Cardiac arrhythmias in critically ill patients: epidemiologic study

Association between triglyceride glucose index and all-cause mortality in patients with critical atrial fibrillation in the MIMIC-IV database

Although several studies have demonstrated the relationship between the triglyceride glucose (TyG) index and the prevalence of atrial fibrillation (AF), more attention needs to be paid to patients with AF in intensive care units because the prevalence of AF is as high as one-third of the population. This study investigated the relationship between the TyG index and short-term prognosis in patients with critical care AF. We selected critically ill patients with AF from the MIMIC-IV database and categorized them into quartiles based on their TyG index levels. The primary outcome assessed was 30-day all-cause mortality, with secondary outcomes of 7-day and 15-day all-cause mortality. We utilized Kaplan-Meier survival curves, restricted cubic spline, and Cox proportional hazards regression models to illustrate the relationship between the TyG index and clinical outcomes in critically ill patients with AF. 1,146 critically ill patients with AF were included in this study, with a mean age of 75.90. The female population accounted for 48.43% of the total. Kaplan-Meier survival curves demonstrated a significant association between the TyG index and all-cause mortality at 7, 15, and 30 days. Cox proportional hazards analysis, after adjusting for multiple confounders, revealed a substantial increase in all-cause mortality in the fourth quartile of the TyG index compared to the first quartile (HR = 1.71, 95% CI: 1.17-2.49). Restricted cubic spline further illustrated that higher TyG index were associated with an elevated risk of all-cause mortality in critically ill patients with AF. The stratified analysis provided additional support for the robustness of this association. The TyG index demonstrated a significant association with 7-day, 15-day, and 30-day all-cause mortality in critically ill patients with AF. These findings suggest that the TyG index may serve as a useful tool in identifying AF patients at a higher risk of all-cause mortality, enabling early and effective intervention strategies.

Cardiooncology in the ICU - Cardiac Urgencies in Cancer Care

Cardiovascular disease is an increasing risk of morbidity and mortality in cancer patients, related to an growing number of aging survivors with pre-existing cardiovascular disease and the use of traditional and novel cancer therapies with cardiotoxic effects. While many cardiac complications are chronic processes that develop over time, there are many acute processes that may arise in hospitalized patients. It is important for hospitalists and critical care physicians to be familiar with the recognition and management of these conditions in this unique population. This article reviews the presentation and management of common cardiac urgencies in critically ill cancer patients including acute decompensated heart failure, acute coronary syndromes, arrhythmias, hypertensive crises, pulmonary embolism, pericardial tamponade and myocarditis.

A nationwide study on new onset atrial fibrillation risk factors and its association with hospital mortality in sepsis patients

Atrial fibrillation (AF) is the most common arrhythmia and its incidence increases with sepsis. However, data on new-onset AF during sepsis hospitalization remain limited in China. We aimed to evaluate the incidence, risk factors, and associated mortality of new-onset AF in sepsis patients in China. We conducted a retrospective study using the National Data Center for Medical Service system, from 1923 tertiary and 2363 secondary hospitals from 31 provinces in China from 2017 to 2019.In total we included 1,425,055 sepsis patients ≥ 18 years without prior AF. The incidence of new-onset AF was 1.49%. Older age, male sex, hypertension, heart failure, coronary disease, valvular disease, and mechanical ventilation were independent risk factor. New-onset AF was associated with a slight increased risk of mortality (adjusted RR 1.03, 95% CI 1.01-1.06). Population attributable fraction suggested AF accounted for 0.2% of sepsis deaths. In this large nationwide cohort, new-onset AF occurred in 1.49% of sepsis admissions and was associated with a small mortality increase. Further research should examine whether optimized AF management can improve sepsis outcomes in China.

Usefulness of lactate to albumin ratio for predicting in-hospital mortality in atrial fibrillation patients admitted to the intensive care unit: a retrospective analysis from MIMIC-IV database

BACKGROUND

High lactate to albumin ratio (LAR) has been reported to be associated to with poor prognosis in patients admitted to the intensive care unit (ICU). However, its role in predicting in-hospital mortality in AF patients admitted to ICU has not been explored.

METHODS

The Medical Information Mart for Intensive Care-IV (MIMIC-IV) database was used to retrieve information on patients who had been diagnosed with AF. X-tile software was utilized to determine the optimal cut-off LAR. Area under the receiver operating characteristic curves (AUC), calibration plots, and decision curve analysis (DCA) were conducted to assess the prediction performance of LAR for in-hospital mortality.

RESULTS

Finally, 8,287 AF patients were included and 1,543 death (18.6%) occurred. The optimal cut-off value of LAR is 0.5. Patients in lower LAR (< 0.5) group showed a better in-hospital survival compared to patients in higher LAR (≥ 0.5) group (HR: 2.67, 95%CI:2.39-2.97, P < 0.001). A nomogram for in-hospital mortality in patients with AF was constructed based on multivariate Cox analysis including age, CCI, β blockers usage, APSIII, hemoglobin and LAR. This nomogram exhibited excellent discrimination and calibration abilities in predicting in-hospital mortality for critically ill AF patients.

CONCLUSION

LAR, as a readily available biomarker, can predict in-hospital mortality in AF patients admitted to the ICU. The nomogram that combined LAR with other relevant variables performed exceptionally well in terms of predicting in-hospital mortality.

Atrial Fibrillation in Critically Ill Patients: Incidence and Outcomes

BACKGROUND

Atrial fibrillation (AF), either chronic or new onset, is common in critically ill patients. Its epidemiology and relationship with clinical outcomes are poorly known.

OBJECTIVE

To understand the burden of AF in patients admitted to the ICU and its impact on patients' outcomes.

METHODS

This is a single-center, retrospective cohort study evaluating all patients with AF admitted to a non-cardiac intensive care unit over the course of 54 months. Clinical outcomes were evaluated in the short (hospital discharge) and long term (two-year follow-up). The hazard ratio (HR) with 95% CI was computed for the whole population as well as for propensity score-matched patients, with or without AF.

RESULTS

A total of 1357 patients were screened (59.1% male), with a mean age of 75 ± 15.2 years, length of intensive care unit stay of 4.7 ± 5.1 days, and hospital mortality of 26%. A diagnosis of AF was found in 215 patients (15.8%), 142 of whom had chronic AF. The hospital all-cause mortality was similar in patients with chronic or new-onset AF (31% vs. 28.8%, p = 0.779). Patients with AF had higher in-hospital, one-year, and two-year crude mortality (30.2% vs. 22.9%, p = 0.024; 47.9% vs. 35.3%, p = 0.001; 52.6% vs. 38.4%, p < 0.001). However, after propensity score matching (N = 213), this difference was no longer significant for in-hospital mortality (OR: 1.17; 95% CI: 0.77-1.79), one-year mortality (OR: 1.38; 95% CI: 0.94-2.03), or two-year mortality (OR: 1.30; 95% CI: 0.89-1.90).

CONCLUSIONS

In ICU patients, the prevalence of AF, either chronic or new-onset, was 15.8%, and these patients had higher crude mortality. However, after adjustment for age and severity on admission, no significant differences were found in the short- and long-term mortality.

Management of Arrhythmias in the Cardiovascular Intensive Care Unit

Arrhythmias in the cardiovascular intensive care unit (CVICU) can be difficult to manage because of the complex hemodynamic and respiratory states of critically ill patients. Treating physicians must be educated to prevent, diagnose, and treat a multitude of tachyarrhythmias and bradyarrhythmias. In this review article, the authors outline a pragmatic approach to patient assessment, arrhythmia diagnosis, and management of the most common arrhythmias seen in the CVICU.

