Preoperative renin-angiotensin system inhibitors use linked to reduced acute kidney injury: a systematic review and meta-analysis

Differences in characteristics and risk factors for acute kidney injury between elderly and very elderly patients: a retrospective review

BACKGROUND

Few epidemiologic studies on acute kidney injury (AKI) have focused on the older adult population. This study aimed to clarify the characteristics and risk factors for AKI in this population.

METHODS

This retrospective observational study was performed with the clinical data of all outpatients and inpatients aged ≥ 65 years at the time of enrolment at Kochi Medical School Hospital between 1 January 1981 and 31 December 2021. The primary cohort was divided into those aged 65-74 and ≥ 75 years. The primary outcome was the occurrence of AKI.

RESULTS

Of 83,822 patients, 38,333 were included in the 65-74-year-old group, whereas 45,489 were included in the ≥ 75-year-old group. Prevalences of the first AKI event in the 65-74-year-old and ≥ 75-year-old groups were 11.9% and 12.4%, respectively. Overall, lower estimated glomerular filtration rate, lower albumin level, lower or higher level of serum uric acid, and histories of diabetes mellitus, chronic heart failure, ischaemic heart disease, non-ischaemic heart disease, cerebrovascular disease, cancer, and liver disease were independent risk factors for an AKI event. The risk factors for AKI unique to each cohort were using non-steroidal anti-inflammatory drugs (NSAIDs) and loop diuretics (L-DI), and histories of hypertension (HT) and vascular diseases (VD) in men aged 65-74 years; using NSAIDs, angiotensin-converting enzyme inhibitors (ACEIs), L-DI and other diuretics (O-DI), and histories of HT and VD in men aged ≥ 75 years; using NSAIDs and O-DI and not using angiotensin-receptor blockers (ARBs), and a history of HT in women aged 65-74 years; and use of L-DI and a history of VD in women aged ≥ 75 years. Presence of proteinuria was a risk factor for developing AKI.

CONCLUSIONS

Many AKI risk factors reported thus far are associated with AKI development. However, there are differences in the effects of the renin-angiotensin system inhibitors, ACEIs, and ARBs (ARBs may be protective). Additionally, the U-shaped relationship between AKI onset and uric acid levels differs between sexes in the elderly population, similar to other age groups, but this sex difference disappears in the very elderly population. Pre-existing chronic kidney disease is a risk factor for the development of AKI.

Incidence, severity, risk factors and outcomes of acute kidney injury in older adults: systematic review and meta-analysis

OBJECTIVES

Old age was identified as a strong risk factor for acute kidney injury (AKI). Our objectives were to provide estimates of AKI, risk factors and outcomes in patients ≥ 75 years for whom data are scarce.

METHODS

Observational studies and randomized controlled trials between 2005 and 2021 with patients of mean or median age ≥ 75 years, reporting AKI according to current definitions. Data on AKI incidence, risk factors and mortality were analyzed separately in unselected (UC) and acute heart failure (AHF) cohorts.

RESULTS

Twenty-six observational studies and 4 randomized controlled trials with 51,111 UC and 25,414 AHF patients were included. Ages averaged 79.4 and 79.8 years, respectively. Pooled risk ratios (RRs) of AKI rates were 26.29% (95% confidence intervals (CI) 13.20-41.97) (UC) and 24.21% (95% CI 20.03-28.65) (AHF). In both cohorts, AKI was associated with decreased estimated glomerular filtration rate at baseline, chronic kidney disease (UC: RR 1.80 (95% CI 1.15-2.80), AHF: RR 1.51 (95% CI 1.26-1.95) and hypertension (UC: RR 1.30 (95% CI 1.09-1.56), AHF: RR 1.07 (95% CI 1.05-1.09). RRs of AKI in patients on renin-angiotensin-inhibitors were 0.87 (95% CI 0.78-0.97) and 0.88 (95% CI 0.78-0.98) in UC and AHF, respectively. AKI was consistently associated with increased risk of in-hospital mortality (UC: RR 3.15 (95% CI 2.28-4.35), AHF: RR 4.28 (95% CI 2.53-7.24).

CONCLUSION

AKI is frequent in patients ≥ 75 years. While reduced renal function at baseline, CKD and hypertension were associated with AKI development, renin-angiotensin-inhibitors may be protective. Older AKI patients showed higher short-term mortality rates.

Acute renal injury events in diabetic patients treated with SGLT2 inhibitors: A comprehensive review with a special reference to RAAS blockers

Renin-angiotensin-aldosterone system (RAAS) blockers and sodium-glucose cotransporter type 2 inhibitors (SGLT2is) are two pharmacological classes that proved a remarkable nephroprotective effect, yet a risk of acute kidney injury (AKI) was also pointed out. In 2016, the US Food and Drug Administration recommended caution with the concomitant use of these medications. While the literature devoted to RAAS blockers remained surprisingly limited, numerous articles were published in recent years with SGLT2is. Safety analyses of large prospective cardiorenal trials showed a reduced rather than an increased number of AKI events in patients with type 2 diabetes treated with SGLT2is compared with those treated with placebo, despite the fact that a majority of patients received RAAS blockers at baseline. Interestingly, retrospective observational studies confirmed these reassuring findings in real-life conditions in more heterogeneous and possibly more frailty populations also commonly treated with RAAS blockers by showing a reduced risk of AKI with SGLT2is compared with other glucose-lowering drugs. Currently, there are no evidence of an increased risk of AKI with RAAS blocker-SGLT2i combinations in absence of haemodynamic instability. Several underlying mechanisms could explain a decreased rather than an increased risk of AKI with SGLT2is, including in patients treated with RAAS blockers.

