Rate Control versus Rhythm Control for Atrial Fibrillation after Cardiac Surgery

The effects of rhythm control strategies versus rate control strategies for atrial fibrillation and atrial flutter: A systematic review with meta-analysis and Trial Sequential Analysis

Background

Atrial fibrillation and atrial flutter may be managed by either a rhythm control strategy or a rate control strategy but the evidence on the clinical effects of these two intervention strategies is unclear. Our objective was to assess the beneficial and harmful effects of rhythm control strategies versus rate control strategies for atrial fibrillation and atrial flutter.

Methods

We searched CENTRAL, MEDLINE, Embase, LILACS, Web of Science, BIOSIS, Google Scholar, clinicaltrials.gov, TRIP, EU-CTR, Chi-CTR, and ICTRP for eligible trials comparing any rhythm control strategy with any rate control strategy in patients with atrial fibrillation or atrial flutter published before November 2016. Our primary outcomes were all-cause mortality, serious adverse events, and quality of life. Our secondary outcomes were stroke and ejection fraction. We performed both random-effects and fixed-effect meta-analysis and chose the most conservative result as our primary result. We used Trial Sequential Analysis (TSA) to control for random errors. Statistical heterogeneity was assessed by visual inspection of forest plots and by calculating inconsistency (I²) for traditional meta-analyses and diversity (D²) for TSA. Sensitivity analyses and subgroup analyses were conducted to explore the reasons for substantial statistical heterogeneity. We assessed the risk of publication bias in meta-analyses consisting of 10 trials or more with tests for funnel plot asymmetry. We used GRADE to assess the quality of the body of evidence.

Results

25 randomized clinical trials (n = 9354 participants) were included, all of which were at high risk of bias. Meta-analysis showed that rhythm control strategies versus rate control strategies significantly increased the risk of a serious adverse event (risk ratio (RR), 1.10; 95% confidence interval (CI), 1.02 to 1.18; P = 0.02; I² = 12% (95% CI 0.00 to 0.32); 21 trials), but TSA did not confirm this result (TSA-adjusted CI 0.99 to 1.22). The increased risk of a serious adverse event did not seem to be caused by any single component of the composite outcome. Meta-analysis showed that rhythm control strategies versus rate control strategies were associated with better SF-36 physical component score (mean difference (MD), 6.93 points; 95% CI, 2.25 to 11.61; P = 0.004; I² = 95% (95% CI 0.94 to 0.96); 8 trials) and ejection fraction (MD, 4.20%; 95% CI, 0.54 to 7.87; P = 0.02; I² = 79% (95% CI 0.69 to 0.85); 7 trials), but TSA did not confirm these results. Both meta-analysis and TSA showed no significant differences on all-cause mortality, SF-36 mental component score, Minnesota Living with Heart Failure Questionnaire, and stroke.

Conclusions

Rhythm control strategies compared with rate control strategies seem to significantly increase the risk of a serious adverse event in patients with atrial fibrillation. Based on current evidence, it seems that most patients with atrial fibrillation should be treated with a rate control strategy unless there are specific reasons (e.g., patients with unbearable symptoms due to atrial fibrillation or patients who are hemodynamically unstable due to atrial fibrillation) justifying a rhythm control strategy. More randomized trials at low risk of bias and low risk of random errors are needed.

Trial registration

PROSPERO CRD42016051433

The future of atrial fibrillation management: integrated care and stratified therapy

Atrial fibrillation is one of the major cardiovascular health problems: it is a common, chronic condition, affecting 2-3% of the population in Europe and the USA and requiring 1-3% of health-care expenditure as a result of stroke, sudden death, heart failure, unplanned hospital admissions, and other complications. Early diagnosis of atrial fibrillation, ideally before the first complication occurs, remains a challenge, as shown by patients who are only diagnosed with the condition when admitted to hospital for acute cardiac decompensation or stroke. Once diagnosed, atrial fibrillation requires chronic, multidimensional management in five domains (acute management, treatment of underlying and concomitant cardiovascular conditions, stroke prevention therapy, rate control, and rhythm control). The consistent provision of these treatment options to all patients with atrial fibrillation is difficult, despite recent improvements in organisation of care, knowledge about atrial fibrillation, and treatment options. Integrated care models that provide patient-centred care in, or close to, the patient's community while maintaining access to all specialist treatment options, emerge as the best approach to achieve consistent delivery of these chronic treatments to all patients with atrial fibrillation. Ongoing research efforts will establish when to initiate oral anticoagulation in patients with device-detected atrial high-rate episodes, quantify the prognostic effect of early and comprehensive rhythm control therapy, including atrial fibrillation ablation, and delineate optimum methods to reduce bleeding complications in patients treated with anticoagulation. Additionally, research efforts are needed to define different types of atrial fibrillation on the basis of the main causes of atrial fibrillation to pave the way for the clinical development of stratified atrial fibrillation therapy.

