A Comparison of Traditional and Novel Definitions (RIFLE, AKIN, and KDIGO) of Acute Kidney Injury for the Prediction of Outcomes in Acute Decompensated Heart Failure

Identification and predicting short-term prognosis of early cardiorenal syndrome type 1: KDIGO is superior to RIFLE or AKIN

Objective

Acute kidney injury (AKI) in patients hospitalized for acute heart failure (AHF) is usually type 1 of the cardiorenal syndrome (CRS) and has been associated with increased morbidity and mortality. Early recognition of AKI is critical. This study was to determine if the new KDIGO criteria (Kidney Disease: Improving Global Outcomes) for identification and short-term prognosis of early CRS type 1 was superior to the previous RIFLE and AKIN criteria.

Methods

The association between AKI diagnosed by KDIGO but not by RIFLE or AKIN and in-hospital mortality was retrospectively evaluated in 1005 Chinese adult patients with AHF between July 2008 and May 2012. AKI was defined as RIFLE, AKIN and KDIGO criteria, respectively. Cox regression was used for multivariate analysis of in-hospital mortality.

Results

Within 7 days on admission, the incidence of CRS type 1 was 38.9% by KDIGO criteria, 34.7% by AKIN, and 32.1% by RIFLE. A total of 110 (10.9%) cases were additional diagnosed by KDIGO criteria but not by RIFLE or AKIN. 89.1% of them were in Stage 1 (AKIN) or Stage Risk (RIFLE). They accounted for 18.4% (25 cases) of the overall death. After adjustment, this proportion remained an independent risk factor for in-hospital mortality [odds ratios (OR)3.24, 95% confidence interval(95%CI) 1.97–5.35]. Kaplan-Meier curve showed AKI patients by RIFLE, AKIN, KDIGO and [K(+)R(−)+K(+)A(−)] had lower hospital survival than non-AKI patients (Log Rank P<0.001).

Conclusion

KDIGO criteria identified significantly more CRS type 1 episodes than RIFLE or AKIN. AKI missed diagnosed by RIFLE or AKIN criteria was an independent risk factor for in-hospital mortality, indicating the new KDIGO criteria was superior to RIFLE and AKIN in predicting short-term outcomes in early CRS type 1.

One-year survival and renal function recovery of acute kidney injury patients with chronic heart failure

OBJECTIVE

To describe and analyze the clinical characteristics of acute kidney injury (AKI) patients with preexisting chronic heart failure (CHF) and to identify the prognostic factors of the 1-year outcome.

METHODS

A total of 120 patients with preexisting CHF who developed AKI between January 2005 and December 2010 were enrolled. CHF was diagnosed according to the European Society of Cardiology guidelines, and AKI was diagnosed using the RIFLE criteria. Clinical characteristics were recorded, and nonrecovery from kidney dysfunction as well as mortality were analyzed.

RESULTS

The median age of the patients was 70 years, and 58.33% were male. 60% of the patients had an advanced AKI stage ('failure') and 90% were classified as NYHA class III/IV. The 1-year mortality rate was 35%. 25.83% of the patients progressed to end-stage renal disease after 1 year. Hypertension, anemia, coronary atherosclerotic heart disease and chronic kidney disease were common comorbidities. Multiple organ dysfunction syndrome (MODS; OR, 35.950; 95% CI, 4.972-259.952), arrhythmia (OR, 13.461; 95% CI, 2.379-76.161), anemia (OR, 6.176; 95% CI, 1.172-32.544) and RIFLE category (OR, 5.353; 95% CI, 1.436-19.952) were identified as risk factors of 1-year mortality. For 1-year nonrecovery from kidney dysfunction, MODS (OR, 8.884; 95% CI, 2.535-31.135) and acute heart failure (OR, 3.281; 95% CI, 1.026-10.491) were independent risk factors.