Obesity, Angiotensin-Blocking Drugs, and Acute Kidney Injury in Orthopedic Surgery

Postoperative acute kidney injury occurs in 7% to 11% of orthopedic surgeries. The effect of preoperative angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) on the development of postoperative acute kidney injury remains controversial. Adipose tissue has its own independently regulated angiotensin system. The primary aim of this study was to examine the effects of obesity and preoperative ACEIs and ARBs on postoperative acute kidney injury. Charts were reviewed of adult elective orthopedic surgery patients during a 2-year period when patients were instructed to take their ACEI or ARB on the morning of surgery. The patients were divided into an obese cohort (body mass index [BMI] ≥30 kg/m²) and a nonobese cohort (BMI <30 kg/m²). A multivariable model was created for the outcome of acute kidney injury, using obesity as a primary predictor and adjusting for demographics, medications, comorbidities, and intraoperative parameters in a logistic regression analysis. Obesity increased the likelihood of developing acute kidney injury after orthopedic surgery (odds ratio [OR], 1.86; 95% CI, 1.07-3.22; P=.028). For every 5-unit increase in BMI, the odds of acute kidney injury were 1.43 (95% CI, 1.26-1.62; P<.001). When receiving ACEIs or ARBs, only the nonobese patients had a statistically increased likelihood of postoperative acute kidney injury (OR, 3.30; 95% CI, 1.12-9.70; P=.030). Obesity is an independent risk factor for postoperative acute kidney injury. Obesity appears to influence the effect that preoperative ACEIs and ARBs have on postoperative acute kidney injury. [Orthopedics. 2021;44(2):e253-e258.].

Impact of Renin-Angiotensin System Blockers on Mortality in Veterans Undergoing Cardiac Surgery

Background

Renin‐angiotensin system blockers (RASBs) have well‐validated benefit in patients with hypertension, coronary artery disease, and left ventricular systolic dysfunction. Their use in the perioperative period, however, has been controversial, including in patients undergoing cardiac surgery, who often have a strong indication for their use. In the current study, we explore the impact of RASB use with 30‐day and 1‐year mortality after cardiac surgery.

Methods and Results

The Veterans Affairs Surgical Quality Improvement Program and Corporate Data Warehouse were data sources for this retrospective cohort study. A total of 37 197 veterans undergoing elective coronary artery bypass grafting and or valve repair or replacement over a 10‐year period met inclusion criteria and were stratified into 4 groups by preoperative exposure (preoperative exposure versus no preoperative exposure) and postoperative continuing exposure (current exposure versus no current exposure) to RASBs. After adjusting for all baseline covariates, the preoperative exposure/current exposure group had lower 30‐day and 1‐year mortality than the preoperative exposure/no current exposure (30‐day hazard ratio [HR], 0.25; 95% CI, 0.19–0.33 [P<0.001] and 1‐year HR, 0.40; 95% CI, 0.33–0.48 [P<0.001] or no preoperative exposure/no current exposure (30‐day HR, 0.44; 95% CI, 0.32–0.60 [P<0.001] and 1‐year HR, 0.72; 95% CI, 0.62–0.84 [P<0.001] groups. The no preoperative exposure/current exposure group had significantly lower 30‐day (HR, 0.31; 95% CI, 0.14–0.71 [P=0.006]) and 1‐year (HR, 0.64; 95% CI, 0.53–0.77 [P<0.001]) mortality than the no preoperative exposure/no current exposure group.

Conclusions

Continuation of preoperative RASBs and initiation before discharge is associated with decreased mortality in veterans undergoing cardiac surgery. Given these findings, continuation of preoperative RASBs or initiation in the early postoperative period should be considered in patients undergoing cardiac surgery.

Meta-analysis of impact of renin-angiotensin system inhibitors on survival after transcatheter aortic valve implantation

INTRODUCTION

To determine whether renin-angiotensin system inhibitor (RASI) prescription is associated with better survival after transcatheter aortic valve implantation (TAVI), we performed the first meta-analysis of currently available studies.

EVIDENCE ACQUISITION

To identify all studies reporting impact of RASI prescription on survival after TAVI, we searched PubMed, Web of Science, Google Scholar, etc. through October 2019. We extracted adjusted (if unavailable, unadjusted) hazard ratios (HRs) with their confidence intervals (CIs) of midterm (up to ≥6-month) all-cause mortality for RASI prescription from each study and combined study-specific estimates using inverse variance-weighted averages of logarithmic HRs in the random-effects model.

EVIDENCE SYNTHESIS

We identified 13 eligible studies with a total of 26,132 TAVI patients and included them in the present meta-analysis. None was a randomized controlled trial, 5 were observational studies comparing patients with versus without RASI prescription (including 3 propensity score matched studies), and 8 were observational studies investigating RASI prescription as one of covariates. The primary meta-analysis of all studies demonstrated that RASI prescription was associated with significantly lower midterm mortality (HR=0.83; 95% CI: 0.76 to 0.92; P=0.0002). Although we identified significant funnel plot asymmetry (P=0.036 by the rank correlation test) suggesting publication bias, correcting for it using the trim-and-fill method did not substantially alter the result favoring RASI prescription (corrected HR=0.85; 95% CI: 0.76 to 0.95; P=0.004).

CONCLUSIONS

RASI prescription may be associated with better midterm survival after TAVI.

Prospective Cohort Study of Renin-Angiotensin System Blocker Usage after Hospitalized Acute Kidney Injury

BACKGROUND AND OBJECTIVES

The risk-benefit ratio of angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy after AKI may be altered due to concerns regarding recurrent AKI. We evaluated, in a prospective cohort, the association between use (versus nonuse) of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and the subsequent risk of AKI and other adverse outcomes after hospitalizations with and without AKI.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We studied 1538 patients recently discharged from the hospital who enrolled in the multicenter, prospective ASSESS-AKI study, with approximately half of patients experiencing AKI during the index hospitalization. All participants were seen at a baseline visit 3 months after their index hospitalization and were categorized at that time on whether they were using angiotensin-converting enzyme inhibitors/angiotensin receptor blockers or not. We used multivariable Cox regression, adjusting for demographics, comorbidities, eGFR, urine protein-creatinine ratio, and use of other medications, to examine the association between angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use and subsequent risks of AKI, death, kidney disease progression, and adjudicated heart-failure events.

RESULTS

The use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers was 50% (386/769) among those with AKI during the index hospitalization and 47% (362/769) among those without. Among those with AKI during the index hospitalization, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use was not associated with a higher risk of recurrent hospitalized AKI (adjusted hazard ratio, 0.88; 95% confidence interval, 0.69 to 1.13). Associations between angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use and death, kidney disease progression, and adjudicated heart-failure events appeared similar in study participants who did and did not experience AKI during the index hospitalization (all interaction P values >0.05).

CONCLUSIONS

The risk-benefit ratio of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker therapy after hospital discharge appears to be similar regardless of whether AKI occurred during the hospitalization.

