated national high-volume heart centers warrant further investigation.

Propensity matched comparison of TAVI and SAVR in intermediate-risk patients with severe aortic stenosis and moderate-to-severe chronic kidney disease: a subgroup analysis from the German Aortic Valve Registry

OBJECTIVE

We compared TAVI vs. SAVR in patients with moderate-to-severe chronic kidney disease (eGFR 15-60 ml/min/1.73 m2) for whom both procedures could possibly be considered (age ≤ 80 years, STS-score 4-8).

BACKGROUND

According to both ACC/AHA and ESC/EACTS recent guidelines, aortic stenosis may be treated with either transcatheter (TAVI) or surgical (SAVR) aortic valve replacement in a subgroup of patients. A shared therapeutic decision is made by a heart team based on individual factors, including chronic kidney disease (CKD).

METHODS

Data from the large nationwide German Aortic Valve Registry were used. A propensity score method was used to select 704 TAVI and 374 SAVR matched patients. Primary endpoint was 1-year survival. Secondary endpoints were clinical complications, including pacemaker implantation, vascular complications, myocardial infarction, bleeding, and the need for new-onset dialysis.

RESULTS

One-year survival was similar (HR [95% CI] for TAVI 1.271 [0.795, 2.031], p = 0.316), with no divergence in Kaplan-Meier curves. In spite of post-procedural short-term survival being numerically higher for TAVI patients and 1-year survival being numerically higher for SAVR patients, such differences did not reach statistical significance (96.4% vs. 94.2%, p = 0.199, and 86.2% vs. 81.2%, p = 0.316, respectively). In weighted analyses, pacemaker implantation, vascular complications, and were significantly more common with TAVI; whereas myocardial infarction, bleeding requiring transfusion, and longer ICU-stay and overall hospitalization were higher with SAVR. Temporary dialysis was more common with SAVR (p < 0.0001); however, a probable need for chronic dialysis was rare and similar in both groups.

CONCLUSION

Both TAVI and SAVR led to comparable and excellent results in patients with moderate-to-severe CKD in an intermediate-risk population of patients with symptomatic severe aortic stenosis for whom both therapies could possibly be considered.

Renal outcomes in valve-in-valve transcatheter versus redo surgical aortic valve replacement: A systematic review and meta-analysis

INTRODUCTION

Postoperative acute kidney injury (AKI) and the requirement for renal replacement therapy (RRT) remain common and significant complications of both transcatheter valve-in-valve aortic valve replacement (ViV-TAVR) and redo surgical aortic valve replacement (SAVR). Nevertheless, the understanding of renal outcomes in the population undergoing either redo SAVR or ViV-TAVR remains controversial.

METHODS

A systematic database search with meta-analysis was conducted of comparative original articles of ViV-TAVR versus redo SAVR in EMBASE, MEDLINE, Cochrane database, and Google Scholar, from inception to September 2021. Primary outcomes were AKI and RRT. Secondary outcomes were stroke, major bleeding, pacemaker implantation rate, operative mortality, and 30-day mortality.

RESULTS

Our search yielded 5435 relevant studies. Eighteen studies met the inclusion criteria with a total of 11,198 patients. We found ViV-TAVR to be associated with lower rates of AKI, postoperative RRT, major bleeding, pacemaker implantation, operative mortality, and 30-day mortality. No significant difference was observed in terms of stroke rate. The mean incidence of AKI in ViV-TAVR was 6.95% (±6%) and in redo SAVR was 15.2% (±9.6%). For RRT, our data showed that VIV-TAVR to be 1.48% (±1.46%) and redo SAVR to be 8.54% (±8.06%).

CONCLUSION

Renoprotective strategies should be put into place to prevent and reduce AKI incidence regardless of the treatment modality. Patients undergoing re-intervention for the aortic valve constitute a high-risk and frail population in which ViV-TAVR demonstrated it might be a feasible option for carefully selected patients. Long-term follow-up data and randomized control trials will be needed to evaluate mortality and morbidity outcomes between these 2 treatments.

