Acute kidney injury in cardiogenic shock: definitions, incidence, haemodynamic alterations, and mortality

Outcomes of temporary mechanical circulatory support in cardiogenic shock due to end-stage heart failure

Background

There are few reports of mechanical circulatory support (MCS) in patients with cardiogenic shock (CS) due to end-stage heart failure (ESHF). We evaluated our institutional MCS strategy and compared the outcomes of INTERMACS 1 and 2 patients with CS due to ESHF.

Methods

Retrospective analysis of prospectively collected data (November 2014 to July 2019) from a single centre. ESHF was defined by a diagnosis of HF prior to presentation with CS. Other causes of CS (eg: acute myocardial infarction) were excluded. We compared the clinical course, complications and 90-day survival of patients with CS due to ESHF in INTERMACS profile 1 and 2.

Results

We included 60 consecutive patients with CS due to ESHF Differences in baseline characteristics were consistent with the INTERMACS profiles. The duration of MCS was similar between INTERMACS 1 and 2 patients (14 (10–33) vs 15 (7–23) days, p = 0.439). There was no significant difference in the number of patients with complications that required intervention. Compared to INTERMACS 2, INTERMACS 1 patients had more organ dysfunction on support and significant lower 90-day survival (66% vs 34%, p = 0.016).

Conclusion

Our temporary MCS strategy, including earlier intervention in patients with CS due to ESHF at INTERMACS 2 was associated with less organ dysfunction and better 90-day survival compared to INTERMACS 1 patients.

Association of miR-21-5p, miR-122-5p, and miR-320a-3p with 90-Day Mortality in Cardiogenic Shock

Cardiogenic shock (CS) is a life-threatening emergency. New biomarkers are needed in order to detect patients at greater risk of adverse outcome. Our aim was to assess the characteristics of miR-21-5p, miR-122-5p, and miR-320a-3p in CS and evaluate the value of their expression levels in risk prediction. Circulating levels of miR-21-5p, miR-122-5p, and miR-320a-3p were measured from serial plasma samples of 179 patients during the first 5-10 days after detection of CS, derived from the CardShock study. Acute coronary syndrome was the most common cause (80%) of CS. Baseline (0 h) levels of miR-21-5p, miR-122-5p, and miR-320a-3p were all significantly elevated in nonsurvivors compared to survivors (p < 0.05 for all). Above median levels at 0h of each miRNA were each significantly associated with higher lactate and alanine aminotransferase levels and decreased glomerular filtration rates. After adjusting the multivariate regression analysis with established CS risk factors, miR-21-5p and miR-320a-3p levels above median at 0 h were independently associated with 90-day all-cause mortality (adjusted hazard ratio 1.8 (95% confidence interval 1.1-3.0), p = 0.018; adjusted hazard ratio 1.9 (95% confidence interval 1.2-3.2), p = 0.009, respectively). In conclusion, circulating plasma levels of miR-21-5p, miR-122-5p, and miR-320a-3p at baseline were all elevated in nonsurvivors of CS and associated with markers of hypoperfusion. Above median levels of miR-21-5p and miR-320a-3p at baseline appear to independently predict 90-day all-cause mortality. This indicates the potential of miRNAs as biomarkers for risk assessment in cardiogenic shock.

Identifying cardiogenic shock in the emergency department

INTRODUCTION

Cardiogenic shock is difficult to diagnose due to diverse presentations, overlap with other shock states (i.e. sepsis), poorly understood pathophysiology, complex and multifactorial causes, and varied hemodynamic parameters. Despite advances in interventions, mortality in patients with cardiogenic shock remains high. Emergency clinicians must be ready to recognize and start appropriate therapy for cardiogenic shock early.

OBJECTIVE

This review will discuss the clinical evaluation and diagnosis of cardiogenic shock in the emergency department with a focus on the emergency clinician.

DISCUSSION

The most common cause of cardiogenic shock is a myocardial infarction, though many causes exist. It is classically diagnosed by invasive hemodynamic measures, but the diagnosis can be made in the emergency department by clinical evaluation, diagnostic studies, and ultrasound. Early recognition and stabilization improve morbidity and mortality. This review will focus on identification of cardiogenic shock through clinical examination, laboratory studies, and point-of-care ultrasound.

CONCLUSIONS

The emergency clinician should use the clinical examination, laboratory studies, electrocardiogram, and point-of-care ultrasound to aid in the identification of cardiogenic shock. Cardiogenic shock has the potential for significant morbidity and mortality if not recognized early.

Acute Kidney Injury: A Frequently Underestimated Problem in Perioperative Medicine

BACKGROUND

Surgical patients are getting older with increasing comorbidity. Acute kidney injury (AKI) is a commonly underesti- mated perioperative complication. 2-18% of hospitalized patients and 22-57% of patients in the intensive care unit develop AKI. Even though it has a major impact on patients' outcomes, it goes unrecognized in 57-75.6% of cases.