Impact of atrial fibrillation on outcomes of patients treated by transcatheter aortic valve implantation: A systematic review and meta-analysis

BACKGROUND

Conflicting data have been reported related to the impact of atrial fibrillation (AF) on the outcomes after transcatheter aortic valve implantation (TAVI). We aimed to assess the prognosis of TAVI-treated patients according to the presence of pre-existing or new-onset AF.

METHODS

Studies published between April 2002 and November 2016 and reporting outcomes of pre-existing AF, new-onset AF, or sinus rhythm in patients undergoing TAVI were identified with an electronic search. Pairwise and network meta-analysis were performed. Outcomes of interest were short- and long-term mortality, stroke, and major bleeding.

RESULTS

Eleven studies (11,033 individuals) were eligible. Compared to sinus rhythm, short-term and long-term mortality were significantly higher in new-onset AF (short-term OR 2.9, P=.002; long-term OR 2.3, P<.0001) and pre-existing AF groups (short-term OR 2.7, P=.004; long-term OR 2.8, P<.0001). Compared to sinus rhythm, new-onset AF increased the risk of stroke at early (OR 2.1, P<.0001) and late follow-up (OR 1.92, P<.0001), and the risk of early bleedings (OR 1.65, P=.002), while pre-existing AF increased the risk of late stroke (OR 1.3, P=0.03), but not the risk of bleeding. Compared to pre-existing AF, new-onset AF correlated with higher risk of early stroke (OR 1.7, P=.002) and major bleedings (OR 1.7, P=.002).

CONCLUSIONS

AF is associated with impaired outcomes after TAVI, including mortality, stroke and (limited to new-onset AF) major bleedings. Compared to pre-existing AF, new-onset AF correlates with higher risk of early stroke and major bleedings. Improved management of AF in the TAVI setting, including tailored antithrombotic treatment strategies, remains a relevant need.

Selective autonomic stimulation of the AV node fat pad to control rapid post-operative atrial arrhythmias

Junctional ectopic tachycardia (JET) and atrial fibrillation (AF) occur in patients recovering from open-heart surgery (OHS). Pharmacologic treatment is used for the control of post-operative atrial arrhythmias (POAA), but is associated with side effects. There is a need for a reversible, modulated solution to rate control. We propose a non-pharmacologic technique that can modulate AV nodal conduction in a selective fashion. Ten mongrel dogs underwent OHS. Stimulation of the anterior right (AR) and inferior right (IR) fat pad (FP) was done using a 7-pole electrode. The IR was more effective in slowing the ventricular rate (VR) to AF (52 +/- 20 vs. 15 +/- 10%, p = 0.003) and JET (12 +/- 7 vs. 0 +/- 0%, p = 0.02). Selective site stimulation within a FP region could augment the effect of stimulation during AF (57 +/- 20% (maximum effect) vs. 0 +/- 0% (minimum effect), p<0.001). FP stimulation at increasing stimulation voltage (SV) demonstrated a voltage-dependent effect (8 +/- 14% (low V) vs. 63 +/- 17 (high V) %, p<0.001). In summary, AV node fat pad stimulation had a selective effect on the AV node by decreasing AV nodal conduction, with little effect on atrial activity.

Cardiothoracic Critical Care

High-value CCC is rapidly evolving to meet the demands of increased patient acuity and to incorporate advances in technology. The high-performing CCC system and culture should aim to learn quickly and continuously improve. CCC demands a proactive, interactive, precise, an expert team, and continuity.

Non-vitamin K oral anticoagulants in patients with atrial fibrillation after cardiac surgery: the results of the European Heart Rhythm Association Survey

The purpose of this European Heart Rhythm Association survey was to assess the current practice concerning the use of oral anticoagulation in patients with post-operative atrial fibrillation (pre-existing or new-onset). The survey highlights the considerable heterogeneity of the type of anticoagulation, with 25% of the centres never using the non-vitamin K antagonist oral anticoagulants (NOACs) in this setting, as well the timing of oral anticoagulation initiation, the use and dosing of low-molecular-weight heparins, and the duration of anticoagulation when sinus rhythm is restored. One-third of the centres stated that they perceived that the risk of major pericardial bleeding requiring pericardiocentesis was higher when NOACs were used compared with vitamin K antagonists. Overall, the responding centres estimated the incidence of major pericardial haemorrhage to be 2.4%. More data are needed to inform practice guidelines in this field.