Management of Acute Kidney Injury Following Major Abdominal Surgery: A Contemporary Review

Acute kidney injury (AKI) is a frequent occurrence following major abdominal surgery and is independently associated with both in-hospital and long-term mortality, as well as with a higher risk of progressing to chronic kidney disease (CKD) and cardiovascular events. Postoperative AKI can account for up to 40% of in-hospital AKI cases. Given the differences in patient characteristics and the pathophysiology of postoperative AKI, it is inappropriate to assume that the management after noncardiac and nonvascular surgery are the same as those after cardiac and vascular surgery. This article provides a comprehensive review on the available evidence on the management of postoperative AKI in the setting of major abdominal surgery.

Change in renal function associated with drug treatment in heart failure: national guidance

Inhibitors of the renin–angiotensin–aldosterone (RAAS) system are cornerstones of the management of patients with heart failure with reduced left ventricular ejection fraction (HFrEF). However, RAAS inhibitors may cause decline in renal function and/or hyperkalaemia, particularly during initiation and titration, intercurrent illness and during worsening of heart failure. There is very little evidence from clinical trials to guide the management of renal dysfunction. The Renal Association and British Society for Heart Failure have collaborated to describe the interactions between heart failure, RAAS inhibitors and renal dysfunction and give clear guidance on the use of RAAS inhibitors in patients with HFrEF. During initiation and titration of RAAS inhibitors, testing renal function is mandatory; a decline in renal function of 30% or more can be acceptable. During intercurrent illness, there is no evidence that stopping RAAS inhibitor is beneficial, but if potassium rises above 6.0 mmol/L, or creatinine rises more than 30%, RAAS inhibitors should be temporarily withheld. In patients with fluid retention, high doses of diuretic are needed and a decline in renal function is not an indication to reduce diuretic dose: if the patient remains congested, more diuretics are required. If a patient is hypovolaemic, diuretics should be stopped or withheld temporarily. Towards end of life, consider stopping RAAS inhibitors. RAAS inhibition has no known prognostic benefit in heart failure with preserved ejection fraction. Efforts should be made to initiate, titrate and maintain patients with HFrEF on RAAS inhibitor treatment, whether during intercurrent illness or worsening heart failure.

Strategies to Reduce Perioperative Nephrotoxicity

Postoperative acute kidney injury (AKI) is a common complication of surgery that is associated with significant adverse outcomes, including increased morbidity and mortality. The perioperative burden of AKI risk factors is complex and potentially large, including high-risk nephrotoxic medications, hypotension, hypovolemia, radiologic contrast, anemia, and surgery-specific factors. Understanding the pathogenesis, risk factors, and potential cumulative impact of perioperative nephrotoxic exposures is particularly important in the prevention and reduction of perioperative AKI. This review outlines the possible strategies to reduce perioperative nephrotoxicity and the development of postoperative AKI.

Diagnostics, Risk Factors, Treatment and Outcomes of Acute Kidney Injury in a New Paradigm

Acute kidney injury (AKI) is a common clinical condition among patients admitted in the hospitals. The condition is associated with both increased short-term and long-term mortality. With the development of a standardized definition for AKI and the acknowledgment of the impact of AKI on patient outcomes, there has been increased recognition of AKI. Two advances from past decades, the usage of computer decision support and the discovery of AKI biomarkers, have the ability to advance the diagnostic method to and further management of AKI. The increasingly widespread use of electronic health records across hospitals has substantially increased the amount of data available to investigators and has shown promise in advancing AKI research. In addition, progress in the finding and validation of different forms of biomarkers of AKI within diversified clinical environments and has provided information and insight on testing, etiology and further prognosis of AKI, leading to future of precision and personalized approach to AKI management. In this this article, we discussed the changing paradigms in AKI: from mechanisms to diagnostics, risk factors, and management of AKI.

Renin-angiotensin system blocker use and the risk of acute kidney injury after colorectal cancer surgery: a population-based cohort study

OBJECTIVES

It is unknown whether preoperative use of ACE inhibitors (ACE-I) or angiotensin receptor blockers (ARBs) affects the risk of acute kidney injury (AKI) after colorectal cancer (CRC) surgery. We assessed the impact of preoperative ACE-I/ARB use on risk of AKI after CRC surgery.

DESIGN

Observational cohort study. Patients were divided into three exposure groups-current, former and non-users-through reimbursed prescriptions within 365 days before the surgery. AKI within 7 days after surgery was defined according to the current Kidney Disease Improving Global Outcome consensus criteria.

SETTING

Population-based Danish medical databases.

PARTICIPANTS

A total of 9932 patients undergoing incident CRC surgery during 2005-2014 in northern Denmark were included through the Danish Colorectal Cancer Group Database.

OUTCOME MEASURE

We computed cumulative incidence proportions (risk) of AKI with 95% CIs for current, former and non-users of ACE-I/ARB, including death as a competing risk. We compared current and former users with non-users by computing adjusted risk ratios (aRRs) using log-binomial regression adjusted for demographics, comorbidities and CRC-related characteristics. We stratified the analyses of ACE-I/ARB users to address any difference in impact within relevant subgroups.

RESULTS

Twenty-one per cent were ACE-I/ARB current users, 6.4% former users and 72.3% non-users. The 7-day postoperative AKI risk for current, former and non-users was 26.4% (95% CI 24.6% to 28.3%), 25.2% (21.9% to 28.6%) and 17.8% (17.0% to 18.7%), respectively. The aRRs of AKI were 1.20 (1.09 to 1.32) and 1.16 (1.01 to 1.34) for current and former users, compared with non-users. The relative risk of AKI in current compared with non-users was consistent in all subgroups, except for higher aRR in patients with a history of hypertension.

CONCLUSIONS

Being a current or former user of ACE-I/ARBs is associated with an increased risk of postoperative AKI compared with non-users. Although it may not be a drug effect, users of ACE-I/ARBs should be considered a risk group for postoperative AKI.

Associations between preoperative continuation of renin-angiotensin system inhibitor and cardiac surgery-associated acute kidney injury: a propensity score-matching analysis

BACKGROUND

Cardiac surgery-associated acute kidney injury (CSA-AKI) is associated with high risk for complications and mortality. Whether renin-angiotensin system (RAS) inhibitor should be continued or withdrawn in patients with long-term use before cardiac surgery has been lack of consensus.

METHODS

We performed this prospective observational cohort study and recruited cardiac surgery patients in the surgical intensive care units between 2000 and 2011. These patients were divided into users and non-users of RAS inhibitor. Propensity score matching and multivariable models were performed to investigate the association between renal outcome, mortality, and preoperative use of RAS inhibitor.

