Postoperative atrial fibrillation: incidence, mechanisms, and clinical correlates. Cardiol Clin. 2014;32:627-636. [PMID: 25443241 DOI: 10.1016/j.ccl.2014.07.002]

Deep Parasternal Intercostal Plane Block for Postoperative Analgesia After Sternotomy for Cardiac Surgery-A Retrospective Cohort Study

OBJECTIVE

To examine the analgesic efficacy of postoperative deep parasternal intercostal plane (DPIP) blocks for patients having cardiac surgery via median sternotomy.

DESIGN

This single-center retrospective study compared patients receiving bilateral DPIP blocks with a matched cohort of patients not receiving DPIP blocks.

SETTING

Large quaternary referral center.

PARTICIPANTS

Adult patients admitted to the authors' institution from January 1, 2016, to August 14, 2020, for elective cardiac surgery via median sternotomy.

INTERVENTIONS

Patients received ultrasound-guided bilateral DPIP blocks.

MEASUREMENTS AND MAIN RESULTS

A total of 113 patients received a DPIP block; 3,461 patients did not. The estimated multiplicative change in cumulative opioid consumption through 24 hours was 0.42 (95% CI 0.32-0.56; p < 0.001), indicating that patients receiving DPIP blocks required 60% fewer opioids than patients who did not. Proportional odds ratios for the average pain score on postoperative day (POD) 0 was 0.46 (95% CI 0.32-0.65; p < 0.001), and POD 1 was 0.67 (95% CI 0.47-0.94; p = 0.021), indicating lower pain scores for patients receiving blocks. The exploratory analysis identified an inverse correlation between DPIP blocks and atrial fibrillation incidence (2% v 15%; inverse probability of treatment weighting odds ratio 0.088, 95% CI 0.02-0.41; p = 0.002).

CONCLUSIONS

The use of DPIP blocks in patients undergoing cardiac surgery via median sternotomy was associated with less opioid use and improved pain scores in the early postoperative period compared with patients not receiving blocks. Prospective randomized controlled studies should further elucidate the efficacy and risks of DPIP blocks in cardiac surgery.

Colchicine in atrial fibrillation: are old trees in bloom?

Colchicine is a widely used drug that was originally used to treat gout and rheumatic diseases. In recent years, colchicine has shown high potential in the cardiovascular field. Atrial fibrillation (AF) is a cardiovascular disease with a high incidence. One of the most frequent complications following cardiovascular surgery is postoperative atrial fibrillation (POAF), which affects patient health and disease burden. This article reviews the research status of colchicine in AF and summarizes the relevant progress.

Predictors of atrial fibrillation post coronary artery bypass graft surgery: new scoring system

BACKGROUND

Atrial fibrillation (AF) following coronary artery bypass graft surgery (CABG) is common and results in significant increases in hospital stay and financial encumbrance.

OBJECTIVE

Determine and use the predictors of postoperative AF (POAF) following CABG to develop a new predictive screening tool.

METHOD

A retrospective case-control study evaluated 388 patients (98 developed POAF and 290 remained in sinus rhythm) who undertook CABG surgery at Townsville University Hospital between 2016 and 2017. The demographic profile, risk factors for AF including hypertension, age≥75 years, transient ischaemic attack or stroke, chronic obstructive pulmonary disease (HATCH) score, electrocardiography features and perioperative factors were determined.

RESULTS

Patients who developed POAF were significantly older. On univariate analysis HATCH score, aortic regurgitation, increased p-wave duration and amplitude in lead II and terminal p-wave amplitude in lead V1 were associated with POAF; as were increased cardiopulmonary bypass time (103.5±33.9 vs 90.6±26.4 min, p=0.001) and increased cross clamp time. On multivariate analysis age (p=0.038), p-wave duration ≥100 ms (p=0.005), HATCH score (p=0.049) and CBP Time ≥100 min (p=0.001) were associated with POAF. Receiver operating characteristic curve demonstrated that with a cut-off of ≥2 for HATCH score, POAF could be predicted with a sensitivity of 72.8% and a specificity of 34.7%. Adding p-wave duration in lead II >100 ms and cardiopulmonary bypass time >100 min to the HATCH score increased the sensitivity to 83.7% with a specificity of 33.1%. This was termed the HATCH-PC score.

CONCLUSION

Patients with HATCH scores ≥2, and those with p-wave duration >100 ms, or cardiopulmonary bypass time >100 min were at greater risk of developing POAF following CABG.

Impact of sleep disordered breathing on postoperative atrial fibrillation in patients who underwent cardiac surgery: a meta-analysis

Objective: An increasing number of studies suggest that sleep disordered breathing (SDB) may be associated with postoperative atrial fibrillation (POAF), but these studies present discrepant results. Thus, this meta-analysis aimed to synthesize the data associating SDB with POAF in patients who underwent cardiac surgery.Methods: A literature search was performed in the Scopus, PubMed, Web of Science, EMBASE, CENTRAL, Weipu, Wanfang Data, and China National Knowledge Infrastructure databases before August 2022. Data were extracted, and the strength of the relationship between SDB and the risk of POAF was evaluated using odds ratio (OR) and 95% confidence intervals (CIs). All statistical analysis was carried out using the Stata 12.0 software.Results: A total of 24 studies with 660,685 subjects were included in current meta-analysis. SDB was significantly associated with the risk of POAF in the patients who underwent cardiac surgery (OR = 1.49; 95% CI, 1.30-1.70; p < .001). Next subgroup analysis revealed that such association may be increased in the group with medical equipment-measured SDB (OR = 2.27; 95% CI, 1.59-3.23; p < .001), prospective studies (OR = 2.17; 95% CI, 1.55-3.03; p < .001), patients without a previous history of atrial fibrillation (OR = 2.04; 95% CI, 1.47-2.82; p < .001), and patients who received a coronary artery bypass graft (OR = 2.10; 95% CI, 1.45-3.05; p < .001). No publication bias was identified.Conclusion: The results of meta-analysis support that SDB may be associated with an increased risk of POAF in patients who had undergone cardiac surgery, and these results should be confirmed in more rigorously designed studies.KEY MESSAGESPatients with SDB who underwent cardiac surgery showed increased risk of POAF.The relationship between SDB and POAF should be explained with caution with the consideration of various covariate.The effect of pre-treatment of SDB on POAF should be examined in future.

