Right Heart Failure-Unrecognized Cause of Cardiorenal Syndrome

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

Kidney Function Trajectories and Right Heart Failure Following LVAD Implantation

BACKGROUND

Preoperative kidney dysfunction is a risk factor for right heart failure (RHF) after implantation of a left ventricular assist device (LVAD). However, characteristic kidney function trajectories before and after post-LVAD RHF are uncertain, so we investigated this.

METHODS AND RESULTS

We identified individuals who received primary continuous-flow LVAD implantation from July 1, 2014 to December 31, 2017 in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) data set. Incident RHF was ascertained using the INTERMACS definition at 1 and 3 months and classified as transient or persistent. Kidney function trajectories before and after RHF onset, and relationships of baseline kidney function with RHF risk at the different time points, were assessed. We identified 8076 LVAD recipients who met inclusion criteria. Incident RHF was present at 1 month in 26.4%. There were 4850 individuals with follow-up at 3 months, with incident RHF in 4.2%. Kidney function trajectories differed from pre-LVAD implantation to 1-month follow-up by RHF category, with those developing persistent RHF having no improvement in baseline kidney function. For trajectories before the 3-month RHF ascertainment time, the shape was similar for those with and without RHF, with lower estimated glomerular filtration rate levels among those who developed RHF. Baseline estimated glomerular filtration rate levels below the normal range were associated with higher risk of RHF at 1 and 3 months.

CONCLUSIONS

In LVAD recipients, preimplantation kidney function and subsequent kidney function trajectories differed substantially by RHF at 1 and 3 months postimplantation, even after adjustment for several confounders. This may demonstrate bidirectional associations between kidney function and right ventricular function in LVAD recipients.

Clinical Features and Outcomes of Acute Kidney Injury in Critically Ill COVID-19 Patients: A Retrospective Observational Study

BACKGROUND

An alarming number of COVID-19 patients, especially in severe cases, have developed acute kidney injury (AKI).

AIM

The study aimed to assess the frequency, risk factors, and impact of AKI on mortality in critically ill COVID-19 patients.

METHODS

The study was a retrospective observational study conducted in the MICU. Univariate and multivariate analyses were performed to identify risk factors for AKI and clinical outcomes.

RESULTS

During the study period, 465 consecutive COVID-19 patients were admitted to the MICU. The patients' characteristics were median age, 64 [54-71] years; median SAPSII, 31 [24-38]; and invasive mechanical ventilation (IMV), 244 (52.5%). The overall ICU mortality rate was 49%. Two hundred twenty-nine (49.2%) patients developed AKI. The factors independently associated with AKI were positive fluid balance (OR, 2.78; 95%CI [1.88-4.11]; p < 0.001), right heart failure (OR, 2.15; 95%CI [1.25-3.67]; p = 0.005), and IMV use (OR, 1.55; 95%CI [1.01-2.40]; p = 0.044). Among the AKI patients, multivariate analysis identified the following factors as independently associated with ICU mortality: age (OR, 1.05; 95%CI [1.02-1.09]; p = 0.012), IMV use (OR, 48.23; 95%CI [18.05-128.89]; p < 0.001), and septic shock (OR, 3.65; 95%CI [1.32-10.10]; p = 0.012).

CONCLUSION

The present study revealed a high proportion of AKI among critically ill COVID-19 patients. This complication seems to be linked to a severe cardiopulmonary interaction and fluid balance management, thus accounting for a poor outcome.

Pulmonary hypertension without heart failure causes cardiorenal syndrome in a porcine model

Cardiorenal syndromes type 1 and 2 are complex disorders in which cardiac dysfunction leads to kidney dysfunction. However, the mechanisms remain incompletely explained, during pulmonary hypertension in particular. The objective of this study is to develop an original preclinical model of cardiorenal syndrome secondary to a pulmonary hypertension in piglets. Twelve 2-month-old Large White piglets were randomized in two groups: (1) induction of pulmonary hypertension by ligation of the left pulmonary artery and iterative embolizations of the right lower pulmonary artery, or (2) Sham interventions. We evaluated the cardiac function using right heart catheterization, echocardiography and measurement of biochemistry markers). Kidney was characterized using laboratory blood and urine tests, histological evaluation, immunostainings for renal damage and repair, and a longitudinal weekly assessment of the glomerular filtration rate using creatinine-based estimation and intravenous injection of an exogenous tracer on one piglet. At the end of the protocol (6 weeks), the mean pulmonary artery pressure (32 ± 10 vs. 13 ± 2 mmHg; p = 0.001), pulmonary vascular resistance (9.3 ± 4.7 vs. 2.5 ± 0.4 WU; p = 0.004) and central venous pressure were significantly higher in the pulmonary hypertension group while the cardiac index was not different. Piglets with pulmonary hypertension had higher troponin I. We found significant tubular damage and an increase in albuminuria in the pulmonary hypertension group and negative correlation between pulmonary hypertension and renal function. We report here the first porcine model of cardiorenal syndrome secondary to pulmonary hypertension.