RESULTS

Preoperative use of RAS inhibitor was identified as the independent protective factor for AKI development (OR 0.41, 95% CI 0.23, 0.63), AKI severity (stage 3 vs. stage 1, OR 0.35, 95% CI 0.18, 0.69), and renal recovery (OR 3.41, 95% CI 1.84, 5.36). Nevertheless, there was no significant protective effect of RAS inhibitor on in-hospital dialysis, in-hospital mortality, and ensuing development of chronic kidney disease (CKD) after AKI. We created a prediction model of CSA-AKI and indicated that preoperative use of RAS inhibitor provided more protective effect in low-risk than high-risk population.

CONCLUSION

Preoperative use of RAS inhibitor was associated with less AKI development and severity, and higher renal recovery. Although more risk reduction of AKI development was shown in low-risk group by our prediction model, continued use of RAS inhibitor before cardiac surgery could provide protective effect in all patients.

Renal chymase-dependent pathway for angiotensin II formation mediated acute kidney injury in a mouse model of aristolochic acid I-induced acute nephropathy

Angiotensin-converting enzyme (ACE) is the primary enzyme that converts angiotensin I (Ang I) to angiotensin II (Ang II) in the renin-angiotensin system (RAS). However, chymase hydrates Ang I to Ang II independently of ACE in some kidney diseases, and it may play an important role. The present study investigated whether chymase played a crucial role in aristolochic acid I (AAI)-induced nephropathy. C57BL/6 mice were treated with AAI via intraperitoneal injection for an accumulated AAI dosage of 45 mg/kg body weight (BW) (15 mg/kg BW per day for 3 days). The animals were sacrificed after acute kidney injury development, and blood, urine and kidneys were harvested for biochemical and molecular assays. Mice exhibited increased serum creatinine, BUN and urinary protein after the AAI challenge. Significant infiltrating inflammatory cells and tubular atrophy were observed in the kidneys, and high immunocytokine levels were detected. Renal RAS-related enzyme activities were measured, and a significantly increased chymase activity and slightly decreased ACE activity were observed in the AAI-treated mice. The renal Ang II level reflected the altered profile of RAS enzymes and was significantly increased in AAI-treated mice. Treatment of AAI-induced nephropathic mice with an ACE inhibitor (ACEI) or chymase inhibitor (CI; chymostatin) reduced renal Ang II levels. The combination of ACEI and CI (ACEI+CI) treatment significantly reversed the AAI-induced changes of Ang II levels and kidney inflammation and injuries. AAI treatment significantly increased renal p-MEK without increasing p-STAT3 and p-Smad3 levels, and p-MEK/p-ERK1/2 signalling pathway was significantly activated. CI and ACEI+CI treatments reduced this AAI-activated signaling pathway. AAI-induced nephropathy progression was significantly mitigated with CI and ACEI+CI treatment. This study elucidates the role of RAS in the pathogenesis of AAI-induced nephropathy.

Acute Kidney Injury in Patients Undergoing Total Hip Arthroplasty: A Systematic Review and Meta-Analysis

Background: The number of total hip arthroplasties (THA) performed across the world is growing rapidly. We performed this meta-analysis to evaluate the incidence of acute kidney injury (AKI) in patients undergoing THA. Methods: A literature search was performed using MEDLINE, EMBASE and Cochrane Database from inception until July 2018 to identify studies assessing the incidence of AKI (using standard AKI definitions of RIFLE, AKIN, and KDIGO classifications) in patients undergoing THA. We applied a random-effects model to estimate the incidence of AKI. The protocol for this meta-analysis is registered with PROSPERO (no. CRD42018101928). Results: Seventeen cohort studies with a total of 24,158 patients undergoing THA were enrolled. Overall, the pooled estimated incidence rates of AKI and severe AKI requiring dialysis following THA were 6.3% (95% CI: 3.8%–10.2%) and 0.5% (95% CI: 0.1%–2.3%). Subgroup analysis based on the countries by continent was performed and demonstrated the pooled estimated incidence of AKI following THA of 9.2% (95% CI: 5.6%–14.8%) in Asia, 8.1% (95% CI: 4.9%–13.2%) in Australia, 7.4% (95% CI: 3.2%–16.3%) in Europe, and 2.8% (95% CI: 1.2%–17.0%) in North America. Meta-regression of all included studies showed significant negative correlation between incidence of AKI following THA and study year (slope = −0.37, p <0.001). There was no publication bias as assessed by the funnel plot and Egger’s regression asymmetry test with p = 0.13 for the incidence of AKI in patients undergoing THA. Conclusion: The overall estimated incidence rates of AKI and severe AKI requiring dialysis in patients undergoing THA are 6.3% and 0.5%, respectively. There has been potential improvement in AKI incidence for patients undergoing THA over time.

Acute kidney injury and 'nephrotoxins': mind your language

The introduction of the term 'acute kidney injury' (AKI) along with an international classification scheme,1 caused some initial confusion, but most clinicians and many patients now understand that the term 'injury' denotes damage to the internal workings of the kidney, rather than physical trauma. However, of greater concern is the use of the term 'nephrotoxic' to include drugs that are, in most settings, nephroprotective. We argue that this imprecise terminology, unfortunately adopted by the National Institute for Health and Care Excellence (NICE) among others, is potentially harmful, and that the terms 'nephrotoxin' and 'nephrotoxic' should not be used to describe haemodynamically mediated and fully reversible effects of some drugs on excretory function.

Preoperative antihypertensive medication intake and acute kidney injury after major vascular surgery

OBJECTIVE

Postoperative acute kidney injury (AKI) is frequent after major vascular surgery and is associated with significant morbidity and mortality. It remains unclear whether the administration of combined oral antihypertensive medications on the day of surgery can increase the risk of postoperative AKI.

METHODS

We performed a retrospective cohort study of hypertensive patients undergoing elective major vascular surgery to determine the association between the number of antihypertensive medications continued on the morning of surgery and AKI at 48 hours postoperatively.