A Genotype-Phenotype Analysis of Glutathione Peroxidase 4 in Human Atrial Myocardium and Its Association with Postoperative Atrial Fibrillation

Heterogeneity in the incidence of postoperative atrial fibrillation (POAF) following heart surgery implies that underlying genetic and/or physiological factors impart a higher risk of this complication to certain patients. Glutathione peroxidase-4 (GPx4) is a vital selenoenzyme responsible for neutralizing lipid peroxides, mediators of oxidative stress known to contribute to postoperative arrhythmogenesis. Here, we sought to determine whether GPX4 single nucleotide variants are associated with POAF, and whether any of these variants are linked with altered GPX4 enzyme content or activity in myocardial tissue. Sequencing analysis was performed across the GPX4 coding region within chromosome 19 from a cohort of patients (N = 189) undergoing elective coronary artery bypass graft (−/+ valve) surgery. GPx4 enzyme content and activity were also analyzed in matching samples of atrial myocardium from these patients. Incidence of POAF was 25% in this cohort. Five GPX4 variants were associated with POAF risk (permutated p ≤ 0.05), and eight variants associated with altered myocardial GPx4 content and activity (p < 0.05). One of these variants (rs713041) is a well-known modifier of cardiovascular disease risk. Collectively, these findings suggest GPX4 variants are potential risk modifiers and/or predictors of POAF. Moreover, they illustrate a genotype−phenotype link with this selenoenzyme, which will inform future mechanistic studies.

Perioperative Cardiac Troponin T and Risk of Postoperative Atrial Fibrillation in Coronary Artery Bypass Graft Surgery

BACKGROUND

Postoperative atrial fibrillation (AF) is a common complication after cardiac surgery. We investigated whether perioperative cardiac troponin T (cTnT) is associated with the risk of AF after coronary artery bypass grafting (CABG).

METHODS

Two thousand four hundred twenty-one patients with isolated CABG were studied. High sensitivity cTnT (hs-cTnT) was assessed before and then at 80 hour and 24 hour after the operation. Logistic regression models were applied to investigate the association of perioperative hs-cTnT with postoperative AF. The ROC curve analysis was applied to determine the optimal cutoff values.

RESULTS

Postoperative AF was occurred in 356 (14.7%) patients. Age (adjusted odds ratio [ORs] 1.087-1.090), male gender (OR 1.390), left atrium size (ORs 1.055-1.111), on-pump coronary bypass (OR 1.561), and application of intra-aortic balloon pump (ORs 2.890-2.966) were independently associated with AF. Preoperative hs-cTnT was associated with AF in patients with off-pump coronary bypass (ORs 1.997-2.375). However, the area under the curve for preoperative hs-cTnT was 0.625 in this group. On-pump coronary bypass had major influence on postoperative hs-cTnT levels regardless of the occurrence of AF.

CONCLUSIONS

Preoperative hs-cTnT level is associated with the risk of AF after isolated CABG in patients undergoing off-pump coronary bypass, but the accuracy of this biomarker is yet inadequate. Postoperative levels of hs-cTnT have no predictive value considering large influence by the surgical technique and the cardiac surgery itself. Therefore, perioperative hs-cTnT is not a clinically useful biomarker for predicting AF following CABG.

Identification of atrial-enriched lncRNA Walras linked to cardiomyocyte cytoarchitecture and atrial fibrillation

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in humans. Genetic and genomic analyses have recently demonstrated that the homeobox transcription factor Pitx2 plays a fundamental role regulating expression of distinct growth factors, microRNAs and ion channels leading to morphological and molecular alterations that promote the onset of AF. Here we address the plausible contribution of long non-coding (lnc)RNAs within the Pitx2>Wnt>miRNA signaling pathway. In silico analyses of annotated lncRNAs in the vicinity of the Pitx2, Wnt8 and Wnt11 chromosomal loci identified five novel lncRNAs with differential expression during cardiac development. Importantly, three of them, Walaa, Walras, and Wallrd, are evolutionarily conserved in humans and displayed preferential atrial expression during embryogenesis. In addition, Walrad displayed moderate expression during embryogenesis but was more abundant in the right atrium. Walaa, Walras and Wallrd were distinctly regulated by Pitx2, Wnt8, and Wnt11, and Wallrd was severely elevated in conditional atrium-specific Pitx2-deficient mice. Furthermore, pro-arrhythmogenic and pro-hypertrophic substrate administration to primary cardiomyocyte cell cultures consistently modulate expression of these lncRNAs, supporting distinct modulatory roles of the AF cardiovascular risk factors in the regulation of these lncRNAs. Walras affinity pulldown assays revealed its association with distinct cytoplasmic and nuclear proteins previously involved in cardiac pathophysiology, while loss-of-function assays further support a pivotal role of this lncRNA in cytoskeletal organization. We propose that lncRNAs Walaa, Walras and Wallrd, distinctly regulated by Pitx2>Wnt>miRNA signaling and pro-arrhythmogenic and pro-hypertrophic factors, are implicated in atrial arrhythmogenesis, and Walras additionally in cardiomyocyte cytoarchitecture.

