Risk indicators for acute kidney injury in cardiogenic shock

Acute kidney injury in patients with acute decompensated heart failure-cardiogenic shock: Prevalence, risk factors and outcome

BACKGROUND

Acute Kidney Injury (AKI) represents a major complication of acute heart failure and cardiogenic shock (CS). There is a paucity of data on AKI complicating acutely decompensated heart failure patients presenting with CS (ADHF-CS). We aimed to investigate AKI prevalence, risk factors and outcomes in this subgroup of patients.

METHODS

Retrospective observational study on patients admitted for ADHF-CS to our 12-bed Intensive Care Unit (ICU), between January 2010 and December 2019. Demographic, clinical, and biochemical variables were collected at baseline and during hospital stay.

RESULTS

Eighty-eight patients were consecutively recruited. The predominant etiologies were idiopathic dilated cardiomyopathy (47%), followed by post-ischemic (24%). AKI was diagnosed in 70 (79.5%) of patients. Forty-three out of 70 patients met the criteria for AKI at ICU admission. On multivariate analysis, a central venous pressure (CVP) higher than 10 mmHg (OR 3.9; 95%CI 1.2-12.6; p = 0.025) and serum lactate higher than 3 mmol/L (OR 4.1; 95%CI 1.01-16.3; p = 0.048) were identified to be independently associated with AKI. Age and AKI stage were independent predictors of 90-day mortality.

CONCLUSION

AKI is a common and early complication of ADHF-CS. Venous congestion and severe hypoperfusion are risk factors for AKI development. Early detection and prevention of AKI could lead to better outcome in this clinical subgroup.

The magnitude, but not the duration of elevated central venous pressure is associated with mortality in sepsis patients: An analysis of the MIMIC-IV database

BACKGROUND

It is unclear whether the magnitude and duration of elevated central venous pressure (ECVP) greater than ten mmHg has the same impact on mortality in sepsis patients.

METHODS

Critically ill patients with sepsis were identified from the Medical Information Mart for Intensive Care (MIMIC)-IV database. The duration and the magnitude of ECVP were calculated. Normalized ECVP load was defined as the ECVP load (the sum of ECVP value times its duration) divided by the total duration of ECVP. The primary endpoint was 28-day mortality. Kaplan-Meier survival analysis was used to compare survival between patients with high or low normalized ECVP load.

RESULTS

A total of 1071 sepsis patients were included. Higher normalized ECVP load was associated with higher mortality rate; in contrast, the duration of ECVP was not associated with mortality. A linear relationship between normalized ECVP load and mortality was identified. Patients with higher normalized ECVP load had less urine output and more positive fluid balance.

CONCLUSION

The magnitude, but not the duration of ECVP, is associated with mortality in sepsis patients. ECVP should be considered as a valuable and easily accessible safety parameter during fluid resuscitation.

Total Testosterone as a Specific Marker of Acute Kidney Injury in Male Patients With Myocardial Infarction

Aim

The aim of the present study was to assess the significance of total testosterone (T) as a marker of acute kidney injury (AKI) in patients with acute myocardial infarction (MI).

Patients and methods

The study was a retrospective, single-center cohort study that included 55 consecutive male patients diagnosed with acute MI who were admitted to the Cardiology Clinic of Alexandrovska University Hospital (Sofia, Bulgaria) between July 2011 and December 2013. The plasma total T levels, measured at admission, the peak levels of myocardial necrosis markers, high-sensitive C-reactive protein (hsCRP), and the left ventricular ejection fraction (LVEF) were analyzed in relation to the incidence of AKI.

Results

The occurrence of AKI was positively predicted by reduced EF (OR=0.825; CI=0.724-0.942; P=0.004), advanced age (OR=1.077; CI=1.038-1.151; P=0.029), and low levels of total T (OR=0.837; CI=0.707-0.990; P=0.037). Reduced systolic function (OR=0.861; 95% CI=0.758-0.978; P=0.022 for EF) and marginally age (OR=1.094; 95% CI=1.000-1.197; P=0.051) contributed to the incidence of AKI in a multivariate model. Total T was not an independent factor (OR=0.841; 95% CI=0.669-1.058; P=0.139) for AKI. The total T levels were significantly inversely correlated with the peak of hsCRP (r= -0.153; P=0.009) and showed a tendency to inverse relation with the SYNTAX score (r= -0.235; P=0.083).