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.

New-Onset Atrial Fibrillation in the Critically Ill

OBJECTIVE

To determine the association of new-onset atrial fibrillation with outcomes, including ICU length of stay and survival.

DESIGN

Retrospective cohort of ICU admissions. We found atrial fibrillation using automated detection (≥ 90 s in 30 min) and classed as new-onset if there was no prior diagnosis of atrial fibrillation. We identified determinants of new-onset atrial fibrillation and, using propensity matching, characterized its impact on outcomes.

SETTING

Tertiary care academic center.

PATIENTS

A total of 8,356 consecutive adult admissions to either the medical or surgical/trauma/burn ICU with available continuous electrocardiogram data.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

From 74 patient-years of every 15-minute observations, we detected atrial fibrillation in 1,610 admissions (19%), with median burden less than 2%. Most atrial fibrillation was paroxysmal; less than 2% of admissions were always in atrial fibrillation. New-onset atrial fibrillation was subclinical or went undocumented in 626, or 8% of all ICU admissions. Advanced age, acute respiratory failure, and sepsis were the strongest predictors of new-onset atrial fibrillation. In propensity-adjusted regression analyses, clinical new-onset atrial fibrillation was associated with increased hospital mortality (odds ratio, 1.63; 95% CI, 1.01-2.63) and longer length of stay (2.25 d; CI, 0.58-3.92). New-onset atrial fibrillation was not associated with survival after hospital discharge (hazard ratio, 0.99; 95% CI, 0.76-1.28 and hazard ratio, 1.11; 95% CI, 0.67-1.83, respectively, for subclinical and clinical new-onset atrial fibrillation).

CONCLUSIONS

Automated analysis of continuous electrocardiogram heart rate dynamics detects new-onset atrial fibrillation in many ICU patients. Though often transient and frequently unrecognized, new-onset atrial fibrillation is associated with poor hospital outcomes.

Atrial fibrillation after cardiac surgery: Prevention and management: The Australasian experience

Background

Atrial fibrillation (AF) after cardiac surgery is a major health problem that is associated with a significant financial burden. This paper aims to highlight this problem and review the current guidelines in the prevention and management of AF after cardiac surgery, providing our experience in the Australasian centers.

Methods

We conducted a literature review using mainly PubMed to compare the current practice with the available evidence. EMBASE and Cochrane library were also searched. We concurrently developed an online questionnaire to collect data from other Australasian centers regarding their approach to this problem.

Results

We identified 194 studies that were considered relevant to our research. We did not find any formal protocols published in the literature. From our Australasian experience; seven centers (58%) had a protocol for AF prophylaxis. The protocols included electrolytes replacement, use of amiodarone and/or β-blockers. Other strategies were occasionally used but were not part of a structured protocol.

Conclusion

The development of an integrated medical and surgical protocol for the prophylaxis of AF after cardiac surgery is an important aspect for the care of postoperative cardiac patients. Considerations of prophylactic strategies other than those routinely used should be included in the protocol. This area should receive considerable attention in order to reduce the postoperative complications and health costs.

Controversies in postoperative atrial fibrillation after noncardiothoracic surgery: clinical and research implications

Post operative atrial fibrillation after non-cardiothoracic surgery is an increasingly common problem. There is little high quality data to guide clinicians in risk prediction as well as short term and long term management. There appears to be a significant risk of recurrent atrial fibrillation and stroke but effective screening strategies have not been tested. In this commentary, we delineate various controversies in the management of post operative atrial fibrillation and briefly review the available evidence. Prospective studies in this clinically important area of cardiology should be encouraged.

Incidence, Predictors, and Outcomes of Early Atrial Arrhythmias After Lung Transplant: A Systematic Review and Meta-Analysis

OBJECTIVES

This study sought to determine the incidence, predictors, and prognostic implications of early post-lung transplant atrial arrhythmias (AAs).

BACKGROUND

Although frequently encountered, the prognostic implications of early AAs after lung transplant remain uncertain.

