Cardiopulmonary bypass time is an independent risk factor for acute kidney injury in emergent thoracic aortic surgery: a retrospective cohort study

Renal dysfunction in adults following cardiopulmonary bypass is linked to declines in S-nitroso hemoglobin: a case series

Background

Impaired kidney function is frequently observed in patients following cardiopulmonary bypass (CPB). Our group has previously linked blood transfusion to acute declines in S-nitroso haemoglobin (SNO-Hb; the main regulator of tissue oxygen delivery), reductions in intraoperative renal blood flow, and postoperative kidney dysfunction. While not all CPB patients receive blood, kidney injury is still common. We hypothesized that the CPB procedure itself may negatively impact SNO-Hb levels leading to renal dysfunction.

Materials and methods

After obtaining written informed consent, blood samples were procured immediately before and after CPB, and on postoperative day (POD) 1. SNO-Hb levels, renal function (estimated glomerular filtration rate; eGFR), and plasma erythropoietin (EPO) concentrations were quantified. Additional outcome data were extracted from the patients' medical records.

Results

Twenty-seven patients were enroled, three withdrew consent, and one was excluded after developing bacteremia. SNO-Hb levels declined after surgery and were directly correlated with declines in eGFR (R=0.48). Conversely, plasma EPO concentrations were elevated and inversely correlated with SNO-Hb (R=-0.53) and eGFR (R=-0.55). Finally, ICU stay negatively correlated with SNO-Hb concentration (R=-0.32).

Conclusion

SNO-Hb levels are reduced following CPB in the absence of allogenic blood transfusion and are predictive of decreased renal function and prolonged ICU stay. Thus, therapies directed at maintaining or increasing SNO-Hb levels may improve outcomes in adult patients undergoing cardiac surgery.

Risk factors for prolonged postoperative ICU stay in the patients with Stanford type A aortic dissection

OBJECTIVE

To investigate the independent risk factors for postoperative prolonged ICU stay in patients with Stanford type A aortic dissection (TAAD) and assess the clinical outcomes of prolonged ICU stay.

METHOD

The clinical data of 100 patients with TAAD admitted to the Department of Cardiovascular Surgery, First Affiliated Hospital of Anhui Medical University from December 2018 to September 2022 were retrospectively collected and analyzed. Patients were divided into two groups, based on the postoperative ICU stay (7 days as the threshold), regular ICU stay group (< 7 days) and prolonged ICU stay group (≥ 7 days). First, preoperative and intraoperative materials were collected for univariate analysis. Then, the significant variables after univariate analysis were analyzed using logistic regression, and the final independent risk factors for prolonged ICU stay were determined. Meanwhile, the postoperative clinical outcomes were analyzed with the aim of assessing the clinical outcomes due to prolonged ICU stay.

RESULTS

There were 65 and 35 patients in the regular ICU stay group and the prolonged ICU stay group, respectively. In accordance with the result of univariate analysis in the two groups, emergency surgery (χ2 = 13.598; P < 0.001), preoperative urea nitrogen (t = 3.006; P = 0.004), cardiopulmonary bypass (CPB) time (t = 2.671; P = 0.001) and surgery time (t = 2.630; P = 0.010) were significant. All significant variates were analyzed through logistic regression, and it was found that emergency surgery (OR = 0.192; 95% CI: 0.065-0.561), preoperative urea nitrogen (OR = 0.775; 95% CI: 0.634-0.947) and cardiopulmonary time (OR = 0.988; 95% CI: 0.979-0.998) were independent risk factors for prolonged postoperative ICU stay. The Receiver Operating Characteristic (ROC) curves of these three factors were also effective in predicting postoperative prolonged ICU stay (Emergency surgery, AUC = 0.308, 95% CI: 0.201-0.415; Preoperative urea nitrogen, AUC = 0.288, 95% CI: 0.185-0.392; cardiopulmonary time, AUC = 0.340, 95% CI: 0.223-0.457). Moreover, compared with a single factor, the predictive value of combined factors was more significant (AUC = 0.810, 95% CI: 0.722-0.897). For the comparison of postoperative data in the two groups,, compared with the regular ICU stay group, the incidence of adverse events in the prolonged ICU stay group increased significantly, including limb disability of limbs (χ2 = 22.182; P < 0.001), severe organ injury (χ2 = 23.077; P < 0.001), tracheotomy (χ2 = 17.582; P < 0.001), reintubation (χ2 = 28.020; P < 0.001), 72 h tracheal extubation after surgery (χ2 = 29.335; P < 0.001), 12 h consciousness recovery after surgery (χ2 = 18.445; P < 0.001), ICU re-entering (χ2 = 9.496; P = 0.002) and irregular discharging (χ2 = 24.969; P < 0.001).

CONCLUSION

Emergency surgery, preoperative urea nitrogen, and CPB time are risk factors for postoperative prolonged ICU stay after TAAD surgery. Furthermore, prolonged ICU stay is associated with worse clinical outcomes. Hence, a reasonable strategy should be adopted proactively focusing on the risk factors to shorten ICU stays and improve clinical outcomes.

A Novel Predictive Model for Acute Kidney Injury Following Surgery of the Aorta

Background

Acute kidney injury (AKI) frequently occurs after aortic surgery and has a significant impact on patient outcomes. Early detection or prediction of AKI is crucial for timely interventions. This study aims to develop and validate a novel model for predicting AKI following aortic surgery.

Methods

We enrolled 156 patients who underwent on-pump aortic surgery in our hospital from February 2023 to April 2023. Postoperative levels of eight cytokines related to macrophage polarization analyzed using a multiplex cytokine assay. All-subset regression was used to select the optimal cytokines to predict AKI. A logistic regression model incorporating the selected cytokines was used for internal validation in combination with a bootstrapping technique. The model's ability to discriminate between cases of AKI and non-AKI was assessed using receiver operating characteristic (ROC) curve analysis.

Results

Of the 156 patients, 109 (69.87%) developed postoperative AKI. Interferon-gamma (IFN- γ ) and interleukin-4 (IL-4) were identified as candidate AKI predictors. The cytokine-based model including IFN- γ and IL-4 demonstrated excellent discrimination (C-statistic: 0.90) and good calibration (Brier score: 0.11). A clinical nomogram was generated, and decision curve analysis revealed that the cytokine-based model outperformed the clinical factor-based model in terms of net benefit. Moreover, both IFN- γ and IL-4 emerged as independent risk factors for AKI. Patients in the second and third tertiles of IFN- γ and IL-4 concentrations had a significantly higher risk of severe AKI, a higher likelihood of requiring renal replacement therapy, or experiencing in-hospital death. These patients also had extended durations of mechanical ventilation and intensive care unit stays, compared with those in the first tertile (all p for group trend < 0.001).

Conclusions

We successfully established a novel and powerful predictive model for AKI, and demonstrating the significance of IFN- γ and IL-4 as valuable clinical markers. These cytokines not only predict the risk of AKI following aortic surgery but are also linked to adverse in-hospital outcomes. This model offers a promising avenue for the early identification of high-risk patients, potentially improving clinical decision-making and patient care.

Predictors of early peritoneal dialysis initiation in newborns and young infants following cardiac surgery

OBJECTIVE

This single-centre, retrospective cohort study was conducted to investigate the predictors of early peritoneal dialysis initiation in newborns and young infants undergoing cardiac surgery.

METHODS

There were fifty-seven newborns and young infants. All subjects received peritoneal dialysis catheter after completion of the cardiopulmonary bypass. Worsening post-operative (post-op) positive fluid balance and oliguria (<1 ml/kg/hour) despite furosemide were the clinical indications to start early peritoneal dialysis (peritoneal dialysis +). Demographic, clinical, and laboratory data were collected from the pre-operative, intra-operative, and immediately post-operative periods.

RESULTS

Baseline demographic data were indifferent except that peritoneal dialysis + group had more newborns. Pre-operative serum creatinine was higher for peritoneal dialysis + group (p = 0.025). Peritoneal dialysis + group had longer cardiopulmonary bypass time (p = 0.044), longer aorta cross-clamp time (p = 0.044), and less urine output during post-op 24 hours (p = 0.008). In the univariate logistic regression model, pre-op serum creatinine was significantly associated with higher odds of being in peritoneal dialysis + (p = 0.021) and post-op systolic blood pressure (p = 0.018) and post-op mean arterial pressure (p=0.001) were significantly associated with reduced odds of being in peritoneal dialysis + (p = 0.018 and p = 0.001, respectively). Post-op mean arterial pressure showed a statistically significant association adjusted odds ratio = 0.89, 95% confidence interval [0.81, 0.96], p = 0.004) with peritoneal dialysis + in multivariate analysis after adjusting for age at surgery.