Conclusion

The total T levels are significantly inversely related to the peak of hsCRP and as a tendency to the SYNTAX score in male patients with acute MI. A low level of plasma total T is not an independent marker of AKI in acute MI. Advanced age and low EF are independent factors for AKI discrimination in a small cohort of patients with acute MI.

Plants with Therapeutic Potential for Ischemic Acute Kidney Injury: A Systematic Review

Acute kidney injury (AKI) is a complex condition which has an intricate pathology mostly involving hemodynamic, inflammatory, and direct toxic effects at the cellular level with high morbidity and mortality ratios. Renal ischemic reperfusion injury (RIRI) is the main factor responsible for AKI, most often observed in different types of shock, kidney transplantation, sepsis, and postoperative procedures. The RIRI-induced AKI is accompanied by increased reactive oxygen species generation together with the activation of various inflammatory pathways. In this context, plant-derived medicines have shown encouraging nephroprotective properties. Evidence provided in this systemic review leads to the conclusion that plant-derived extracts and compounds exhibit nephroprotective action against renal ischemic reperfusion induced-AKI by increasing endogenous antioxidants and decreasing anti-inflammatory cytokines. However, there is no defined biomarker or target which can be used for treating AKI completely. These plant-derived extracts and compounds are only tested in selected transgenic animal models. To develop the results obtained into a therapeutic entity, one should apply them in proper vertebrate multitransgenic animal models prior to further validation in humans.

Development and External Validation of a Nomogram for Predicting Acute Kidney Injury in Cardiogenic Shock Patients in Intensive Care Unit

Background

The aim of this study was to construct and external validate a nomogram for predicting cardiogenic shock acute kidney injury (CS-AKI) in patients in intensive care unit (ICU).

Methods

All patients diagnosed with CS from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database and the eICU Collaborative Research Database (eICU-CRD) were included in this study. Least absolute shrinkage and selection operator (LASSO) regression and recursive feature elimination for support vector machine (SVM-RFE) were used to determine the overlapping clinical features associated with CS-AKI. The predictive nomogram was established based on the significant clinical parameters and externally verified in this study.

Results

LASSO regression and SVM-RFE demonstrated that Charlson Comorbidity Index (CCI), usage of mechanical ventilation, SOFA score, white blood cell, albumin, eGFR, anion gap, and positive fluid balance were closely associated with CS-AKI in the training cohort. The predictive nomogram based on the eight parameters showed good predictive performance as calculated by C-index were 0.823 (95% confidence index, 95% CI 0.798–0.849), 0.819 (95% CI 0.769–0.849), and 0.733 (95% CI 0.704–0.763) in the training set, in the internal validation set and in the external validation sets, respectively. Moreover, the nomogram exhibited not only encouraging calibration ability but also great clinical utility in the training set and in the validation sets.

Conclusion

CCI, usage of mechanical ventilation, SOFA score, white blood cell, albumin, eGFR, anion gap, and positive fluid balance were closely associated with CS-AKI. The predictive nomogram for CS-AKI manifested well-predictive ability for the identification of ICU patients with CS-AKI.

Role of TRPC6 in kidney damage after acute ischemic kidney injury

Transient receptor potential channel subfamily C, member 6 (TRPC6), a non-selective cation channel that controls influx of Ca²⁺ and other monovalent cations into cells, is widely expressed in the kidney. TRPC6 gene variations have been linked to chronic kidney disease but its role in acute kidney injury (AKI) is unknown. Here we aimed to investigate the putative role of TRPC6 channels in AKI. We used Trpc6^-/- mice and pharmacological blockade (SH045 and BI-749327), to evaluate short-term AKI outcomes. Here, we demonstrate that neither Trpc6 deficiency nor pharmacological inhibition of TRPC6 influences the short-term outcomes of AKI. Serum markers, renal expression of epithelial damage markers, tubular injury, and renal inflammatory response assessed by the histological analysis were similar in wild-type mice compared to Trpc6^-/- mice as well as in vehicle-treated versus SH045- or BI-749327-treated mice. In addition, we also found no effect of TRPC6 modulation on renal arterial myogenic tone by using blockers to perfuse isolated kidneys. Therefore, we conclude that TRPC6 does not play a role in the acute phase of AKI. Our results may have clinical implications for safety and health of humans with TRPC6 gene variations, with respect to mutated TRPC6 channels in the response of the kidney to acute ischemic stimuli.