New-Onset Atrial Fibrillation in the Critically Ill COVID-19 Patients Hospitalized in the Intensive Care Unit

New-onset atrial fibrillation (NOAF) is the most frequently encountered cardiac arrhythmia observed in patients with COVID-19 infection, particularly in Intensive Care Unit (ICU) patients. The purpose of the present review is to delve into the occurrence of NOAF in COVID-19 and thoroughly review recent, pertinent data. However, the causality behind this connection has yet to be thoroughly explored. The proposed mechanisms that could contribute to the development of AF in these patients include myocardial damage resulting from direct virus-induced cardiac injury, potentially leading to perimyocarditis; a cytokine crisis and heightened inflammatory response; hypoxemia due to acute respiratory distress; disturbances in acid-base and electrolyte levels; as well as the frequent use of adrenergic drugs in critically ill patients. Additionally, secondary bacterial sepsis and septic shock have been suggested as primary causes of NOAF in ICU patients. This notion gains strength from the observation of a similar prevalence of NOAF in septic non-COVID ICU patients with ARDS. It is plausible that both myocardial involvement from SARS-CoV-2 and secondary sepsis play pivotal roles in the onset of arrhythmia in ICU patients. Nonetheless, there exists a significant variation in the prevalence of NOAF among studies focused on severe COVID-19 cases with ARDS. This discrepancy could be attributed to the inclusion of mixed populations with varying degrees of illness severity, encompassing not only patients in general wards but also those admitted to the ICU, whether intubated or not. Furthermore, the occurrence of NOAF is linked to increased morbidity and mortality. However, it remains to be determined whether NOAF independently influences outcomes in critically ill COVID-19 ICU patients or if it merely reflects the disease's severity. Lastly, the management of NOAF in these patients has not been extensively studied. Nevertheless, the current guidelines for NOAF in non-COVID ICU patients appear to be effective, while accounting for the specific drugs used in COVID-19 treatment that may prolong the QT interval (although drugs like lopinavir/ritonavir, hydrochlorothiazide, and azithromycin have been discontinued) or induce bradycardia (e.g., remdesivir).

Types and Outcomes of Arrhythmias in a Cardiac Care Unit in Western Kenya: A Prospective Study

Background

Sustained arrhythmias are frequently encountered in cardiac care units (CCU), but their types and outcomes in Africa are unknown. Studies from high-income countries suggest arrhythmias are associated with worse outcomes.

Objectives

To determine the types and proportion of cardiac arrhythmias among patients admitted to the CCU at Moi Teaching and Referral Hospital (MTRH), and to compare 30-day outcomes between patients with and without arrhythmias at the time of CCU admission.

Methods

We conducted a prospective study of a cohort of all patients admitted to MTRH-CCU between March and December 2021. They were stratified on the presence or absence of arrhythmia at the time of CCU admission, irrespective of whether it was the primary indication for CCU care or not. Clinical characteristics were collected using a structured questionnaire. Participants were followed up for 30 days. The primary outcome of interest was 30-day all-cause mortality. Secondary outcomes were 30-day all-cause readmission and length of hospital stay. The 30-day outcomes were compared between the patients with and without arrhythmia, with a p value < 0.05 being considered statistically significant.

Results

We enrolled 160 participants. The median age was 46 years (IQR 31, 68), and 95 (59.4%) were female. Seventy (43.8%) had a diagnosis of arrhythmia at admission, of whom 62 (88.6%) had supraventricular tachyarrhythmias, five (7.1%) had ventricular tachyarrhythmias, and three (4.3%) had bradyarrhythmia. Atrial fibrillation was the most common supraventricular tachyarrhythmia (82.3%). There was no statistically significant difference in the primary outcome of 30-day mortality between those who had arrhythmia at admission versus those without: 32.9% versus 30.0%, respectively (p = 0.64).

Conclusion

Supraventricular tachyarrhythmias were common in critically hospitalized cardiac patients in Western Kenya, with atrial fibrillation being the most common. Thirty-day all-cause mortality did not differ significantly between the group admitted with a diagnosis of arrhythmia and those without.

Triggers of Atrial Fibrillation in the Geriatric Medical Intensive Care Unit: An Observational Study

Background

Atrial fibrillation (AF) is a common arrhythmia in the non-cardiac intensive care unit (ICU). However, data concerning AF incidence and predictors in such populations are scarce and controversial. The study aimed to investigate the contributing factors of new-onset AF in elderly patients within the medical intensive care setting.

Methods

Patients admitted to ICU during a 6-month period were prospectively studied. Patients admitted for short period postoperative monitoring and patients with chronic or paroxysmal AF were excluded. The conditions involved as AF risk factors or "triggers" from demographic data, history, and echocardiography were recorded. Acute Physiology and Chronic Health Evaluation II score was calculated. Electrolytes including some trace elements (zinc, copper, and magnesium) were analyzed.

Results

The study included 142 patients (49% females). Mean age was 69.5 ± 7.3 years. AF was observed in 12%. Diagnosis of pneumonia (P < 0.001), low copper (P < 0.0001) and low zinc levels (P < 0.0001) was significantly associated with the occurrence of AF. By multivariate analysis, they remained statistically significant (odds ratio, 7.0; 95% confidence interval, 2.0 - 24.6; P < 0.01).

Conclusions

A significant fraction of ICU elderly patients manifests AF. The relevant factors contributing to AF incidence in the elderly are pneumonia and low zinc and low copper.

Epidemiology, Risk Factors, and Outcome of Cardiac Dysrhythmias in a Noncardiac Intensive Care Unit

Introduction

Several extrinsic factors contribute to the development of cardiac dysrhythmias. In intensive care unit (ICU) settings and among critically ill patients who are exposed to a large number of risk factors, cardiac disturbances are more common.

Objectives

This study aimed to examine the epidemiology, risk factors, and outcome of cardiac dysrhythmias in a non-cardiac ICU.

Methods

This is a retrospective, single-center, observational study conducted in a tertiary noncardiac ICU at Imam Khomeini Hospital in Ahvaz, Iran. Out of the 360 adult patients aged 18 years and older who were admitted to ICU for longer than 24 h, 340 cases who met the study inclusion criteria were recruited between March 2018 until October 2018.

Results

The most common nonsinus dysrhythmias were new-onset atrial fibrillation (NOAF) (12.9%) and ventricular tachycardia (21 patients—6.2%). According to our results, previous percutaneous coronary instrumentation, acute kidney injury, sepsis, and hyperkalemia act as risk factors in the development of cardiac dysrhythmias. Additionally, we found out that thyroid dysfunction and pneumonia can predict the development of NOAF in critically ill patients. The estimated mortality rate among patients with NOAF in this study was 15.7% (p < .05).

Conclusion

Cardiac dysrhythmias are common in ICU patients and treating the risk factors can help to prevent their development and improve patient management and outcome.

Elderly Patients and Management in Intensive Care Units (ICU): Clinical Challenges

There is a growing population of older adults requiring admission to the intensive care unit (ICU). This population outpaces the ability of clinicians with geriatric training to assist in their management. Specific training and education for intensivists in the care of older patients is valuable to help understand and inform clinical care, as physiologic changes of aging affect each organ system. This review highlights some of these aging processes and discusses clinical implications in the vulnerable older population. Other considerations when caring for these older patients in the ICU include functional outcomes and morbidity, as opposed to merely a focus on mortality. An overall holistic approach incorporating physiology of aging, applying current evidence, and including the patient and their family in care should be used when caring for older adults in the ICU.

Effect of Esmolol on Clinical Outcomes in Critically Ill Patients: Data from the MIMIC-IV Database

BACKGROUND AND AIMS

Esmolol is a common short-acting drug to control ventricular rate. This study aimed to evaluate the association between use of esmolol and mortality in critically ill patients.

METHODS

This is a retrospective cohort study from MIMIC-IV database containing adult patients with a heart rate of over 100 beats/min during the intensive care unit (ICU) stay. Multivariable Cox proportional hazard models and logistic regression were used to explore the association between esmolol and mortality and adjust confounders. A 1:1 nearest neighbor propensity score matching (PSM) was performed to minimize potential cofounding bias. The comparison for secondary outcomes was performed at different points of time using an independent t-test.

