Cryoballoon pulmonary vein isolation as first-line treatment of typical atrial flutter: long-term outcomes of the CRAFT trial.

BACKGROUND: CRAFT was an international, multicentre, randomised controlled trial across 11 sites in the United UK and Switzerland. Given the evidence that pulmonary vein triggers may be responsible for atrial flutter (AFL) as well as atrial fibrillation (AF), we hypothesised that cryoballoon pulmonary vein isolation (PVI) would provide greater symptomatic arrhythmia reduction than cavotricuspid isthmus (CTI) ablation, whilst also reducing the subsequent burden of AF. Twelve-month outcomes were previously reported. In this study, we report the extended outcomes of the CRAFT study to 36 months. METHODS: Patients with typical AFL and no evidence of AF were randomised 1:1 to cryoballoon PVI or radiofrequency CTI. All patients received an implantable loop recorder (ILR) for continuous cardiac rhythm monitoring. The primary outcome was time-to-symptomatic arrhythmia recurrence > 30 s. Secondary outcomes included time-to-first-AF episode ≥ 2 min. The composite safety outcome included death, stroke and procedural complications. RESULTS: A total of 113 patients were randomised to cryoballoon PVI (n = 54) or radiofrequency CTI ablation (n = 59). Ninety-one patients reconsented for extended follow-up beyond 12 months. There was no difference in the primary outcome between arms, with the primary outcome occurring in 12 PVI vs 11 CTI patients (HR 0.97; 95% CI 0.43-2.20; p = 0.994). AF ≥ 2 min was significantly less frequent in the PVI arm, affecting 26 PVI vs 36 CTI patients (HR 0.48; 95% CI 0.29-0.79; p = 0.004). The composite safety outcome occurred in 5 PVI and 6 CTI patients (p = 0.755). CONCLUSION: Cryoballoon PVI shows similar efficacy to radiofrequency CTI ablation in reducing symptomatic arrhythmia recurrence in patients presenting with isolated typical AFL but significantly reduces the occurrence of subsequent AF.

Anticoagulation with edoxaban in patients with long atrial high-rate episodes ≥24†h.

BACKGROUND AND AIMS: Patients with long atrial high-rate episodes (AHREs) ≥24 h and stroke risk factors are often treated with anticoagulation for stroke prevention. Anticoagulation has never been compared with no anticoagulation in these patients. METHODS: This secondary pre-specified analysis of the Non-vitamin K antagonist Oral anticoagulants in patients with Atrial High-rate episodes (NOAH-AFNET 6) trial examined interactions between AHRE duration at baseline and anticoagulation with edoxaban compared with placebo in patients with AHRE and stroke risk factors. The primary efficacy outcome was a composite of stroke, systemic embolism, or cardiovascular death. The safety outcome was a composite of major bleeding and death. Key secondary outcomes were components of these outcomes and electrocardiogram (ECG)-diagnosed atrial fibrillation. RESULTS: Median follow-up of 2389 patients with core lab-verified AHRE was 1.8 years. AHRE ≥24 h were present at baseline in 259/2389 patients (11%, 78 ± 7 years old, 28% women, CHA2DS2-VASc 4). Clinical characteristics were not different from patients with shorter AHRE. The primary outcome occurred in 9/132 patients with AHRE ≥24 h (4.3%/patient-year, 2 strokes) treated with anticoagulation and in 14/127 patients treated with placebo (6.9%/patient-year, 2 strokes). Atrial high-rate episode duration did not interact with the efficacy (P-interaction = .65) or safety (P-interaction = .98) of anticoagulation. Analyses including AHRE as a continuous parameter confirmed this. Patients with AHRE ≥24 h developed more ECG-diagnosed atrial fibrillation (17.0%/patient-year) than patients with shorter AHRE (8.2%/patient-year; P < .001). CONCLUSIONS: This hypothesis-generating analysis does not find an interaction between AHRE duration and anticoagulation therapy in patients with device-detected AHRE and stroke risk factors. Further research is needed to identify patients with long AHRE at high stroke risk.