RESULTS

A total of 406 patients who had undergone suprainguinal vascular surgery were included, and 10.3% suffered postoperative AKI. In multivariable analysis, the number of antihypertensive medications taken on the morning of surgery was independently associated with AKI (P = .026). Compared with patients who took no medication, taking one medication (adjusted odds ratio [aOR], 1.58; 95% confidence interval [CI], 0.68-3.75) and taking two or more medications (aOR, 2.70; 95% CI, 1.13-6.44) were associated with a 1.6-fold and 2.7-fold increased risk of postoperative AKI, respectively. Other predictors of AKI were suprarenal surgery (aOR, 3.37; 95% CI, 1.53-7.44), age (aOR, 2.29 per 10 years; 95% CI, 1.40-3.74), length of surgery (aOR, 1.40 per 1 hour; 95% CI, 1.10-1.76), hemoglobin drop (aOR, 1.37 per 10 g/L; 95% CI, 1.10-1.74), and history of coronary artery disease (aOR, 2.33; 95% CI, 1.08-5.00).

CONCLUSIONS

In patients undergoing major vascular surgery who are treated with chronic antihypertensive therapy, the administration of antihypertensive drugs on the morning of surgery is independently associated with an increased risk of postoperative AKI. Further prospective studies are needed to confirm this finding.

Impact of admission serum potassium on mortality in patients with chronic kidney disease and cardiovascular disease

BACKGROUND

Little is known about the effect of admission potassium (K) on risk of in-hospital mortality in chronic kidney disease (CKD) and cardiovascular disease (CVD) patients.

AIM

The aim of this study was to assess the relationship between admission serum K and in-hospital mortality in all hospitalized patients stratified by CKD and/or CVD status.

DESIGN AND METHODS

All adult hospitalized patients who had admission serum K between years 2011 and 2013 were enrolled. Admission serum K was categorized into seven groups (<3.0, 3.0-3.5, 3.5-4.0, 4.0-4.5, 4.5-5.0, 5.0-5.5 and ≥5.5 mEq/L). The odds ratio (OR) of in-hospital mortality by admission serum K, using K 4.0-4.5 mEq/L as the reference group, was obtained by logistic regression analysis.

RESULTS

73,983 patients were studied. The lowest incidence of in-hospital mortality was associated with serum K within 4.0-4.5 mEq/L. A U-shaped curve emerged demonstrating higher in-hospital mortality associated with both serum K < 4.0 and >4.5 mEq/L. After adjusting for potential confounders, both serum K < 4.0 mEq/L and >5.0 mEq/L were associated with increased in-hospital mortality with ORs of 3.26 (95% CI 2.03-4.98), 2.40 (95% CI 1.89-3.04), 1.38 (95%CI 1.15-1.66), 1.89 (95% CI 1.49-2.38) and 3.62 (95%CI 2.73-4.76) when serum K were within <3.0, 3.0-3.5, 3.5-4.0, 5.0-5.5, and ≥5.5 mEq/L, respectively. In CVD patients, the highest in-hospital mortality was associated with serum K < 3.0 mEq/L (OR 1.70, 95%CI 1.31-2.18). In CKD patients, the highest in-hospital mortality was associated with serum K ≥ 5.5 mEq/L (OR 3.26, 95%CI 2.14-4.90).

CONCLUSION

Admission serum K < 4.0 mEq/L and >5.0 mEq/L were associated with increased in-hospital mortality. The mortality risk among patients with various admission potassium levels was affected by CKD and/or CVD status.

Determinants of Acute Kidney Injury and Renal Function Decline After Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVE/BACKGROUND

Endovascular aneurysm repair (EVAR) may be associated with renal injury and more insight is needed into potential risk factors. The aim was to identify clinical, anatomical, and peri-procedural parameters as potential risk factors for the occurrence of acute kidney injury (AKI) and to evaluate chronic kidney disease (CKD) after EVAR.

METHODS

A cohort of 212 consecutive patients who underwent elective EVAR for abdominal aortic aneurysm from January 2009 to October 2016 was included. A subgroup of 149 patients with 2 years follow-up was compared with a set of 135 non-operated aneurysm patients with smaller aneurysms (similar cardiovascular risk profile) to assess CKD. Primary outcomes were AKI (Acute Kidney Injury Network criteria) and CKD measured by estimated glomerular filtration rate (Kidney Disease Improving Global Outcomes guidelines). For AKI, candidate risk factors were identified by univariate and multivariate logistic regression analysis; for chronic renal function decline, risk factors were identified using Cox regression analysis.

RESULTS

AKI occurred in 30 patients (15%). On multivariate analysis, the use of angiotensin II blocker (odds ratio [OR] 4.08, 95% confidence interval [CI] 1.38-12.07) and peri-operative complications (OR 3.12, 95% CI 1.20-8.10) were independent risk factors for AKI, whereas statin use was a protective factor (OR 0.19, 95% CI 0.07-0.52). EVAR resulted in a significant increase (23.5%) in the occurrence of CKD compared with the control group (6.7%; p <.001). On univariate and multivariate Cox regression the risk factors: aortic neck diameter (per mm increase) (hazard ratio [HR] 1.13, 95% CI 1.02-1.25), renal artery stenosis >50% (HR 2.24, 95% CI 1.05-4.79), and the occurrence of AKI (HR 2.19, 95% CI 0.99-4.85) were significant predictors of CKD.

CONCLUSION

This study identified use of angiotensin II blockers and peri-operative complications as risk factors for AKI. In addition, the problem of renal function decline after EVAR is highlighted, which indicates that prolonged protective measures (e.g., in those patients at high risk) over time are needed to improve patient outcomes.

Persistent acute kidney injury following transcatheter aortic valve replacement

BACKGROUND

Acute kidney injury (AKI) and its severity after transcatheter aortic valve replacement (TAVR) have been associated with worse outcomes. Studies have shown that AKI duration (transient or persistent) affects outcomes independently of AKI severity. This study was undertaken to determine the association, risk factors, and outcomes associated with persistent AKI (pAKI) after TAVR.

METHODS

Adult patients undergoing TAVR at Mayo Clinic between January 1, 2008 and June 30, 2014 were enrolled. pAKI was defined as an increased serum creatinine at hospital discharge (≥0.3 mg/dL or ≥50% from baseline). Risk factors associated with pAKI were identified with multivariate logistic regression.