RESULTS

A total of 30,332 patients were reviewed and identified as critically ill. There was no significant difference in 28-day mortality between two groups before (HR = 0.90, 95% CI = 0.73-1.12, p = 0.343) and after PSM (HR = 0.84, 95% CI = 0.65-1.08, p = 0.167). Similar results were shown in 90-day mortality before (HR = 0.93, 95% CI = 0.75-1.14, p = 0.484) and after PSM (HR = 0.85, 95% CI = 0.67-1.09, p = 0.193). However, esmolol treatment was associated with higher requirement of vasopressor use before (HR = 2.89, 95% CI = 2.18-3.82, p < 0.001) and after PSM (HR = 2.66, 95% CI = 2.06-3.45, p < 0.001). Esmolol treatment statistically reduced diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (all p < 0.001) and increased fluid balance at 24 hours (p < 0.05) but did not significantly lower SBP (p = 0.721). Patients in esmolol group showed no significant difference in lactate levels and daily urine output when compared with those in non-esmolol group when adjusted for confounders (all p > 0.05).

CONCLUSION

Esmolol treatment was associated with reduced heart rate and lowered DBP and MAP, which may increase vasopressor use and fluid balance at the timepoint of 24 hours in critically ill patients during ICU stay. However, after adjusting for confounders, esmolol treatment was not associated with 28-day and 90-day mortality.

In-hospital Outcomes of Patients with Septic Shock and Underlying Chronic Atrial Fibrillation: A Propensity Matched Analysis from A National Dataset

INTRODUCTION

Atrial fibrillation (AF) is one of the most common arrhythmias among hospitalized patients. Among patients admitted with septic shock (SS), the new occurrence of atrial fibrillation has been associated with an increase in intensive care unit (ICU) length of stay and in-hospital mortality. This is partially related to further reduction in cardiac output and thus worsening organ perfusion due to atrial fibrillation. However, there is a paucity of research on the outcomes of patients who have underlying chronic AF (UCAF) and then develop SS. This study aimed to identify the clinical characteristics and outcomes of patients with UCAF admitted with SS compared to patients with SS without UCAF.

METHODS

This study was a retrospective analysis of the 2016 and 2017 Nationwide Readmission Database. ICD-10 codes were used to identify patients with SS, and these patients were stratified into those with and without UCAF. Propensity matching analyses were performed to compare clinical outcomes and in-hospital mortality between the two groups.

RESULTS

A total of 353,422 patients with hospitalization for SS were identified, 5.8% (n = 20,772) of whom had UCAF. After 2:1 propensity matching, 20,719 patients were identified as having SS with UCAF, and 41,438 patients were identified as having SS without UCAF. Patients with SS and UCAF had a higher incidence of ischemic stroke [2.5% versus 2.2%, p = 0.012], length of stay [11.5 days versus 10.9 days, p < 0.001], mean total charges [$154,094 versus $144,037, p < 0.001] compared to those with SS without UCAF. In-hospital mortality was high in both groups, but was slightly higher among those with SS and UCAF than those with SS and no UCAF [34.4% versus 34.1%, p = 0.049].

CONCLUSIONS

This study identified UCAF as an adverse prognosticator for clinical outcomes. Patients with SS and UCAF need to be identified as a higher risk category of SS who will require more intensive management.

Association between Anemia and New-Onset Atrial Fibrillation in Critically Ill Patients in the Intensive Care Unit: A Retrospective Cohort Analysis

New-onset atrial fibrillation (NOAF) is one of the leading causes of morbidity and mortality, especially in older patients in the intensive care unit (ICU). Although many comorbidities are associated with NOAF, the effect of anemia on the onset of atrial fibrillation is still unknown. This study aimed to test the hypothesis that anemia is associated with an increased risk of developing NOAF in critically ill patients in intensive care. We performed a retrospective analysis of critically ill patients who underwent routine hemoglobin and electrocardiography monitoring in the ICU. Receiver operating characteristics analysis determined the hemoglobin (Hb) value that triggered NOAF formation. Bivariate correlation was used to determine the relationship between anemia and NOAF. The incidence of NOAF was 9.9% in the total population, and 12.8% in the patient group with anemia. Analysis of 1931 patients revealed a negative association between anemia and the development of NOAF in the ICU. The stimulatory Hb cut-off value for the formation of NOAF was determined as 9.64 g/dL. Anemia is associated with the development of NOAF in critically ill patients in intensive care.

Pharmacological and non-pharmacological treatments and outcomes for new-onset atrial fibrillation in ICU patients: the CAFE scoping review and database analyses

BACKGROUND

New-onset atrial fibrillation occurs in around 10% of adults treated in an intensive care unit. New-onset atrial fibrillation may lead to cardiovascular instability and thromboembolism, and has been independently associated with increased length of hospital stay and mortality. The long-term consequences are unclear. Current practice guidance is based on patients outside the intensive care unit; however, new-onset atrial fibrillation that develops while in an intensive care unit differs in its causes and the risks and clinical effectiveness of treatments. The lack of evidence on new-onset atrial fibrillation treatment or long-term outcomes in intensive care units means that practice varies. Identifying optimal treatment strategies and defining long-term outcomes are critical to improving care.

OBJECTIVES

In patients treated in an intensive care unit, the objectives were to (1) evaluate existing evidence for the clinical effectiveness and safety of pharmacological and non-pharmacological new-onset atrial fibrillation treatments, (2) compare the use and clinical effectiveness of pharmacological and non-pharmacological new-onset atrial fibrillation treatments, and (3) determine outcomes associated with new-onset atrial fibrillation.

METHODS

We undertook a scoping review that included studies of interventions for treatment or prevention of new-onset atrial fibrillation involving adults in general intensive care units. To investigate the long-term outcomes associated with new-onset atrial fibrillation, we carried out a retrospective cohort study using English national intensive care audit data linked to national hospital episode and outcome data. To analyse the clinical effectiveness of different new-onset atrial fibrillation treatments, we undertook a retrospective cohort study of two large intensive care unit databases in the USA and the UK.

RESULTS

Existing evidence was generally of low quality, with limited data suggesting that beta-blockers might be more effective than amiodarone for converting new-onset atrial fibrillation to sinus rhythm and for reducing mortality. Using linked audit data, we showed that patients developing new-onset atrial fibrillation have more comorbidities than those who do not. After controlling for these differences, patients with new-onset atrial fibrillation had substantially higher mortality in hospital and during the first 90 days after discharge (adjusted odds ratio 2.32, 95% confidence interval 2.16 to 2.48; adjusted hazard ratio 1.46, 95% confidence interval 1.26 to 1.70, respectively), and higher rates of subsequent hospitalisation with atrial fibrillation, stroke and heart failure (adjusted cause-specific hazard ratio 5.86, 95% confidence interval 5.33 to 6.44; adjusted cause-specific hazard ratio 1.47, 95% confidence interval 1.12 to 1.93; and adjusted cause-specific hazard ratio 1.28, 95% confidence interval 1.14 to 1.44, respectively), than patients who did not have new-onset atrial fibrillation. From intensive care unit data, we found that new-onset atrial fibrillation occurred in 952 out of 8367 (11.4%) UK and 1065 out of 18,559 (5.7%) US intensive care unit patients in our study. The median time to onset of new-onset atrial fibrillation in patients who received treatment was 40 hours, with a median duration of 14.4 hours. The clinical characteristics of patients developing new-onset atrial fibrillation were similar in both databases. New-onset atrial fibrillation was associated with significant average reductions in systolic blood pressure of 5 mmHg, despite significant increases in vasoactive medication (vasoactive-inotropic score increase of 2.3; p < 0.001). After adjustment, intravenous beta-blockers were not more effective than amiodarone in achieving rate control (adjusted hazard ratio 1.14, 95% confidence interval 0.91 to 1.44) or rhythm control (adjusted hazard ratio 0.86, 95% confidence interval 0.67 to 1.11). Digoxin therapy was associated with a lower probability of achieving rate control (adjusted hazard ratio 0.52, 95% confidence interval 0.32 to 0.86) and calcium channel blocker therapy was associated with a lower probability of achieving rhythm control (adjusted hazard ratio 0.56, 95% confidence interval 0.39 to 0.79) than amiodarone. Findings were consistent across both the combined and the individual database analyses.