Prognostic value of functional tricuspid regurgitation quantified by cardiac magnetic resonance in heart failure

AIMS

Quantitative assessment of tricuspid regurgitation (TR) is challenging, and the prognostic implications of cardiac magnetic resonance (CMR)-quantified measures of TR remain unclear in patients with heart failure with reduced ejection fraction (HFrEF). This study investigated the prognostic value of functional TR quantified by CMR in patients with HFrEF.

METHODS AND RESULTS

A total of 262 patients with HFrEF who underwent CMR were analysed. Patients who had primary TR, who had acute HF, or for whom cardiac surgery was planned were excluded. TR volume and fraction were indirectly calculated via subtracting methods. The primary outcome was defined as a composite of all-cause death and hospitalization for HF. Renal outcome was defined as a composite of a decrease in estimated glomerular filtration rate ≥50% or progression to end-stage renal disease. During the follow-up period (median 921 days), 62 primary outcomes and 48 renal outcomes occurred. When divided into two or three groups based on TR fraction in Kaplan-Meier analysis, patients with higher TR fractions showed worse primary outcomes and renal outcomes than those with lower TR fractions. In Cox regression analysis, a 10% increase in TR fraction was significantly associated with primary outcome [hazard ratio (HR) 1.49, 95% confidence interval (CI) 1.29-1.73, P < 0.001] and renal outcome (HR 1.31, 95% CI 1.12-1.55, P = 0.001). TR fraction exhibited a strong positive linear relationship with primary outcomes and renal outcomes in restricted cubic spline curves.

CONCLUSION

CMR-quantified measures of TR were independently associated with adverse clinical outcomes in patients with HFrEF.

Recent Developments in the Evaluation and Management of Cardiorenal Syndrome: A Comprehensive Review

Cardiorenal syndrome (CRS) is an increasingly recognized diagnostic entity associated with high morbidity and mortality among acutely ill heart failure (HF) patients with acute and/ or chronic kidney diseases (CKD). While traditionally viewed as a state of decline in glomerular filtration rate (GFR) due to decreased renal perfusion, mainly due to therapeutic interventions to relieve congestive in HF, recent insights into the underlying pathophysiologic mechanisms of CRS led to a broader definition and further classification of CRS into 5 distinct types. In this comprehensive review, we discuss the classification of CRS, highlighting the underlying common pathogenetic pathways of heart failure and kidney injury, including increased congestion, neurohormonal dysregulation, oxidative stress as well as inflammation, and cytokine storm that are particularly evident in COVID-19 patients with multiorgan failure and also in those with other disorders including sepsis, systemic lupus erythematosus and amyloidosis. In this review we also present the recent advances in the diagnostic strategies of CRS including cardiac and renal biomarkers as well as advanced cardiac and renal imaging techniques that are available to aid in the diagnosis as well as in the prognostication of this disorder. Finally, we discuss the various therapeutic options available to-date, including fluid optimization, hemofiltration, renal replacement therapy as well as the role of SGLT2 inhibitors in light of recent data from RCTs. It is important to note that, CRS population are either excluded or underrepresented, at best, in major RCTs and therefore, therapeutic recommendations are largely extrapolated from HF and CKD clinical trials.

Clinical implications of preoperative echocardiographic findings on cardiovascular outcomes following vascular surgery: An observational trial

INTRODUCTION

Peripheral artery disease and cardiac disease are often comorbid conditions. Echocardiography is a diagnostic tool that can be performed preoperatively to risk stratify patients by a functional cardiac test. We hypothesized that ventricular dysfunction and valvular lesions were associated with an increased incidence of expanded major adverse cardiac events (Expanded MACE).