Impact of oral anticoagulation therapy on postoperative atrial fibrillation outcomes: a systematic review and meta-analysis

BACKGROUND

Post-operative atrial fibrillation (POAF) is the most common complication after cardiac surgery. Recent studies had shown this phenomenon is no longer considered transitory and is associated with higher risk of thromboembolic events or death. The aim of this study was to systematically review and analyze previous studies comparing oral anticoagulation therapy with no anticoagulation, regarding these long-term outcomes.

METHODS

PubMed/MEDLINE, EMBASE, Web of Science and Cochrane Database were systematically searched to identify the studies comparing the risk of stroke, or thromboembolic events or mortality of POAF patients who received anticoagulation compared with those who were not anticoagulated. Incidence of stroke, thromboembolic events and all-cause mortality were evaluated up to 10 years after surgery. Time-to-event outcomes were collected through hazard ratio (HR) along with their variance and the early endpoints using frequencies or odds ratio (OR). Random effect models were used to compute statistical combined measures and 95% confidence intervals (CI). Heterogeneity was evaluated through Q statistic-related measures of variance (Tau2, I2, Chi-squared test).

RESULTS

Eight observational cohort studies were selected, including 15,335 patients (3492 on Oral Anticoagulants (OAC) vs 11,429 without OAC) that met the inclusion criteria for qualitative synthesis. Patients had a wide gender distribution (38.6-82.3%), each study with a mean age above 65 years (67.5-85). Vitamin K antagonists were commonly prescribed anticoagulants (74.3-100%). OAC was associated with a protective impact on all-cause mortality at a mean of 5.0 years of follow-up (HR is 0.85 [0.72-1.01]; p = 0.07; I2 = 48%). Thromboembolic events did not differ between the two treatment arms (HR 0.68 [0.40-1.15], p = 0.15).

CONCLUSION

Current literature suggests a possibly protective impact of OAC therapy for all-cause mortality in patients with new-onset atrial fibrillation after cardiac surgery. However, it does not appear to impact thromboembolism rate.

Perioperative Amiodarone to Prevent Atrial fibrillation after Septal Myectomy in obstrUctive hypeRtroPHic cardiomyopathy

Aims

Amiodarone reduces the incidence of atrial fibrillation (AF) following coronary artery bypass surgery; however, the benefit of perioperative amiodarone in patients undergoing septal myectomy (SM) for obstructive hypertrophic cardiomyopathy (oHCM) has not been studied. We hypothesized that prophylactic amiodarone would reduce the incidence of postoperative AF (POAF) following SM for oHCM.

Methods and Results

A single‐centre, pre‐post intervention open‐label study of oral amiodarone (200 mg twice daily starting 7 days preoperatively and 200 mg once daily continuing for 30 days postoperatively) in patients without prior AF undergoing SM for oHCM from 2014 to 2018. The primary outcome was incident AF within 30 days. Secondary outcomes were unplanned readmission, AF treatment, total and intensive care unit (ICU) length of stay (LOS), and pacemaker implantation for high‐grade atrioventricular (AV) block. 61 patients met inclusion criteria with 34 (55.8%) in the pre‐intervention (control) group and 27 (44.2%) in the post‐intervention (amiodarone) group. The incidence of POAF was 11.0% in the amiodarone group compared with 38.2% in the control group (P = 0.017). After adjusting for age, amiodarone was associated with less POAF [adjusted odds ratio (aOR) 0.21; 95% confidence interval (CI) 0.05, 0.76; P = 0.016]. ICU (2 days [IQR 1, 4] vs. 3 days [IQR 2, 4]; P = 0.165) and total (6 days [IQR 5, 6] vs. 6 days [IQR 5, 7]; P = 0.165) LOS were similar, as was the rate of pacemaker implantation (7.4% vs. 8.3%, P > 0.999). There were no adverse events associated with amiodarone.

Conclusions

Perioperative oral amiodarone is safe and was associated with lower incidence of POAF following SM for oHCM.

Posterior pericardiotomy to prevent new-onset atrial fibrillation after coronary artery bypass grafting: a systematic review and meta-analysis of 10 randomized controlled trials

BACKGROUND

Atrial fibrillation (AF) is associated with adverse events after cardiac surgery. Multiple studies have reported that posterior pericardiotomy (PP) may be effective for preventing AF after coronary artery bypass grafting (CABG), but some conflicting results have been reported and the quality of evidence from previous meta-analyses has been limited. The present study aimed to systematically evaluate the safety and efficacy of PP for preventing AF after CABG in adults.

METHODS

We conducted a quantitative meta-analysis of randomized controlled trials (RCTs) published before May 31, 2021. The primary outcome was AF after CABG under cardiopulmonary bypass. Secondary outcomes included early pericardial effusion, late pericardial effusion, pericardial tamponade, pleural effusion, length of hospital stay, length of intensive care unit (ICU) stay, pulmonary complications, intra-aortic balloon pump use, revision surgery for bleeding, and mortality.