CONCLUSIONS

Existing evidence for new-onset atrial fibrillation management in intensive care unit patients is limited. New-onset atrial fibrillation in these patients is common and is associated with significant short- and long-term complications. Beta-blockers and amiodarone appear to be similarly effective in achieving cardiovascular control, but digoxin and calcium channel blockers appear to be inferior.

FUTURE WORK

Our findings suggest that a randomised controlled trial of amiodarone and beta-blockers for management of new-onset atrial fibrillation in critically ill patients should be undertaken. Studies should also be undertaken to provide evidence for or against anticoagulation for patients who develop new-onset atrial fibrillation in intensive care units. Finally, given that readmission with heart failure and thromboembolism increases following an episode of new-onset atrial fibrillation while in an intensive care unit, a prospective cohort study to demonstrate the incidence of atrial fibrillation and/or left ventricular dysfunction at hospital discharge and at 3 months following the development of new-onset atrial fibrillation should be undertaken.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN13252515.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 71. See the NIHR Journals Library website for further project information.

Complete heart block in patients infected with SARS-CoV-2: A case series from a developing country

Coronavirus Disease 19 (COVID-19) has led to a global pandemic and has been the center of attention across the entire medical community. This novel virus was initially thought to affect primarily the respiratory system, but now it is evident that it has a multitude of effects on the human body. Our point of interest is to establish the effect of COVID-19 infection on the conducting system of the heart. We present a case series of four patients who developed complete heart block (CHB) shortly after being infected with COVID-19 without any previous known risk factors of complete heart block. There have only been a few previous case reports on the occurrence of CHB in COVID-19 patients highlighting the importance and the need of our case series to the literature of cardiovascular outcomes in COVID-19 patients. Our case series highlight that COVID-19 can indeed affect the conduction system of the heart and cause CHB in patients who then recovered spontaneously further elucidating the transient nature of cardiovascular effects caused by the novel virus.

Treatment strategies for new onset atrial fibrillation in patients treated on an intensive care unit: a systematic scoping review

BACKGROUND

New-onset atrial fibrillation (NOAF) in patients treated on an intensive care unit (ICU) is common and associated with significant morbidity and mortality. We undertook a systematic scoping review to summarise comparative evidence to inform NOAF management for patients admitted to ICU.

METHODS

We searched MEDLINE, EMBASE, CINAHL, Web of Science, OpenGrey, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews of Effects, ISRCTN, ClinicalTrials.gov, EU Clinical Trials register, additional WHO ICTRP trial databases, and NIHR Clinical Trials Gateway in March 2019. We included studies evaluating treatment or prevention strategies for NOAF or acute anticoagulation in general medical, surgical or mixed adult ICUs. We extracted study details, population characteristics, intervention and comparator(s), methods addressing confounding, results, and recommendations for future research onto study-specific forms.

RESULTS

Of 3,651 citations, 42 articles were eligible: 25 primary studies, 12 review articles and 5 surveys/opinion papers. Definitions of NOAF varied between NOAF lasting 30 s to NOAF lasting > 24 h. Only one comparative study investigated effects of anticoagulation. Evidence from small RCTs suggests calcium channel blockers (CCBs) result in slower rhythm control than beta blockers (1 study), and more cardiovascular instability than amiodarone (1 study). Evidence from 4 non-randomised studies suggests beta blocker and amiodarone therapy may be equivalent in respect to rhythm control. Beta blockers may be associated with improved survival compared to amiodarone, CCBs, and digoxin, though supporting evidence is subject to confounding. Currently, the limited evidence does not support therapeutic anticoagulation during ICU admission.

CONCLUSIONS

From the limited evidence available beta blockers or amiodarone may be superior to CCBs as first line therapy in undifferentiated patients in ICU. The little evidence available does not support therapeutic anticoagulation for NOAF whilst patients are critically ill. Consensus definitions for NOAF, rate and rhythm control are needed.

Cardiac arrhythmias in critically ill patients with coronavirus disease 2019: A retrospective population-based cohort study

BACKGROUND

Coronavirus disease 2019 (COVID-19) may be associated with cardiac arrhythmias in hospitalized patients, but data from the ICU setting are limited. We aimed to describe the epidemiology of cardiac arrhythmias in ICU patients with COVID-19.

METHODS

We conducted a multicenter, retrospective cohort study including all ICU patients with an airway sample positive for severe acute respiratory syndrome corona-virus 2 from March 1st to June 1st in the Capital Region of Denmark (1.8 million inhabitants). We registered cardiac arrhythmias in ICU, potential risk factors, interventions used in ICU and outcomes.

RESULTS

From the seven ICUs we included 155 patients with COVID-19. The incidence of cardiac arrhythmias in the ICU was 57/155 (37%, 95% confidence interval 30-45), and 39/57 (68%) of these patients had this as new-onset arrhythmia. Previous history of tachyarrhythmias and higher disease severity at ICU admission were associated with cardiac arrhythmias in the adjusted analysis. Fifty-four of the 57 (95%) patients had supraventricular origin of the arrhythmia, 39/57 (68%) received at least one intervention against arrhythmia (eg amiodarone, IV fluid or magnesium) and 38/57 (67%) had recurrent episodes of arrhythmia in ICU. Patients with arrhythmias in ICU had higher 60-day mortality (63%) as compared to those without arrhythmias (39%).

CONCLUSION

New-onset supraventricular arrhythmias were frequent in ICU patients with COVID-19 and were related to previous history of tachyarrhythmias and severity of the acute disease. The mortality was high in these patients despite the frequent use of interventions against arrhythmias.

Electrical remodeling and cardiotoxicity precedes structural and functional remodeling of mouse hearts under hyperoxia treatment

Clinical reports suggest a high incidence of ICU mortality with the use of hyperoxia during mechanical ventilation in patients. Our laboratory is pioneer in studying effect of hyperoxia on cardiac pathophysiology. In this study for the first time, we are reporting the sequence of cardiac pathophysiological events in mice under hyperoxic conditions in time-dependent manner. C57BL/6J male mice, aged 8-10 weeks, were treated with either normal air or >90% oxygen for 24, 48, and 72 h. Following normal air or hyperoxia treatment, physical, biochemical, functional, electrical, and molecular parameters were analyzed. Our data showed that significant reduction of body weight observed as early as 24 h hyperoxia treatment, whereas, no significant changes in heart weight until 72 h. Although we do not see any fibrosis in these hearts, but observed significant increase in cardiomyocyte size with hyperoxia treatment in time-dependent manner. Our data also demonstrated that arrhythmias were present in mice at 24 h hyperoxia, and worsened comparatively after 48 and 72 h. Echocardiogram data confirmed cardiac dysfunction in time-dependent manner. Dysregulation of ion channels such as Kv4.2 and KChIP2; and serum cardiac markers confirmed that hyperoxia-induced effects worsen with each time point. From these observations, it is evident that electrical remodeling precedes structural remodeling, both of which gets worse with length of hyperoxia exposure, therefore shorter periods of hyperoxia exposure is always beneficial for better outcome in ICU/critical care units.