Predictors of In-hospital Mortality in Cardiogenic Shock Patients on Vasoactive or Inotropic Support

Background:

Though controversial, the short-duration in-patient use of inotropes in cardiogenic shock (CS) remain an ACC/AHA Class IIa indication, and are frequently used in the initial treatment of CS. We evaluated in-patient mortality and effect on mortality risk of commonly used vasoactive inotropic medications for the medical management of SCAI stage B and C cardiogenic shock patients in a tertiary care cardiac care unit: dobutamine, dopamine, milrinone, and norepinephrine.

Methods:

We retrospectively evaluated 342 patients who received dobutamine, milrinone, dopamine, norepinephrine or a combination of these medications for SCAI stage B and C cardiogenic shock. Cox proportional hazards were used to form longitudinal mortality predictions.

Results:

Overall in-patient mortality was 18%. Each 1 µg/kg/minute increase in dobutamine independently corresponded to a 15% increase in risk of mortality. High dose dobutamine >3 µg/kg/minute is associated with 3-fold increased risk compared to ⩽3 µg/kg/minute (P < .001). Use of milrinone, norepinephrine, and dopamine were not independently associated with mortality.

Conclusion:

We demonstrate that the overall in-hospital mortality of SCAI stage B and C cardiogenic shock patients medically managed on inotropes was not in excess of prior studies. Dobutamine was independently associated with mortality, while other vasoactive inotropic medications were not. Inotropes remain a feasible method of managing SCAI stage B and C cardiogenic shock.

Acute Kidney Injury in Cardiogenic Shock: An Updated Narrative Review

Acute myocardial infarction with cardiogenic shock (AMI-CS) is associated with high mortality and morbidity despite advancements in cardiovascular care. AMI-CS is associated with multiorgan failure of non-cardiac organ systems. Acute kidney injury (AKI) is frequently seen in patients with AMI-CS and is associated with worse mortality and outcomes compared to those without. The pathogenesis of AMI-CS associated with AKI may involve more factors than previously understood. Early use of renal replacement therapies, management of comorbid conditions and judicious fluid administration may help improve outcomes. In this review, we seek to address the etiology, pathophysiology, management, and outcomes of AKI complicating AMI-CS.

Acute kidney injury in cardiogenic shock: A comprehensive review

Acute kidney injury (AKI) is an ominous predictor of mortality in cardiogenic shock. The present review examines the pathophysiology of AKI in cardiogenic shock (CS), summarizes the pertinent literature including the diagnostic criteria/definitions for AKI and possible role of biomarkers, and identifies risk factors and possible therapeutic interventions for AKI in CS. Our review finds that AKI is common in patients with CS and is associated with increased morbidity and mortality. Urinary biomarkers of renal tubular injury appear more sensitive for detection of AKI but have yet to be incorporated into daily practice. Emerging data would suggest vasopressor choices, mechanical circulatory support, and renal replacement therapy may have important therapeutic roles in the management of CS.

Clinical use of peripheral perfusion parameters in septic shock

PURPOSE OF REVIEW

Current goals of resuscitation in septic shock are mainly a fixed volume of fluids and vasopressors to correct hypotension and improve tissue perfusion indicated by decreasing lactate levels.

RECENT FINDINGS

Abnormal peripheral perfusion by objective and subjective parameters are associated with increased mortality in various phases of the treatment of critically ill patients including patients with septic shock. Ongoing resuscitation in septic shock patients with normal peripheral perfusion is not associated with improved outcome, rather with increased mortality. Mitigation of fluid resuscitation by using parameters of peripheral perfusion in septic shock seems to be safe.

SUMMARY

Septic shock patients with normal peripheral perfusion represent a different clinical phenotype of patients that might benefit from limited resuscitation efforts. Parameters of peripheral perfusion could be used to guide the individualization of patients with septic shock.