RESULTS

Ten RCTs with 1829 patients (910 in the PP group and 919 in the control group) were included in the current meta-analysis. The incidence of AF was 10.3% (94/910) in the PP group and 25.7% (236/919) in the control group. A random-effects model indicated that incidence of AF after CABG significantly lower in the PP group than in the control group (risk ratio = 0.45, 95% confidence interval 0.29-0.64, P < 0.0001). PP also effectively reduced the post-CABG occurrence of early pericardial effusion (RR = 0.28, 95% CI 0.15-0.50; P < 0.05), late pericardial effusion (RR = 0.06, 95% CI 0.02-0.16; P < 0.05), and pericardial tamponade (RR = 0.08, 95% CI 0.02-0.33; P < 0.05) as well as the length of ICU stay (weighted mean difference [WMD] = 0.91,95% CI 0.57-1.24; P < 0.05), while increasing the occurrence pleural effusion (RR = 1.51, 95% CI 1.19-1.92; P < 0.05). No significant differences length of hospital stay (WMD =  - 0.45, 95% CI - 2.44 to 1.54, P = 0.66), pulmonary complications (RR = 0.99, 95% CI 0.71-1.39, P = 0.97), revision surgery for bleeding (RR = 0.84, 95% CI 0.43-1.63, P = 0.60), use of IABP (RR = 1, 95% CI 0.61-1.65, P = 1.0), or death (RR = 0.45, 95% CI 0.07-3.03, P = 0.41) were observed between the PP and control groups.

CONCLUSIONS

PP may be a safe, effective, and economical method for preventing AF after CABG in adult patients.

Effects of corticosteroids on new-onset atrial fibrillation after cardiac surgery: A meta-analysis of randomized controlled trials

BACKGROUND

Postoperative atrial fibrillation (POAF) occurs commonly after cardiac surgery. Studies suggest that corticosteroid can reduce the incident of POAF. However, the results remain controversial. This meta-analysis aimed to evaluate the efficacy and safety corticosteroid on the prevention of POAF following cardiac surgery.

METHODS

Randomized controlled trials were identified through a systematic literature search. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. Primary outcome was the incidence of POAF as well as length of hospital stay and intensive care unit stay, wound and other infection, mortality, duration of ventilation, myocardial infarction, gastrointestinal complications, high blood sugar, stroke, and postoperative bleeding.

RESULTS

Fourteen studies with 13,803 patients were finally involved in the present study. Overall, corticosteroid significantly decreased the risk of POAF (relative risk [RR], 0.7; 95% confidence interval [CI], 0.55-0.89; P = .003). There were no significant differences in the incidence of length of intensive care unit stay (RR, -2.32; 95% CI, -5.44 to 0.80; P = .14) and hospital stay (RR, -0.43; 95% CI, -0.84 to -0.02; P = .04), infections (RR, 1.01; 95% CI, 0.83-1.23; P = .9), mortality (RR, 0.87; 95% CI, 0.71-1.06; P = .16), duration of ventilation (RR, -0.29; 95% CI, -0.65 to 0.07; P = .12), gastrointestinal complications (RR, 1.26; 95% CI, 0.91-1.76; P = .16), high blood sugar (RR, 1.98; 95% CI, 0.91-4.31; P = .09), stroke (RR, 0.9; 95% CI, 0.69-1.18; P = .45), postoperative bleeding (RR -44.54; 95% CI, -115.28 to 26.20; P = .22) and myocardial infarction (RR, 1.71; 95% CI, 0.96-1.43; P = .12).

CONCLUSION

Our review suggests that the efficacy of corticosteroid might be beneficial to POAF development in patients undergoing cardiac surgery. The strength of this association remains uncertain because of statistical and clinical heterogeneity among the included studies.

Pulmonary Delivery of Antiarrhythmic Drugs for Rapid Conversion of New-Onset Atrial Fibrillation

Pharmacologic management of atrial fibrillation (AF) is a pressing problem. This arrhythmia afflicts >5 million individuals in the United States and prevalence is estimated to rise to 12 million by 2050. Although the pill-in-the-pocket regimen for self-administered AF cardioversion introduced over a decade ago has proven useful, significant drawbacks exist. Among these are the relatively long latency of effects in the range of hours along with potential for hypotension and other adverse effects. This experience prompted development of a new strategy for increasing plasma concentrations of antiarrhythmic drugs rapidly and for a limited time, namely, pulmonary delivery. In preclinical studies in Yorkshire pigs, intratracheal administration of flecainide was shown to cause a rapid, reproducible increase in plasma drug levels. Moreover, pulmonary delivery of flecainide converted AF to normal sinus rhythm by prolonging atrial depolarization, which slows intra-atrial conduction and seems to be directly correlated with efficacy in converting AF. The rapid rise in plasma flecainide levels optimizes its anti-AF effects while minimizing adverse influences on ventricular depolarization and contractility. A more concentrated and soluble formulation of flecainide using a novel cyclodextrin complex excipient reduced net drug delivery for AF conversion when compared to the acetate formulation. Inhalation of the beta-adrenergic blocking agent metoprolol slows ventricular rate and can also terminate AF. In human subjects, oral inhalation of flecainide acetate with a hand-held, breath-actuated nebulizer results in signature prolongation of the QRS complex without serious adverse events. Thus, pulmonary delivery is a promising advance in pharmacologic approach to management of AF.

Interleukin-6 Receptor Asp358 A>C Polymorphism Is Associated With Postoperative Atrial Fibrillation

BACKGROUND

This study examined the associations of single-nucleotide polymorphisms in the interleukin-6 receptor gene (Asp358 A>C) and the interleukin-6 promoter (-174G>C and -597G>A) with interleukin-6 levels and postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG).

METHODS

The study enrolled 371 Chinese Han patients who were undergoing CABG. Serum interleukin-6 levels were measured preoperatively and at 6, 12, and 18 hours postoperatively. Genotypes for the 3 polymorphisms were determined.