Anticoagulation with Edoxaban in Patients with Atrial High-Rate Episodes.

BACKGROUND: Device-detected atrial high-rate episodes (AHREs) are atrial arrhythmias detected by implanted cardiac devices. AHREs resemble atrial fibrillation but are rare and brief. Whether the occurrence of AHREs in patients without atrial fibrillation (as documented on a conventional electrocardiogram [ECG]) justifies the initiation of anticoagulants is not known. METHODS: We conducted an event-driven, double-blind, double-dummy, randomized trial involving patients 65 years of age or older who had AHREs lasting for at least 6 minutes and who had at least one additional risk factor for stroke. Patients were randomly assigned in a 1:1 ratio to receive edoxaban or placebo. The primary efficacy outcome was a composite of cardiovascular death, stroke, or systemic embolism, evaluated in a time-to-event analysis. The safety outcome was a composite of death from any cause or major bleeding. RESULTS: The analysis population consisted of 2536 patients (1270 in the edoxaban group and 1266 in the placebo group). The mean age was 78 years, 37.4% were women, and the median duration of AHREs was 2.8 hours. The trial was terminated early, at a median follow-up of 21 months, on the basis of safety concerns and the results of an independent, informal assessment of futility for the efficacy of edoxaban; at termination, the planned enrollment had been completed. A primary efficacy outcome event occurred in 83 patients (3.2% per patient-year) in the edoxaban group and in 101 patients (4.0% per patient-year) in the placebo group (hazard ratio, 0.81; 95% confidence interval [CI], 0.60 to 1.08; P = 0.15). The incidence of stroke was approximately 1% per patient-year in both groups. A safety outcome event occurred in 149 patients (5.9% per patient-year) in the edoxaban group and in 114 patients (4.5% per patient-year) in the placebo group (hazard ratio, 1.31; 95% CI, 1.02 to 1.67; P = 0.03). ECG-diagnosed atrial fibrillation developed in 462 of 2536 patients (18.2% total, 8.7% per patient-year). CONCLUSIONS: Among patients with AHREs detected by implantable devices, anticoagulation with edoxaban did not significantly reduce the incidence of a composite of cardiovascular death, stroke, or systemic embolism as compared with placebo, but it led to a higher incidence of a composite of death or major bleeding. The incidence of stroke was low in both groups. (Funded by the German Center for Cardiovascular Research and others; NOAH-AFNET 6 ClinicalTrials.gov number, NCT02618577; ISRCTN number, ISRCTN17309850.).

Atrioventricular nodal ablation is an effective management strategy for atrial fibrillation in patients with hypertrophic cardiomyopathy.

BACKGROUND: Atrial fibrillation (AF) is common in patients with hypertrophic cardiomyopathy (HCM) and can be challenging to manage. Atrioventricular nodal (AVN) ablation may be an effective management strategy for AF in these patients. OBJECTIVE: The purpose of this study was to assess the efficacy of AVN ablation in HCM patients who have failed medical therapy and/or catheter ablation for AF. METHODS: A multicenter study with retrospective analysis of a prospectively collated HCM registry was performed. AVN ablation patients were identified. Baseline characteristics and device and procedural indications were collected. Symptoms defined by New York Heart Association and European Heart Rhythm Association classification and echocardiographic findings during follow-up were assessed. RESULTS: Fifty-nine patients were included in the study. Indications for AVN ablation were 6 (10.2%) inappropriate implantable cardioverter-defibrillator shock, 35 (59.3%) ineffective rate control, and 18 (30.5%) to regularize rhythm for symptom improvement. During post-AVN ablation follow-up of 79.4 ± 61.1 months, left ventricular ejection fraction (LVEF) remained stable (pre-LVEF 48.9% ± 12.6% vs post-LVEF 50.1% ± 10.1%; P = .29), even in those without a cardiac resynchronization therapy (CRT) device (pre-LVEF 54.3% ± 8.0% vs post-LVEF 53.8% ± 8.0%; P = .65). Forty-nine patients (83.1%) reported an improvement in symptoms regardless of AF type (17/21 [81.0%] paroxysmal vs 32/38 [84.2%] persistent; P = 1.00), presence of baseline left ventricular impairment (22/26 [84.6%] LVEF ≤50% vs 27/33 [81.8%] LVEF ≥50%; P = 1.00) or CRT device (27/32 [84.4%] CRT vs 22/27 [81.5%] no CRT; P = 1.00). Symptoms improved in 16 patients (89.0%) who underwent AVN ablation to regularize rhythm. CONCLUSION: AVN ablation improved symptoms without impacting left ventricular function in the majority of patients. The data suggest that AVN ablation is an effective and safe management approach for AF in HCM and should be further evaluated in larger prospective studies.