The Role of Transcatheter Aortic Valve Replacement in Asymptomatic Aortic Stenosis: A Feasibility Analysis

Surgical aortic valve replacement (SAVR) is the current treatment of choice for good surgical candidates with moderate to severe symptomatic aortic stenosis (AS). As transcatheter aortic valvular replacement (TAVR) has shown an improved one and two-year all-cause mortality, it has been chosen for moderately symptomatic severe AS patients. The purpose of this review was to perform a clinical comparison of TAVR vs. SAVR and to analyze the Health Index Factor (HIF) that makes TAVR a treatment of choice in asymptomatic AS patients. 

An extensive literature search of PubMed, Cochrane, and Embase databases was performed using the keywords “Aortic stenosis”, “SAVR”, “TAVR”, and “Asymptomatic”. A total of 45 prospective randomized clinical trials in the English language that were published from the year 2000 onwards were included in the final analysis. It has been found that 59.3% of asymptomatic AS patients are likely to die in the next five years without proactive treatment. Multiple studies have proven that early intervention with aortic valve replacement is superior to conservative treatment in severe asymptomatic AS; however, the choice between SAVR and TAVR is not well established. The NOTION Trial, SURTAVI Trail, and PARTNER 3 study have shown the non-inferiority of TAVR over SAVR, during one-year follow-up for low surgical risk patients. Evolut Low-Risk study and Early TAVR are the only two prospective studies performed to date that have enrolled patients with asymptomatic severe AS. The Evolut Trial demonstrated no difference in all-cause mortality at 30 days (1.3% vs. 4.8%. p=0.23), and 12 days (1.3% vs. 6.5%, p=0.11). Additionally, TAVR also decreases the risk of post-procedural atrial fibrillation, acute kidney injury (AKI), and rehospitalization, and leads to significant improvement in the mean trans-aortic pressure gradient. TAVR also showed marked improvement in the 30-day Quality of Life (QOL) index, where SAVR did not report any significant change in the QOL index. However, the official recommendations of Early TAVR are still awaited. TAVR has consistently shown a statistically non-significant difference in case mortality, risk of stroke, and rehospitalization with moderate to high surgical risk patients whereby recent initial trials have shown significant improvement in the QOL index and hemodynamic index for patients with asymptomatic disease. More extensive studies are required to prove the risk stratifications, long-term outcomes, and clinical characteristics that would make TAVR a preferred intervention in asymptomatic patients.

Use and outcomes of cerebral embolic protection for transcatheter aortic valve replacement: A US nationwide study

BACKGROUND

Outcomes data on the use of cerebral embolic protection devices (CPDs) with transcatheter aortic valve replacement (TAVR) remain limited. Previous randomized trials were underpowered for primary outcomes of stroke prevention and mortality.

METHODS

The National Inpatient Sample and Nationwide Readmissions Database were queried from 2017 to 2018 to study utilization and inpatient mortality, neurological complications (ischemic stroke, hemorrhagic stroke, and transient ischemic attack), procedural complications, resource utilization, and 30-day readmissions with and without use of CPD. A 1:3 ratio propensity score matched model was created.

RESULTS

Among 108,315 weighted encounters, CPD was used in 4380 patients (4.0%). Adjusted mortality was lower in patients undergoing TAVR with CPD (1.3% vs. 0.5%, p < 0.01). Neurological complications (2.5% vs. 1.7%, p < 0.01), hemorrhagic stroke (0.2% vs. 0%, p < 0.01) and ischemic stroke (2.2% vs. 1.4%, p < 0.01) were also lower in TAVR with CPD. Multiple logistic regression showed CPD use was associated with lower adjusted mortality (odds ratio (OR], 0.34 [95% confidence interval [CI], 0.22-0.52), p < 0.01) and lower adjusted neurological complications (OR, 0.68 (95% CI, 0.54-0.85], p < 0.01). On adjusted analysis, 30-day all-cause readmissions (Hazard ratio, HR 0.839, [95% CI, 0.773-0.911], p < 0.01) and stroke (HR, 0.727 [95% CI, 0.554-0.955), p = 0.02) were less likely in TAVR with CPD.

CONCLUSION

We report real-world data on utilization and in-hospital outcomes of CPD use in TAVR. CPD use is associated with lower inpatient mortality, neurological, and clinical complications as compared to TAVR without CPD.

Non-contrast transoesophageal echo-guided transapical transcatheter aortic valve replacement: 10-year experience of a renoprotective strategy

OBJECTIVES

This study aims to evaluate the efficacy, safety and long-term outcomes of a renoprotective non-contrast, transoesophageal echocardiography-guided transapical (TA) transcatheter aortic valve replacement (TAVR) strategy with a balloon-expandable prosthesis, as well as to determine its impact on renal function.