CONCLUSION

AKI patients with preexisting CHF were mainly elderly patients who had an advanced AKI stage and NYHA classification. Their 1-year mortality and nonrecovery from kidney dysfunction rates were high. Identifying risk factors may help to improve their outcome.

Assessing continuous renal replacement therapy as a rescue strategy in cardiorenal syndrome 1

Background

Patients with acute decompensated heart failure (ADHF) and cardiorenal syndrome (CRS) 1 have poor outcomes. Ultrafiltration (UF) is used to mechanically remove salt and water in ADHF patients with diuretic resistance. However, little is known about the outcomes of ADHF patients on inotropes and/or vasopressors who require continuous renal replacement therapy (CRRT) for both UF and solute clearance in severe acute kidney injury.

Methods

We retrospectively analyzed 37 consecutive critically ill patients who were admitted for ADHF from 2005–13 and were on inotropes and/or vasopressors at the time of CRRT initiation. The primary outcome was in-hospital mortality.

Results

In-hospital mortality rate was 62%. Median survival was 15.5 days after CRRT initiation, and 10 months following hospital discharge. When comparing renal and cardiovascular variables for survivors and non-survivors at baseline, admission and CRRT initiation, survivors were less likely to need vasopressors. After controlling for multiple predictors, vasopressor use remained associated with time to death (HR 9.9; 95% CI 2.3–43.3; P = 0.002). Patients with isolated right ventricular dysfunction had an in-hospital mortality of 45% compared with 69% in those with left ventricular dysfunction (P = 0.27). Age of >70 years was associated with 100% in-hospital mortality.

Conclusions

Rescue therapy using CRRT in refractory CRS1 was associated with high in-hospital mortality, especially when vasopressors were used and when patient age exceeded 70 years. Additionally, survivors had a poor long-term prognosis.

Novel emboli protection system during cardiac surgery: a multi-center, randomized, clinical trial

BACKGROUND

Stroke is a major cause of morbidity and mortality during open-heart surgery. Up to 60% of intraoperative cerebral events are emboli induced. This randomized, controlled, multicenter trial is the first human study evaluating the safety and efficacy of a novel aortic cannula producing simultaneous forward flow and backward suction for extracting solid and gaseous emboli from the ascending aorta and aortic arch upon their intraoperative release.

METHODS

Sixty-six patients (25 females; 68±10 years) undergoing elective aortic valve replacement surgery, with or without coronary artery bypass graft surgery, were randomized to the use of the CardioGard (CardioGard Medical, Or-Yehuda, Israel) Emboli Protection cannula ("treatment") or a standard ("control") aortic cannula. The primary endpoint was the volume of new brain lesions measured by diffusion-weighted magnetic resonance imaging (DW-MRI), performed preoperatively and postoperatively. Device safety was investigated by comparisons of complications rate, namely neurologic events, stroke, renal insufficiency and death.

RESULTS

Of 66 patients (34 in the treatment group), 51 completed the presurgery and postsurgery MRI (27 in the treatment group). The volume of new brain lesion for the treatment group was (mean±standard error of the mean) 44.00±64.00 versus 126.56±28.74 mm3 in the control group (p=0.004). Of the treatment group, 41% demonstrated new postoperative lesions versus 66% in the control group (p=0.03). The complication rate was comparable in both groups.

CONCLUSIONS

The CardioGard cannula is safe and efficient in use during open-heart surgery. Efficacy was demonstrated by the removal of a substantial amount of emboli, a significant reduction in the volume of new brain lesions, and the percentage of patients experiencing new brain lesions.