The influence of atrial high-rate episodes on stroke and cardiovascular death: an update.

Atrial high-rate episodes (AHRE) are atrial tachyarrhythmias detected by continuous rhythm monitoring by pacemakers, defibrillators, or implantable cardiac monitors. Atrial high-rate episodes occur in 10-30% of elderly patients without atrial fibrillation. However, it remains unclear whether the presence of these arrhythmias has therapeutic consequences. The presence of AHRE increases the risk of stroke compared with patients without AHRE. Oral anticoagulation would have the potential to reduce the risk of stroke in patients with AHRE but is also associated with a rate of major bleeding of ∼2%/year. The stroke rate in patients with AHRE appears to be lower than the stroke rate in patients with atrial fibrillation. Wearables like smart-watches will increase the absolute number of patients in whom atrial arrhythmias are detected. It remains unclear whether anticoagulation is effective and, equally important, safe in patients with AHRE. Two randomized clinical trials, NOAH-AFNET6 and ARTESiA, are expected to report soon. They will provide much-needed information on the efficacy and safety of oral anticoagulation in patients with AHRE.

Management of Psychiatric Conditions in Patients With Comorbid Postural Orthostatic Tachycardia Syndrome: A Literature Review and Case Vignette.

Importance: Disorders of the autonomic nervous system are relatively common and have a significant impact on quality of life, offer very subtle diagnostic clues, and often mimic other disease processes, including certain psychiatric disorders. Pharmacologic treatment for psychiatric conditions in this group of patients can also be complicated by the pathophysiology of the various syndromes. Postural orthostatic tachycardia syndrome (POTS) is the final common pathway of a heterogenous group of underlying disorders that display similar characteristics.Observations: The current literature regarding the association between POTS and psychiatric conditions was reviewed. The literature showed an increased prevalence of mild/moderate depression and sleep disturbance in this population. Also, when psychiatric disorders occur in patients with POTS, clinicians may face challenges with regard to selecting appropriate psychopharmacologic interventions.Conclusions and Relevance: This review provides an evidence-based approach to treating common psychiatric conditions in those who suffer from POTS, with a particular emphasis on side effects that may worsen the associated symptoms. A list of the classes of psychopharmacologic treatment with a focus on adverse effects on heart rate and blood pressure is included, as is a case vignette of a patient with complex comorbid psychiatric conditions. It is of significant value to highlight the complexities associated with POTS; to raise awareness of the disorder, particularly in the context of psychiatric comorbidities; and to disseminate evidence-based information to aid clinicians in making informed medication choices with their patients.

Cryoballoon Pulmonary Vein Isolation as First-Line Treatment for Typical Atrial Flutter.