CONCLUSIONS

In our single-centre cohort, pre-op serum creatinine, post-op systolic blood pressure, and mean arterial pressure demonstrated statistically significant association with peritoneal dialysis +. This finding may help to better risk stratify newborns and young infants for early peritoneal dialysis start following cardiac surgery.

Incidence of Acute Kidney Injury and Risk Factors of Prognosis in Patients with Acute Stanford Type A Aortic Dissection

PURPOSE

We aimed to investigate the prognosis and impact of postoperative acute kidney injury (AKI) in acute Stanford type A aortic dissection (ATAAD) patients, and to analyze the predictors of short- and medium-term survival.

METHODS

A total of 192 patients who underwent ATAAD surgery were included between May 2014 and May 2019. Perioperative data of these patients were analyzed. All of the discharged patients were followed up for 2 years.

RESULTS

Postoperative AKI was identified in 43 of 192 patients (22.4%). The two-year survival rate of patients with AKI after discharge was 88.2% and that without AKI was 97.2%.The difference was statistically significant (χ2 = 5.355, log-rank P = 0.021). Cox hazards regression showed that age (hazard ratio [HR], 1.070; P = 0.002), cardiopulmonary bypass (CPB) time (HR, 1.026; P = 0.026), postoperative AKI (HR, 3.681; P = 0.003), and red blood cell transfusion (HR, 1.548; P = 0.001) were independent risk factors for the short- and medium-term total mortality of ATAAD patients.

CONCLUSION

The incidence of postoperative AKI is high in ATAAD, and the mortality of patients with AKI increases significantly within 2 years. Age, CPB time, and red blood cell transfusion were also independent risk factors for short-and medium-term prognoses.

Sutureless vs. rapid-deployment valve: a systemic review and meta-analysis for a direct comparison of intraoperative performance and clinical outcomes

Background

Sutureless and rapid-deployment valves are bioprostheses anchoring within the aortic annulus with few sutures, and they act as a hybrid of conventional surgical and transcatheter valves under aortic valve replacement. Considering that the 3F Enable valve is now off-market, the only two sutureless and rapid-deployment valves available on the world marketplace are the Perceval and Intuity valves. However, a direct comparison of the function of these two valves eludes researchers.

Purpose

Against this background, we performed this systematic review and meta-analysis comparing the intraoperative performance and early clinical outcomes between the Perceval valve and the Intuity valve under sutureless and rapid-deployment aortic valve replacement.

Methods

We systematically searched electronic databases through PubMed/MEDLINE, OvidWeb, Web of Science, and Cochrane Central Register of Controlled Trials (from the establishment of the database to November 17, 2022, without language restriction) for studies comparing the sutureless valve (the Perceval) and the rapid-deployment valve (the Intuity) under aortic valve replacement. Our primary outcomes were early mortality and postoperative transvalvular pressure gradients. The secondary outcomes were defined to include aortic cross-clamp and cardiopulmonary bypass time, paravalvular leak (any paravalvular leak, moderate-to-severe paravalvular leak) after aortic valve replacement, need for pacemaker implantation, postoperative neurological events (stroke), and intensive care unit stay.

Results

This meta-analysis included ten non-randomized trials with 3,526 patients enrolled (sutureless group = 1,772 and rapid-deployment group = 1,754). Quality assessments were performed, with the mean scores of the studies reading 6.90 (SD = 0.99) out of 9 according to the Newcastle-Ottawa Scale. Compared with rapid-deployment aortic valve replacement, sutureless aortic valve replacement was associated with higher mean and peak transvalvular pressure gradients postoperatively. In contrast, aortic cross-clamp and cardiopulmonary time were needed less in sutureless aortic valve replacement vs. rapid-deployment aortic valve replacement. There was no evidence of significant publication bias observed by the funnel plot and Egger's test.

Conclusions

For postoperative hemodynamics, sutureless aortic valve replacement was associated with increased mean and peak transvalvular pressure gradients compared with rapid-deployment aortic valve replacement. In sharp contrast, sutureless aortic valve replacement significantly reduced the amount of time needed for fixing the aortic cross-clamp and the cardiopulmonary bypass procedure.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022343884.

Risk factors for in-hospital mortality after total arch procedure in patients with acute type A aortic dissection

Object

Knowledge about the risk factors of in-hospital mortality for acute type A aortic dissection (ATAAD) patients who received total arch procedure is limited. This study aims to investigate preoperative and intraoperative risk factors of in-hospital mortality of these patients.

Methods

From May 2014 to June 2018, 372 ATAAD patients received the total arch procedure in our institution. These patients were divided into survival and death groups, and patients` in-hospital data were retrospectively collected. Receiver operating characteristic curve analysis was adopted to determine the optimal cut-off value of continuous variables. Univariate and multivariable logistic regression analyses were used to detect independent risk factors for in-hospital mortality.

Results

A total of 321 patients were included in the survival group and 51 in the death group. Preoperative details showed that patients in the death group were older (55.4 ± 11.7 vs. 49.3 ± 12.6, P = 0.001), had more renal dysfunction (29.4% vs. 10.9%, P = 0.001) and coronary ostia dissection (29.4% vs. 12.2%, P = 0.001), and decreased left ventricular ejection fraction (LVEF) (57.5 ± 7.9% vs. 59.8 ± 7.3%, P = 0.032). Intraoperative results showed that more patients in the death group experienced concomitant coronary artery bypass grafting (35.3% vs. 15.3%, P = 0.001) with increased cardiopulmonary bypass (CPB) time (165.7 ± 39.0 vs. 149.4 ± 35.8 min, P = 0.003), cross-clamp time (98.4 ± 24.5 vs. 90.2 ± 26.9 min, P = 0.044), and red blood cell transfusion (913.7 ± 629.0 vs. 709.7 ± 686.6 ml, P = 0.047). Logistic regression analysis showed that age >55 years, renal dysfunction, CPB time >144 min, and RBC transfusion >1,300 ml were independent risk factors for in-hospital mortality in patients with ATAAD.

Conclusion

In the present study, we identified that older age, preoperative renal dysfunction, long CPB time, and intraoperative massive transfusion were risk factors for in-hospital mortality in ATAAD patients with the total arch procedure.

Systematic Innominate Artery Cannulation Strategy in Acute Type A Aortic Dissection: Better Perfusion, Better Results

(1) Background: Arterial cannulation in type A acute aortic dissection (TAAAD) is still subject to debate. We describe a systematic approach of using the innominate artery for arterial perfusion (2) Methods: The hospital records of 110 consecutive patients with acute TAAAD operated on between January 2014 and December 2022 were retrospectively analyzed. The effect of the cannulation site on early and late mortality, as well as on cardio-pulmonary perfusion indices (lactate and base excess levels, and cooling and rewarming speed) were investigated. (3) Results: There was a significant difference in early mortality (8.82% vs. 40.79%, p < 0.01) but no difference in long-term survival beyond the first 30 days. Using the innominate artery enabled the use of approximately 20% higher CPB flows (2.73 ± 0.1 vs. 2.42 ± 0.06 L/min/m² BSA, p < 0.01), which resulted in more rapid cooling (1.89 ± 0.77 vs. 3.13 ± 1.62 min/°C/m² BSA, p < 0.01), rewarming (2.84 ± 1.36 vs. 4.22 ± 2.23, p < 0.01), lower mean base excess levels during CPB (-5.01 ± 2.99 mEq/L vs. -6.66 ± 3.37 mEq/L, p = 0.01) and lower lactate levels at the end of the procedure (4.02 ± 2.48 mmol/L vs. 6.63 ± 4.17 mmol/L, p < 0.01). Postoperative permanent neurologic insult (3.12% vs. 20%, p = 0.02) and acute kidney injury (3.12% vs. 32.81%, p < 0.01) were significantly reduced. (4) Conclusions: systematic use of the innominate artery enables better perfusion and superior results in TAAAD repair.

Incidence and outcomes of acute kidney disease in patients after type A aortic dissection surgery

BACKGROUND

Acute kidney injury (AKI), acute kidney disease (AKD) and CKD (chronic kidney disease) were a continuous process. There has been little discussion of risk factors for AKD in the population undergoing surgery for acute type A aortic dissection (AAAD).

OBJECTIVE

The main objective of this study was to investigate the risk factors for AKD after surgery for acute type A aortic dissection and the impact of AKD on early and late mortality.

DESIGN

AKI was to be defined as an increase in serum creatinine to >0.3 mg/dL or 1.5 times above baseline within 7 days. AKD was defined as the kidney damage within 90 days after AKI. Logistic regression models were performed to identify the risk factors of AKD and the association between AKD and early mortality after AAAD surgery.

PARTICIPANTS

Patients with AKI after AAAD surgery admitted in ICU from March 2009 to September 2021 were included.