RESULTS

Overall, POAF developed in 30.2% of patients. The CC genotype and C allele frequencies for the interleukin-6 receptor Asp358 A>C polymorphism were significantly higher in patients with POAF than in patients without POAF (P = .003), and the interleukin-6 levels were significantly higher in patients with the CC genotype compared with A allele carriers at 6, 12, and 18 hours in the overall cohort and at 12 and 18 hours in the POAF subgroup, but there were no significant differences in the non-POAF subgroup. However, the allele and genotype frequencies of the interleukin-6 -174G>C and -597G>A polymorphisms were similar among groups, and there were no differences in interleukin-6 levels at any time point between the C/A allele carriers and the patients with GG genotypes. Univariate analysis showed that the CC genotype for interleukin-6 receptor Asp358 A>C, age, and history of cerebrovascular disease were associated with POAF. Multivariable regression showed that the CC genotype was independently related to the development of POAF (odds ratio, 2.01; 95% confidence interval: 1.15 to 3.52; P = .014).

CONCLUSIONS

The interleukin-6 receptor Asp358 A>C polymorphism may contribute to genetic susceptibility to POAF after CABG.

Postoperative Atrial Fibrillation Following Cardiac Surgery: From Pathogenesis to Potential Therapies

Postoperative atrial fibrillation (POAF) is a major complication after cardiac surgery which can lead to high rates of morbidity and mortality, an enhanced length of hospital stay, and an increased cost of care. POAF is postulated to be a multifactorial phenomenon; however, some major pathogeneses have been proposed, including inflammatory pathways, oxidative stress, and autonomic dysfunction. Genetic studies also showed that inflammatory pathways, beta-1 adrenoreceptor variants, G protein-coupled receptor kinase 5 gene variants, and non-coding single-nucleotide polymorphisms in the 4q25 chromosomal locus are involved in this phenomenon. Moreover, several predisposing factors lead to the development of POAF, consisting of pre-, intra-, and postoperative contributors. The main predisposing factors comprise age, prior history of major cardiovascular risk factors, and ischemia-reperfusion injury during surgery. The management of POAF is based on the usual therapies used for non-surgical AF, including medications for either rate control or rhythm control in hemodynamically unstable patients. The perioperative administration of β-blockers and some antiarrhythmic agents has been recommended in major international guidelines. In addition, upstream therapies consisting of colchicine, magnesium, statins, and antioxidants have attenuated the incidence of POAF; however, some uncomfortable side effects developed in large randomized trials. The use of anticoagulation has also resulted in less mortality in patients with POAF at higher risk of thromboembolic events. Despite these recommendations, the actual regimen for the prevention of POAF remains controversial. In this review, we highlight the pathogenesis, predisposing factors, and potential therapeutic options for the management of patients at risk for or with POAF following cardiac surgery.

Importância do Desenvolvimento de Fibrilação Atrial no Pós-Operatório em Cirurgia Cardíaca: Desfechos Intra-Hospitalares em Centro Terciário de Cardiologia Catarinense

Objetivo: Determinar a incidência de fibrilação atrial no pós-operatório (FAPO) de cirurgia cardíaca, seu impacto sobre a morbimortalidade e o tempo de internação hospitalar em um centro terciário de cardiologia do estado de Santa Catarina, Brasil. Métodos: Estudo de coorte com 134 pacientes adultos submetidos à cirurgia cardíaca. Resultados: A incidência foi de 32,8%. Após análise multivariada, os pacientes que não receberam betabloqueador estiveram associados à FAPO com razão de chances risco relativo (RR) 10,73 (p < 0,001). A maior taxa de eventos cardiovasculares (acidente vascular cerebral, mortalidade e síndrome coronariana aguda) foi de 25% no grupo FAPO vs. 10% (RR 3,21; p = 0,035) o que, consequentemente, gerou tempo de internação maior nesses pacientes (19,1 vs. 12,5; p = 0,01). Conclusão: A incidência de FAPO foi elevada, ocasionou significativo aumento de morbimortalidade e tempo de internação hospitalar e consolidou o papel da terapia betabloqueadora na sua prevenção, podendo servir como base a futuras políticas de prevenção dessa intercorrência.

Importance of Postoperative Atrial Fibrillation Development in Heart Surgery: Intra-Hospital Outcomes in Santa Catarina Tertiary Cardiology Center

Objective: To determine the incidence of postoperative atrial fibrillation (PAF) of cardiac surgery, its impact on morbimortality and duration of hospital stay in a tertiary cardiology center of the state of Santa Catarina, Brazil. Methods: Cohort study with 134 adult patients submitted to cardiac surgery. Results: the incidence was 32.8%. After multivariate analysis, patients who did not receive beta-blockers were associated with PAF with a relative risk odds ratio (RR) 10.73 (p <0.001). The highest rate of cardiovascular events (cerebrovascular accident, mortality, and acute coronary syndrome) was 25% in the PAF group. 10% (RR 3.21; p = 0.035) which, consequently, generated longer hospitalization time in these patients (19.1 vs. 12.5; p = 0.01). Conclusion: the incidence of PAF was high, caused a significant increase in morbimortality and duration of hospital stay, and consolidated the role of beta-blocker therapy in its prevention, and may serve as a basis for future prevention policies.

Post-operative atrial fibrillation: should we anticoagulate?

The prevalence of atrial fibrillation (AF) is estimated to be 12 million by the year 2030. A subset of those patients fall into the category of post-operative atrial fibrillation (POAF) and either develop POAF after cardiac procedures [coronary artery bypass graft (CABG) and valvular procedures] or non-cardiac procedures. With the rise in surgical procedures, POAF represents a significant economic burden. POAF usually converts to sinus rhythm on its own, prompting questions about whether there is a need to treat it and if there is a need for anticoagulation. This review discusses risk factors, pathophysiology, complications of POAF, and mechanisms of risk stratifying patients to determine when to anticoagulate.