METHODS AND MATERIALS

Retrospective cohort study from 2011 to 2020 including all patients from a major academic center who had vascular surgery and an echocardiographic study within two years of the index procedure.

RESULTS

813 patients were included in the study; a majority had a history of smoking (86%), an ASA score of 3 (65%), and were male (68%). Carotid endarterectomy was the most common surgery (24%) and the least common surgery was open abdominal aortic aneurysm repair (5%). We found no significant association between the echocardiographic findings of left ventricular dysfunction, right ventricular dysfunction, or valvular lesions and the postoperative development of Expanded MACE.

CONCLUSIONS

The preoperative echocardiographic findings of left ventricular dysfunction, right ventricular dysfunction and moderate to severe valvular lesions were not predictive of an increased incidence of postoperative Expanded MACE. We identified a significant association between RV dysfunction and post-operative dialysis that should be interpreted carefully due to the small number of outcomes. The transition from open to endovascular surgery and advances in perioperative management may have led to improved cardiovascular outcomes.

TRIAL REGISTRATION

Trial Registration: NCT04836702 (clinicaltrials.gov). https://www.google.com/search?client=firefox-b-d&q=NCT04836702.

Cardiovascular Alterations and Structural Changes in the Setting of Chronic Kidney Disease: a Review of Cardiorenal Syndrome Type 4

Cardiovascular and renal physiology are interrelated. More than a decade ago this was codified in guidelines defining the five subtypes of the cardiorenal syndrome. Morbidity and mortality for those with the cardiorenal syndrome is high compared to demographically matched individuals without cardiorenal disease, acute or chronic. The focus of this review will be the epidemiology, the impact of chronic kidney disease on cardiac structure and function, and associated clinical symptoms, outcomes, and potential treatments for patients with chronic reno-cardiac syndrome, or cardiorenal syndrome type 4. Cardiac structural changes can be profound and are described in detail both at a cellular and physiologic level. Integrating therapies for the treatment of causative or resulting comorbidities may ultimately slow progression of both cardiac and renal disease as well as minimize symptoms and death.

Right Heart Function in Cardiorenal Syndrome

PURPOSE OF REVIEW

Since CRS is critically dependent on right heart function and involved in interorgan crosstalk, assessment and monitoring of both right heart and kidney function are of utmost importance for clinical outcomes. This systematic review aims to comprehensively report on novel diagnostic and therapeutic paradigms that are gaining importance for the clinical management of the growing heart failure population suffering from CRS.

RECENT FINDINGS

Cardiorenal syndrome (CRS) in patients with heart failure is associated with poor outcome. Although systemic venous congestion and elevated central venous pressure have been recognized as main contributors to CRS, they are often neglected in clinical practice. The delicate hemodynamic balance in CRS is particularly determined by the respective status of the right heart. The consideration of hemodynamic and CRS profiles is advantageous in tailoring treatment for better preservation of renal function. Assessment and monitoring of right heart and renal function by known and emerging tools like renal Doppler ultrasonography or new biomarkers may have direct clinical implications.

The Diabetic Cardiorenal Nexus

The end-stage of the clinical combination of heart failure and kidney disease has become known as cardiorenal syndrome. Adverse consequences related to diabetes, hyperlipidemia, obesity, hypertension and renal impairment on cardiovascular function, morbidity and mortality are well known. Guidelines for the treatment of these risk factors have led to the improved prognosis of patients with coronary artery disease and reduced ejection fraction. Heart failure hospital admissions and readmission often occur, however, in the presence of metabolic, renal dysfunction and relatively preserved systolic function. In this domain, few advances have been described. Diabetes, kidney and cardiac dysfunction act synergistically to magnify healthcare costs. Current therapy relies on improving hemodynamic factors destructive to both the heart and kidney. We consider that additional hemodynamic solutions may be limited without the use of animal models focusing on the cardiomyocyte, nephron and extracellular matrices. We review herein potential common pathophysiologic targets for treatment to prevent and ameliorate this syndrome.