RESULTS

A total of 386 patients met the inclusion criteria. Fifty patients (13%) had pAKI. Independent risk factors for pAKI on multivariate analysis included diabetes mellitus (odds ratio [OR], 2.43; 95% confidence interval [CI], 1.29-4.66), prior percutaneous coronary intervention (PCI) (OR, 2.39; 95%CI, 1.24-4.80), intra-aortic balloon pump (IABP) use (OR, 8.14; 95%CI, 1.60-45.78), and blood transfusion (OR, 2.22; 95%CI, 1.15-4.27). Protective factors for pAKI included a higher baseline estimated glomerular filtration rate (eGFR) (OR, 0.83 per 10-mL/min/1.73 m² increase in eGFR; 95%CI, 0.71-0.99). After adjusting for the Society of Thoracic Surgeons cardiac surgery risk score, pAKI occurrence remained significantly associated with increased 2-year mortality among hospital survivors (hazard ratio, 2.65; 95%CI, 1.51-4.41).

CONCLUSION

pAKI was significantly associated with higher mortality risk following TAVR. Baseline eGFR, diabetes mellitus, previous PCI, IABP, and blood transfusion were risk factors for post-procedural pAKI.

Angiotensin Receptor Blockade Improves Cardiac Surgical Outcomes in Patients With Metabolic Syndrome

BACKGROUND

Perioperative use of angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors (ACEis) in patients undergoing cardiac operations remains controversial. The current practice of discontinuing renin-angiotensin-system inhibitors preoperatively may negate their beneficial effects in vulnerable populations, including patients with metabolic syndrome, who exhibit elevated renin-angiotensin system activity. We hypothesized that preoperative ARB use is associated with reduced incidence of postoperative complications, compared with ACEi or no drug, in patients with metabolic syndrome undergoing coronary artery bypass grafting.

METHODS

We used propensity matching to derive a cohort of 1,351 patients from 2,998 who underwent coronary artery bypass grafting based on preoperative use of ARBs, ACEis, or no renin-angiotensin-system inhibitors. Our primary end point was a composite of adverse events occurring within 30 days after the operation: new-onset atrial fibrillation/flutter, arrhythmia requiring cardioversion, perioperative myocardial infarction, acute renal failure, need for dialysis, cerebrovascular accidents, acute respiratory failure, or perioperative death.

RESULTS

At least one adverse event occurred in 524 (38.8%) of matched cohort patients (1,184 [39.6% of all patients]). Adjusting for European System for Cardiac Operative Risk Evaluation and metabolic syndrome in the matched cohort, preoperative use of ARBs was associated with a lower incidence of adverse events in patients with metabolic syndrome compared with preoperative use of no renin-angiotensin-system inhibitors (odds ratio, 0.43; 95% confidence interval, 0.19 to 0.99) or ACEis (odds ratio, 0.38; 95% confidence interval, 0.16 to 0.88).

CONCLUSIONS

Preoperative use of ARBs, but not ACEis, confers a benefit within 30 days after cardiac operations in patients with metabolic syndrome, suggesting potential efficacy differences of these drug classes in reducing cardiovascular morbidity and death in ambulatory vs surgical patients.

Management of patients at risk of acute kidney injury

Acute kidney injury (AKI) is a multifaceted syndrome that occurs in different settings. The course of AKI can be variable, from single hit and complete recovery, to multiple hits resulting in end-stage renal disease. No interventions to improve outcomes of established AKI have yet been developed, so prevention and early diagnosis are key. Awareness campaigns and education for health-care professionals on diagnosis and management of AKI-with attention to avoidance of volume depletion, hypotension, and nephrotoxic interventions-coupled with electronic early warning systems where available can improve outcomes. Biomarker-based strategies have not shown improvements in outcome. Fluid management should aim for early, rapid restoration of circulatory volume, but should be more limited after the first 24-48 h to avoid volume overload. Use of balanced crystalloid solutions versus normal saline remains controversial. Renal replacement therapy should only be started on the basis of hard criteria, but should not be delayed when criteria are met. On the basis of recent evidence, the risk of contrast-induced AKI might be overestimated for many conditions.

Incidence and risk factors of acute kidney injury following transcatheter aortic valve replacement

AIM

This study aimed to determine the incidence and risk factors of acute kidney injury (AKI) following transcatheter aortic valve replacement (TAVR).

METHODS

We included all adult patients undergoing TAVR for aortic stenosis from 1 January 2008 to 30 June 2014 at a tertiary referral hospital. AKI was defined based on Kidney Disease: Improving Global Outcomes criteria. We performed a multivariate logistic regression to identify factors associated with post-procedural AKI occurrence.

RESULTS

Three hundred eighty-six patients met the inclusion criteria, of which 106 (28%) developed AKI. In multivariate analysis, AKI development was independently associated with a transapical approach (odds ratio (OR), 2.81; 95% confidence interval (CI), 1.72-4.65 compared with transfemoral approach) and the need for an intra-aortic balloon pump (OR, 9.11; 95% CI, 1.77-68.29). Higher baseline renal function (OR, 0.78 per 10 mL/min per 1.73 m² increment in glomerular filtration rate; 95% CI, 0.68-0.87) was significantly associated with a decreased risk of AKI. After adjustment for the Society of Thoracic Surgeons' risk score, post-procedural AKI development remained significantly associated with an increased in-hospital (OR, 4.74; 95% CI, 1.39-18.48) and 6-month mortality (OR, 4.66; 95% CI, 2.32-9.63).

CONCLUSION

In a cohort of patients undergoing TAVR for aortic stenosis, AKI commonly occurred and was significantly associated with increased mortality. Baseline renal function, procedure approach and the need for circulatory support were important predictive factors for post-procedural AKI occurrence.

Contrast-induced acute kidney injury in kidney transplant recipients: A systematic review and meta-analysis

AIM

To evaluate the incidence of contrast-induced acute kidney injury (CIAKI) in kidney transplant recipients.

METHODS

A literature search was performed using MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews from the inception of the databases through July 2016. Studies assessing the incidence of CIAKI in kidney transplant recipients were included. We applied a random-effects model to estimate the incidence of CIAKI.

RESULTS

Six studies of 431 kidney transplant recipients were included in the analyses to assess the incidence of CIAKI in kidney transplant recipients. The estimated incidence of CIAKI and CIAKI-requiring dialysis were 9.6% (95%CI: 4.5%-16.3%) and 0.4% (95%CI: 0.0%-1.2%), respectively. A sensitivity analysis limited only to the studies that used low-osmolar or iso-osmolar contrast showed the estimated incidence of CIAKI was 8.0% (95%CI: 3.5%-14.2%). The estimated incidences of CIAKI in recipients who received contrast media with cardiac catheterization, other types of angiogram, and CT scan were 16.1% (95%CI: 6.6%-28.4%), 10.1% (95%CI: 4.2%-18.0%), and 6.1% (95%CI: 1.8%-12.4%), respectively. No graft losses were reported within 30 d post-contrast media administration. However, data on the effects of CIAKI on long-term graft function were limited.