Genetics of Atrial Fibrilation: In Search of Novel Therapeutic Targets

Atrial fibrillation (AF) is the most frequent arrhythmogenic disease in humans, ranging from 2% in the general population and rising up to 10-12% in 80+ years. Genetic analyses of AF familiar cases have identified a series of point mutations in distinct ion channels, supporting a causative link. However, these genetic defects only explain a minority of AF patients. Genomewide association studies identified single nucleotide polymorphisms (SNPs), close to PITX2 on 4q25 chromosome, that are highly associated to AF. Subsequent GWAS studies have identified several new loci, involving additional transcription and growth factors. Furthermore, these risk 4q25 SNPs serve as surrogate biomarkers to identify AF recurrence in distinct surgical and pharmacological interventions. Experimental studies have demonstrated an intricate signalling pathway supporting a key role of the homeobox transcription factor PITX2 as a transcriptional regulator. Furthermore, cardiovascular risk factors such as hyperthyroidism, hypertension and redox homeostasis have been identified to modulate PITX2 driven gene regulatory networks. We provide herein a state-of-the-art review of the genetic bases of atrial fibrillation, our current understanding of the genetic regulatory networks involved in AF and its plausible usage for searching novel therapeutic targets.

The more you look, the more you find: atrial fibrillation - nowhere to hide

PURPOSE OF REVIEW

We provide an updated review on the incidence of postoperative atrial fibrillation (POAF) after cardiac surgery as determined by enhanced cardiac rhythm monitoring technology and provide a rationale for why a more aggressive detection approach for POAF may be clinically useful.

RECENT FINDINGS

Most of the published literature had focused on the in-hospital incidence of POAF after cardiac surgery. However, recent studies using continuous cardiac rhythm technologies revealed that the incidence of POAF during the postdischarge, subacute (<1 month) phase could be as high as 28%. This is a clinically relevant finding since that POAF is linked with occurrence of future, 'late' atrial fibrillation, and adverse clinical outcomes even beyond 1 year after cardiac surgery. Furthermore, the role of oral anticoagulation is still not well established for cardiac surgical patients with POAF because of lack of randomized trials specifically designed for this patient population.

SUMMARY

Emerging data suggest that POAF after cardiac surgery is not a transient, self-resolving phenomenon. Rather, its occurrence is associated with future risk of atrial fibrillation and long-term adverse outcomes such as stroke and death. This highlights the potential importance of enhanced cardiac rhythm monitoring to refine prognostic stratification in this high-risk patient population.

Preoperative P-wave duration as a predictor of atrial fibrillation after coronary artery bypass grafting: A prospective cohort study with meta-analysis

Objectives

Methods

Results

Conclusion

Evaluating the Usability and Usefulness of a Mobile App for Atrial Fibrillation Using Qualitative Methods: Exploratory Pilot Study

BACKGROUND

Atrial fibrillation (AFib) is the most common form of heart arrhythmia and a potent risk factor for stroke. Nonvitamin K antagonist oral anticoagulants (NOACs) are routinely prescribed to manage AFib stroke risk; however, nonadherence to treatment is a concern. Additional tools that support self-care and medication adherence may benefit patients with AFib.

OBJECTIVE

The aim of this study was to evaluate the perceived usability and usefulness of a mobile app designed to support self-care and treatment adherence for AFib patients who are prescribed NOACs.

METHODS

A mobile app to support AFib patients was previously developed based on early stage interview and usability test data from clinicians and patients. An exploratory pilot study consisting of naturalistic app use, surveys, and semistructured interviews was then conducted to examine patients' perceptions and everyday use of the app.

RESULTS

A total of 12 individuals with an existing diagnosis of nonvalvular AFib completed the 4-week study. The average age of participants was 59 years. All participants somewhat or strongly agreed that the app was easy to use, and 92% (11/12) reported being satisfied or very satisfied with the app. Participant feedback identified changes that may improve app usability and usefulness for patients with AFib. Areas of usability improvement were organized by three themes: app navigation, clarity of app instructions and design intent, and software bugs. Perceptions of app usefulness were grouped by three key variables: core needs of the patient segment, patient workflow while managing AFib, and the app's ability to support the patient's evolving needs.

CONCLUSIONS

The results of this study suggest that mobile tools that target self-care and treatment adherence may be helpful to AFib patients, particularly those who are newly diagnosed. Additionally, participant feedback provided insight into the varied needs and health experiences of AFib patients, which may improve the design and targeting of the intervention. Pilot studies that qualitatively examine patient perceptions of usability and usefulness are a valuable and often underutilized method for assessing the real-world acceptability of an intervention. Additional research evaluating the AFib Connect mobile app over a longer period, and including a larger, more diverse sample of AFib patients, will be helpful for understanding whether the app is perceived more broadly to be useful and effective in supporting patient self-care and medication adherence.

Hyperthyroidism, but not hypertension, impairs PITX2 expression leading to Wnt-microRNA-ion channel remodeling

PITX2 is a homeobox transcription factor involved in embryonic left/right signaling and more recently has been associated to cardiac arrhythmias. Genome wide association studies have pinpointed PITX2 as a major player underlying atrial fibrillation (AF). We have previously described that PITX2 expression is impaired in AF patients. Furthermore, distinct studies demonstrate that Pitx2 insufficiency leads to complex gene regulatory network remodeling, i.e. Wnt>microRNAs, leading to ion channel impairment and thus to arrhythmogenic events in mice. Whereas large body of evidences has been provided in recent years on PITX2 downstream signaling pathways, scarce information is available on upstream pathways influencing PITX2 in the context of AF. Multiple risk factors are associated to the onset of AF, such as e.g. hypertension (HTN), hyperthyroidism (HTD) and redox homeostasis impairment. In this study we have analyzed whether HTN, HTD and/or redox homeostasis impact on PITX2 and its downstream signaling pathways. Using rat models for spontaneous HTN (SHR) and experimentally-induced HTD we have observed that both cardiovascular risk factors lead to severe Pitx2 downregulation. Interesting HTD, but not SHR, leads to up-regulation of Wnt signaling as well as deregulation of multiple microRNAs and ion channels as previously described in Pitx2 insufficiency models. In addition, redox signaling is impaired in HTD but not SHR, in line with similar findings in atrial-specific Pitx2 deficient mice. In vitro cell culture analyses using gain- and loss-of-function strategies demonstrate that Pitx2, Zfhx3 and Wnt signaling influence redox homeostasis in cardiomyocytes. Thus, redox homeostasis seems to play a pivotal role in this setting, providing a regulatory feedback loop. Overall these data demonstrate that HTD, but not HTN, can impair Pitx2>>Wnt pathway providing thus a molecular link to AF.