Lung-kidney interactions and their role in chronic kidney disease-associated pulmonary diseases

Chronic illnesses rarely present in a vacuum, devoid of other complications, and chronic kidney disease is hardly an exception. Comorbidities associated with chronic kidney disease lead to faster disease progression, expedited dialysis dependency, and a higher mortality rate. Although chronic kidney disease is most commonly accompanied by cardiovascular diseases and diabetes, there is clear cross talk between the lungs and kidneys pH balance, phosphate metabolism, and immune system regulation. Our present understanding of the exact underlying mechanisms that contribute to chronic kidney disease-related pulmonary disease is poor. This review summarizes the current research on kidney-pulmonary interorgan cross talk in the context of chronic kidney disease, highlighting various acute and chronic pulmonary diseases that lead to further complications in patient care. Treatment options for patients presenting with chronic kidney disease and lung disease are explored by assessing activated molecular pathways and the body's compensatory response mechanisms following homeostatic imbalance. Understanding the link between the lungs and kidneys will potentially improve health outcomes for patients and guide healthcare professionals to better understand how and when to treat each of the pulmonary comorbidities that can present with chronic kidney disease.

The impact of relative hypotension on acute kidney injury progression after cardiac surgery: a multicenter retrospective cohort study

BACKGROUND

Cardiac surgery is performed worldwide, and acute kidney injury (AKI) following cardiac surgery is a risk factor for mortality. However, the optimal blood pressure target to prevent AKI after cardiac surgery remains unclear. We aimed to investigate whether relative hypotension and other hemodynamic parameters after cardiac surgery are associated with subsequent AKI progression.

METHODS

We retrospectively enrolled adult patients admitted to 14 intensive care units after elective cardiac surgery between January and December 2018. We defined mean perfusion pressure (MPP) as the difference between mean arterial pressure (MAP) and central venous pressure (CVP). The main exposure variables were time-weighted-average MPP-deficit (i.e., the percentage difference between preoperative and postoperative MPP) and time spent with MPP-deficit > 20% within the first 24 h. We defined other pressure-related hemodynamic parameters during the initial 24 h as exploratory exposure variables. The primary outcome was AKI progression, defined as one or more AKI stages using Kidney Disease: Improving Global Outcomes' creatinine and urine output criteria between 24 and 72 h. We used multivariable logistic regression analyses to assess the association between the exposure variables and AKI progression.

RESULTS

Among the 746 patients enrolled, the median time-weighted-average MPP-deficit was 20% [interquartile range (IQR): 10-27%], and the median duration with MPP-deficit > 20% was 12 h (IQR: 3-20 h). One-hundred-and-twenty patients (16.1%) experienced AKI progression. In the multivariable analyses, time-weighted-average MPP-deficit or time spent with MPP-deficit > 20% was not associated with AKI progression [odds ratio (OR): 1.01, 95% confidence interval (95% CI): 0.99-1.03]. Likewise, time spent with MPP-deficit > 20% was not associated with AKI progression (OR: 1.01, 95% CI 0.99-1.04). Among exploratory exposure variables, time-weighted-average CVP, time-weighted-average MPP, and time spent with MPP < 60 mmHg were associated with AKI progression (OR: 1.12, 95% CI 1.05-1.20; OR: 0.97, 95% CI 0.94-0.99; OR: 1.03, 95% CI 1.00-1.06, respectively).

CONCLUSIONS

Although higher CVP and lower MPP were associated with AKI progression, relative hypotension was not associated with AKI progression in patients after cardiac surgery. However, these findings were based on exploratory investigation, and further studies for validating them are required. Trial Registration UMIN-CTR, https://www.umin.ac.jp/ctr/index-j.htm , UMIN000037074.

Kidney vascular congestion exacerbates acute kidney injury in mice

Heart failure is frequently accompanied by kidney failure and co-incidence of these organ failures worsens the mortality in patients with heart failure. Recent clinical observations revealed that increased kidney venous pressure, rather than decreased cardiac output, causes the deterioration of kidney function in patients with heart failure. However, the underlying pathophysiology is unknown. Here, we found that decreased blood flow velocity in peritubular capillaries by kidney congestion and upregulation of endothelial nuclear factor-κB (NF-κB) signaling synergistically exacerbate kidney injury. We generated a novel mouse model with unilateral kidney congestion by constriction of the inferior vena cava between kidney veins. Intravital imaging highlighted the notable dilatation of peritubular capillaries and decreased kidney blood flow velocity in the congestive kidney. Damage after ischemia reperfusion injury was exacerbated in the congestive kidney and accumulation of polymorphonuclear leukocytes within peritubular capillaries was noted at the acute phase after injury. Similar results were obtained in vitro, in which polymorphonuclear leukocytes adhesion on activated endothelial cells was decreased in flow velocity-dependent manner but cancelled by inhibition of NF-κB signaling. Pharmacological inhibition of NF-κB for the mice subjected by both kidney congestion and ischemia reperfusion injury ameliorated the accumulation of polymorphonuclear leukocytes and subsequent exacerbation of kidney injury. Thus, our study demonstrates the importance of decreased blood flow velocity accompanying activated NF-κB signaling in aggravation of kidney injury. Hence, inhibition of NF-κB signaling may be a therapeutic candidate for the vicious cycle between heart and kidney failure with increased kidney venous pressure.