METHODS

Between 2009 and 2019, 200 consecutive patients underwent a non-contrast, transoesophageal echocardiography-guided TA TAVR with a balloon-expandable prosthesis.

RESULTS

The device success rate was 95.5%. Transoesophageal echocardiography-guided deployment demonstrated a low rate of procedure-related complications: 9.5% of acute kidney injury, 8% postoperative bleeding, 6% low-cardiac output, 4.5% postprocedural aortic regurgitation ≥+2, 4% implantation of permanent pacemaker and 2% stroke. There were no significant differences between preoperative and on discharge estimated glomerular filtration rate (53.9 ± 22.2 vs 54.3 ± 22.9 ml/min/1.73 m2, P = 0.60). Logistic regression analysis confirmed postoperative bleeding as an independent predictor for acute kidney injury (odds ratio (OR) 11.148, 95% confidence interval 3.537-35.140, P < 0.001). In-hospital mortality was 7.5%. The mean follow-up was 48.5 ± 39.9 months. Renal function and patient's chronic kidney disease stage did not significantly vary during follow-up. Long-term cumulative survival at 1, 5 and 10 years was 84.2 ± 0.027%, 42.9 ± 0.038% and 32.5 ± 0.044%, respectively. Renal function affected on neither in-hospital mortality nor long-term survival.

CONCLUSIONS

Non-contrast, transoesophageal echocardiography-guided TA TAVR is a safe and reproducible technique with a low incidence of periprocedural complications that avoids the use of contrast and mitigates the incidence of acute kidney injury.

Meta-Analysis Comparing Renal Outcomes after Transcatheter versus Surgical Aortic Valve Replacement

Background

Acute kidney injury (AKI) is a common complication of aortic valve replacement. However, comparative on the incidence of (AKI) following transcatheter (TAVR) versus surgical valve replacement (SAVR) is sparse.

Methods

We performed a meta-analysis of the randomized controlled trials (RCT) and propensity-matched observational studies comparing (A) incidence of AKI and (B) incidence of dialysis-requiring AKI at 30 days after TAVR and SAVR.

Results

Twenty-six studies (20 propensity-matched studies; 6 RCTs) including 19,954 patients were analyzed. The incidence of AKI was lower after TAVR than after SAVR (7.1% vs. 12.1%, OR 0.52; 95%CI, 0.39-0.68; p<0.001, I²=57%), but the incidence of dialysis-requiring AKI was similar (2.8% vs. 4.1%, OR 0.78; 95%CI, 0.49-1.25; p=0.31, I²=70%). Similar results were observed in a sensitivity analysis including RCTs only for both AKI ([5 RCTs; 5,418 patients], 2.0% vs. 5.0%, OR 0.39; 95%CI, 0.28-0.53; p<0.001, I²=0%), and dialysis-requiring AKI ([2 RCTs; 769 patients]; 2.9% vs. 2.6%, OR 1.1; 95%CI, 0.47-2.58; p=0.83, I²=0%). However, in studies including low-intermediate risk patients only, TAVR was associated with lower incidence of AKI ([10 studies; 6,510 patients], 7.6% vs. 12.4%, OR 0.55, 95%CI 0.39-0.77, p<0.001, I²=57%), and dialysis-requiring AKI, ([10 studies; 12,034 patients], 2.0% vs. 3.6%, OR 0.57, 95%CI 0.38-0.85, p=0.005, I²=23%).

Conclusions

TAVR is associated with better renal outcomes at 30 days in comparison with SAVR, especially in patients at low-intermediate surgical risk. Further studies are needed to assess the impact of AKI on long-term outcomes of patients undergoing TAVR and SAVR.

Epidemiology of Cardiorenal Syndrome

Cardiorenal syndrome is a spectrum of disorders that emphasizes the bidirectional nature of cardiac and kidney injury. Observational and retrospective studies have helped us to understand the prevalence and burden of each of the 5 types of cardiorenal syndromes. Cardiorenal syndrome type 1 is the most common. The nature of epidemiologic data limits clear delineation between cardiorenal syndrome types 2 and 4. Overall, the presence of cardiac or renal dysfunction strongly predicts a poor outcome of the contrary organ.