OBJECTIVE: We aimed to compare cryoballoon pulmonary vein isolation (PVI) with standard radiofrequency cavotricuspid isthmus (CTI) ablation as first-line treatment for typical atrial flutter (AFL). METHODS: Cryoballoon Pulmonary Vein Isolation as First-Line Treatment for Typical Atrial Flutter was an international, multicentre, open with blinded assessment trial. Patients with CTI-dependent AFL and no documented atrial fibrillation (AF) were randomised to either cryoballoon PVI alone or radiofrequency CTI ablation. Primary efficacy outcome was time to first recurrence of sustained (>30 s) symptomatic atrial arrhythmia (AF/AFL/atrial tachycardia) at 12 months as assessed by continuous monitoring with an implantable loop recorder. Primary safety outcome was a composite of death, stroke, tamponade requiring drainage, atrio-oesophageal fistula, pacemaker implantation, serious vascular complications or persistent phrenic nerve palsy. RESULTS: Trial recruitment was halted at 113 of the target 130 patients because of the SARS-CoV-2 pandemic (PVI, n=59; CTI ablation, n=54). Median age was 66 (IQR 61-71) years, with 98 (86.7%) men. At 12 months, the primary outcome occurred in 11 (18.6%) patients in the PVI group and 9 (16.7%) patients in the CTI group. There was no significant difference in the primary efficacy outcome between the groups (HR 1.11, 95% CI 0.46 to 2.67). AFL recurred in six (10.2%) patients in the PVI arm and one (1.9%) patient in the CTI arm (p=0.116). Time to occurrence of AF of ≥2 min was significantly reduced with cryoballoon PVI (HR 0.46, 95% CI 0.25 to 0.85). The composite safety outcome occurred in four patients in the PVI arm and three patients in the CTI arm (p=1.000). CONCLUSION: Cryoballoon PVI as first-line treatment for AFL is equally effective compared with standard CTI ablation for preventing recurrence of atrial arrhythmia and better at preventing new-onset AF. TRIAL REGISTRATION NUMBER: NCT03401099.

Increased long-term mortality following new-onset atrial fibrillation in the intensive care unit: A systematic review and meta-analysis.

PURPOSE: We performed a systematic review and meta-analysis to investigate the long-term outcomes of patients who develop new-onset atrial fibrillation (NOAF) during an intensive care unit (ICU) admission. METHODS: We searched the MEDLINE and EMBASE databases from 2000 to 2022. We included studies of adults based in general ICUs that evaluated long-term outcomes (at least 30 days after hospital discharge) of NOAF. We excluded studies involving patients with a history of atrial fibrillation (AF). We performed risk of bias assessment of the included studies based on a modified Newcastle Ottawa score (NOS). We extracted summary data for long-term outcomes. Where the outcome was reported in three or more studies we pooled effect sizes. RESULTS: We screened 2206 studies and included 15 studies reporting data from 561,797 patients. Pooled analysis of 4 studies using a random effects model revealed an association between NOAF acquired in an ICU and 90-day mortality (including ICU and hospital mortality) (RR 1.53, 95% CI 1.12-2.08). We also found an association between NOAF and 1-year mortality from 7 studies (RR 1.79, 95% CI 1.65-1.96), which remained when analysing 1-year mortality in hospital survivors (RR 1.72 (95% CI 1.49-1.98). CONCLUSIONS: In patients who develop NOAF in an ICU, both 90-day and 1-year mortality are increased in comparison to those who do not develop NOAF. Current evidence suggests an increased risk of thromboembolic events after hospital discharge in patients who develop NOAF in an ICU.

New-onset atrial fibrillation in intensive care: epidemiology and outcomes.