Cardiorenal interactions in acute decompensated heart failure: contemporary concepts facing emerging controversies

Simultaneous dysfunction of the heart and the kidney represents a distinct spectrum of disease states composed of complex clinical scenarios with adverse outcomes. Worsening renal function (WRF) in the setting of acute decompensated heart failure (ADHF) is one such clinical setup for which the underlying mechanisms are poorly understood. Apparent discrepancies exist between the emerging data on the cardiorenal interactions of patients with ADHF and contemporary concepts such as the low forward flow or the high backward pressure hypotheses. The findings of recent retrospective studies also suggest that apparent "improvement in renal function" might be yet another risk factor for untoward outcomes in this patient population, further challenging our current understanding of the cardiorenal interactions. Besides, these data do not seem to fully support our conventional thinking about other aspects of these interactions such as the independent adverse impact of WRF on the outcomes of patients with ADHF, pointing to congestion as a possibly overlooked factor. In this article, we provide an overview of these emerging controversial issues with the goal of identifying the areas where clinical research could be most helpful, because it is of paramount importance to characterize the pathways leading to WRF in ADHF to develop a mechanistically relevant management strategy. Although the paucity of data coupled with the complexity of this field precludes any firm conclusion, these discussions are meant to prompt clinicians and researchers to revisit a number of long-believed concepts surrounding the cardiorenal interactions in ADHF.

Early serum creatinine changes and outcomes in patients admitted for acute heart failure: the cardio-renal syndrome revisited

BACKGROUND

The changes in renal function that occurred in patients with acute decompensated heart failure (ADHF) are prevalent, and have multifactorial etiology and dissimilar prognosis. To what extent the prognostic role of such changes may vary according to the presence of renal insufficiency at admission is not clear. Accordingly, we sought to determine whether early creatinine changes (ΔCr) (admission to 48-72 hours) had an effect on 1-year mortality relative to the presence of renal insufficiency at admission.

METHODS

We included 705 consecutive patients admitted with the diagnosis of ADHF. Admission renal insufficiency was defined as serum creatinine ≥1.4mg/dl (A-RI_cr) or estimated glomerular filtration rate <60ml/min/1.73m² (A-RI_GFR). Appropriate survival regression techniques were used.

RESULTS

The mean age was 72.9±11.4 years and 51.2% were males. Patients with admission renal insufficiency (24.7% and 42.8% for A-RIcr and A-RIGFR, respectively) had higher prevalence of extreme values in ΔCr in either direction (increasing/decreasing). At 1-year follow-up, 114 (16.2%) deaths were registered. The multivariable analysis showed a significant interaction between admission renal insufficiency and ΔCr ( p=0.004 and p=0.019 for A-RIcr and A-RIGFR, respectively). In the presence of renal insufficiency, the continuum of ΔCr followed a positive and almost linear relationship with mortality risk. Conversely, in patients without renal insufficiency, those changes adopted a 'J-shape' trajectory with increased mortality at both ends of the curve distribution.

CONCLUSIONS

In patients with ADHF the effect of ΔCr on 1-year mortality varied according to its magnitude and the presence of admission renal insufficiency. There was a graded-association with mortality when renal insufficiency was present on admission.

Risk factors for mortality in patients with septic acute kidney injury in intensive care units in Beijing, China: a multicenter prospective observational study

Objective. To discover risk factors for mortality of patients with septic AKI in ICU via a multicenter study. Background. Septic AKI is a serious threat to patients in ICU, but there are a few clinical studies focusing on this. Methods. This was a prospective, observational, and multicenter study conducted in 30 ICUs of 28 major hospitals in Beijing. 3,107 patients were admitted consecutively, among which 361 patients were with septic AKI. Patient clinical data were recorded daily for 10 days after admission. Kidney Disease: Improving Global Outcomes (KDIGO) criteria were used to define and stage AKI. Of the involved patients, 201 survived and 160 died. Results. The rate of septic AKI was 11.6%. Twenty-one risk factors were found, and six independent risk factors were identified: age, APACHE II score, duration of mechanical ventilation, duration of MAP <65 mmHg, time until RRT started, and progressive KIDGO stage. Admission KDIGO stages were not associated with mortality, while worst KDIGO stages were. Only progressive KIDGO stage was an independent risk factor. Conclusions. Six independent risk factors for mortality for septic AKI were identified. Progressive KIDGO stage is better than admission or the worst KIDGO for prediction of mortality. This trial is registered with ChiCTR-ONC-11001875.