KEY RESULTS

Among the 328 patients who developed AKI after AAAD surgery, 98 patients (29.9%) progressed to AKD. Multivariable analysis revealed that AKI stage 2 (OR, 3.032) and AKI stage 3 (OR, 4.001) have been shown to be independent risk factors for the development of AKD. AKD (OR, 3.175) proved to be an independent risk factor for early mortality, while no significant difference in late mortality was observed between patients in the AKD and non-AKD groups.

CONCLUSION

The severity of AKI after surgery of AAAD was independently associated with AKD. The occurrence of AKD had a negative impact on early mortality.

CLINICAL TRIAL REGISTRATION

ChiCTR, ChiCTR1900021290. Registered 12 February 2019, http://www.chictr.org.cn/showproj.aspx?proj=35795.

Challenging Paradigm Limits of Retrograde Cerebral Perfusion During Lower Body Circulatory Arrest

INTRODUCTION

Retrograde cerebral perfusion (RCP) is a safe and effective technique to augment cerebral protection during lower body circulatory arrest in patients undergoing elective hemiarch replacement. However, recommendations guiding optimal temperature, flow rate, and perfusion pressure are outdated and potentially overly limiting. We report our experience using RCP for elective hemiarch replacement with parameters that challenge the currently accepted paradigm.

METHODS

This was a single-center, retrospective analysis of 319 adult patients who underwent elective hemiarch replacement between February 2010 and 2021 using hypothermic lower body circulatory arrest with RCP alone, RCP followed by antegrade cerebral perfusion (ACP), or ACP alone. Flow rates were adjusted to maintain cerebral perfusion pressure between 30 and 50 mm Hg for RCP and between 40 and 60 mm Hg for ACP.

RESULTS

RCP was used in 22.6% (n = 72) of cases, whereas ACP alone was performed in 77.4% (n = 247) of cases. Baseline patient characteristics were similar between groups. Patients undergoing RCP demonstrated shorter cross-clamp time (97.0 min versus 100.0 min, P = 0.034) and shorter lower body circulatory arrest time (7.0 min versus 10.0 min, P < 0.0001) compared with ACP alone. Nadir bladder temperature was equivalent between groups (27.3°C versus 27.5°C, P = 0.752). There were no significant differences in postoperative complications, neurologic outcomes, or mortality.

CONCLUSIONS

Moderate hypothermic lower body circulatory arrest combined with RCP at target perfusion pressures of 30-50 mm Hg in patients undergoing elective hemiarch replacement results in equivalent neurologic outcomes and overall morbidity to cases using ACP alone. These results challenge the currently accepted paradigm for RCP, which typically uses deep hypothermia while keeping perfusion pressures below 25 mm Hg.

Efficacy of tolvaptan in postoperative volume therapy for acute Stanford type A aortic dissection

BACKGROUND

Despite the increasing application of tolvaptan in cardiac surgery, there is no information on the use of tolvaptan in Stanford patients with type A aortic dissection. This study aimed to evaluate the postoperative clinical effects of tolvaptan in patients with type A aortic dissection  after tafter surgery.

METHODS

A retrospective analysis was performed on 45 patients treated for type A aortic dissection in our hospital from 2018 to 2020. These included 21 patients who were treated with tolvaptan (Group T) and 24 patients who received traditional diuretics (Group L). The hospital's electronic health records were used to obtain perioperative data.

RESULTS

Group T did not differ significantly from Group L in terms of the duration of mechanical ventilation, postoperative blood required, length of catecholamine use, or the amount of intravenous diuretic drugs administered (all P > 0.05). The development of postoperative atrial fibrillation was significantly less in the tolvaptan group (P = 0.023). The urine volumes and change in body weight loss were slightly higher in group T than in group L but the differences were non-significant (P > 0.05). Serum potassium, creatinine, and urea nitrogen levels did not differ between the groups in the week after surgery, At the same time, sodium was significantly higher in the Group T group on day 7 after transfer from the ICU (P = 0.001). In Group L, sodium levels were also elevated by day 7 (P = 0.001). On days 3 and 7, serum creatinine and urea nitrogen levels increased in both groups (both P < 0.05).

CONCLUSIONS

Both tolvaptan and traditional diuretics were found to be effective and safe for patients with acute Stanford type A aortic dissection. Moreover, tolvaptan may be associated with reducing the incidence of postoperative atrial fibrillation.

Risk factor prediction of severe postoperative acute kidney injury at stage 3 in patients with acute type A aortic dissection using thromboelastography

Objective

Perioperative blood transfusions and postoperative drainage volume not only are the commonly recognized risk factors for acute kidney injury (AKI) but also are indirect indicators of coagulopathy in patients with acute type A aortic dissection (ATAAD). However, standard laboratory tests fail to accurately reflect and assess the overall coagulopathy profile in patients with ATAAD. Thus, this study aimed to explore the association between the hemostatic system and severe postoperative AKI (stage 3) in patients with ATAAD using thromboelastography (TEG).

Methods

We selected 106 consecutive patients with ATAAD who underwent emergency aortic surgery at Beijing Anzhen Hospital. All participants were categorized into the stage 3 and non-stage 3 groups. The hemostatic system was evaluated using routine laboratory tests and TEG preoperatively. We undertook univariate and multivariate stepwise logistic regression analyses to determine the potential risk factors for severe postoperative AKI (stage 3), with a special investigation on the association between hemostatic system biomarkers and severe postoperative AKI (stage 3). The receiver operating characteristic (ROC) curves were generated to assess the predictive ability of hemostatic system biomarkers for severe postoperative AKI (stage 3).

Results

A total of 25 (23.6%) patients developed severe postoperative AKI (stage 3), including 21 patients (19.8%) who required continuous renal replacement therapy (RRT). Multivariate logistic regression analysis demonstrated that the preoperative fibrinogen level (OR, 2.02; 95% CI, 1.03 to 3.00; p = 0.04), platelet function (MA level) (OR, 1.23; 95% CI, 1.09 to 1.39; p = 0.001), and cardiopulmonary bypass (CPB) time (OR, 1.01; 95% CI, 1.00 to 1.02; p = 0.02) were independently associated with severe postoperative AKI (stage 3). The cutoff values of preoperative fibrinogen and platelet function (MA level) for predicting severe postoperative AKI (stage 3) were determined to be 2.56 g/L and 60.7 mm in the ROC curve [area under the curve (AUC): 0.824 and 0.829; p < 0.001].

Conclusions

The preoperative fibrinogen level and platelet function (measured by the MA level) were identified as potential predictive factors for developing severe postoperative AKI (stage 3) in patients with ATAAD. Thromboelastography could be considered a potentially valuable tool for real-time monitoring and rapid assessment of the hemostatic system to improve postoperative outcomes in patients.

The preoperative plasma histamine level as a possible protective biomarker for postoperative acute kidney injury

Acute kidney injury (AKI) is a life-threatening complication of acute type A aortic dissection (ATAAD) patients. Increasing evidence suggests that histamine ameliorates the pathology of renal injury. However, data on the association between histamine levels and postoperative AKI in ATAAD patients are limited. The purpose of our study was to explore the incidence and independent risk factors of postoperative AKI, with special emphasis on the relationship between preoperative plasma histamine levels and the severity of postoperative ATAAD-AKI. This retrospective single-center study evaluated 160 patients with ATAAD admitted to the Beijing Anzhen Hospital aortic surgery database between April 2020 and December 2021. Univariate and multivariate logistic regression analyses were performed to determine the potential risk factors for postoperative ATAAD-AKI. A subgroup analysis was performed to investigate the association between preoperative plasma histamine levels and the severity of postoperative ATAAD-AKI or continuous renal replacement therapy (CRRT). ATAAD-AKI occurred in 84 of 160 patients (52.5%), including 32 with stage 1 (38.1%), 14 with stage 2 (16.7%), 38 with stage 3 (45.2%), and 34 (21.3%) received postoperative CRRT. The in-hospital mortality rate was 19.0% (16/84) in the AKI group and 2.6% (2/76) in the non-AKI group (P = .02). Preoperative lower plasma histamine levels (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.10-1.52; P = .004) were an important factor related to postoperative ATAAD-AKI in multivariate logistic regression analysis. Subgroup analysis revealed that low preoperative plasma histamine level was independently associated with postoperative ATAAD-AKI (stage 3) (OR, 1.38; 95% CI, 1.10-1.73; P = .005) and CRRT (OR, 1.44; 95% CI, 1.13-1.79; P = .008). Low preoperative plasma histamine level was an independent prognostic indicator of postoperative AKI in patients with ATAAD, especially for postoperative AKI (stage 3) and CRRT. Preoperative plasma histamine levels may serve as potential protective biomarkers of postoperative ATAAD-AKI.