AIMS: New-onset atrial fibrillation (NOAF) is common in patients treated on an intensive care unit (ICU), but the long-term impacts on patient outcomes are unclear. We compared national hospital and long-term outcomes of patients who developed NOAF in ICU with those who did not, before and after adjusting for comorbidities and ICU admission factors. METHODS AND RESULTS: Using the RISK-II database (Case Mix Programme national clinical audit of adult intensive care linked with Hospital Episode Statistics and mortality data), we conducted a retrospective cohort study of 4615 patients with NOAF and 27 690 matched controls admitted to 248 adult ICUs in England, from April 2009 to March 2016. We examined in-hospital mortality; hospital readmission with atrial fibrillation (AF), heart failure, and stroke up to 6 years post discharge; and mortality up to 8 years post discharge. Compared with controls, patients who developed NOAF in the ICU were at a higher risk of in-hospital mortality [unadjusted odds ratio (OR) 3.22, 95% confidence interval (CI) 3.02-3.44], only partially explained by patient demographics, comorbidities, and ICU admission factors (adjusted OR 1.50, 95% CI 1.38-1.63). They were also at a higher risk of subsequent hospitalization with AF [adjusted cause-specific hazard ratio (aCHR) 5.86, 95% CI 5.33-6.44], stroke (aCHR 1.47, 95% CI 1.12-1.93), and heart failure (aCHR 1.28, 95% CI 1.14-1.44) independent of pre-existing comorbidities. CONCLUSION: Patients who develop NOAF during an ICU admission are at a higher risk of in-hospital death and readmissions to hospital with AF, heart failure, and stroke than those who do not.

Efficacy and safety of same-day discharge after atrial fibrillation ablation compared with post-procedural overnight stay: a systematic review and meta-analysis.

AIMS: Catheter ablation for atrial fibrillation (AF) has historically required inpatient admission post-procedure, but same-day discharge (SDD) has recently been reported. We aimed to assess the efficacy and safety of SDD compared with overnight stay (OS) post-ablation. METHODS AND RESULTS: We performed a systematic search of the PubMed database. Random-effects meta-analysis was performed to assess the efficacy (successful SDD) and safety (24 h complications, 30-day complications, 30-day re-admissions, and 30-day mortality) of a SDD AF ablation strategy. Fourteen non-randomized observational studies met criteria for inclusion, encompassing 26488 patients undergoing AF ablation, of whom 9766 were SDD. The mean age of participants was 61.9 years, and 67.9% were male. Around 61.7% underwent ablation for paroxysmal AF. The pooled success rate of SDD was 83.2% [95% confidence intervals (CIs): 61.5-97.0%, I2 100%]. The risk of bias was severe for all effect estimates due to confounding, as most cohorts were retrospectively identified without appropriately matched comparators. There was no significant difference in 30-day complications [odds ratio (OR): 0.95, 95% CI: 0.65-1.40, I2 53%] or 30-day re-admission (OR 0.96, 95% CI: 0.49-1.89, I2 82%) between groups. There were insufficient data for meta-analysis of 24 h complications and 30-day mortality. Where reported, no re-admissions occurred due to 24 h complications after SDD. Two deaths (0.04%) were reported in both SDD and OS groups. CONCLUSION: Same-day discharge after AF ablation appears to be an effective and safe strategy in selected patients. However, the available evidence is of low quality, and more robust prospective studies comparing SDD to OS are needed.

Brugada syndrome: should we be screening patients before prescribing psychotropic medication?

Brugada syndrome (BrS) presents with a characteristic electrocardiogram (ECG) and is associated with sudden cardiac death. Until now, prolongation of QTc interval and its association with Torsade de Pointe and possible fatal arrhythmia have been the focus of routine baseline ECGs before prescribing psychotropic medication. A semi-systematic literature review was conducted using PubMed. The terms 'Brugada', 'Brugada Syndrome' AND 'psychotropic' 'antipsychotic' 'antidepressant' 'mood stabilisers' 'clozapine' 'Tricyclic Antidepressants' 'Lithium' were searched. From a search that delivered over 200 articles, 82 articles were included. Those that included details around causative medication, doses of medication and where clear timeline on drug cause were included. Where clarification was needed, the manufacturer of the medication was contacted directly. Psychotropic medication can be associated with BrS, Brugada phenocopy or unmasking of BrS, in overdose or in normal doses. Our results include a table summarising a number of psychotropic overdoses that led to BrS unmasking. Routine screening for BrS in patients before prescribing psychotropic medication is a natural extension of the baseline ECG currently routinely done to rule out QTc prolongation. Psychiatrists need to invest in ensuring better skills in interpreting ECGs and work closer with cardiologists in interpreting ECGs.