METHODS

A systematic review of MEDLINE and the Cochrane Library was conducted for all studies that reported early post-lung transplant AAs. Random-effects DerSimonian-Laird risk ratios (RRs) were calculated for categorical variables and standardized mean difference (SMD) for continuous variables.

RESULTS

A total of 12 studies with 3,203 patients (mean age 57 ± 3 years; 52% males) were included. The incidence of early post-lung transplant AAs during hospitalization was 26.6% at mean follow-up duration of 6.7 days. Predictors of post-lung transplant AAs included advanced age (SMD: 0.50; 95% confidence interval [CI]: 0.35 to 0.64), male gender (RR: 1.37; 95% CI: 1.28 to 1.47), history of smoking (RR: 1.23; 95% CI: 1.05 to 1.46), hypertension (RR: 1.35; 95% CI: 1.13 to 1.59), hyperlipidemia (RR: 1.39; 95% CI: 1.18 to 1.63), coronary artery disease (RR: 1.40; 95% CI: 1.12 to 1.7), left atrial diameter (SMD: 0.25; 95% CI: 0.07 to 0.44), and restrictive lung disease (RR: 1.34; 95% CI: 1.13 to 1.59). Post-lung transplant AAs were associated with increased all-cause mortality (adjusted RR: 1.63; 95% CI: 1.22 to 2.19) at mean follow-up of 27.8 months and length of hospital stay (36.5 ± 16.5 days vs. 26.1 ± 14.3 days; p < 0.001).

CONCLUSIONS

Early AAs post-lung transplant are associated with increased mortality and length of hospital stay. Advanced age, male sex, smoking, hypertension, hyperlipidemia, coronary artery disease, increased left atrial diameter, and restrictive lung disease are independent predictors of early AAs in post-lung transplant patients.

Noteworthy Literature Published in 2016 for Cardiothoracic Critical Care

In 2016, demand for the presence of cardiothoracic anesthesiologists outside of the cardiac operating rooms continues to expand. This article is the second in this annual series to review relevant contributions in postoperative cardiac critical care that may impact the cardiac anesthesiologist. We explore the use of extracorporeal membrane oxygenation (ECMO), management of postoperative atrial fibrillation, coagulopathy, respiratory failure, and role of quality in cardiac surgery.

Noteworthy Literature Published in 2016 for the Cardiothoracic Anesthesiologist

Clinical research and outcome studies dominated the publication spectrum for the cardiothoracic anesthesiologist in 2016. Echocardiography is an important tool in the armamentarium of the cardiothoracic anesthesiologist. Technology is advancing at a fast pace: A new method to quantify the regurgitant volume in mitral regurgitation has been described in an experimental model and been validated in humans. Interesting studies on key elements of our daily practice have been published: Does tranexamic acid decrease the transfusion requirements after cardiac surgery? Are patients with a postoperative cognitive deficit at risk for dementia 7.5 years after surgery? What is the best strategy for post–cardiac surgery atrial fibrillation? What is the mechanism of preconditioning with remifentanil? Large multicenter looked at the treatment strategies for moderate and severe ischemic mitral regurgitation and benefits of transcatheter aortic valve replacement versus the surgical approach. These studies may give us ideas on how to tailor treatment to optimize the patients’ outcome and to minimize the associated risks.

Perioperative statin therapy in cardiac surgery: a meta-analysis of randomized controlled trials

BACKGROUND

Several studies suggest beneficial effects of perioperative statin therapy on postoperative outcome after cardiac surgery. However, recent randomized controlled trials (RCTs) show potential detrimental effects. The objective of this systematic review is to examine the association between perioperative statin therapy and clinical outcomes in cardiac surgery patients.

METHODS

Electronic databases were searched up to 1 November 2016 for RCTs of preoperative statin therapy versus placebo or no treatment in adult cardiac surgery. Postoperative outcomes were acute kidney injury, atrial fibrillation, myocardial infarction, stroke, infections, and mortality. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using fixed-effects meta-analyses. Primary analysis was restricted to trials with low risk of bias according to Cochrane methodology, and sensitivity analyses examined whether the risk of bias of included studies was associated with different results. We performed trial sequential analysis (TSA) to test the strength of the results.