Relationship between preoperative lymphocyte to monocyte ratio and surgery outcome in type A aortic dissection

Background

Lymphocyte-to-monocyte ratio (LMR) is associated with the mortality of cardiovascular diseases. However, the relationship between preoperative LMR and the prognosis of patients with Stanford type A aortic dissection (TAAD) undergoing surgical treatment remains to be determined.

Methods

We enrolled 879 patients with TAAD undergoing surgical treatment between January 2018 and December 2021. Patients were divided into two groups: the Deceased group and the Survived group. The baseline clinical and operative characteristics of the two groups were compared and analyzed.

Results

In univariate and multivariate logistic regression analysis, the association between LMR and in-hospital mortality was significant, and LMR (OR = 1.598, 95% CI 1.114-2.485, P = 0.022) remained significant after adjusting for confounders.

Conclusion

Lower LMR may be independently associated with higher in-hospital mortality in TAAD undergoing surgical treatment.

Risk factors for acute kidney injury after Stanford type A aortic dissection repair surgery: a systematic review and meta-analysis

Background: Risk factors for acute kidney injury (AKI) after Stanford type A aortic dissection (TAAD) repair are inconsistent in different studies. This meta-analysis systematically analyzed the risk factors so as to early identify the therapeutic targets for preventing AKI.

Methods: Studies exploring risk factors for AKI after TAAD repair were searched from four databases from inception to June 2022. The synthesized incidence and risk factors of AKI and its impact on mortality were calculated.

Results: Twenty studies comprising 8223 patients were included. The synthesized incidence of postoperative AKI was 50.7%. Risk factors for AKI included cardiopulmonary bypass (CPB) time >180 min [odds ratio (OR), 4.89, 95% confidence interval (CI), 2.06–11.61, I² = 0%], prolonged operative time (>7 h) (OR, 2.73, 95% CI, 1.95–3.82, I² = 0), advanced age (per 10 years) (OR, 1.34, 95% CI, 1.21–1.49, I² = 0], increased packed red blood cells (pRBCs) transfusion perioperatively (OR, 1.09, 95% CI, 1.07–1.11, I² = 42%), elevated body mass index (per 5 kg/m²) (OR, 1.23, 95% CI, 1.18–1.28, I² = 42%) and preoperative kidney injury (OR, 3.61, 95% CI, 2.48–5.28, I² = 45%). All results were meta-analyzed using fixed-effects model finally (p < 0.01). The in-hospital or 30-day mortality was higher in patients with postoperative AKI than in that without AKI [risk ratio (RR), 3.12, 95% CI, 2.54–3.85, p < 0.01].

Conclusions: AKI after TAAD repair increased the in-hospital or 30-day mortality. Reducing CPB time and pRBCs transfusion, especially in elderly or heavier weight patients, or patients with preoperative kidney injury were important to prevent AKI after TAAD repair surgery.

Prediction model of acute kidney injury after different types of acute aortic dissection based on machine learning

Objective

A clinical prediction model for postoperative combined Acute kidney injury (AKI) in patients with Type A acute aortic dissection (TAAAD) and Type B acute aortic dissection (TBAAD) was constructed by using Machine Learning (ML).

Methods

Baseline data was collected from Acute aortic division (AAD) patients admitted to First Affiliated Hospital of Xinjiang Medical University between January 1, 2019 and December 31, 2021. (1) We identified baseline Serum creatinine (SCR) estimation methods and used them as a basis for diagnosis of AKI. (2) Divide their total datasets randomly into Training set (70%) and Test set (30%), Bootstrap modeling and validation of features using multiple ML methods in the training set, and select models corresponding to the largest Area Under Curve (AUC) for follow-up studies. (3) Screening of the best ML model variables through the model visualization tools Shapley Addictive Explanations (SHAP) and Recursive feature reduction (REF). (4) Finally, the pre-screened prediction models were evaluated using test set data from three aspects: discrimination, Calibration, and clinical benefit.

Results

The final incidence of AKI was 69.4% (120/173) in 173 patients with TAAAD and 28.6% (81/283) in 283 patients with TBAAD. For TAAAD-AKI, the Random Forest (RF) model showed the best prediction performance in the training set (AUC = 0.760, 95% CI:0.630–0.881); while for TBAAD-AKI, the Light Gradient Boosting Machine (LightGBM) model worked best (AUC = 0.734, 95% CI:0.623–0.847). Screening of the characteristic variables revealed that the common predictors among the two final prediction models for postoperative AKI due to AAD were baseline SCR, Blood urea nitrogen (BUN) and Uric acid (UA) at admission, Mechanical ventilation time (MVT). The specific predictors in the TAAAD-AKI model are: White blood cell (WBC), Platelet (PLT) and D dimer at admission, Plasma The specific predictors in the TBAAD-AKI model were N-terminal pro B-type natriuretic peptide (BNP), Serum kalium, Activated partial thromboplastin time (APTT) and Systolic blood pressure (SBP) at admission, Combined renal arteriography in surgery. Finally, we used in terms of Discrimination, the ROC value of the RF model for TAAAD was 0.81 and the ROC value of the LightGBM model for TBAAD was 0.74, both with good accuracy. In terms of calibration, the calibration curve of TAAAD-AKI's RF fits the ideal curve the best and has the lowest and smallest Brier score (0.16). Similarly, the calibration curve of TBAAD-AKI's LightGBM model fits the ideal curve the best and has the smallest Brier score (0.15). In terms of Clinical benefit, the best ML models for both types of AAD have good Net benefit as shown by Decision Curve Analysis (DCA).

Conclusion

We successfully constructed and validated clinical prediction models for the occurrence of AKI after surgery in TAAAD and TBAAD patients using different ML algorithms. The main predictors of the two types of AAD-AKI are somewhat different, and the strategies for early prevention and control of AKI are also different and need more external data for validation.

Postoperative Fluid Therapy in Adult Cardiac Surgical Patients and Acute Kidney Injury: A Prospective Observational Study

Background Normal saline (0.9% NS) is a common intravenous fluid used worldwide. Recent studies have shown that NS use is associated with increased incidence of acute kidney injury (AKI) and a need for renal replacement therapy (RRT). The practice is changing toward using balanced solutions to prevent AKI. Postcardiac surgery patients are more prone to develop AKI after cardiopulmonary bypass (CPB). We aim to study the type of fluid administrated, incidence of AKI, need for RRT, and overall outcome of these patients.

Methods This prospective observational study was conducted in the cardiothoracic intensive care unit (cardiothoracic and vascular surgery intensive care unit) in a cohort of 197 adult patients who underwent on pump cardiac surgery in our hospital from July 2021 to October 2021 as a pilot study. Data was analyzed using SPSS 20.0 (IBM, Chicago, Illinois, United States). A p-value < 0.05 was considered significant.

Results In our study, 58 (29.34%) patients developed AKI in the first three postoperative days and 16 (8.12%) patients required RRT. Incidence of AKI was found to be higher in patients who received NS only, as fluid of choice was 34.48% compared with other intravenous fluids. Patients with AKI had higher positive fluid balance (p < 0.001), longer CPB (p < 0.001), and aortic cross clamp (p = 0.006) times. Intensive care unit and hospital stay and mortality rates were higher in AKI patients than those without AKI (p < 0.001).

Conclusion Our study demonstrated that NS was the commonly used crystalloid in our patients and was associated with increased incidence of AKI and RRT when compared with other balanced salts solutions.

Acute Kidney Injury After Open Heart Surgery

Introduction: Acute kidney injury (AKI) is a term used to describe when the kidney loses its function rapidly. And it’s associated with an increase in the level of serum creatinine by 0.5 to 1mg/dL. It can be diagnosed by a plethora of criteria such as the Kidney Disease Improving Global Outcomes (KDIGO) and the Risk, Injury, Failure, Loss, End-stage (RIFLE) criteria. Cardiac surgery-associated AKI (CSA-AKI) is the most prevalent complication in patients following cardiac surgery and is also linked to increased mortality and morbidity rates. In addition, exogenous and endogenous toxins, ischemia and reperfusion, inflammation, oxidative stress, metabolic factors, and neurohormonal activation may all play a role in the development of CSA-AKI. All these factors may be active at varying time intervals and with different degrees of intensity, or may function simultaneously. 

Methods: In late 2019, a retrospective study was conducted by reviewing the health data of patients who underwent coronary artery bypass graft (CABG), valvular repairs, and other open cardiac surgeries at the King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia, between November 2014 and June 2019. Information was obtained from the Hospital information system, Jeddah, Saudi Arabia. Of the 159 patients who underwent open-heart surgery at KAUH, 126 (79.2%) were male and 33 (20.8%) were female. Patients below 15 years of age and those with poor renal function prior to open cardiac surgery were excluded. The KDIGO criteria were used to diagnose AKI for our patients.