Cardiovascular Outcomes in the Acute Phase of COVID-19

The cumulative number of cases in the current global coronavirus disease 19 (COVID-19) pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has exceeded 100 million, with the number of deaths caused by the infection having exceeded 2.5 million. Recent reports from most frontline researchers have revealed that SARS-CoV-2 can also cause fatal non-respiratory conditions, such as fatal cardiovascular events. One of the important mechanisms underlying the multiple organ damage that is now known to occur during the acute phase of SARS-CoV-2 infection is impairment of vascular function associated with inhibition of angiotensin-converting enzyme 2. To manage the risk of vascular dysfunction-related complications in patients with COVID-19, it would be pivotal to clearly elucidate the precise mechanisms by which SARS-CoV-2 infects endothelial cells to cause vascular dysfunction. In this review, we summarize the current state of knowledge about the mechanisms involved in the development of vascular dysfunction in the acute phase of COVID-19.

Hospital outcomes associated with new-onset atrial fibrillation during ICU admission: A multicentre competing risks analysis

PURPOSE

New onset atrial fibrillation (NOAF) in critically ill patients has been associated with increased short-term mortality. Analyses that do not take into account the time-varying nature of NOAF can underestimate its association with hospital outcomes. We investigated the prognostic association of NOAF with hospital outcomes using competing risks methods.

MATERIALS AND METHODS

We undertook a retrospective cohort study in three general adult intensive care units (ICUs) in the UK from June 2008 to December 2015. We excluded patients with known prior atrial fibrillation or an arrhythmia within four hours of ICU admission. To account for the effect of NOAF on the rate of death per unit time and the rate of discharge alive per unit time we calculated subdistribution hazard ratios (SDHRs).

RESULTS

Of 7541 patients that fulfilled our inclusion criteria, 831 (11.0%) developed NOAF during their ICU admission. NOAF was associated with an increased duration of hospital stay (CSHR 0.68 (95% CI 0.63-0.73)) and an increased rate of in-hospital death per unit time (CSHR 1.57 (95% CI 1.37-1.1.81)). This resulted in a strong prognostic association with dying in hospital (adjusted SDHR 2.04 (1.79-2.32)). NOAF lasting over 30 min was associated with increased hospital mortality.

CONCLUSIONS

Using robust methods we demonstrate a stronger prognostic association between NOAF and hospital outcomes than previously reported.

Approach to Ventricular Arrhythmias in the Intensive Care Unit

Arrhythmias are commonly encountered in the intensive care unit as a primary admitting diagnosis or secondary to an acute illness. Appropriate identification and treatment of ventricular arrhythmias in this setting are particularly important to reduce morbidity and mortality. This review highlights the epidemiology, mechanisms, electrocardiographic features, and treatment of ventricular arrhythmias.

Propofol abolishes torsade de pointes in different models of acquired long QT syndrome

There is conflicting evidence regarding the impact of propofol on cardiac repolarization and the risk of torsade de pointes (TdP). The purpose of this study was to elucidate the risk of propofol-induced TdP and to investigate the impact of propofol in drug-induced long QT syndrome. 35 rabbit hearts were perfused employing a Langendorff-setup. 10 hearts were perfused with increasing concentrations of propofol (50, 75, 100 µM). Propofol abbreviated action potential duration (APD₉₀) in a concentration-dependent manner without altering spatial dispersion of repolarization (SDR). Consequently, no proarrhythmic effects of propofol were observed. In 12 further hearts, erythromycin was employed to induce prolongation of cardiac repolarization. Erythromycin led to an amplification of SDR and triggered 36 episodes of TdP. Additional infusion of propofol abbreviated repolarization and reduced SDR. No episodes of TdP were observed with propofol. Similarly, ondansetron prolonged cardiac repolarization in another 13 hearts. SDR was increased and 36 episodes of TdP occurred. With additional propofol infusion, repolarization was abbreviated, SDR reduced and triggered activity abolished. In this experimental whole-heart study, propofol abbreviated repolarization without triggering TdP. On the contrary, propofol reversed prolongation of repolarization caused by erythromycin or ondansetron, reduced SDR and thereby eliminated drug-induced TdP.

Prevalence, Outcomes, and Risk Factors of New-Onset Atrial Fibrillation in Critically Ill Patients

The purpose of this article is to systematically evaluate the prevalence, outcomes, and risk factors of new-onset atrial fibrillation (AF) in critically ill patients.Medline, Embase, Science Citation Index, Wanfang, CNKI, and Wiley Online Library were thoroughly searched to identify relevant studies. Studies were assessed for methodological quality using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Odds ratio (OR) and weighted mean difference (WMD) with 95% confidence interval (CI) were used to assess the strength of the association. Heterogeneity, subgroup, sensitivity analyses, and publication bias were conducted.A total of 25 studies were included. The prevalence of new-onset AF ranged from 4.1% to 46%.The random-effects pooled prevalence was 10.7%. The pooled result jumped up to 35.8% in patients with septic shock. Pooled analysis showed significant associations between new-onset AF with intensive care unit (ICU) mortality and in-hospital mortality over those patients without AF (OR = 3.11; 95%CI 2.45-3.96 and OR = 1.63; 95%CI 1.27-2.08). The pooled analysis also indicated that both ICU and hospital length of stay are longer in patients with new-onset AF than those without AF (WMD = 1.87; 95%CI 0.89-2.84 and WMD = 2.73; 95%CI 0.77-4.69). Independent risk factors included increasing age, shock, sepsis, use of a pulmonary artery catheter and mechanical ventilation, fluid loading, and organ failures.New-onset AF incidence rate is high in critically ill patients. New-onset AF is associated with worse outcomes. Further studies should be done to explore how to prevent and treat new-onset AF in critically ill patients.

Stroke prophylaxis in critically-ill patients with new-onset atrial fibrillation

Despite a high incidence of new onset atrial fibrillation (NOAF) in critically ill patients and its association with short and long-term incidence of stroke, there is limited data assessing anticoagulation on hospital discharge in these patients. We retrospectively reviewed electronic medical records of all adult patients admitted to non-cardiac ICUs at our institution between January 2009 and March 2016. Patients with NOAF were identified and CHA₂DS₂-VASc score of ICU survivors was calculated. Prescription of oral anticoagulant therapy on hospital discharge was analyzed. A total of 640 (1.7% [38,708 patients]; 95% CI 1.5%, 1.8%) patients developed NOAF during the study period. CHA₂DS₂-VASc score was calculated for 615 patients, of which 82.2% had a CHA₂DS₂-VASc score ≥ 2. Of the 428 eligible patients, only 96 patients (22.4%) were discharged on oral anticoagulant therapy. Patients with a history of congestive heart failure (33.7% vs. 19.7%) and stroke/TIA or other thromboembolic disease (35.9% vs. 18.0%) were more likely to be discharged on an oral anticoagulant. Patients with a higher score were also more likely to be discharged on an oral anticoagulant (OR 1.27; 95% CI 1.10, 1.47). NOAF is common in critically ill patients admitted to non-cardiac ICUs and a significant proportion of these patients have a CHA₂DS₂-VASc score ≥ 2. However, only a minority of them are discharged on an oral anticoagulant. There is a need to identify ways to improve implementation of effective stroke prophylaxis in these patients.

CHA2DS2-VASc Score and In-Hospital Mortality in Critically Ill Patients With New-Onset Atrial Fibrillation

OBJECTIVE

To examine the role of the CHA₂DS₂-VASc (Congestive heart failure; Hypertension; Age ≥75 years [doubled]; Diabetes; previous Stroke, transient ischemic attack, or thromboembolism [doubled]; Vascular disease; Age 65-75 years; and Sex category) score as a prognostic marker of in-hospital mortality in critically ill patients who develop new-onset atrial fibrillation (NOAF).

DESIGN

Retrospective analyses.

SETTING

A single-center study in a tertiary care academic medical center.