METHODS

This review is based on pertinent papers retrieved by a selective search in PubMed and the Cochrane Library employ- ing the searching terms "acute kidney injury," "biomarker," "perioperative," "renal function," and "KDIGO."

RESULTS

The pathophysiology of AKI is complex. Conventional biomarkers are either not specific enough (urine output) or not sensitive enough (serum creatinine) for timely diagnosis. In view of the pathophysiology of the condition and the limited treat- ment options for it, the early detection of subclinical AKI (kidney damage without functional impairment) would seem to be a reasonable first step toward the prevention of worsening or permanent renal injury. New biomarkers of damage enable the early initiation of nephroprotective interventions. According to the "Kidney Disease: Improving Global Outcomes" (KDIGO) statement, a multimodal treatment approach is needed, including, among other things, optimization of hemodynamics and the discontinu- ation of nephrotoxic drugs.

CONCLUSION

It is essential to identify patients at risk and sensitize the treating personnel to the implementation of the guidelines. The incorporation of new biomarkers into routine clinical practice is also reasonable and necessary. Future clinical trials must show in what form these biomarkers should be used (singly or collectively).

Approach to Acute Cardiovascular Complications in COVID-19 Infection

The novel coronavirus disease 2019, otherwise known as COVID-19, is a global pandemic with primary respiratory manifestations in those who are symptomatic. It has spread to >187 countries with a rapidly growing number of affected patients. Underlying cardiovascular disease is associated with more severe manifestations of COVID-19 and higher rates of mortality. COVID-19 can have both primary (arrhythmias, myocardial infarction, and myocarditis) and secondary (myocardial injury/biomarker elevation and heart failure) cardiac involvement. In severe cases, profound circulatory failure can result. This review discusses the presentation and management of patients with severe cardiac complications of COVID-19 disease, with an emphasis on a Heart-Lung team approach in patient management. Furthermore, it focuses on the use of and indications for acute mechanical circulatory support in cardiogenic and/or mixed shock.

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.

Value of Hemodynamic Monitoring in Patients With Cardiogenic Shock Undergoing Mechanical Circulatory Support

The recent widespread availability and use of mechanical circulatory support is transforming the management and outcomes of cardiogenic shock (CS). Clinical decision-making regarding the optimization of therapies for patients with CS can be guided effectively by hemodynamic monitoring with a pulmonary artery catheter (PAC). Because several studies regarding the benefit of PACs are ambiguous, the use of PACs is variable among clinicians treating patients with CS. More notable is that PAC use has not been studied as part of a randomized, controlled trial in patients with CS with or without mechanical circulatory support. Standardized approaches to hemodynamic monitoring in these patients can improve decision-making and outcomes. In this review, we summarize the hemodynamics of CS and mechanical circulatory support with PAC-derived measurements, and provide a compelling rationale for the use of PAC monitoring in patients with CS receiving mechanical circulatory support.

The sympathetic nervous system in acute kidney injury

Acute kidney injury (AKI) is frequently accompanied by activation of the sympathetic nervous system (SNS). This may result from pre-exisiting chronic diseases associated with sympathetic activation prior to AKI or it may be induced by stressors that ultimately lead to AKI such as endotoxins and arterial hypotension in circulatory shock. Conversely, sympathetic activation may also result from acute renal injury. Focusing on studies in experimental renal ischaemia and reperfusion (IR), this review summarizes the current knowledge on how the SNS is activated in IR-induced AKI and on the consequences of sympathetic activation for the development of acute renal damage. Experimental studies show beneficial effects of sympathoinhibitory interventions on renal structure and function in response to IR. However, few clinical trials obtained in scenarios that correspond to experimental IR, namely major elective surgery, showed that peri-operative treatment with centrally acting sympatholytics reduced the incidence of AKI. Apparently, discrepant findings on how sympathetic activation influences renal responses to acute IR-induced injury are discussed and future areas of research in this field are identified.