Results: In this study, 34% of the patients experienced AKI after open cardiac surgery, and the most frequent risk factor encountered was diabetes mellitus (DM), which was present in 97 (61%) patients, followed by angina pectoris in 93 (58.5%) patients. Hypertension was identified in 85 (53.5%) and acute myocardial infarction in 82 (51.6%) patients. There were only two (1.3%) patients with known cases of chronic obstructive lung disease (COPD). Of the surgeries, 131 (82.4%) were classified as elective and 28 (17.6%) were urgent.

Conclusion: The most common risk factor associated with AKI following open-heart surgery is DM, followed by angina pectoris. However, further studies are required to investigate all the cardiac procedures.

Prediction of Acute Kidney Injury by Cystatin C and [TIMP-2]*[IGFBP7] after Thoracic Aortic Surgery with Moderate Hypothermic Circulatory Arrest

(1) Background: Acute kidney injury (AKI) is a common complication following thoracic aortic surgery (TAS), with moderate hypothermic circulatory arrest (MHCA). However, prediction of AKI with classical tools remains uncertain. Therefore, it was the aim of the present study to evaluate the role of new biomarkers in patients after MHCA. (2) Methods: 101 consecutive patients were prospectively enrolled. Measurements of urinary [TIMP-2]*[IGFBP7] and Cystatin C in the blood were performed perioperatively. Primary endpoint was the occurrence of AKI stage 2 or 3 (KDIGO-classification) within 48 h after surgery (AKI group). (3) Results: Mean age of patients was 69.1 ± 10.9 years, 35 patients were female (34%), and 13 patients (13%) met the primary endpoint. Patients in the AKI group had a prolonged ICU-stay (6.9 ± 7.4 days vs. 2.5 ± 3.1 days, p < 0.001) as well as a higher 30-day-mortality (9/28 vs. 1/74, p < 0.001). Preoperative serum creatinine (169.73 ± 148.97 μmol/L vs. 89.74 ± 30.04 μmol/L, p = 0.027) as well as Cystatin C (2.41 ± 1.54 mg/L vs. 1.13 ± 0.35 mg/L, p = 0.029) were higher in these patients. [TIMP-2]*[IGFBP7] increased significantly four hours after surgery (0.6 ± 0.69 mg/L vs. 0.37 ± 0.56 mg/L, p = 0.03) in the AKI group. Preoperative Cystatin C (AUC 0.828, p < 0.001) and serum creatinine (AUC 0.686, p = 0.002) as well as [TIMP-2]*[IGFBP7] 4 h after surgery (AUC 0.724, p = 0.020) were able to predict postoperative AKI. The predictive capacity of Cystatin C was superior to serum creatinine (p = 0.0211) (4) Conclusion: Cystatin C represents a very sensitive and specific biomarker to predict AKI in patients undergoing thoracic surgery with MHCA even before surgery, whereas the predictive capacity of [TIMP-2]*[IGFBP7] is only moderate and inferior to that of serum creatinine.

Higher Mean Arterial Pressure during Cardiopulmonary Bypass May Not Prevent Acute Kidney Injury in Elderly Patients Undergoing Cardiac Surgery

We aimed to evaluate the role of higher mean arterial pressure (MAP) during cardiopulmonary bypass (CPB) in preventing development of acute kidney injury (AKI). Methods. We evaluated a population of elderly individuals >60 years of age undergoing CPB to find correlation of MAP during CPB with development of AKI after the surgery. Patients who experienced sustained low MAP during the CPB defined as that of <65 mmHg were compared with those that had sustained high MAP of >65 mmHg for their outcome with regard to AKI. The KDIGO criteria were used to define presence of acute kidney injury. Results. Of the total 92 patients, 50 were in the low-pressure group and 42 were in the high-pressure group. The MAP was 61.14 ± 5.54 mmHg in the low-pressure group and 68.97 ± 3.65 mmHg in the high-pressure group (p < 0.001). 13 (26%) in the low-pressure group and 17 (40.48%) in the high-pressure group developed AKI (p = 0.140). Male sex was associated with an increased incidence of cardiac surgery-associated AKI (p = 0.034). Conclusions. A higher MAP in the range of 65-75 mmHg during the cardiopulmonary bypass does not significantly prevent acute kidney injury in elderly patients undergoing cardiac valve surgery.

Age-dependent differences in the prognostic relevance of body composition-related variables in type A aortic dissection patients

Background

The current research is allocated to appraise the association between the parameters of body composition and findings in type A aortic dissection (TAAD) cases in diverse age groups.

Methods

Data from consecutive TAAD patients undergoing implantation of modified triple-branched stent-graft from January 2017 and December 2019 were prospectively collected and analyzed. A regression model of Cox proportional hazard was employed to assess correlations among body composition-related variables (body mass index [BMI], lean body mass [LBM], body surface area [BSA], and LBM index) as well as cumulative mortality.

Results

Overall, 258 patients (53.9 ± 11.1 years old; 72.9% male) were separated into young (n = 110) and elderly (n = 148) age groups based upon whether they were younger or older than 50 years of age. Of these patients, 247 survivors were included in subsequent analyses over an average 26.8 ± 11.6 month follow-up duration. Multivariate analyses in the elderly group instead of young group indicated that increased BMI (p = 0.042), BMI ≤ 18.5 kg/m² (p = 0.025), and lower LBM index values (p = 0.019) were significant predictors of increased total all-cause cumulative mortality. BMI was considerably positively correlated with estimated all-cause cumulative mortality in elderly but not young TAAD cases.

Conclusion

Briefly, these results suggest that BMI and LBM indices are only significant predictors of TAAD patient all-cause mortality in elderly patient cohorts, whereas they do not offer significant prognostic value for younger patients. As such, these age differences must be taken into consideration when conducting stratified risk assessments based upon TAAD patient body composition characteristics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01742-1.

Determining Factors for Independent Walking in Patients Undergoing Cardiovascular Surgery: Differences between Coronary Artery Bypass Grafting, Heart Valve Surgery, and Aortic Surgery

Physical deconditioning often occurs during the acute phase after cardiovascular surgery, and unassisted walking is required to achieve independence, to manage cardiac diseases, and to prevent recurrences. This study aims to investigate the characteristics of independent walking after cardiovascular surgery. We conducted a retrospective cohort study in patients who underwent cardiovascular surgeries (total of 567 patients): 153 in the coronary artery bypass grafting (CABG) group, 312 in the heart valve surgery group, and 102 in the aortic surgery group. We evaluated the effect of each surgery group on the cardiac rehabilitation (CR) progression. The factors associated with independent walking were age, renal diseases, intensive care unit (ICU) length of stay, and post-operative respiratory complications in the CABG group. In the heart valve surgery group, the factors were New York Heart Association functional classification, renal and respiratory diseases, ICU length of stay, duration of mechanical ventilatory support, and post-operative cardiovascular and respiratory complications. In the aortic surgery group, these were ICU length of stay and acute kidney injury. The CR progression in patients who underwent aortic surgery was significantly longer than those who underwent CABG and heart valve surgery (p < 0.001). New intervention strategies are needed for patients with prolonged ICU stays.

En Bloc Arch Reconstruction With the Frozen Elephant Trunk Technique for Acute Type a Aortic Dissection

Objective: The study objective was to evaluate the effect of en bloc arch reconstruction with frozen elephant trunk (FET) technique for acute type A aortic dissection.

Methods: 41 patients with acute Stanford type A dissection underwent en bloc arch reconstruction combined with FET implantation between April 2018 and August 2020. The mean age of the patients was 46 ± 13 years, and 9 patients were female. One patient had Marfan syndrome. Six patients had pericardial tamponade, 9 had pleural effusion, 5 had transient cerebral ischemic attack, and 3 had chronic kidney disease.

Results: The hospital mortality rate was 9.8% (4 patients). 2 (4.9%) patients had stroke, 23 (56.1%) had acute kidney injury, and 5 (12.2%) had renal failure requiring hemodialysis. During follow-up, the rate of complete false lumen thrombosis was 91.6% (33/36) around the FET, 69.4% (25/36) at the diaphragmatic level, and 27.8% (10/36) at the superior mesenteric artery level. The true lumen diameter at the same three levels of the descending aorta increased significantly while the false lumen diameter reduced at the two levels: pulmonary bifurcation and the diaphragm. The 1-, 2-and 3-year actuarial survival rates were 90.2% [95% confidence interval (CI), 81.2–99.2], 84.2% (95% CI, 70.1–98.3) and 70.2% (95% CI, 42.2–98), respectively.

Conclusions: In patients with acute type A dissection, en bloc arch reconstruction with FET technique appeared to be feasible and effective with early clinical follow-up results. Future studies including a large sample size and long-term follow-up are required to evaluate the efficacy.