CONCLUSION

The estimated incidence of CIAKI in kidney transplant recipients is 9.6%. The risk stratification should be considered based on allograft function, indication, and type of procedure.

Intravenous Fluids in AKI: A Mechanistically Guided Approach

Acute kidney injury (AKI) has been associated with an increased risk of death and morbidity in many clinical scenarios. The prevention and treatment of AKI therefore has been advocated as a high-priority research focus. However, nearly all strategies tested in this setting have failed to prevent or cure AKI and fluid loading remains a cornerstone of preventive and curative treatment of AKI. Concerns have been raised, however, regarding both the efficacy and safety of fluid loading to prevent or reverse AKI. In this review, we address the question of the best use of fluid loading based on current preclinical and clinical data in a mechanistically guided approach. Impacts of fluid resuscitation on renal hemodynamics, from macrocirculation to microcirculation, with physiological end points as well as renal consequences of different fluids available are discussed. Finally, the complex relationship between renal hemodynamics is discussed.

Stratification and Risk Reduction of Perioperative Acute Kidney Injury

Perioperative acute kidney injury (AKI) is associated with an increased morbidity and mortality. The incidence of AKI varies depending on preoperative risk factors and the surgical setting. Preoperative risk stratification is critical for informed consent and perioperative planning. Perioperative renal protection strategies are potentially invaluable in the prevention of AKI. Current advances in the development of biomarkers may offer the opportunity for early diagnosis and the implementation of therapeutic strategies. Increased awareness and concerted efforts by all perioperative physicians are needed to provide an improved outcome for surgical patients.

The Effect of Renin-angiotensin System Inhibitors on Kidney Allograft Survival: A Systematic Review and Meta-analysis

Background:

The use of renin-angiotensin system (RAS) inhibitors in patients with chronic kidney disease, and especially in diabetic kidney disease, has been shown to provide renoprotective effects and slow progression to end-stage renal disease. However, this protective effect in kidney transplant patient populations is unclear.

Aim:

The objective of this systematic review and meta-analysis was to evaluate the effect of RAS inhibitors on kidney allograft survival.

Materials and Methods:

A literature search for randomized controlled trials (RCTs) was performed from inception through February 2016. Studies that reported relative risks or hazard ratios comparing the risks of renal graft loss in renal transplant recipients who received RAS inhibitors vs. controls were included. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using a random-effect, generic inverse variance method.

Results:

Five studies (3 RCTs and 2 cohort studies) with 20024 kidney transplant patients were included in the meta-analysis. Pooled RR of allograft failure in recipients who received RAS inhibitors was 0.73 (95% CI: 0.45–1.21). When meta-analysis was limited only to RCTs, the pooled RR of allograft failure in patients using RAS inhibitors was 0.59 (95%: CI 0.20–1.69). The risk for mortality (RR: 1.13 [95% CI: 0.62–2.07]) in patients using RAS inhibitors compared to controls was not significantly reduced.

Conclusion:

This meta-analysis demonstrated insignificant reduced risks of renal graft loss among renal transplant recipients who received RAS inhibitors. Future studies assessing the potential benefits of RAS inhibitors on allograft survival in specific kidney transplant patient populations are needed.

Update in perioperative medicine: practice-changing evidence published in 2015

Evidence in perioperative medicine is published in a wide variety of journals, given the multidisciplinary nature of its practice which spans medicine and its subspecialties, as well as surgery and anesthesiology. It can be difficult to identify new and important evidence, as perioperative practice continues to evolve in multiple areas such as medication management, anticoagulation and cardiac risk stratification, among others. New, high-quality evidence is published each year, and must be placed into the context of not only existing literature, but also practical real-world patient care. We sought to systematically identify, critically evaluate and concisely summarize the practice implications of 10 articles published in 2015 for the practicing perioperative clinician.

The risk of acute kidney injury following transapical versus transfemoral transcatheter aortic valve replacement: a systematic review and meta-analysis

Background

The aim of this systematic review is to examine the literature for the risk of acute kidney injury (AKI) in patients who underwent transcatheter aortic valve replacement (TAVR) based on transapical (TA) versus transfemoral (TF) approaches.

Methods

A literature search was conducted utilizing Embase, Medline, Cochrane Database of Systematic Reviews and ClinicalTrials.gov from inception through December 2015. Studies that reported relative risk, odds ratio or hazard ratio comparing the AKI risk in patients who underwent TA-TAVR versus TF-TAVR were included. Pooled risk ratio (RR) and 95% confidence interval (CI) were calculated using a random effect, generic inverse variance method.

Results

Seventeen cohort studies with 5085 patients were enrolled in the analysis to assess the risk of AKI in patients undergoing TA-TAVR versus TF-TAVR. The pooled RR of AKI in patients who underwent TA-TAVR was 2.26 (95% CI 1.79–2.86) when compared with TF-TAVR. When meta-analysis was confined to the studies with adjusted analysis for confounders evaluating the risk of AKI following TAVR, the pooled RR of TA-TAVR was 2.89 (95% CI 2.12–3.94). The risk for moderate to severe AKI [RR 1.02 (95% CI 0.57–1.80)] in patients who underwent TA-TAVR compared with TF-TAVR was not significantly higher.

Conclusions

Our meta-analysis demonstrates an association between TA-TAVR and a higher risk of AKI. Future studies are required to assess the risks of moderate to severe AKI and mortality following TA-TAVR versus TF-TAVR.

The comparison of the commonly used surrogates for baseline renal function in acute kidney injury diagnosis and staging

BACKGROUND

Baseline serum creatinine (SCr) level is frequently not measured in clinical practice. The aim of this study was to investigate the effect of various methods of baseline SCr determination measurement on accuracy of acute kidney injury (AKI) diagnosis in critically ill patients.