PARTICIPANTS

The study comprised all adult patients with NOAF admitted to noncardiac intensive care units (ICUs) at a tertiary care academic institution between January 2009 and March 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The authors retrospectively reviewed electronic medical records of all adult patients admitted to noncardiac ICUs at a tertiary care academic institution between January 2009 and March 2016. Patients with NOAF were identified and their CHA₂DS₂-VASc score was calculated. The authors evaluated the association of CHA₂DS₂-VASc score and its individual components with in-hospital mortality in these patients. A total of 640 (1.7% [38,708 patients]; 95% CI 1.5%-1.8%) patients developed NOAF during the study period. The in-hospital mortality rate in patients included in the analysis was 14.3%. There was no association between in-hospital mortality and CHA₂DS₂VASc score. However, the likelihood of in-hospital death was 1.56  times greater for patients having atrial fibrillation and concomitant vascular disease (95% CI 1.003-2.429; p = 0.049).

CONCLUSIONS

New-onset atrial fibrillation is common in critically ill patients and is associated with high in-hospital mortality. The authors found that the CHA₂DS₂-VASc score itself is not a reliable prognostic marker of in-hospital mortality in these patients. However, the presence of vascular disease in patients with NOAF may increase the mortality associated with this disease.

Evaluation of Amiodarone Use for New-Onset Atrial Fibrillation in Critically Ill Patients With Septic Shock

Objective: To describe the use of amiodarone in critically ill, septic shock patients experiencing new-onset atrial fibrillation (NOAF) during the acute resuscitative phase of septic shock. Methods: Single-center, retrospective review of adult medical or surgical intensive care unit (ICU) patients with septic shock and NOAF. All patients received amiodarone for NOAF during the acute resuscitative phase of septic shock. The cohort was analyzed via descriptive statistics. Associations between amiodarone exposure and clinical outcomes were analyzed via a Cox proportional-hazards model. An a priori defined sensitivity analysis of hospital survivors was also employed. Main Results: A total of 239 patients were included in the analysis. Patients had a median baseline Charlson Comorbidity Index of 4 (interquartile range [IQR]: 2-6) and were acutely ill with a median Acute Physiology and Chronic Health Evaluation II (APACHE II) score of 18 (IQR: 13-22) and an incidence of mechanical ventilation of 85%. In-hospital mortality was 56% with median ICU and hospital length of stay (LOS) of 9 and 15 days, respectively. Included patients received a median of 2760 (IQR: 1110-6415) mg of intravenous (IV) amiodarone during their ICU stay. Receipt of more than or equal to 2700 mg of amiodarone was identified as an independent factor associated with longer ICU LOS (hazard ratio [HR]: 1.30; 95% confidence interval [CI], 1.10-2.28). In a sensitivity analysis of hospital survivors (n = 105), receipt of more than or equal to 2700 mg of amiodarone remained independently associated with longer ICU LOS (HR: 1.64; 95% CI, 1.05-2.58). Conclusions: Exposure to more than or equal to 2700 mg of amiodarone in the setting of NOAF and septic shock is positively correlated with longer ICU LOS. Identifying opportunities to limit amiodarone exposure and address/resolve potential precipitating causes of NOAF in this clinical scenario may reduce the morbidity associated with septic shock.

Mitigating clinical waste in the trauma intensive care unit: Limited clinical utility of cardiac troponin testing for trauma patients with atrial fibrillation

BACKGROUND

The clinical significance of obtaining cardiac troponin (cTn) levels among trauma patients with new onset arrhythmias is unknown. We aimed to assess whether cTn levels actually influence clinical decision making or represent an inappropriate use of resources.

METHODS

Trauma patients admitted from 2013 to 2014 diagnosed with atrial fibrillation (AF) were retrospectively reviewed using the institutional trauma database. Demographics, cTn levels, and myocardial infarction (MI) diagnosis data were recorded. Standard univariate tests were used to compare data between patients with and without cTn.

RESULTS

There were 258 patients included of which 126 patients had cTn levels obtained (48.8%, TEST group). The remaining 132 patients (51.2%) were untested (noTEST group). Among TEST patients, use of echocardiography nearly doubled and cardiology consultations increased (all p < 0.05). No TEST patients suffered MI or PE.

CONCLUSIONS

Obtaining cTn values in trauma patients with new-onset AF resulted in increased resource utilization without clinical utility.

New-onset atrial fibrillation in adult critically ill patients: a scoping review

PURPOSE

New-onset atrial fibrillation (NOAF) is common and associated with increased morbidity and mortality. However, its clinical importance and management in critically ill patients are not well described. The aim of this scoping review is to assess the epidemiology and management strategies of NOAF during critical illness.

METHOD

The review was conducted in accordance with the PRISMA extension for scoping reviews. We searched PubMed, EMBASE and the Cochrane Library for studies assessing the incidence, outcome and management strategies of NOAF in adult critically ill patients. The quality of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

A total of 99 studies were included, of which 79 were observational and 20 were interventional. The incidence of NOAF varied from 1.7% to 43.9% with considerable inter-population variation (very low quality of evidence). Commonly identified risk factors for NOAF included higher age, cardiovascular comorbidities and sepsis. The occurrence of NOAF was associated with adverse outcomes, including stroke, prolonged length of stay and mortality (very low quality of evidence). We found limited data on the optimal management strategy with no evidence for firm benefit or harm for any intervention (very low/low quality of evidence).

CONCLUSIONS

The definition and incidence of NOAF in critically ill patients varied considerably and many risk factors were identified. NOAF seemed to be associated with adverse outcomes, but data were very limited and current management strategies are not evidence-based.

Model-Based Quantification of Left Ventricular Diastolic Function in Critically Ill Patients with Atrial Fibrillation from Routine Data: A Feasibility Study

Introduction

Left ventricular diastolic dysfunction (LVDD) and atrial fibrillation (AF) are connected by pathophysiology and prevalence. LVDD remains underdiagnosed in critically ill patients despite potentially significant therapeutic implications since direct measurement cannot be performed in routine care at the bedside, and echocardiographic assessment of LVDD in AF is impaired. We propose a novel approach that allows us to infer the diastolic stiffness, β, a key quantitative parameter of diastolic function, from standard monitoring data by solving the nonlinear, ill-posed inverse problem of parameter estimation for a previously described mechanistic, physiological model of diastolic filling. The beat-to-beat variability in AF offers an advantageous setting for this.

Methods

By employing a global optimization algorithm, β is inferred from a simple six parameter and an expanded seven parameter model of left ventricular filling. Optimization of all parameters was limited to the interval ]0, 400[ and initialized randomly on large intervals encompassing the support of the likelihood function. Routine ECG and arterial pressure recordings of 17 AF and 3 sinus rhythm (SR) patients from the PhysioNet MGH/MF Database were used as inputs.

Results

Estimation was successful in 15 of 17 AF patients, while in the 3 SR patients, no reliable estimation was possible. For both models, the inferred β (0.065 ± 0.044 ml⁻¹ vs. 0.038 ± 0.033 ml⁻¹ (p=0.02) simple vs. expanded) was compatible with the previously described (patho) physiological range. Aortic compliance, α, inferred from the expanded model (1.46 ± 1.50 ml/mmHg) also compared well with literature values.

Conclusion

The proposed approach successfully inferred β within the physiological range. This is the first report of an approach quantifying LVDF from routine monitoring data in critically ill AF patients. Provided future successful external validation, this approach may offer a tool for minimally invasive online monitoring of this crucial parameter.