The Predictive Role of Lymphocyte-to-Monocyte Ratio in Acute Kidney Injury in Acute Debakey Type I Aortic Dissection

Background: The post-operative acute kidney injury (AKI) represents a common complication in the Acute Debakey Type I Aortic Dissection (ADTIAD) and predicts a poorer prognosis. The clinical evidence is scarce supporting the predictive value of the pre-operative lymphocyte-to-monocyte ratio (LMR) in post-operative AKI in ADTIAD.

Methods: In this retrospective cohort study, 190 consecutive patients with ADTIAD enrolled for surgical treatment between January 1, 2013, and December 31, 2018. The diagnosis of AKI followed the Kidney Disease: Improving Global Outcomes guidelines (KDIGO). Pre-operative LMR and other possible risk factors were analyzed for their prognostic value in the post-operative AKI in ADTIAD.

Results: The subjects were assigned to the low-LMR and high-LMR groups according to the median value of pre-operative LMR. For post-operative AKI, the incidence and the severity in the low-LMR group were statistically different from that of the high-LMR group. Besides, the lower LMR was statistically associated with the more extended ICU stay and intubation time and higher incidences of ischemic stroke and in-hospital mortality. Additionally, in the multivariable analysis, the pre-operative LMR was an independent predictor for post-operative AKI in ADTIAD. A predictive model for post-operative AKI in ADTIAD was established incorporating LMR.

Conclusions: LMR is an independent prognostic indicator incorporated into the predictive model with other risk factors to predict the post-operative AKI in ADTIAD.

The prognosis and risk factors for acute kidney injury in high-risk patients after surgery for type A aortic dissection in the ICU

Background

Acute kidney injury (AKI) is a major complication of cardiac surgery, with high rates of morbidity and mortality. The aim of this study was to identify risk factors for the incidence and prognosis of AKI in high-risk patients before and after surgery for acute type A aortic dissection (TAAD) in the intensive care unit (ICU).

Methods

We performed a retrospective cohort study from April 2018 to April 2019. The primary end points of this study were morbidity due to AKI and risk factors for incidence, and the secondary end points were mortality at 28 days and risk factors for death.

Results

We enrolled 60 patients, 52 (86.67%) patients developed postoperative AKI, 28 (53.84%) patients died. Preoperative lactic acid level (P=0.022) and cardiopulmonary bypass (CPB) duration (P=0.009) were identified as independent risk factors for postoperative AKI. The 28-day mortality for postoperative patients with TAAD was 46.67%, 53.84% for those with TAAD and AKI, 67.5% for those who required continue renal replacement therapy (CRRT). The risk factors for 28-day mortality due to postoperative AKI for patients requiring CRRT were CPB duration (P=0.019) and norepinephrine dose upon diagnosis of AKI (P=0.037).

Conclusions

Morbidity due to AKI in postoperative patients with TAAD was 86.67%, and preoperative lactic acid level and CPB duration were independent risk factors. The 28-day mortality of postoperative patients with TAAD was 46.67%, 53.84% for those with TAAD and AKI, and 67.5% for those requiring CRRT. CPB duration and norepinephrine dose upon diagnosis of AKI may influence patients’ short-term prognosis.

Thrombotic microangiopathy following aortic surgery with hypothermic circulatory arrest: a single-centre experience of an underestimated cause of acute renal failure

OBJECTIVES

Acute kidney injury (AKI) following surgery involving the heart-lung-machine is associated with high mortality and morbidity. In addition to the known mechanisms, thrombotic microangiopathy (TMA) triggered by the dysregulation of complement activation was recently described as another pathophysiological pathway for AKI following aortic surgery. The aim of this retrospective study was to analyse incidence, predictors and outcome in these patients.

METHODS

Between January 2018 and September 2019, consecutive patients undergoing aortic surgery requiring hypothermic circulatory arrest were retrospectively reviewed. If suspected, diagnostic algorithm was initiated to identify a TMA and its risk factors, and postoperative outcome parameters were comparably investigated.

RESULTS

The incidence of TMA in the analysed cohort (n = 247) was 4.5%. Multivariable logistic regression indicated female gender {odds ratio (OR) 4.905 [95% confidence interval (CI) 1.234-19.495], P = 0.024} and aortic valve replacement [OR 8.886 (95% CI 1.030-76.660), P = 0.047] as independent predictors of TMA, while cardiopulmonary bypass, X-clamp and hypothermic circulatory arrest times showed no statistically significance. TMA resulted in postoperative AKI (82%), neurological disorders (73%) and thrombocytopaenia [31 (interquartile range 25-42) G/l], corresponding to the diagnostic criteria. Operative mortality and morbidity were equal to patients without postoperative TMA, despite a higher incidence of re-exploration for bleeding (27 vs 6%; P = 0.027). After 6 months, survival, laboratory parameters and need for dialysis were comparable between the groups.

CONCLUSIONS

TMA is a potential differential diagnosis for the cause of AKI following aortic surgery regardless of the hypothermic circulatory arrest time. Timely diagnosis and appropriate treatment resulted in a comparable outcome concerning mortality and renal function.

Preservation of renal endothelial integrity and reduction of renal edema by aprotinin does not preserve renal perfusion and function following experimental cardiopulmonary bypass

BACKGROUND

Acute kidney injury is a severe complication following cardiopulmonary bypass (CPB) and is associated with capillary leakage and microcirculatory perfusion disturbances. CPB-induced thrombin release results in capillary hyperpermeability via activation of protease-activated receptor 1 (PAR1). We investigated whether aprotinin, which is thought to prevent thrombin from activating PAR1, preserves renal endothelial structure, reduces renal edema and preserves renal perfusion and reduces renal injury following CPB.

METHODS

Rats were subjected to CPB after treatment with 33.000 KIU/kg aprotinin (n = 15) or PBS (n = 15) as control. A secondary dose of 33.000 KIU/kg aprotinin was given 60 min after initiation of CPB. Cremaster and renal microcirculatory perfusion were assessed using intravital microscopy and contrast echography before CPB and 10 and 60 min after weaning from CPB. Renal edema was determined by wet/dry weight ratio and renal endothelial structure by electron microscopy. Renal PAR1 gene and protein expression and markers of renal injury were determined.

RESULTS

CPB reduced cremaster microcirculatory perfusion by 2.5-fold (15 (10-16) to 6 (2-10) perfused microvessels, p < 0.0001) and renal perfusion by 1.6-fold (202 (67-599) to 129 (31-292) au/sec, p = 0.03) in control animals. Both did not restore 60 min post-CPB. This was paralleled by increased plasma creatinine (p < 0.01), neutrophil gelatinase-associated lipocalin (NGAL; p = 0.003) and kidney injury molecule-1 (KIM-1; p < 0.01). Aprotinin treatment preserved cremaster microcirculatory perfusion following CPB (12 (7-15) vs. 6 (2-10) perfused microvessels, p = 0.002), but not renal perfusion (96 (35-313) vs. 129 (31-292) au/s, p > 0.9) compared to untreated rats. Aprotinin treatment reduced endothelial gap formation (0.5 ± 0.5 vs. 3.1 ± 1.4 gaps, p < 0.0001), kidney wet/dry weight ratio (4.6 ± 0.2 vs. 4.4 ± 0.2, p = 0.046), and fluid requirements (3.9 ± 3.3 vs. 7.5 ± 3.0 ml, p = 0.006) compared to untreated rats. In addition, aprotinin treatment reduced tubulointerstitial neutrophil influx by 1.7-fold compared to untreated rats (30.7 ± 22.1 vs. 53.2 ± 17.2 neutrophil influx/section, p = 0.009). No differences were observed in renal PAR1 expression and plasma creatinine, NGAL or KIM-1 between groups.

CONCLUSIONS

Aprotinin did not improve renal perfusion nor reduce renal injury during the first hour following experimental CPB despite preservation of renal endothelial integrity and reduction of renal edema.

Short-term outcomes of acute coronary involvement in type A aortic dissection without myocardial ischemia: a multiple center retrospective cohort study

Background

To evaluate the early prognosis and management of acute coronary involvement (ACI) in type A aortic dissection (ATAAD) patients without myocardial ischemia (MI).

Methods

We conducted a retrospective cohort study on a multicenter database. A total of 931 ATAAD patients without MI underwent thoracic aortic surgery between 2018 and 2019 in the Acute Aortic Syndrome Cooperation Network (AASCN) and were enrolled in our study. Patients were divided into two groups: ACI group and non-ACI group.