Cardiogenic Shock: Reflections at the Crossroad Between Perfusion, Tissue Hypoxia, and Mitochondrial Function

Cardiogenic shock is classically defined by systemic hypotension with evidence of hypoperfusion and end organ dysfunction. In modern practice, however, these metrics often incompletely describe cardiogenic shock because patients present with more advanced cardiovascular disease and greater degrees of multiorgan dysfunction. Understanding how perfusion, congestion, and end organ dysfunction contribute to hypoxia at the cellular level are central to the diagnosis and management of cardiogenic shock. Although, in clinical practice, increased lactate level is often equated with hypoxia, several other factors might contribute to an elevated lactate level including mitochondrial dysfunction, impaired hepatic and renal clearance, as well as epinephrine use. To this end, we present the evidence underlying the value of lactate to pyruvate ratio as a potential discriminator of cellular hypoxia. We will then discuss the physiological implications of hypoxia and congestion on hepatic, intestinal, and renal physiology. Organ-specific susceptibility to hypoxia is presented in the context of their functional architecture. We discuss how the concepts of contractile reserve, fluid responsiveness, tissue oxygenation, and cardiopulmonary interactions can help personalize the management of cardiogenic shock. Finally, we highlight the limitations of using lactate for tailoring therapy in cardiogenic shock.

Incidence and Outcomes of Acute Kidney Injury Requiring Renal Replacement Therapy in Patients on Percutaneous Mechanical Circulatory Support with Impella-CP for Cardiogenic Shock

BACKGROUND

Acute kidney injury (AKI) complicating cardiogenic shock is associated with increased mortality. We hypothesize that renal replacement therapy (RRT) improves survival in cardiogenic shock supported by Impella-CP (Abiomed, Danvers, MA) complicated by AKI.

METHODS

A retrospective chart review identified 34 patients on Impella-CP for cardiogenic shock between January 2015 and December 2017. AKI was defined as an increase in serum creatinine≥0.3 mg/dL from baseline. Three groups were analyzed: AKI plus RRT, AKI minus RRT, and no AKI. Pre-existing dialysis patients were excluded. The only indication for RRT was AKI not responding to diuretics. Thirty-day mortality was analyzed.

RESULTS

There were 13 patients with no AKI, 9 with AKI plus RRT groups, and 12 with AKI minus RRT. Thirty-day mortality was similar between no AKI and AKI plus RRT groups [30.8% (4/13) vs.22.2% (2/9), p=0.48; relative risk [RR] 2.25 (95% confidence interval [CI] 0.22-22.1)]. Thirty-day mortality was higher in AKI minus RRT group compared to the no AKI group [75.0% (9/12) vs. 30.8% (4/13); p=0.03; RR 6.75 (95% CI 1.16-39.2)].

CONCLUSION

In cardiogenic shock patients on Impella-CP, AKI minus RRT is associated with a higher 30-day mortality compared to patients without AKI and/or patients with AKI plus RRT. Short-term mortality may improve in cardiogenic shock patients with AKI who are treated with RRT.

Semiquantitative Power Doppler Ultrasound Score to Predict Acute Kidney Injury in Patients With Sepsis or Cardiac Failure: A Prospective Observational Study

BACKGROUND

Diagnosing acute kidney injury (AKI) stage 3 in critically ill patients may help physicians in making treatment decisions. This diagnosis relies chiefly on urinary output and serum creatinine, which may be of limited value. This study aimed to explore the diagnostic performance of renal resistive index (RRI) and semiquantitative power Doppler ultrasound (PDU) scores in predicting AKI stage 3 in patients with sepsis or cardiac failure.

METHODS

This study is a prospective observational study that included 83 patients (40 with sepsis and 43 with cardiac failure). Renal resistive index and semiquantitative PDU scores were measured within 6 hours following admission to the intensive care unit. Acute kidney injury was defined according to the criteria set by Kidney Disease Improving Global Outcomes.

RESULTS

The predictive values of RRI (area under the curve [AUC] = 0.772, 95% confidence interval [CI] = 0.658-0.886) and PDU score (AUC = 0.780, 95% CI = 0.667-0.892) were similar in all patients. Power Doppler ultrasound score (AUC = 0.910, 95% CI = 0.815-1.000) could effectively predict AKI stage 3 in the cardiac failure subgroup, and the optimal cutoff for this parameter was ≤ 1 (sensitivity = 87.5%, specificity = 92.6%, Youden index = 0.801, accuracy in our population = 90.7%). However, PDU scores (AUC = 0.620, 95% CI = 0.425-0.814) could not predict AKI stage 3 in the sepsis subgroup. The predictive values of RRI for AKI stage 3 in the cardiac failure (AUC = 0.820, 95% CI = 0.666-0.974) and sepsis (AUC = 0.724, 95% CI = 0.538-0.910) subgroups were similar.

CONCLUSIONS

Power Doppler ultrasound scores could effectively predict AKI stage 3 in patients with cardiac failure but not in patients with sepsis. Renal resistive index is a poor predictor of AKI stage 3 in patients with sepsis or cardiac failure.