Circadian variation in new-onset atrial fibrillation in patients in ICUs.

New-onset atrial fibrillation (NOAF) is common in patients treated on an intensive care unit (ICU). Onset of certain arrhythmias exhibit circadian variation. Whether NOAF follows a circadian rhythm in patients in ICU is unknown. We undertook a retrospective observational study of two ICU databases to explore the timing of NOAF onset. We identified 2017 patients who developed NOAF during their ICU stay. NOAF onset exhibited a bimodal distribution with peaks at 8 am and 8 pm, consistent with the onset of paroxysmal AF in patients in the community. Future studies in ICUs should record time of AF onset, as understanding high risk periods may inform timing of preventative interventions.

An active fixation quadripolar left ventricular lead for cardiac resynchronization therapy with reduced postoperative complication rates.

BACKGROUND: The rate of left ventricular (LV) lead displacement after cardiac resynchronization therapy (CRT) remains high despite improvements in lead technology. In 2017, a novel quadripolar lead with active fixation technology became available in the UK. METHODS: This was a retrospective, observational study analyzing device complications in 476 consecutive patients undergoing successful first-time implantation of a CRT device at a tertiary center from 2017 to 2020. RESULTS: Both active (n = 135) and passive fixation (n = 341) quadripolar leads had similar success rates for implantation (99.3% vs. 98.8%, p = 1.00), although the pacing threshold (0.89 [0.60-1.25] vs. 1.00 [0.70-1.60] V, p = .01) and lead impedance (632 [552-794] vs. 730 [636-862] Ohms, p < .0001) were significantly lower for the active fixation lead. Patients receiving an active fixation lead had a reduced incidence of lead displacement at 6 months (0.74% vs. 4.69%, p = .036). There was no significant difference in the rate of right atrial (RA) and right ventricular (RV) lead displacement between the two groups (RA: 1.48% vs. 1.17%, p = .68; RV: 2.22% vs. 1.76%, p = .72). Reprogramming the LV lead after displacement was unsuccessful in most cases (successful reprogramming: Active fix = 0/1, Passive fix = 1/16) therefore nearly all patients required a repeat procedure. As a result, the rate of intervention within 6 months for lead displacement was significantly lower when patients were implanted with the active fixation lead (0.74% vs. 4.40%, p = .049). CONCLUSION: The novel active fixation lead in our study has a lower incidence of lead displacement and re-intervention compared to conventional quadripolar leads for CRT.

Comparative effectiveness of common treatments for new-onset atrial fibrillation within the ICU: Accounting for physiological status.

BACKGROUND: New-onset atrial fibrillation (NOAF) is common in patients on an intensive care unit (ICU). Evidence guiding treatments is limited, though recent reports suggest beta blocker (BB) therapy is associated with reduced mortality. METHODS: We conducted a multicentre cohort study of adult patients admitted to 3 ICUs in the UK and 5 ICUs in the USA. We analysed the haemodynamic changes associated with NOAF. We analysed rate control, rhythm control, and hospital mortality associated with common NOAF treatments. We balanced admission and post-NOAF, pre-treatment covariates across treatment groups. RESULTS: NOAF was followed by a systolic blood pressure reduction of 5 mmHg (p < 0.001). After adjustment, digoxin therapy was associated with inferior rate control versus amiodarone (adjusted hazard ratio (aHR) 0.56, [95% CI 0.34-0.92]). Calcium channel blocker (CCB) therapy was associated with inferior rhythm control versus amiodarone (aHR 0.59 (0.37-0.92). No difference was detected between BBs and amiodarone in rate control (aHR 1.15 [0.91-1.46]), rhythm control (aHR 0.85, [0.69-1.05]), or hospital mortality (aHR 1.03 [0.53-2.03]). CONCLUSIONS: NOAF in ICU patients is followed by decreases in blood pressure. BBs and amiodarone are associated with similar cardiovascular control and appear superior to digoxin and CCBs. Accounting for key confounders removes previously reported mortality benefits associated with BB treatment.