Signal Transducer and Activator of Transcription 3/MicroRNA-21 Feedback Loop Contributes to Atrial Fibrillation by Promoting Atrial Fibrosis in a Rat Sterile Pericarditis Model

Supplemental Digital Content is available in the text.

Background—

Postoperative atrial fibrillation is a frequent complication in cardiac surgery. The aberrant activation of signal transducer and activator of transcription 3 (STAT3) contributes to the pathogenesis of atrial fibrillation. MicroRNA-21 (miR-21) promotes atrial fibrosis. Recent studies support the existence of reciprocal regulation between STAT3 and miR-21. Here, we test the hypothesis that these 2 molecules might form a feedback loop that contributes to postoperative atrial fibrillation by promoting atrial fibrosis.

Methods and Results—

A sterile pericarditis model was created using atrial surfaces dusted with sterile talcum powder in rats. The inflammatory cytokines interleukin (IL)-1β, IL-6, transforming growth factor-β, and tumor necrosis factor-α, along with STAT3 and miR-21, were highly upregulated in sterile pericarditis rats. The inhibition of STAT3 by S3I-201 resulted in miR-21 downregulation, which ameliorated atrial fibrosis and decreased the expression of the fibrosis-related genes, α-smooth muscle actin, collagen-1, and collagen-3; reduced the inhomogeneity of atrial conduction; and attenuated atrial fibrillation vulnerability. Meanwhile, treatment with antagomir-21 decreased STAT3 phosphorylation, alleviated atrial remodeling, abrogated sterile pericarditis–induced inhomogeneous conduction, and prevented atrial fibrillation promotion. The culturing of cardiac fibroblasts with IL-6 resulted in progressively augmented STAT3 phosphorylation and miR-21 levels. S3I-201 blocked IL-6 induced the expression of miR-21 and fibrosis-related genes in addition to cardiac fibroblast proliferation. Transfected antagomir-21 decreased the IL-6–induced cardiac fibroblast activation and STAT3 phosphorylation. The overexpression of miR-21 in cardiac fibroblasts caused the upregulation of STAT3 phosphorylation, enhanced fibrosis-related genes, and increased cell numbers.

Conclusions—

Our results have uncovered a novel reciprocal loop between STAT3 and miR-21 that is activated after heart surgery and can contribute to atrial fibrillation.

Storage time of intraoperative transfused allogeneic red blood cells is not associated with new-onset postoperative atrial fibrillation in cardiac surgery

BACKGROUND

Allogeneic red blood cell (RBC) transfusion has been associated with new-onset postoperative atrial fibrillation (POAF) following cardiac surgery. Prolonged storage time of RBC may increase the risk. The primary aim of the study was to evaluate whether the storage time of RBC is associated with development of POAF.

MATERIALS AND METHODS

Pre-, per- and postoperative data were retrieved from the Western Denmark Heart Registry and local blood banks regarding patients who underwent coronary artery bypass surgery, valve surgery or combined procedures in Aalborg or Aarhus University Hospital during 2010-2014. Multiple logistic regression was used to determine the risk of POAF according to transfusion of RBC on the day of surgery. Furthermore, we determined trend in storage time of RBC according to risk of POAF using restricted cubic splines. Patients with a history of preoperative atrial fibrillation, patients who received transfusions preoperative and patients who died at the day of surgery were among excluded patients.

RESULTS

A total of 2,978 patients with a mean age of 66.4 years were included and 609 patients (21%) received RBC transfusion on the day of surgery. POAF developed in 752 patients (25%) and transfused patients were at an increased risk compared with non-transfused patients (adjusted Odds Ratios for patients receiving RBC: 1.37; 95% CI: 1.11-1.69, P-value = 0.004). However, RBC transfusion was not necessarily the cause of POAF and may only be a marker for development of POAF. There was no significant association between storage time of RBC and POAF.

CONCLUSIONS

In contrast to intraoperative allogeneic RBC transfusion in general, increased storage time of RBC is not associated with development of POAF in cardiac surgery.

Predictive factors of atrial fibrillation after coronary artery bypass grafting

Objective

To analyze predictive demographic and perioperative variables of postoperative atrial fibrillation in patients who underwent exclusively coronary artery bypass grafting.

Methods

This was a retrospective cohort. We randomly selected 105 medical records of patients who underwent exclusively coronary artery bypass grafting in 2014. Demographic, clinical (preoperative and immediate postoperative) data and related with surgical procedure were collected from medical records. The occurrence of postoperative atrial fibrillation was considered until the third day after the surgery. Variables were analyzed using descriptive and inferential statistics. To identify predictive factors of postoperative atrial fibrillation we used a decision tree model with Classification and Regression Trees algorithm.

Results

Atrial fibrillation incidence was 19.0% (n=20). Patients with left atrial >40.5mm and aged >64.5 years were more likely to develop the arrhythmia during the post-surgical period.

Conclusion

Left atrial diameter and advanced age were predictive factors of atrial fibrillation in patients who underwent exclusively coronary artery bypass grafting.

