Reversible preoperative renal dysfunction does not add to the risk of postoperative acute kidney injury after cardiac valve surgery

Worsening renal function after transcatheter aortic valve replacement and surgical aortic valve replacement

Several prior reports have investigated worsening renal function around transcatheter aortic valve replacement (TAVR) procedures. However, in clinical practice, it seems more important to evaluate changes associated with TAVR-related procedures, including preoperative enhanced computed tomography (CT), as well as the TAVR procedure itself, as CT assessment is considered essential for safe TAVR. This study evaluated worsening renal function during the TAVR perioperative period, from the preoperative enhanced CT to 1 month after TAVR, and then compared the incidence with that in patients undergoing surgical aortic valve replacement (SAVR). This retrospective single-center study investigated 123 TAVR patients and 130 SAVR patients. We evaluated baseline renal function before enhanced CT in TAVR patients and before operation in SAVR patients, and again at 1 month post-operatively. We defined worsening renal function at 1 month according to three definitions: (1) an increase in serum creatinine ≥ 0.3 mg/dL or ≥ 1.5-fold from baseline or initiation of dialysis, (2) a decline in eGFR at 1 month ≥ 20% from baseline or initiation of dialysis, (3) a decline in eGFR at 1 month ≥ 30% from baseline or initiation of dialysis. TAVR patients were significantly older and had higher surgical risk scores than SAVR patients. In TAVR patients, serum creatinine levels were 1.00 ± 0.32 mg/dL at baseline and 1.01 ± 0.40 mg/dL at 1 month post-operatively (p = 0.58), while in SAVR patients, these levels were 0.99 ± 0.51 mg/dL and 0.98 ± 0.49 mg/dL, respectively (p = 0.59). In TAVR patients, 7 (5.7%), 14 (11.4%), and 3 (2.4%) patients experienced worsening renal function according to the three definitions, respectively, but there were no significant differences from those in SAVR patients, for any definition. Worsening renal function after TAVR was uncommon, and the incidence rate was comparable to that in SAVR patients, even though TAVR patients had worse baseline characteristics.

Renal Injury in All-Comers After Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis

Background

Acute kidney injury (AKI) following aortic valve replacement is associated with poor prognosis. Transcatheter aortic valve replacement (TAVR) is a novel strategy with a percutaneous approach and early recovery time. We conducted this meta-analysis to compare TAVR to surgical aortic valve replacement (SAVR) and their respective renal outcomes.

Methods

We searched for randomized controlled trials (RCTs) using MEDLINE, PUBMED, and Google Scholar databases from their inception till April 6, 2019, and included eight trials comparing TAVR to SAVR in cases that reported AKIs.

Results

We found a significant reduction in AKI after TAVR compared to SAVR at 30 days [n = 66 vs. n = 160, respectively; odds ratio (OR) = 0.38, 95% confidence interval (CI) = 0.28-0.51; p: <0.00001, I² = 0%]. At one year, a trend towards reduced renal failure was noted in the TAVR arm compared to the SAVR arm (n = 74 vs. n = 129, respectively; OR = 0.57, 95% CI = 0.32-1.01; p = 0.05, I² = 69%).

Conclusion

Based on our findings and analysis, we have concluded that TAVR is associated with significantly reduced renal injury at 30 days when compared to SAVR.

Meta-Analysis Comparing Outcomes and Need for Renal Replacement Therapy of Transcatheter Aortic Valve Implantation Versus Surgical Aortic Valve Replacement

Acute kidney injury (AKI) is commonly associated with aortic valve replacement. Surgical aortic valve replacement (SAVR) is a known risk factor for AKI but little is known about the short- and long-term effects of transcatheter aortic valve implantation (TAVI). The purpose of our analysis is to identify the short- and long-term effect of TAVI on renal outcomes. We searched Medline and PUBMED from January 1, 2000 to November 6, 2017 for randomized control trials (RCTs) comparing TAVI to SAVR in patients with severe aortic stenosis. Three hundred sixty-nine trials were identified, 6 RCTs were included in our analysis. RevMan version 5.3 was used for statistical analysis. Heterogeneity is calculated using I² statistics. Primary outcomes were AKI within 30 days and 1 year of TAVI, and requirement for renal replacement therapy. We included 5,536 patients (2,796 in TAVI and 2,740 in SAVR arm) from 6 RCTs. Baseline characteristics were similar. There was reduced incidence of AKI at 30 days of TAVI compared with SAVR, 57 versus 133 (odds ratio [OR] 0.40, confidence interval [CI] 0.28 to 0.56, p <0.00001, I² = 7%) with no difference at 1 year (OR 0.65, CI 0.32 to 1.32, p = 0.23, I² = 76%) and need for renal replacement therapy OR 0.95, CI 0.50 to 1.80, p = 0.87, I² = 0%). Permanent pacemaker was more frequent in the TAVI arm compared with SAVR arm, 379 versus 110, (OR 3.75, CI 1.67 to 8.42, p = 0.001, I² = 89%). In conclusion, TAVI is associated with a reduction in AKIs at 30 days despite the exposure to contrast and higher incidence of new permanent pacemaker placement.

Epidemiological characteristics of and risk factors for patients with postoperative acute kidney injury: a multicenter prospective study in 30 Chinese intensive care units

BACKGROUND

Although there were studies to investigate the risk factors for acute kidney injury (AKI) after surgery, most of them focused on one specific type of surgeries. The risk factors for postoperative AKI in patients undergoing all surgeries in intensive care units (ICU) have not been reported.

METHODS

Data from 1731 patients undergoing surgery in 30 ICUs of 28 tertiary hospitals in Beijing from March to August 2012 were prospectively collected. AKI was defined and staged by the KDIGO criteria. Multivariate logistic regression analysis was performed to assess independent risk factors for postoperative AKI.

RESULTS

Postoperative AKI occurred in 44.8% of patients (stage 1 54.8%; stage 2 21.9%, stage 3 23.3%). Cardiovascular surgery was identified as an independent factor for postoperative AKI as well as emergency surgery [odds ratio (OR) 1.403], nephrotoxic drugs (OR 1.303), APACHE II score (OR 1.055), SOFA score (OR 1.115), duration for positive fluid balance (OR 1.165), use of diuretics (OR 2.293), sepsis (OR 1.501), and CKD (OR 4.517). AKI stage 3 versus stages 1-2 was associated with higher mortality in ICU, hospital, and 28-day follow-up after cardiovascular, abdominal, limb, and chest surgeries, while this was not observed after neurosurgery or other surgeries.

CONCLUSION

Risk factors for AKI in ICU patients after different types of surgery were identified. This might be the first step to reduce the high incidence of AKI after surgery. The presence of AKI in ICU patients was associated with higher mortality after most types of surgery, but not after neurosurgery.

TRIAL REGISTRATION

ChiCTR-ONC-11001875.