Monitoring coherence between the macro and microcirculation in septic shock

PURPOSE OF REVIEW

Currently, the treatment of patients with shock is focused on the clinical symptoms of shock. In the early phase, this is usually limited to heart rate, blood pressure, lactate levels and urine output. However, as the ultimate goal of resuscitation is the improvement in microcirculatory perfusion the question is whether these currently used signs of shock and the improvement in these signs actually correspond to the changes in the microcirculation.

RECENT FINDINGS

Recent studies have shown that during the development of shock the deterioration in the macrocirculatory parameters are followed by the deterioration of microcirculatory perfusion. However, in many cases the restoration of adequate macrocirculatory parameters is frequently not associated with improvement in microcirculatory perfusion. This relates not only to the cause of shock, where there are some differences between different forms of shock, but also to the type of treatment.

SUMMARY

The improvement in macrohemodynamics during the resuscitation is not consistently followed by subsequent changes in the microcirculation. This may result in both over-resuscitation and under-resuscitation leading to increased morbidity and mortality. In this article the principles of coherence and the monitoring of the microcirculation are reviewed.

Cardiogenic shock and acute kidney injury: the rule rather than the exception

Cardiogenic shock (CS) is a life-threatening condition of poor end-organ perfusion, caused by any cardiovascular disease resulting in a severe depression of cardiac output. Despite recent advances in replacement therapies, the outcome of CS is still poor, and its management depends more on empirical decisions rather than on evidence-based strategies. By its side, acute kidney injury (AKI) is a frequent complication of CS, resulting in the onset of a cardiorenal syndrome. The combination of CS with AKI depicts a worse clinical scenario and holds a worse prognosis. Many factors can lead to acute renal impairment in the setting of CS, either for natural disease progression or for iatrogenic causes. This review aims at collecting the current evidence-based acknowledgments in epidemiology, pathophysiology, clinical features, diagnosis, and management of CS with AKI. We also attempted to highlight the major gaps in evidence as well as to point out possible strategies to improve the outcome.

Acute Kidney Injury in Cardiogenic Shock

This column is supplied by Amol Patel, DO, and Peter Nguyen, MD. Dr. Patel is an internal medicine resident at Houston Methodist Hospital, where he is in his final year as chief resident. He received his bachelor's degree in biomedical engineering at Texas A&M University and his medical degree at UNT Health Science center in Forth Worth, Texas. Dr. Nguyen is a nephrologist with Houston Kidney Consultants and practices at Houston Methodist Hospital, where he is currently the secretary of the medical staff. He obtained his medical degree from Texas Tech School of Medicine and completed his residency and nephrology fellowship at Baylor College of Medicine in Houston, Texas.

Assessment of microcirculation in cardiogenic shock

PURPOSE OF REVIEW

Adequate tissue perfusion is of utmost importance to avoid organ failure in patients with cardiogenic shock. Within the recent years, the microcirculation, defined as the perfusion of the smallest vessels, has been identified to play a crucial role. Microcirculatory changes may include capillary flow disturbances as well as changes in the density of perfused vessels. Due to the availability of new technologies to assess the microcirculation, interesting new data came up and it is the purpose of this review to summarize recent studies in the field.

RECENT FINDINGS

Nowadays, an increasing number of studies confirm parameters of the microcirculation, derived by intravital microscopy, to represent strong outcome predictors in cardiogenic shock. In addition, microcirculation as read-out parameter in innovative clinical studies has meanwhile been accepted as serious endpoint. Treatment strategies such as mechanical assist devices, blood pressure regulating agents or fluids use tissue perfusion and microcirculatory network density as targets in addition to clinical perfusion evaluation and decreasing serum lactate levels.

SUMMARY

The parameter most frequently used to detect tissue malperfusion is serum lactate. Novel, noninvasive methods to quantify microvascular perfusion have the potential to guide treatment in terms of optimizing organ perfusion and oxygenation probably paving the way for an individualized therapy.

Elevated central venous pressure is associated with increased mortality and acute kidney injury in critically ill patients: a meta-analysis

Background

The association of central venous pressure (CVP) and mortality and acute kidney injury (AKI) in critically ill adult patients remains unclear. We performed a meta-analysis to determine whether elevated CVP is associated with increased mortality and AKI in critically ill adult patients.