METHODS

This was a retrospective cohort study. All adult intensive care unit (ICU) patients admitted at a tertiary referral hospital from January 1, 2011 through December 31, 2011, with at least one measured SCr value during ICU stay, were included in this study. The baseline SCr was considered either an admission SCr (SCrADM) or an estimated SCr, using MDRD formula, based on an assumed glomerular filtration rate (GFR) of 75 ml/min/1.73 m(2) (SCrGFR-75). Determination of AKI was based on the KDIGO SCr criterion. Propensity score to predict the likelihood of missing SCr was used to generate a simulated cohort of 3566 patients with baseline outpatient SCr, who had similar characteristics with patients whose outpatient SCr was not available.

RESULTS

Of 7772 patients, 3504 (45.1 %) did not have baseline outpatient SCr. Among patients without baseline outpatient SCr, AKI was detected in 571 (16.3 %) using the SCrADM and 997 (28.4 %) using SCrGFR-75 (p < .001). Compared with non-AKI patients, patients who met AKI only by SCrADM, but not SCrGFR-75, were significantly associated with 60-day mortality (OR 2.90; 95 % CI 1.66-4.87), whereas patients who met AKI only by SCrGFR-75, but not SCrADM, had a non-significant increase in 60-day mortality risk (OR 1.33; 95 % CI 0.94-1.88). In a simulated cohort of patients with baseline outpatient SCr, SCrGFR-75 yielded a higher sensitivity (77.2 vs. 50.5 %) and lower specificity (87.8 vs. 94.8 %) for the AKI diagnosis in comparison with SCrADM.

CONCLUSIONS

When baseline outpatient SCr was not available, using SCrGFR-75 as surrogate for baseline SCr was found to be more sensitive but less specific for AKI diagnosis compared with using SCrADM. This resulted in higher incidence of AKI with larger likelihood of false-positive cases.

Competing Actions of Type 1 Angiotensin II Receptors Expressed on T Lymphocytes and Kidney Epithelium during Cisplatin-Induced AKI

Inappropriate activation of the renin-angiotensin system (RAS) contributes to many CKDs. However, the role of the RAS in modulating AKI requires elucidation, particularly because stimulating type 1 angiotensin II (AT1) receptors in the kidney or circulating inflammatory cells can have opposing effects on the generation of inflammatory mediators that underpin the pathogenesis of AKI. For example, TNF-α is a fundamental driver of cisplatin nephrotoxicity, and generation of TNF-α is suppressed or enhanced by AT1 receptor signaling in T lymphocytes or the distal nephron, respectively. In this study, cell tracking experiments with CD4-Cre mT/mG reporter mice revealed robust infiltration of T lymphocytes into the kidney after cisplatin injection. Notably, knockout of AT1 receptors on T lymphocytes exacerbated the severity of cisplatin-induced AKI and enhanced the cisplatin-induced increase in TNF-α levels locally within the kidney and in the systemic circulation. In contrast, knockout of AT1 receptors on kidney epithelial cells ameliorated the severity of AKI and suppressed local and systemic TNF-α production induced by cisplatin. Finally, disrupting TNF-α production specifically within the renal tubular epithelium attenuated the AKI and the increase in circulating TNF-α levels induced by cisplatin. These results illustrate discrepant tissue-specific effects of RAS stimulation on cisplatin nephrotoxicity and raise the concern that inflammatory mediators produced by renal parenchymal cells may influence the function of remote organs by altering systemic cytokine levels. Our findings suggest selective inhibition of AT1 receptors within the nephron as a promising intervention for protecting patients from cisplatin-induced nephrotoxicity.

Periprocedural Nebivolol for the Prevention of Contrast-Induced Acute Kidney Injury: A Systematic Review and Meta-analysis

Background:

Nebivolol provides a protective effect on contrast-induced acute kidney injury (CIAKI) in animal models. However, the reports on the efficacy of nebivolol for the prevention of CIAKI in human remain unclear.

Aims:

The objective of this meta-analysis was to assess the effect of nebivolol for the prevention of CIAKI.

Materials and Methods:

Comprehensive literature searches were performed using MEDLINE, EMBASE, and Cochrane Database from inception through February 2015. Studies that reported relative risks, odd ratios, or hazard ratios comparing the risk of CIAKI in patients who received nebivolol versus those who did not were included. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

Results:

Four studies (2 randomized controlled trials and 2 cohort studies) with 543 patients were included in our analysis to assess the risk of CIAKI and the use of nebivolol. Patients in the nebivolol group had an overall lower incidence of CIAKI (14.4%) compared to the control group (18.4%). The pooled RR of CIAKI in patients receiving nebivolol was 0.66 (95% CI: 0.38-1.15, I² = 0). When meta-analysis was limited only to randomized control trials (RCTs), the pooled RR of CIAKI in patients receiving nebivolol was 0.79 (95% CI: 0.35-1.79, I² = 0%).

Conclusions:

Despite no statistical significance, there was a trend toward reduced CIAKI risk in patients receiving nebivolol. The findings of our meta-analysis suggest the need of a large RCT with very careful attention to the balance of benefits and harms.

AKI after Transcatheter or Surgical Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) is an alternative to surgical aortic valve replacement (SAVR) for patients with symptomatic severe aortic stenosis who are at high risk of perioperative mortality. Previous studies showed increased risk of postoperative AKI with TAVR, but it is unclear whether differences in patient risk profiles confounded the results. To conduct a propensity-matched study, we identified all adult patients undergoing isolated aortic valve replacement for aortic stenosis at Mayo Clinic Hospital in Rochester, Minnesota from January 1, 2008 to June 30, 2014. Using propensity score matching on the basis of clinical characteristics and preoperative variables, we compared the postoperative incidence of AKI, defined by Kidney Disease Improving Global Outcomes guidelines, and major adverse kidney events in patients treated with TAVR with that in patients treated with SAVR. Major adverse kidney events were the composite of in-hospital mortality, use of RRT, and persistent elevated serum creatinine ≥200% from baseline at hospital discharge. Of 1563 eligible patients, 195 matched pairs (390 patients) were created. In the matched cohort, baseline characteristics, including Society of Thoracic Surgeons risk score and eGFR, were comparable between the two groups. Furthermore, no significant differences existed between the TAVR and SAVR groups in postoperative AKI (24.1% versus 29.7%; P=0.21), major adverse kidney events (2.1% versus 1.5%; P=0.70), or mortality >6 months after surgery (6.0% versus 8.3%; P=0.51). Thus, TAVR did not affect postoperative AKI risk. Because it is less invasive than SAVR, TAVR may be preferred in high-risk individuals.