RESULTS

We included data from 23 RCTs involving 5102 patients. Meta-analysis of trials with low risk of bias showed that statin therapy was associated with an increase in acute kidney injury (314 of 1318 (23.82%) with statins versus 262 of 1319 (19.86%) with placebo; OR 1.26 (95%CI 1.05 to 1.52); p = 0.01); these results were supported by TSA. No difference in postoperative atrial fibrillation, myocardial infarction, stroke, infections, or mortality was present. On sensitivity analysis, statin therapy was associated with a slight increase in hospital mortality. Meta-analysis including also trials with high or unclear risk of bias showed no beneficial effects of statin therapy on any postoperative outcomes.

CONCLUSIONS

There is no evidence that statin therapy in the days prior to cardiac surgery is beneficial for patients' outcomes. Particularly, statins are not protective against postoperative atrial fibrillation, myocardial infarction, stroke, or infections. Statins are associated with a possible increased risk of acute kidney injury and a detrimental effect on hospital survival could not be excluded. Future RCTs should further evaluate the safety profile of this therapy in relation to patients' outcomes and assess the more appropriate time point for discontinuation of statins before cardiac surgery.

The State of the Art: Atrial Fibrillation Epidemiology, Prevention, and Treatment

As the most common sustained arrhythmia in adults, atrial fibrillation (AF) is an established and growing epidemic. To provide optimal patient care, it is important for clinicians to be aware of AF's epidemiological trends, methods of risk reduction, and the various available treatment modalities. Our understanding of AF's pathophysiology has advanced, and with this new understanding has come advancements in prevention strategies as well as pharmacological and nonpharmacological treatment options. Following PubMed and MEDLINE searches for AF risk factors, epidemiology, and therapies, we reviewed relevant articles (and bibliographies of those articles) published from 2000 to 2016. This "state-of-the-art" review provides a comprehensive update on the understanding of AF in the world today, contemporary therapeutic options, and directions of ongoing and future study.

Pre- and postoperative atrial fibrillation in CABG patients have similar prognostic impact

OBJECTIVES

To study pre- and postoperative atrial fibrillation and its long-term effects in a cohort of aortocoronary bypass surgery patients.

DESIGN

Altogether 615 patients undergoing aortocoronary bypass graft surgery in 1999-2000 were studied. Forty-four (7%) had preoperative atrial fibrillation. Postoperative atrial fibrillation occurred in 165/615 patients (27%) while 406/615 patients (66%) had no atrial fibrillation. After a median follow-up of 15 years, symptoms and medication in survivors were recorded, and cause of death in the deceased was obtained.

RESULTS

Death due to cerebral ischaemia was most common in the pre- and postoperative atrial fibrillation groups (7% and 5%, respectively, v. 2% among those without atrial fibrillation, p = .038), as were death due to heart failure (18% and 14%, v. 7%, p = .007) and sudden death (9% and 5%, v. 2%, p = .029). The presence of pre- or postoperative atrial fibrillation was an independent risk factor for late mortality (hazard ratios 1.47 (1.02-2.12) and 1.28 (1.01-1.63), respectively).

CONCLUSIONS

Patients with pre- or postoperative atrial fibrillation undergoing aortocoronary bypass surgery have increased long-term mortality and risk of cerebral ischemic and cardiovascular death compared with patients in sinus rhythm.

CTS trials network: Rate control vs rhythm control for atrial fibrillation after cardiac surgery - Do bitter pills have blessed effects?

New onset AF is a very common sequel of cardiac surgery with an incidence reaching 50% in some studies. This post-operative complication leads to increased morbidity, hospital stay and, consequently, hospital costs¹. Currently there is a great variability in the management of this condition. Despite efforts to produce best practice guidelines², what best to do for a patient who develops AF post-operatively remains a question. In a systematic attempt to find an answer to this question, the Cardiothoracic Trials Network have recently published the results of their trial “Rate Control Versus Rhythm Control for Atrial Fibrillation After Cardiac Surgery”³ (clinicaltrials.gov number: NCT02132767).

Report of the American College of Cardiology (ACC) Scientific Sessions 2016, Chicago

The 65(th)Annual Scientific Sessions of the American College of Cardiology (ACC) were held at McCormick Place, Chicago, from April 2-4, 2016. The ACC Scientific Sessions are one of the 2 major scientific cardiology meetings in the USA and one of the major scientific meetings of cardiology in the world. It had an attendance of 18,769 and over 2,000 oral and poster abstracts, including 8 late-breaking clinical trials. This report presents the key presentations and the highlights from the ACC Scientific Sessions 2016 in Chicago. (Circ J 2016; 80: 1308-1313).