The impact of surgical left atrial appendage amputation/ligation on stroke prevention in patients undergoing off-pump coronary artery bypass grafting

Stroke is a major adverse event in patients developing atrial fibrillation (AF) after cardiac surgery. Surgical left atrial appendage amputation/ligation (LAA-A/L) during off-pump coronary artery bypass grafting (OPCAB) is routinely performed in our institution. We analyzed 578 consecutive patients (mean age 69 years, male 82%) undergoing OPCAB with or without concomitant LAA-A/L from 2011 to 2014 at our institution in a prospective observational manner. The safety and efficacy of the concomitant LAA-A/L on preventing early (<30 days) and overall postoperative stroke were examined. A total of 193 patients (33.4%) underwent LAA-A/L, consisting of amputation in 154 and ligation in 39 patients (80 and 20% of the cases, respectively). Preoperative characteristics, operative time, requirement of blood transfusion, and 30-day mortality were not significantly different between those with and without LAA-A/L. The incidences of postoperative AF and early and overall stroke were not significantly different between the groups in the analysis based on a total cohort. In a subanalysis of patients without LAA-A/L, early and overall stroke occurred more frequently in those developing postoperative AF than those without AF (2.8 vs. 0%; p = 0.005, 6.2 vs. 1.5%; p = 0.017, respectively), while in patients receiving LAA-A/L, stroke incidences did not differ between those with and without AF. Multivariate logistic regression showed postoperative AF without LAA-A/L as the only independent positive predictor of overall stroke (OR 3.69, p = 0.03). Concomitant LAA-A/L with OPCAB can safely prevent postoperative stroke occurrence in case patients develop AF, the most common arrhythmia associated with stroke.

Management of postoperative atrial fibrillation after cardiac surgery

PURPOSE OF REVIEW

Postoperative atrial fibrillation (POAF) occurs commonly after cardiac surgery and is associated with a number of adverse outcomes. This article will review the available evidence on the prevention and treatment of atrial fibrillation after cardiac surgery. Using this knowledge, we propose a conceptual framework on the management of patients with POAF during various phases after cardiac surgery.

RECENT FINDINGS

Perioperative β-blockade is the cornerstone in preventing POAF after cardiac surgery. Results from randomized trials do not support routine use of colchicine or corticosteroids to prevent POAF. There is no study examining the impact of rate versus rhythm control on 'hard' clinical outcomes such as mortality or stroke in the cardiac surgical population. Furthermore, there is a paucity of research on the optimal timing and choice of oral anticoagulation among POAF cardiac surgical patients who are at risk for stroke.

SUMMARY

In spite of the plethora of therapies available to treat and prevent POAF in the cardiac surgical population, there is little data to address whether they can improve key clinical outcomes such as death or stroke. Guideline recommendations on rate/rhythm control and oral anticoagulation for stroke prevention in the cardiac surgical population are largely extrapolated from studies of nonsurgical atrial fibrillation patients. Further research is needed to address these key atrial fibrillation management issues specific to the cardiac surgical population.

Gene regulatory networks in atrial fibrillation

Atrial fibrillation (AF) is the most frequent arrhythmogenic syndrome in humans. With an estimate incidence of 1%-2% in the general population, AF raises up to almost 10%-12% in 80+ years. Thus, AF represents nowadays a highly prevalent medical problem generating a large economic burden. At the electrophysiological level, distinct mechanisms have been elucidated. Yet, despite its prevalence, the genetic and molecular culprits of this pandemic cardiac electrophysiological abnormality have remained largely obscure. Molecular genetics of AF familiar cases have demonstrated that single nucleotide mutations in distinct genes encoding for ion channels underlie the onset of AF, albeit such alterations only explain a minor subset of patients with AF. In recent years, analyses by means of genome-wide association studies have unraveled a more complex picture of the etiology of AF, pointing out to distinct cardiac-enriched transcription factors, as well as to other regulatory genes. Furthermore a new layer of regulatory mechanisms have emerged, i.e., post-transcriptional regulation mediated by non-coding RNA, which have been demonstrated to exert pivotal roles in cardiac electrophysiology. In this manuscript, we aim to provide a comprehensive review of the genetic regulatory networks that if impaired exert electrophysiological abnormalities that contribute to the onset, and subsequently, on self-perpetuation of AF.

Early Postoperative Outcome of Off-Pump Coronary Artery Bypass Grafting: A Report from the Highest-Volume Center in Japan

BACKGROUND

Off-pump coronary artery bypass grafting (OPCAB) has evolved into a standard technique in coronary artery bypass grafting. However, a detailed investigation in Japanese population undergoing OPCAB has not yet been fully elucidated.

METHODS

A total of 1109 consecutive patients undergoing isolated OPCAB between 2006 and 2013 at Juntendo University were reviewed. The data was evaluated in the light of previously published OPCAB-associated reports.

RESULTS

There were 904 male (81.5%) and a mean was 67.5 ± 9.8 years. Eight patients (0.5%) died within 30 days postoperatively or before discharge, which was equivalent to or rather better than the previously reported mortality rates, including the European System for Cardiac Operation Risk Evaluation II (2.1 ± 2.1) data. A morbidity analysis revealed that prolonged intubation (>24 h) occurred in 43 patients (3.6%), surgical site infections in 18 (1.9%), neurological complications in 13 (1.3%). A reduced preoperative left ventricular ejection fraction (less than 40%) was found to be a risk factor for early postoperative death (odds ratio 10.58, respectively, p <0.05) in our cohort.

CONCLUSIONS

Early postoperative mortality and morbidity rates in Japanese population after OPCAB were rather satisfactory and similar to those reported by other countries.