Characterization of the Effect of Prolonged Therapeutic Hypothermia on Serum Magnesium and Potassium Following Neurological Injury

Current American Heart Association/American Stroke Association guidelines for the management of spontaneous intracerebral hemorrhage suggest therapeutic hypothermia (TH) as a salvage therapy in patients with elevated intracranial pressure. Electrolyte disorders may develop at any stage of the cooling process. Such deregulation can place patients at an increased risk for arrhythmias and worsened neurologic outcomes. The impact of TH on serum electrolyte concentration has been described, but electrolyte changes and repletions are yet to be quantified. The primary objective of this study was to quantify the trends in serum potassium and magnesium concentrations during TH and determine the median amount of electrolyte repletions administered. This study was a single-center retrospective cohort conducted at Virginia Commonwealth University Health. Data were collected from neurosurgical patients with intracranial hypertension who underwent TH (<36°C) for ≥48 hours. Patients with a primary neurological insult cooled with the Arctic Sun^® 5000 Temperature Management System, who were ≥13 years of age at the time of therapy with a core body temperature of ≥36°C before therapeutic hypothermia, were eligible for inclusion. Forty-three patients meeting the inclusion criteria were analyzed. A total of 42 patients (98%) experienced hypokalemia (<3.5 mEq/L) during TH. A median of 45 mEq per day of potassium repletion was administered during the maintenance phase of cooling. Despite those repletions, patients remained hypokalemic 30% of the time. Median serum magnesium concentrations during the maintenance phase of TH remained consistently within goal range of 1.8-2.5 mg/dL. Five patients (12%) experienced at least one episode of cardiac dysrhythmia during the cooling period. Standard potassium electrolyte repletion protocols did not adequately maintain serum potassium concentrations above our target of 3.5 mEq/L in neurosurgical patients undergoing TH. Standard magnesium repletion protocols were sufficient to maintain a normal serum concentration in this patient population when magnesium sulfate was not used for other indications.

Risk factors for new-onset atrial fibrillation on the general adult ICU: protocol for a systematic review

INTRODUCTION

Atrial fibrillation (AF) is a common arrhythmia in the critical care environment. New-onset AF is associated with increased mortality and intensive care unit (ICU) length of stay. Observational studies have identified several epidemiological and disease severity-related factors associated with developing new-onset AF on the ICU. However, there are limited data on the modifiable risk factors in the general adult ICU population.We describe a protocol for a systematic review of modifiable and non-modifiable risk factors for new-onset AF in the general adult ICU population. The results of this review will aid the development of risk prediction tools and inform future research into AF prevention on the ICU.

METHODS AND ANALYSIS

Medical Literature Analysis and Retrieval System Online, Excerpta Medica database and the Cochrane Library, including Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials will be searched for studies that assess the association of patient variables, investigation results, interventions and diagnoses associated with subsequent new-onset AF on the ICU.Only studies involving adult patients admitted to non-service-specific ICUs will be included. We will extract data relating to the statistical association between reversible and non-reversible factors and AF, the quality of the studies and the generalisability of the results. This systematic review will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

ETHICS AND DISSEMINATION

This proposed systematic review will be based on published data, and therefore ethical approval is not required. The findings of this study will be disseminated through publication in a peer reviewed journal and will be presented at conferences.

PROSPERO REGISTRATION NUMBER

CRD42017074221.

Comedication with interacting drugs predisposes amiodarone users in cardiac and surgical intensive care units to acute liver injury: A retrospective analysis

Risk factors and underlying mechanisms for liver injury associated with amiodarone remain elusive. This study aimed to investigate the drug-related covariates for acute liver injury by amiodarone-an intriguing compound of high lipophilicity, with a long half-life and notable efficacy.The medical, pharmacy, and laboratory records of new amiodarone users admitted to the cardiac or surgical intensive care units of a medical center were examined retrospectively. A Cox regression model with time-varying dose-related variables of amiodarone was utilized to estimate the hazard ratio (HR) of amiodarone-associated liver injury while adjusting for concomitant therapy and relevant covariates.Of the 131 eligible patients among 6,572 amiodarone users (46,402 prescriptions), 6 were identified as amiodarone-associated liver injury cases. In comparison to controls (n = 125), this liver injury cohort (n = 6) had significantly higher numbers of amiodarone-interacting (2.7 ± 2.0 vs 0.9 ± 0.9 drugs, P = .02) and hepatotoxic (3.8 ± 0.8 vs 2.5 ± 1.7 drugs, P = .03) comedications. The number of comedications with amiodarone-interacting potential (HR 2.07, 95% confidence interval [CI] 1.02-4.22, P = .04) and amiodarone cumulative doses standardized by body surface area (HR 6.82, 95% CI 1.72-27.04, P = .01) were independent risk factors for liver injury associated with amiodarone.Drug-related (amiodarone cumulative dose, interacting drugs) factors were significant predictors of amiodarone-associated acute liver injury. A prudent evaluation of each medication profile is warranted to attain precision medicine at the level of patient care, especially for those treated by medications with complex physicochemical and pharmacokinetic properties, such as amiodarone.

Atrial Fibrillation in the ICU

Atrial fibrillation (AF) is the most common arrhythmia encountered in the ICU. Preexisting AF is highly prevalent among older patients with chronic conditions who are at risk for critical illness, whereas new-onset AF can be triggered by accelerated atrial remodeling and arrhythmogenic triggers encountered during critical illness. The acute loss of atrial systole and onset of rapid ventricular rates that characterize new-onset AF often lead to decreased cardiac output and hemodynamic compromise. Thus, new-onset AF is both a marker of disease severity as well as a likely contributor to poor outcomes, similar to other manifestations of organ dysfunction during critical illness. Evaluating immediate hemodynamic effects of new-onset AF during critical illness is an important component of rapid clinical assessment aimed at identifying patients in need of urgent direct current cardioversion, treatment of reversible inciting factors, and identification of patients who may benefit from pharmacologic rate or rhythm control. In addition to acute hemodynamic effects, new-onset AF during critical illness is associated with both short- and long-term increases in the risk of stroke, heart failure, and death, with AF recurrence rates of approximately 50% within 1 year following hospital discharge. In the absence of a strong evidence base, there is substantial practice variation in the choice of strategies for management of new-onset AF during critical illness. We describe acute and long-term evaluation and management strategies based on current evidence and propose future avenues of investigation to fill large knowledge gaps in the management of patients with AF during critical illness.

Predictors of de novo atrial fibrillation in a non-cardiac intensive care unit

OBJECTIVE

To assess the predictors of de novo atrial fibrillation in patients in a non-cardiac intensive care unit.

METHODS

A total of 418 hospitalized patients were analyzed between January and September 2016 in a non-cardiac intensive care unit. Clinical characteristics, interventions, and biochemical markers were recorded during hospitalization. In-hospital mortality and length of hospital stay in the intensive care unit were also evaluated.

RESULTS

A total of 310 patients were included. The mean age of the patients was 61.0 ± 18.3 years, 49.4% were male, and 23.5% presented de novo atrial fibrillation. The multivariate model identified previous stroke (OR = 10.09; p = 0.016) and elevated levels of pro-B type natriuretic peptide (proBNP, OR = 1.28 for each 1,000pg/mL increment; p = 0.004) as independent predictors of de novo atrial fibrillation. Analysis of the proBNP receiver operating characteristic curve for prediction of de novo atrial fibrillation revealed an area under the curve of 0.816 (p < 0.001), with a sensitivity of 65.2% and a specificity of 82% for proBNP > 5,666pg/mL. There were no differences in mortality (p = 0.370), but the lengths of hospital stay (p = 0.002) and stay in the intensive care unit (p = 0.031) were higher in patients with de novo atrial fibrillation.

CONCLUSIONS

A history of previous stroke and elevated proBNP during hospitalization were independent predictors of de novo atrial fibrillation in the polyvalent intensive care unit. The proBNP is a useful and easy- and quick-access tool in the stratification of atrial fibrillation risk.

Modeling of Amiodarone Effect on Heart Rate Control in Critically Ill Patients with Atrial Tachyarrhythmias

AIMS

Amiodarone is the gold-standard medication to control heart rate in critically ill patients with atrial tachyarrhythmias (ATs); however, effective doses and covariates influencing its efficacy remain unknown. We therefore performed pharmacodynamic modeling of heart rate reduction induced by amiodarone in these patients.