Provocation Testing and Therapeutic Response in a Newly Described Channelopathy: RyR2 Calcium Release Deficiency Syndrome.

BACKGROUND: A novel familial arrhythmia syndrome, cardiac ryanodine receptor (RyR2) calcium release deficiency syndrome (CRDS), has recently been described. We evaluated a large and well characterized family to assess provocation testing, risk factor stratification and response to therapy in CRDS. METHODS: We present a family with multiple unheralded sudden cardiac deaths and aborted cardiac arrests, primarily in children and young adults, with no clear phenotype on standard clinical testing. RESULTS: Genetic analysis, including whole genome sequencing, firmly established that a missense mutation in RYR2, Ala4142Thr, was the underlying cause of disease in the family. Functional study of the variant in a cell model showed RyR2 loss-of-function, indicating that the family was affected by CRDS. EPS (Electrophysiological Study) was undertaken in 9 subjects known to carry the mutation, including a survivor of aborted sudden cardiac death, and the effects of flecainide alone and in combination with metoprolol were tested. There was a clear gradation in inducibility of nonsustained and sustained ventricular arrhythmia between subjects at EPS, with the survivor of aborted sudden cardiac death being the most inducible subject. Administration of flecainide substantially reduced arrhythmia inducibility in this subject and abolished arrhythmia in all others. Finally, the effects of additional metoprolol were tested; it increased inducibility in 4/9 subjects. CONCLUSIONS: The Ala4142Thr mutation of RYR2 causes the novel heritable arrhythmia syndrome CRDS, which is characterized by familial sudden death in the absence of prior symptoms or a recognizable phenotype on ambulatory monitoring or exercise stress testing. We increase the experience of a specific EPS protocol in human subjects and show that it is helpful in establishing the clinical status of gene carriers, with potential utility for risk stratification. Our data provide evidence that flecainide is protective in human subjects with CRDS, consistent with the effect previously shown in a mouse model.

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.

BACKGROUND: Atrial fibrillation can cause heart failure and stroke. It can also affect heart rate in different ways. It is common for patients admitted to intensive care units to develop atrial fibrillation. When patients have never had atrial fibrillation before, this is called 'new-onset atrial fibrillation'. We do not know how new-onset atrial fibrillation in patients treated in an intensive care unit affects heart rate and blood pressure, what the best treatments are or how treatments affect how people recover. METHODS: We looked at studies of new-onset atrial fibrillation treatments in intensive care units to see if some treatments have been shown to work better. We used a national database to see what happens to intensive care unit patients in the UK who develop new-onset atrial fibrillation. We also used two databases from intensive care units in the UK and the USA to see how many patients in the intensive care units have new-onset atrial fibrillation, how atrial fibrillation affects heart rate and blood pressure, and whether or not some treatments work better than others. RESULTS: Between 6% and 11% of intensive care unit patients develop new-onset atrial fibrillation. These patients are more likely to die in hospital and in the first 90 days after discharge than those who do not. They are also more likely to be readmitted to hospital with atrial fibrillation, stroke and heart failure. The evidence for new-onset atrial fibrillation treatments is limited, but suggests that beta-blockers or amiodarone may work better than calcium channel blockers or digoxin. CONCLUSIONS: New-onset atrial fibrillation in intensive care units is common, and outcomes are worse in patients who develop new-onset atrial fibrillation than in those who do not. Our research shows that some new-onset atrial fibrillation treatments work better than others. This information will help us to plan a study to improve health after new-onset atrial fibrillation.