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.

Cardiac Ultrasound for the Nephrologist: Know Thy Heart to Know Thy Kidneys

Kidney disease patients have a high prevalence of cardiovascular morbidity and mortality. It can be challenging to adequately assess their cardiovascular status based on physical examination alone. Cardiac ultrasound has proven to be a powerful tool to accomplish this objective and is increasingly being adopted by noncardiologists to augment their skills and expedite clinical decision-making. With the advent of inexpensive and portable ultrasound equipment, simplified protocols, and focused training, it is becoming easier to master basic cardiac ultrasound techniques. After a short course of training in focused cardiac ultrasound, nephrologists can quickly and reliably assess ventricular size and function, detect clinically relevant pericardial effusion and volume status in their patients. Additional training in Doppler ultrasound can extend their capability to measure cardiac output, right ventricular systolic pressure, and diastolic dysfunction. This information can be instrumental in effectively managing patients in inpatient, office, and dialysis unit settings. The purpose of this review is to highlight the importance and feasibility of incorporating cardiac ultrasound in nephrology practice, discuss the principles of basic and Doppler ultrasound modalities and their clinical utility from a nephrologist's perspective.

AT1 receptor blocker, but not an ACE inhibitor, prevents kidneys from hypoperfusion during congestive heart failure in normotensive and hypertensive rats

To provide novel insights into the pathogenesis of heart failure-induced renal dysfunction, we compared the effects of ACE inhibitor (ACEi) and AT₁ receptor blocker (ARB) on systemic and kidney hemodynamics during heart failure in normotensive HanSD and hypertensive transgenic (TGR) rats. High-output heart failure was induced by creating an aorto-caval fistula (ACF). After five weeks, rats were either left untreated or treatment with ACEi or ARB was started for 15 weeks. Subsequently, echocardiographic, renal hemodynamic and biochemical measurements were assessed. Untreated ACF rats with ACF displayed significantly reduced renal blood flow (RBF) (HanSD: 8.9 ± 1.0 vs. 4.7 ± 1.6; TGR: 10.2 ± 1.9 vs. 5.9 ± 1.2 ml/min, both P < .001), ACEi had no major RBF effect, whereas ARB completely restored RBF (HanSD: 5.6 ± 1.1 vs. 9.0 ± 1.5; TGR: 7.0 ± 1.2 vs. 10.9 ± 1.9 ml/min, both P < .001). RBF reduction in untreated and ACEi-treated rats was accompanied by renal hypoxia as measured by renal lactate dehydrogenase activity, which was ameliorated with ARB treatment (HanSD: 40 ± 4 vs. 42 ± 3 vs. 29 ± 5; TGR: 88 ± 4 vs. 76 ± 4 vs. 58 ± 4 milliunits/mL, all P < .01). Unlike improvement seen in ARB-treated rats, ACE inhibition didn’t affect urinary nitrates compared to untreated ACF TGR rats (50 ± 14 vs. 22 ± 13 vs. 30 ± 13 μmol/mmol Cr, both P < .05). ARB was more effective than ACEi in reducing elevated renal oxidative stress following ACF placement. A marker of ACEi efficacy, the angiotensin I/angiotensin II ratio, was more than ten times lower in renal tissue than in plasma. Our study shows that ARB treatment, in contrast to ACEi administration, prevents renal hypoperfusion and hypoxia in ACF rats with concomitant improvement in NO bioavailability and oxidative stress reduction. The inability of ACE inhibition to improve renal hypoperfusion in ACF rats may result from incomplete intrarenal RAS suppression in the face of depleted compensatory mechanisms.