METHODS AND RESULTS

This observational study included 80 consecutive severely ill patients receiving amiodarone to treat ATs. A total of 1348 time-heart rate observations with 361 amiodarone dose administrations were analyzed during a period of up to 6 days after hospital treatment initiation using a nonlinear mixed-effect model. Pretreatment with amiodarone before intensive care administration, paroxysmal versus persistent AT, catecholamine infusion, and fluid and magnesium loading were among the covariates assessed in the model. In case of paroxysmal AT in a patient not pretreated with amiodarone, a 300 mg intravenous loading dose combined with an 800 mg oral dose on the first day, followed by 800 mg/day orally for 4 days was effective in achieving a heart rate between 80 and 115 bpm within the first day, and to maintain it during the next 4 days. Corresponding doses were twice as high in patients with persistent AT. Use of intravenous magnesium (p < 0.02) and fluid loading (p < 0.02) was associated with an earlier and greater heart rate decrease, while use of dobutamine had an opposite influence (p < 0.05).

CONCLUSIONS

In critically ill patients with AT, the dose of amiodarone required to control heart rate is influenced by the type of AT and by other easily measurable conditions which may allow better individualization of amiodarone dosing.

Current practice in the management of new-onset atrial fibrillation in critically ill patients: a UK-wide survey

BACKGROUND

New-onset atrial fibrillation (AF) is the most common arrhythmia in critically ill patients. Although evidence base and expert consensus opinion for management have been summarised in several international guidelines, no specific considerations for critically ill patients have been included. We aimed to establish current practice of management of critically ill patients with new-onset AF.

METHODS

We designed a short user-friendly online questionnaire. All members of the Intensive Care Society were invited via email containing a link to the questionnaire, which comprised 21 questions. The online survey was conducted between November 2016 and December 2016.

RESULTS

The response rate was 397/3152 (12.6%). The majority of respondents (81.1%) worked in mixed Intensive Care Units and were consultants (71.8%). Most respondents (39.5%) would start intervention on patients with fast new-onset AF and stable blood pressure at a heart rate between 120 and 139 beats/min. However, 34.8% of participants would treat all patients who developed new-onset fast AF. Amiodarone and beta-blockers (80.9% and 11.6% of answers) were the most commonly used anti-arrhythmics. A total of 63.8% of respondents do not regularly anti-coagulate critically ill patients with new-onset fast AF, while 30.8% anti-coagulate within 72 hours. A total of 68.0% of survey respondents do not routinely use stroke risk scores in critically ill patients with new-onset AF. A total of 85.4% of participants would consider taking part in a clinical trial investigating treatment of new-onset fast AF in the critically ill.

DISCUSSION

Our results suggest a considerable disparity between contemporary practice of management of new-onset AF in critical illness and treatment recommendations for the general patient population suffering from AF, particularly with regard to anti-arrhythmics and anti-coagulation used. Amongst intensivists, there is a substantial interest in research for management of new-onset AF in critically ill patients.

New-onset, postoperative tachyarrhythmias in critically ill surgical patients

Tachyarrhythmias in critically ill surgical patients can have varying effects, from minimal consequence to lifetime sequelae. Atrial fibrillation can be common in the post-operative period, often a result of fluctuations in volume status and electrolyte derangements. While there is extensive literature regarding the critically ill medical or cardiac patient, there is less focusing on the critically ill surgical or trauma patient. More specifically, there is minimal regarding tachyarrhythmias in burn patients. The latter population tends to have frequent and wide variations in volume status given initial resuscitation and after major excisions, concomitant with acute blood loss anemia, which can contribute to cardiac disturbances. A literature review was conducted to investigate the incidence and consequences of tachyarrhythmias in critically ill surgical and trauma patients, with a focus on the burn population. While some similarities and conclusions can be drawn between these surgical populations, further inquiry into the unique burn patient is necessary.

Evaluation of Deprescribing Amiodarone After New-Onset Atrial Fibrillation in Critical Illness

BACKGROUND

Recent studies have shed light on the continued prescription of inpatient medications upon hospital discharge, despite the original intent of short-term inpatient therapy. Amiodarone, an antiarrhythmic associated with significant adverse effects with long-term use, is commonly used for new-onset atrial fibrillation in critical illness (NAFCI). Although it is often preferred in this setting of hemodynamic instability, a prescription for long-term use should be carefully considered, preferably by a cardiologist. This study was conducted to evaluate the incidence of patients discharged on amiodarone without a cardiology consult or referral after being initiated on amiodarone for NAFCI.

METHODS

We conducted a retrospective review of all patients newly prescribed amiodarone for NAFCI over a 2-year period. The primary outcome was the percentage of patients who were continued on amiodarone upon hospital discharge without review by or outpatient referral to a cardiologist.

RESULTS

Of the 100 patients who met inclusion criteria, 59 patients were prescribed amiodarone upon hospital discharge. Of these, 48 patients (81.4%) had converted to normal sinus rhythm with the resolution of critical illness. Of 100 patients, 23 received prescriptions for amiodarone upon discharge without a cardiology consult or referral.

CONCLUSION

Amiodarone was frequently continued upon discharge without referral to a cardiologist in patients initiated on this therapy for NAFCI. This may contribute to unnecessary long-term therapy, thereby increasing the risk for significant side effects, drug interactions, and increased healthcare costs. This study suggests that careful medication reconciliation through all transitions of care, including discharge, is essential.

Effectiveness of heart rate control on hemodynamics in critically ill patients with atrial tachyarrhythmias managed by amiodarone

Atrial tachyarrhythmias (AT) are common in intensive care unit (ICU) patients and might contribute to hemodynamic instability if heart rate (HR) is persistently too rapid. We aimed to assess if HR control below 115 or 130bpm with amiodarone improves hemodynamics in ICU patients with AT. This observational study included 73 ICU patients with disabling AT receiving amiodarone for HR control. A total of 525 changes (mainly within 4-8h) in mean arterial pressure (MAP) and 167 changes in plasma lactate in response to HR variations above 115 or 130bpm were analyzed. Epinephrine, sedative drugs, fluid loading, use of diuretics, continuous renal replacement therapy and amiodarone dosing were among covariables assessed. Univariable analysis showed that HR variations above 115bpm were poorly correlated to change in MAP (r=0.11, p<0.01). Multivariable analysis showed that changes in MAP were still positively associated to HR variation (p<0.05) and to initiation or termination of epinephrine (p<0.05) or sedatives infusions (p<0.05). Changes in plasma lactate did not correlate to HR variations above 115bpm. When considering 130 bpm as a threshold, HR variations were not associated to changes in MAP or to changes in plasma lactate. Amiodarone dose was associated to HR decrease but not to MAP or plasma lactate increase. In ICU patients with AT, strict HR control below 115bpm or 130bpm with amiodarone does not improve hemodynamics. A prospective randomized trial assessing strict versus lenient HR control in this setting is needed.

Stroke Prevention for Patients with Atrial Fibrillation: Beyond the Guidelines

Atrial fibrillation (AF) is the most common serious heart rhythm disorder, with a lifetime incidence of 1 in 4 for patients >40 years of age[1]. AF is a major cause of death and disability, as it is associated with a 4-5 fold increase in the risk of ischemic stroke[2]. In patients with AF, oral anticoagulation (OAC) therapy can reduce the risk of stroke by about two-thirds and the risk of all-cause mortality by approximately one-quarter, but is associated with an increased risk of bleeding[3], [4]. Atrial fibrillation (AF) is the most common serious heart rhythm disorder and is associated with an increased risk of ischemic stroke. This risk can be moderated with oral anticoagulation therapy, but the decision to do so must be balanced against the risks of bleeding. Herein, we discuss three emerging areas where more high-quality evidence is required to guide risk stratification: 1) the relationships between the pattern and burden of AF and stroke 2) the risk conferred by short episodes of device-detected "sub-clinical" atrial fibrillation (SCAF) and 3) the significance of AF that occurs transiently with stress (AFOTS), as is often detected during medical illness or after surgery. Risk stratification is important to identify patients with AF who can benefit from OAC therapy. There are, however, several common clinical scenarios where guidelines do not yet provide direction for stroke prevention; or do so based on limited high-quality evidence.