Cardiorenal Syndrome: Pathophysiology

Cardiorenal syndrome commonly refers to the collective dysfunction of heart and kidney resulting in a cascade of feedback mechanism causing damage to both the organs and is associated with adverse clinical outcomes. The pathophysiology of cardiorenal syndrome is complex, multifactorial, and dynamic. Improving the understanding of disease mechanisms will aid in developing targeted pharmacologic and nonpharmacologic therapies for the management of this syndrome. This article discusses the various mechanisms involved in the pathophysiology of the cardiorenal syndrome.

Sex disparities in acute kidney injury complicating acute myocardial infarction with cardiogenic shock

Aims

To evaluate sex‐specific disparities in acute kidney injury (AKI) complicating acute myocardial infarction‐related cardiogenic shock (AMI‐CS) in the United States.

Methods and results

This was a retrospective cohort study from 2000 to 2014 from the National Inpatient Sample (20% sample of all hospitals in the United States). Patients >18 years admitted with a primary diagnosis of AMI and concomitant CS that developed AKI were included. The endpoints of interest were the prevalence, trends, and outcomes of men and women with AKI in AMI‐CS. Multivariable hierarchical logistic regression was used to control for confounding, and a two‐sided P < 0.05 was considered statistically significant. During this 15 year period, 440 257 admissions with AMI‐CS met the inclusion criteria, with AKI noted in 155 610 (35.3%). Women constituted 36.3% of the cohort and were older, of non‐White race, and with higher co‐morbidity compared with men. Women with AKI less often received coronary angiography (59% vs. 66%), percutaneous coronary intervention (39% vs. 43%), mechanical circulatory support (39% vs. 48%), mechanical ventilation (49% vs. 54%), and haemodialysis (9% vs. 10%) compared with men (all P < 0.001). Adjusted in‐hospital mortality was higher in women—odds ratio 1.16 (95% confidence interval 1.14–1.19); P < 0.001—compared with men. Women had shorter lengths of stay (12 ± 14 vs. 13 ± 14 days), lower hospital costs ($150 071 ± 180 796 vs. $181 260 ± 209 674), and were less often discharged to home (19% vs. 31%) (all P < 0.001).

Conclusions

Women with AKI in AMI‐CS received fewer cardiac and non‐cardiac interventions, had higher in‐hospital mortality, and were less often discharged to home compared with men.

The modern cardiovascular care unit: the cardiologist managing multiorgan dysfunction

PURPOSE OF REVIEW

Despite many advances in the management of critically ill patients, cardiogenic shock remains a challenge because it is associated with high mortality. Even if there is no universally accepted definition of cardiogenic shock, end-perfusion organ dysfunction is an obligatory and major criterion of its definition.Organ dysfunction is an indicator that cardiogenic shock is already at an advanced stage and is undergoing a rapid self-aggravating evolution. The aim of the review is to highlight the importance to diagnose and to manage the organ dysfunction occurring in the cardiogenic shock patients by providing the best literature published this year.

RECENT FINDINGS

The first step is to diagnose the organ dysfunction and to assess their severity. Echo has an important and increasing place regarding the assessment of end-organ impairment whereas no new biomarker popped up.

SUMMARY

In this review, we aimed to highlight for intensivists and cardiologists managing cardiogenic shock, the recent advances in the care of end-organ dysfunctions associated with cardiogenic shock. The management of organ dysfunction is based on the improvement of the cardiac function by etiologic therapy, inotropes and assist devices but will often necessitate organ supports in hospitals with the right level of equipment and multidisciplinary expertise.

Mean arterial pressure during targeted temperature management and renal function after out-of-hospital cardiac arrest

PURPOSE

This study investigates the association between mean arterial pressure (MAP) and renal function after out-of-hospital cardiac arrest (OHCA).

MATERIALS AND METHODS

Post-hoc analysis of 851 comatose OHCA-patients surviving >48 h included in the targeted temperature management (TTM)-trial.

RESULTS

Patients were stratified by mean MAP during TTM in the following groups; <70 mmHg (22%), 70-80 mmHg (43%), and > 80 mmHg (35%). Median (interquartile range) eGFR (ml/min/1.73 m²) 48 h after OHCA was inversely associated with MAP-group (70 (47-102), 84 (56-113), 94 (61-124), p < .001, for the <70-group, 70-80-group and > 80-group respectively). After adjusting for potential confounders, in a mixed model including eGFR after 1, 2 and 3 days this association remained significant (p_{group_adjusted} = 0.0002). Higher mean MAP was independently associated with lower odds of renal replacement therapy (odds ratio_adjusted = 0.77 [95% confidence interval, 0.65-0.91] per 5 mmHg increase; p = .002]).

CONCLUSIONS

Low mean MAP during TTM was independently associated with decreased renal function and need of renal replacement therapy in a large cohort of comatose OHCA-patients. Increasing MAP above the recommended 65 mmHg could potentially be renal-protective. This hypothesis should be investigated in prospective trials.