RNA interactions in right ventricular dysfunction induced type II cardiorenal syndrome

Right ventricular (RV) dysfunction induced type II cardiorenal syndrome (CRS) has a high mortality rate, but little attention has been paid to this disease, and its unique molecular characteristics remain unclear. This study aims to investigate the transcriptomic expression profile in this disease and identify key RNA pairs that regulate related molecular signaling networks. We established an RV dysfunction-induced type II CRS mouse model by pulmonary artery constriction (PAC). PAC mice developed severe RV hypertrophy and fibrosis; renal atrophy and dysfunction with elevated creatinine were subsequently observed. Expression profiles in RV and kidney tissues were obtained by whole transcriptome sequencing, revealing a total of 741 and 86 differentially expressed (DE) mRNAs, 159 and 29 DEmiRNAs and 233 and 104 DEcircRNAs between RV and kidney tissue, respectively. Competing endogenous RNA (ceRNA) networks were established. A significant alteration in proliferative, fibrotic and metabolic pathways was found based on GO and KEGG analyses, and the network revealed key ceRNA pairs, such as novel_circ_002631/miR-181a-5p/Creb1 and novel_circ_002631/miR-33-y/Kpan6. These findings indicate that significantly dysregulated pathways in RV dysfunction induced type II CRS include Ras, PI3K/Akt, cGMP-PKG pathways, and thyroid metabolic pathways. These ceRNA pairs can be considered potential targets for the treatment of type II CRS.

Renal venous congestion following hemorrhagic shock due to traumatic liver injury

A 78-year-old woman who sustained traumatic liver injury with hemorrhagic shock was hospitalized. She was admitted to the ICU after blood transfusion and emergent angiography. AKI was observed on the following day. Blood transfusion was continued because initial assessment was prerenal AKI due to hypovolemia. Despite transfusion of blood products and administration of diuretics, aggravated renal dysfunction, and low urine output continued, resulting in respiratory failure due to pulmonary edema. Renal venous congestion was suspected as the primary cause of AKI, since IVC compression from a hematoma with IVC injury was observed on CT imaging captured on admission, and renal Doppler ultrasonography demonstrated an intermittent biphasic pattern of renal venous flow. It was finally concluded that renal venous congestion resulted from IVC compression, since urine output increased remarkably after RRT without additional diuretics, and follow-up CT and renal Doppler ultrasonography revealed improvements in IVC compression and renal venous flow pattern, respectively. Renal venous congestion has been often reported to be associated with acute decompensated heart failure and, to our knowledge, this is the first report to describe trauma-induced renal venous congestion. Trauma patients are at risk for renal venous congestion due to massive blood transfusion after recovery from hemorrhagic shock; therefore, if they develop AKI that cannot be explained by other etiologies, physicians should consider the possibility of trauma-induced renal venous congestion and perform renal Doppler ultrasonography.

Short, and long-term mortality among cardiac intensive care unit patients started on continuous renal replacement therapy

PURPOSE

Patients requiring continuous renal replacement therapy (CRRT) are at high risk of death. Predictors of hospital mortality and post-discharge survival in cardiac intensive care unit (CICU) patients requiring CRRT have not been reported.

MATERIALS AND METHODS

Retrospective review of 198 CICU patients undergoing CRRT from 2006 to 2015. Multivariable regression identified predictors of hospital mortality and Cox proportional-hazards identified predictors of post-discharge mortality among hospital survivors.

RESULTS

The indication for CRRT was volume overload in 129 (65%) and metabolic abnormalities in 76 (38%). 105 (53%) subjects died in hospital, with 22% dialysis-free hospital survival. Cardiogenic shock was present in 159 (80%) subjects; 150 (76%) subjects received vasopressors and 101 (51%) subjects required mechanical ventilation. Hospital mortality was similar in cardiogenic and non-cardiogenic causes of CICU admission. Predictors of hospital death included semi-quantitative RV function, Braden score, VIS, and PaO2/FIO2 ratio. Median post-discharge Kaplan-Meier survival was 1.9 years. Predictors of post-hospital death included age, VIS, diabetes, Braden score, semi-quantitative RV function, prior heart failure, and dialysis dependence. The indication for CRRT was not predictive of survival.

CONCLUSION

Mortality is high among CICU patients requiring CRRT, and is predicted by the Braden score, RV dysfunction, respiratory failure and vasopressor load.