Worsening renal function in heart failure: the need for a consensus definition

Acute decompensated heart failure is a common cause of hospitalisation. This is a period of vulnerability both in altered pathophysiology and also the potential for iatrogenesis due to therapeutic interventions. Renal dysfunction is often associated with heart failure and portends adverse outcomes. Identifying heart failure patients at risk of renal dysfunction is important in preventing progression to chronic kidney disease or worsening renal function, informing adjustment to medication management and potentially preventing adverse events. However, there is no working or consensus definition in international heart failure management guidelines for worsening renal function. In addition, there appears to be no concordance or adaptation of chronic kidney disease guidelines by heart failure guideline development groups for the monitoring of chronic kidney disease in heart failure. Our aim is to encourage the debate for an agreed definition given the prognostic impact of worsening renal function in heart failure. We present the case for the uptake of the Acute Kidney Injury Network criteria for acute kidney injury with some minor alterations. This has the potential to inform study design and meta-analysis thereby building the knowledgebase for guideline development. Definition consensus supports data element, clinical registry and electronic algorithm innovation as instruments for quality improvement and clinical research for better patient outcomes. In addition, we recommend all community managed heart failure patients have their baseline renal function classified and routinely monitored in accordance with established renal guidelines to help identify those at increased risk for worsening renal function or progression to chronic kidney disease.

Epidemiology, outcomes and validation of RIFLE and AKIN criteria in acute kidney injury (AKI) in critically ill patients: Indian perspective

Although the epidemiology and the impact of Acute Kidney Injury on outcomes are well-known in the Western literature, good data is lacking from India. Most studies published from India have not evaluated epidemiology of Acute Kidney Injury in the Intensive Care Unit setting and/or have not used validated criteria. In our observational study of 250 patients, admitted to a tertiary level ICU, we have explored the epidemiology of Acute Kidney Injury using both RIFLE and AKIN criteria and have validated them. We have also demonstrated that the severity of AKI is an independent predictor of mortality in critically ill patients. Our results are very much comparable to other studies and we feel that this study will remain as an epidemiological reference point for Indian clinicians dealing with AKI.

Validation of the Kidney Disease Improving Global Outcomes criteria for AKI and comparison of three criteria in hospitalized patients

BACKGROUND AND OBJECTIVES

AKI is a major clinical problem and predictor of outcome in hospitalized patients. In 2013, the Kidney Disease: Improving Global Outcomes (KDIGO) group published the third consensus AKI definition and classification system after the Risk, Injury, Failure, Loss of Kidney Function, and End-Stage Kidney Disease (RIFLE) and the Acute Kidney Injury Network (AKIN) working group systems. It is unclear which system achieves optimal prognostication in hospital patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A retrospective observational study using hospital laboratory, admission, and discharge databases was performed that included adult patients admitted to a teaching hospital in Tokyo, Japan between April 1, 2008, and October 31, 2011. AKI occurring during each hospital stay was identified, and discriminative ability of each AKI classification system based on serum creatinine for the prediction of hospital mortality was assessed. The receiver operating characteristic curve, a graphical measure of test performance, and the area under the curve were used to evaluate how classifications preformed on the study population.

RESULTS

In total, 49,518 admissions were studied, of which 11.0% were diagnosed with RIFLE criteria and 11.6% were diagnosed with KDIGO criteria, but only 4.8% were diagnosed with AKIN criteria. Overall hospital mortality was 3.0%. AKI staging and hospital mortality were closely correlated in all systems. Discrimination for hospital mortality was similar for RIFLE and KDIGO criteria (area under the curve=0.77 versus 0.78; P=0.02), whereas AKIN discrimination was inferior (area under the curve=0.69 versus RIFLE [P<0.001] versus KDIGO [P<0.001]).

CONCLUSION

Among hospital patients, KDIGO and RIFLE criteria achieved similar discrimination, but the discrimination of AKIN was inferior.