Methods

We searched PubMed and Embase through June 2019 to identify studies that investigated the association between CVP and mortality and/or AKI in critically ill adult patients admitted into the intensive care unit. We calculated the summary odds ratio (OR) and 95% CI using a random-effects model.

Results

Fifteen cohort studies with a broad spectrum of critically ill patients (mainly sepsis) were included. On a dichotomous scale, elevated CVP was associated with an increased risk of mortality (3 studies; 969 participants; OR, 1.65; 95% CI, 1.19–2.29) and AKI (2 studies; 689 participants; OR, 2.09; 95% CI, 1.39–3.14). On a continuous scale, higher CVP was associated with greater risk of mortality (5 studies; 7837 participants; OR, 1.10; 95% CI, 1.03–1.17) and AKI (6 studies; 5446 participants; OR, 1.14; 95% CI, 1.06–1.23). Furthermore, per 1 mmHg increase in CVP increased the odds of AKI by 6% (4 studies; 5150 participants; OR, 1.06; 95% CI, 1.01–1.12). Further analyses restricted to patients with sepsis showed consistent results.

Conclusions

Elevated CVP is associated with an increased risk of mortality and AKI in critically ill adult patients admitted into the intensive care unit.

Trial registration

PROSPERO, CRD42019126381

Outcome in Patients Resuscitated following Myocardial Infarction with Acute Kidney Injury

Background: Data on acute kidney injury (AKI) in patients with myocardial infarction (MI) who underwent percutaneous coronary intervention (PCI) after cardiac arrest are scarce. The prevalence of AKI, as classified by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria; and its possible association with 30-day mortality were assessed. Methods: Data on 6387 patients with MI, 342 (5.3%) with out-of-hospital cardiac arrest or arrest immediately after admission before PCI, were retrospectively analyzed. The AKI and no-AKI groups were compared. The 30-day mortality was determined. Results: Ninety-three (27.2%) patients suffered AKI. AKI KDIGO stages 1, 2 and 3 occurred in 45 (13.2%), 8 (2.3%) and 40 (11.7%) patients, respectively. Higher mortality was found in AKI patients [56 (60.2%) vs. no-AKI patients 32 (12.9%); p<0.0001]. More patients died in the higher AKI KDIGO stages. In AKI KDIGO stages 1/2 and stage 3, 20 (37.7%) patients and 36 (90.0%) patients died, respectively compared to 32 (12.9%) no-AKI patients; p<0.0001. AKI was the strongest predictor of 30-day mortality (adjusted OR 6.98; 95% CI 3.42 to 14.23; p<0.0001). Other predictors were bleeding, cardiogenic shock, contrast volume-to-glomerular filtration rate ratio, and female sex. The adjusted OR for AKI KDIGO stages 1/2 and stage 3 were 3.68; 95% CI 1.53 to 8.32; p=0.002 and 29.10; 95% CI 8.31 to 101.88; p<0.0001, respectively. Conclusion: In patients resuscitated after MI undergoing PCI, AKI had a deleterious impact on the prognosis. A graded increase in the severity of AKI according to the KDIGO definition was associated with a progressively increased risk of 30-day mortality.

Acute kidney injury following left ventricular assist device implantation: Contemporary insights and future perspectives

Currently, an increasing number of patients with end-stage heart failure are being treated with left ventricular assist device (LVAD) therapy as bridge-to-transplantation, bridge-to-candidacy, or destination therapy (DT). Potential life-threatening complications may occur, specifically in the early post-operative phase, which positions LVAD implantation as a high-risk surgical procedure. Acute kidney injury (AKI) is a frequently observed complication after LVAD implantation and is associated with high morbidity and mortality. The rapidly growing number of LVAD implantations necessitates better approaches of identifying high-risk patients, optimizing peri-operative management, and preventing severe complications such as AKI. This holds especially true for those patients receiving an LVAD as DT, who are typically older (with higher burden of comorbidities) with impaired renal function and at increased post-operative risk. Herein we outline the definition, diagnosis, frequency, pathophysiology, and risk factors for AKI in patients with an LVAD. We also review possible strategies to prevent and manage AKI in this patient population.