Results

There were 139 ACI patients (14.9%) and 792 non-ACI patients (85.1%) in our cohort. ACI group had higher 30-day mortality after surgery than non-ACI group (log-rank test: P = 0.028,Cox regression: hazard ratio [HR], 2.3; 95% confidence interval [95% CI], 1.1–5.39; P = 0.047), especially in sub-group of advanced age (53–80 years; HR, 4.0; 95% CI, 1.3–12.8; P = 0.017), low diastolic blood pressure (29-69 mmHg, HR, 3.8; 95% CI, 1.3–11.2; P = 0.018), low systolic blood pressure (51–119 mmHg, HR, 3.6; 95% CI, 1.1–12.4; P = 0.040), high body mass index (BMI;27.25–47.52 kg/m²; HR, 3.7; 95% CI, 1.3–10.7; P = 0.015) and high hemoglobin (>145 g/L; HR, 4.3; 95% CI, 1.2–16.0; P = 0.030). Acute renal failure was significant more in ACI group than non-ACI group (24.5% vs. 15.9%; P = 0.014).

Conclusions

ACI increases the short-term postoperative mortality and acute renal failure in ATAAD patients without MI. ATAAD patients with ACI may need a narrower control range of blood pressure even if without myocardial ischemia.

Trial registration

ChiCTR1900022637. Retrospectively registered 19 April 2019.

Outcome of the frozen elephant trunk procedure as a redo operation

 

OBJECTIVES

The goal of this study was to determine the outcome of patients undergoing an elective frozen elephant trunk (FET) procedure as a redo operation following previous cardiac surgery.

METHODS

One hundred and eighteen consecutive patients underwent FET procedures between October 2010 and October 2019 at our centre. Patients were registered in a dedicated database and analysed retrospectively. Clinical and follow-up characteristics were compared between patients undergoing a FET operation as a primary (primary group) or a redo procedure (redo group) using logistic regression and Cox regression analysis. Emergency procedures (n = 33) were excluded from the analysis.

RESULTS

A total of 36.5% (n = 31) of the FET procedures were redo operations (redo group) and 63.5% (n = 54) of the patients underwent primary surgery (primary group). There was no significant difference in the 30-day mortality [primary group: 7.4%; redo group: 3.2%; 95% confidence interval (CI) (0.19-35.29); P = 0.63] and the 3-year mortality [primary group: 22.2%; redo group: 16.7%; 95% CI (0.23-3.23); P = 0.72] between redo and primary cases. Furthermore, the adjusted statistical analysis did not reveal significant differences between the groups in the occurrence of transient or permanent neurological deficit, paraplegia, acute renal failure and resternotomy. The redo group showed a higher rate of recurrent nerve palsy, which did not reach statistical significance [primary group: 3.7% (n = 2); redo group: 19.4% (n = 6); P = 0.091].

CONCLUSIONS

Elective FET procedures as redo operations performed by a dedicated aortic team following previous cardiac surgery demonstrate an adequate safety profile.

Impact of autologous platelet rich plasma use on postoperative acute kidney injury in type A acute aortic dissection repair: a retrospective cohort analysis

BACKGROUND

Perioperative coagulopathy and blood transfusion are common in patients undergoing Stanford type A acute aortic dissection (AAD) repair. The autologous platelet-rich plasmapheresis (aPRP) technique is a blood conservation approach to reduce blood transfusions and morbidity in patients at high risk of bleeding. The purpose of this study was to analyze the effect of aPRP on outcomes, especially in postoperative acute kidney injury (post-AKI), in patients undergoing AAD surgery.

METHODS

Six hundred sixty patients were divided into aPRP and non-aPRP groups according to aPRP use. The primary endpoint was the difference in the incidence of post-AKI between two groups. The secondary endpoints were risk factors for post-AKI and to assess clinical outcomes. The risk factors associated with post-AKI were calculated, and all outcomes were adjusted by propensity-score matching analysis.

RESULTS

A total of 272 patients (41.2%) received aPRP, whereas 388 were in the non-aPRP group. Compared to non-aPRP group, the occurrence of post-AKI increased by 14.1% (p = 0.002) and 11.1% (p = 0.010) with and without propensity adjustment in the aPRP group, respectively. The aPRP group required fewer intraoperative transfusions (p < 0.05) and shortened the duration of mechanical ventilation (p < 0.05) than those in the non-aPRP group. Multiple regression analyses showed that aPRP (odds ratio: 1.729, 95% confidence interval: 1.225-2.440; p < 0.001) was one of the independent risk factors for post-AKI.

CONCLUSIONS

The use of aPRP significantly reduced intraoperative blood transfusions and decreased postoperative mortality-adjusted mechanical ventilation. However, aPRP use was independently associated with an increased hazard of post-AKI after adjusting for confounding factors.

Sleep Quality after Coronary Artery Bypass Graft Surgery: Comparing Pulsatile and Nonpulsatile Pump Flow

Poor postoperative sleep quality is a common problem in patients undergoing coronary artery bypass graft surgery (CABG). The purpose of this study was to compare the effect of pulsatile and nonpulsatile pump flow on sleep quality of these patients. In this clinical trial, 52 patients undergoing on pump CABG surgery with the roller pump were randomly divided into two equal groups of 26 patients: group 1 using pulsatile pump flow and group 2 nonpulsatile pump flow while the heart was arrested. Sleep score of both groups was evaluated by Pittsburgh Sleep Quality Index questionnaire 2 days before operation and 1 month after operation, and they were compared with each other. Analysis was performed with SPSS software version 22 (SPSS for Windows Inc., Chicago, IL) using the independent t-test, chi-square test, and Fisher exact test. Both groups were the same in demographic characteristics and risk factors such as age, gender, diabetes mellitus, hypertension, hyperlipidemia, smoking, body mass index, and preoperative ejection fraction. Operation data showed no difference between two groups considering cardiopulmonary bypass time and cardiac arrest time. Preoperative sleep quality score of both groups had no significant difference (p = .84). One month postoperative sleep quality score of the pulsatile group was significantly better than that of the nonpulsatile group (p = .04). Using pulsatile flow cardiopulmonary bypass can effectively decrease postoperative sleep disorders in comparison to nonpulsatile flow.

Novel Blood Cytokine-Based Model for Predicting Severe Acute Kidney Injury and Poor Outcomes After Cardiac Surgery

Background Alterations in serum creatinine levels delay the identification of severe cardiac surgery-associated acute kidney injury. To provide timely diagnosis, novel predictive tools should be investigated. Methods and Results This prospective observational study consists of a screening cohort (n=204) and a validation cohort (n=198) from 2 centers from our hospital. Thirty-two inflammatory cytokines were measured via a multiplex cytokine assay. Least absolute shrinkage and selection operator regression was conducted to select the cytokine signatures of severe cardiac surgery-associated acute kidney injury. Afterwards, the significant candidates including interferon-γ, interleukin-16, and MIP-1α (macrophage inflammatory protein-1 alpha) were integrated into the logistic regression model to construct a predictive model. The predictive accuracy of the model was evaluated in these 2 cohorts. The cytokine-based model yielded decent performance in both the screening (C-statistic: 0.87, Brier 0.10) and validation cohorts (C-statistic: 0.86, Brier 0.11). Decision curve analysis revealed that the cytokine-based model had a superior net benefit over both the clinical factor-based model and the established plasma biomarker-based model for predicting severe acute kidney injury. In addition, elevated concentrations of each cytokine were associated with longer mechanical ventilation times, intensive care unit stays, and hospital stays. They strongly predicted the risk of composite events (defined as treatment with renal replacement therapy and/or in-hospital death) (OR of the fourth versus the first quartile [95% CI]: interferon-γ, 27.78 [3.61-213.84], interleukin-16, 38.07 [4.98-291.07], and MIP-1α, 9.13 [2.84-29.33]). Conclusions Our study developed and validated a promising blood cytokine-based model for predicting severe acute kidney injury after cardiac surgery and identified prognostic biomarkers for assisting in outcome risk stratification.

Long-term outcomes of treatment with different stent grafts in acute DeBakey type I aortic dissection

BACKGROUND

We developed an integrated triple-branched stent to treat acute DeBakey type I aortic dissection (AD) and modified it to enhance its adaptability. However, whether the patients treated by the modified stent would achieve better long-term prognosis is unknown.

METHODS

This study enrolled 147 patients with acute DeBakey type I AD. The original integrated triple-branched stents were used in 57 patients (Group A) between July 2012 and August 2013, and the modified stents in 90 patients (Group B) between September 2013 and March 2015. Clinical characteristics, surgical data, postoperative complications, mortality, and follow-up data of the two groups were analyzed.

RESULTS

The two groups presented comparable early death rates (Group A = 7.0%, Group B = 5.9%; p = .719). The incidence of postoperative acute kidney injury (AKI) was lower in Group B (10.0%) versus Group A (24.6%) (p = .018). Compared with the original integrated triple-branched stent graft, the modified stent could reduce the risk of early postoperative AKI (OR [95% CI] = 0.36 [0.14, 0.94]). Early endoleak rates were significantly lower in Group B (1.0%) compared to Group A (9.4%) (p = .004). During follow-up, there were five deaths in Group A (9.4%) and six deaths in Group B (7.2%) (p = .646). Chronic kidney injury (7.5% vs. 3.6%; p = .311), delayed endoleak (11.3% vs. 4.8%; p = .157), and late reinterventions (7.5% vs. 2.4%; p = .155) in the two groups were similar.

CONCLUSIONS

In patients with acute DeBakey type I AD, the modified stent showed feasible and safe treatment outcomes and reduced early endoleak rates. However, the long-term effects were similar to the original treatment.

Acute type A aortic dissection in-hours versus out-of-hours: A systematic review and meta-analysis

OBJECTIVE

We sought to compare clinical outcomes in patients with acute type A aortic dissection that undergone surgical repair during in-hours (IH) versus out-of-hours (OOH).

METHODS

An electronic literature search was done till March 2020 to include studies with comparative cohorts of IH versus OOH. Primary outcomes were 30-day mortality, stroke, and reoperation for bleeding; secondary outcomes were acute kidney injury, total hospital stay, and intensive care unit stay.

RESULTS

Six articles with a total of 3744 patients met the inclusion criteria. Mean age was similar, 60 ± 12 versus 60 ± 13 in IH versus OOH (p = .25). Aortic root and total arch replacement were similar in both cohorts, 22% in IH versus 25% in OOH (risk ratio [RR], 1.10; 95% confidence interval [CI: 0.78, 1.55]; p = .58) and 29% in IH versus 32% in OOH (RR, 0.96; 95% CI [0.89, 1.04], p = .37) respectively. Reoperation for bleeding and stroke rate were similar, with 18% in IH versus 23% in OOH (RR, 0.89; 95% CI [0.73, 1.08]; p = .24), and 12% in IH versus 13% in OOH (RR, 0.83; 95% CI [0.66, 1.03]; p = .09) respectively. Thirty-day mortality was significantly lower in IH (RR, 0.81; 95% CI [0.72, 0.90]; p = .0001).

CONCLUSION

There was higher 30-day mortality rate during OOH surgery, yet this difference diminished following sensitivity analysis. There were no significant differences in major postoperative outcomes. Therefore, operating on such cases should be decided on clinical priority without delay.

Acute Kidney Injury in Asia: Disease Burden

Acute kidney injury (AKI) is a common and critical clinical disorder with non-negligible morbidity and mortality and remains a large public health problem. Asia, as the world's largest and most populous continent, is crucial in eliminating unsatisfactory outcomes of AKI. The diversities in climate, customs, and economic status lead to various clinical features of AKI across Asia. In this review, we focus on the epidemiologic data and clinical features of AKI in different Asian countries and clinical settings, and we show the huge medical and economic burden of AKI in Asian countries. Drugs and sepsis are the most common etiologies for AKI, however, an adequate surveillance system has not been well established. There is significant undertreatment of AKI in many regions, and medical resources for renal replacement therapy are not universally available. Although substantial improvement has been achieved, health care for AKI still needs improvement, especially in developing regions.

Early respiratory outcomes following cardiac surgery in patients with COVID-19

BACKGROUND

Both coronavirus disease (COVID-19) and cardiac surgery have a negative impact on pulmonary function. This study aimed to determine the postoperative respiratory outcomes of patients with COVID-19 who underwent cardiac surgery.

METHODS

In this retrospective study, we reviewed and analyzed the patient characteristics and clinical data of 25 asymptomatic patients with COVID-19 who underwent urgent or emergency cardiac surgery at Tehran Heart Center Hospital, Iran, between 29 February and 10 April 2020.

RESULTS

The mean age, EuroSCORE, and body mass index were 57.3 ± 15.1 years, 6.65 ± 1.29, and 25.7 ± 3.7 kg/m² , respectively. Four patients underwent off-pump cardiac surgery and 21 underwent on-pump cardiac surgery with a median cardiopulmonary bypass time of 85 minutes (interquartile range (IQR, 50-147). The overall mortality rate and the length of stay in the intensive care unit (ICU) were higher compared to those of a propensity-matched group of patients who underwent cardiac surgery in the pre-COVID era. The median intubation time was 13 hours (IQR, 9.5-18), which was comparable to that of pre-COVID cardiac surgery patients. The readmission rate to the ICU was 16%. In this ICU readmitted group, the mean oxygen index, FiO₂ , and mortality rate were higher and the PaO₂ /FiO₂ ratio was lower than those of the nonreadmitted patients.

CONCLUSIONS

Although early respiratory outcomes of asymptomatic COVID-19 patients who underwent early cardiac surgery appeared to be satisfactory, compared to the propensity-scored matched non-COVID group, the postoperative outcomes were worse, especially in the ICU readmitted patients. We suggest postponing cardiac operations unless the patient requires emergency surgery.

Characteristics and outcomes of Stanford type A aortic dissection patients with severe post-operation hyperbilirubinemia: a retrospective cohort study

BACKGROUND

Hyperbilirubinemia is one of the common complications after cardiac surgery and is associated with increased mortality. However, to the best of our knowledge, the reports on clinical significance of postoperative severe hyperbilirubinemia in Stanford type A aortic dissection (AAD) patients were limited.

METHODS

Patients who underwent surgical treatment for AAD in our center between January 2015 and December 2018 were retrospectively screened. In-hospital mortality, long-term mortality, acute kidney injury (AKI), and the requirement of continuous renal replacement therapy (CRRT) were assessed as endpoints. Univariate and multivariate regression models were employed to identify the risk factors of these endpoints.

RESULTS

After screening, 271 patients were included in our present study. Of the included patients, 222 (81.9%) experienced postoperative AKI, and 50 (18.5%) received CRRT. The in-hospital mortality was 30.3%. The 1-year, 2-year, and 3-year cumulative mortality were 32.9, 33.9, and 35.3%, respectively. Multivariate Logistic regression analysis indicated that age (P < 0.033), AKI stage 3 (P < 0.001), the amount of blood transfusion after surgery (P = 0.019), mean arterial pressure (MAP) in the first postoperative day (P = 0.012), the use of extracorporeal membrane oxygenation (ECMO) (P = 0.02), and the peak total bilirubin (TB) concentration (P = 0.023) were independent risk factors of in-hospital mortality. The optimal cut-off value of peak TB on predicting in-hospital mortality was 121.2 μmol/L. Patients with post-operation TB ≥ 121 μmol/L was associated with worse long-term survival as well.

CONCLUSIONS

Severe post-operation hyperbilirubinemia is a common clinical situation in patients had AAD repair. In AAD patients with severe post-operation hyperbilirubinemia, older age, lower MAP, increased blood transfusion, stage 3 AKI, the use of ECMO, and the increased peak TB lead to increase in-hospital mortality.

Application of a Modified Extracorporeal Circulation Perfusion Method During Surgery for Acute Stanford Type A Aortic Dissection

AIM

The aim of this study was to investigate the effect of the modified extracorporeal circulation perfusion method during surgery for acute Stanford type A aortic dissection in patients who underwent stented elephant trunk implantation and arch replacement.

METHOD

A total of 69 patients with acute Stanford type A aortic dissection who underwent stented elephant trunk implantation and arch replacement were retrospectively analysed from 2017 to 2018. According to the perfusion method of extracorporeal circulation, patients were divided into a routine perfusion (RP) group and a modified perfusion (MP) group. Clinical data were collected, including the time of extracorporeal circulation and deep hypothermic circulatory arrest, incidence of acute kidney injury and neurological complications, and comparisons between the two groups were conducted by using independent sample t-tests for normally distributed qualitative data, the Mann-Whitney U-test for skewed qualitative data, and the chi square test or Fisher's exact test for categorical data.

RESULTS

There were 55 (80%) males and 14 (20%) females in the entire cohort, and the mean ± standard deviation age was 50.4±9.0 years. A total of 53 (77%) patients were included in the RP group, and 16 (23%) were included in the MP group. Patients in the MP group were older (55.5±7.8 vs 48.8±8.9 years), and the difference was significant (p=0.008). Compared with the RP group, the time of extracorporeal circulation (218.0 [44.7] vs 246.0 [58.0] min; p=0.005) and deep hypothermic circulatory arrest (4.0 [2.0] vs 25.0 [10.0] min; p<0.001) was shorter, and the incidence of postoperative acute kidney injury (n=6 [37.5%] vs n=36 [67.9%]; p=0.029) was lower in the MP group; the differences were significant. Six (6) patients died in the RP group; no patients died in the MP group. The total in-hospital mortality rate was 8.7%.

CONCLUSIONS

The modified extracorporeal circulation perfusion method is feasible, with satisfactory results.