Acute atrial tachyarrhythmia induces angiotensin II type 1 receptor-mediated oxidative stress and microvascular flow abnormalities in the ventricles

Coronary microvascular dysfunction, arrythmias, and sudden cardiac death: A literature review

The coronary vascular system has a unique structure and function that is adaptive to myocardial demand. It is composed of a continuous network of vessels receding in size from epicardial arteries to the microvascular circulation. Failure to meet myocardial demand results in ischemia, angina, and adverse myocardial outcomes. It is evident that 50 % of patients with angina have a non-obstructive coronary disease and 66 % of these patients have coronary microvascular dysfunction (CMD). The impact of CMD on the atria and ventricles is exhibited through its association with atrial fibrillation and distortion of ventricular repolarization. Ultimately, this influence increases the risk of mortality, morbidity, and sudden cardiac arrest. CMD serves as an independent risk for atrial fibrillation, increases ventricular electrical inhomogeneity, and contributes to the progression of cardiac disease. The underlying pathogenesis may be attributed to oxidative stress evident through reactive oxygen species, impaired vasoactive function, and structural disorders such as fibrotic changes. Myocardial ischemia, brought about by a demand-supply mismatch in CMD, may create a milieu for ventricular arrythmia and sudden cardiac arrest through distortion of ventricular repolarization parameters such as QT dispersion and corrected QT dispersion.

Oxidized high-density lipoprotein associates with atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is the most common heart arrhythmia and considered to be a progressive chronic disease associated with increased morbidity and mortality. Recent data suggest a link between inflammation, oxidative stress, and AF, although the underlying mechanisms are not fully understood. Because oxidized lipoproteins cause structural damage and electrophysiologic changes in cardiomyocytes, it is feasible that the transformation of atheroprotective high-density lipoprotein (HDL) into dysfunctional HDL contributes to the development of AF.

OBJECTIVE

The purpose of this study was to determine whether a reduced antioxidant function of HDL is associated with the presence of AF.

METHODS

In this multicenter cross-sectional cohort study, we assessed HDL function in sera of 1206 participants. Patients were divided into groups according to the presence of AF (n = 233) or no AF (n = 973). A validated cell-free biochemical assay was used to determine reduced HDL antioxidant function as assessed by increased normalized HDL lipid peroxide content (nHDLox).

RESULTS

Participants with AF had a 9% higher mean relative nHDLox compared to persons without AF (P = .025). nHDLox was strongly associated with AF in all models of logistic regression, including the analysis adjusted for age, sex, and risk factors for AF (all P ≤.01).

CONCLUSION

Reduced antioxidant HDL function is associated with the presence of AF, which supports growing evidence that impaired lipoprotein function is linked to electrophysiological changes in cardiomyocytes. nHDLox is one of several contributors to the initiation and perpetuation of AF.

Atrial fibrillation: better symptom control with rate and rhythm management

Atrial fibrillation (AF) is often associated with limiting symptoms, and with significant impairment in quality of life. As such, treatment strategies aimed at symptom control form an important pillar of AF management. Such treatments include a wide variety of drugs and interventions, including, increasingly, catheter ablation. These strategies can be utilised either singly or in combination, to improve and restore quality of life for patients, and this review covers the current evidence base underpinning their use. In this Review, we discuss the pros and cons of rate vs. rhythm control, while offering practical tips to non-specialists on how to utilise various treatments and counsel patients about all relevant treatment options. These include antiarrhythmic and rate control medications, as well as interventions such as cardioversion, catheter ablation, and pace-and-ablate.

Evaluation of troponin I serum levels in patients with arrhythmias with and without coronary artery disease

BACKGROUND

Elevated levels of cardiac enzymes in the blood are an indicator of ongoing cardiac ischemia. Persistent tachycardia may lead to myocardial ischemia due to oxygen supply-demand mismatch.

OBJECTIVES

We sought to evaluate the probability of underlying coronary artery disease (CAD) in patients with symptomatic supraventricular (SVT) or ventricular tachyarrhythmias (VT) based on cardiac enzyme level fluctuation.

MATERIALS AND METHODS

Troponin I (TNI) levels were measured twice and coronary angiography was also performed in patients without a history of cardiovascular disease and symptomatic SVT or VT.

RESULTS

Of the 114 (group A: CAD (n = 40), group B: no CAD (n = 74)) patients eligible for the study, 34 patients in group A and 64 patients in group B had SVT, while 6 patients in group A and 10 patients in group B had VT. All patients with underlying CAD developed a significantly elevated TNI level compared to baseline, irrespective of arrhythmia type (2.02 ± 7.98 ng/ml vs. 5.64 ± 13.38, p = 0.031). In patients without CAD, TNI level was not significantly elevated compared to the baseline level, irrespective of arrhythmia type (0.34 ± 1.38 ng/ml vs. 0.48 ± 1.48 ng/ml, p = 0.158). Most patients with normal TNI levels (46 of 47 patients; 98 %) had SVT. CAD was present in 13 of 47 patients (27 %) with tachycardia, despite normal TNI levels.

CONCLUSIONS

Elevated TNI levels are not helpful to discriminate between SVT and VT. An increase in TNI level in repeated blood sampling can help identify patients with higher probability of underlying CAD. Patients with VT demonstrated higher increases in TNI levels, compared to patients with SVT.

Association between Troponin Elevation and Decreased Myocardial Blood Flow Reserve in Patients without Obstructive Coronary Artery Disease

INTRODUCTION

To study the prognostic factors of patients with chest pain and without obstructive coronary artery disease is of great significance for the management of such patients. We assessed whether a high-sensitivity troponin I (hs-TnI) is associated with prognosis in patients with chest pain and without obstructive coronary artery disease.

METHODS

From 2011 to 2017, 489 consecutively hospitalized patients with chest pain and without significant coronary artery stenosis (<50%) were tested for hs-TnI and underwent stress myocardial contrast echocardiography (MCE). Myocardial blood flow reserve (MBFR) was measured by stress MCE. Patients were followed (median, 41 months) for composite endpoints, including cardiovascular death and non-fatal myocardial infarction. Cox proportional hazards models were performed to determine associations between hs-TnI and the composite endpoints.

RESULTS

Among 489 patients with chest pain and without significant coronary artery stenosis, 257 patients (52.6%) had elevated hs-TnI. Compared to patients with normal hs-TnI, patients with elevated hs-TnI were older (p = 0.013) and had a higher prevalence of atrial fibrillation (p = 0.003), higher left ventricular mass index (p = 0.002) and E/e' septal (p < 0.001), and a lower MBFR (p < 0.001). After adjustment, there was still a significant association between hs-TnI and MBFR (odds ratio = 1.145; 95% confidence interval [CI], 1.079-1.214; p < 0.001). Compared with patients with normal hs-TnI, patients with elevated hs-TnI had a greater cumulative event rate (log-rank p = 0.002). Males (hazard ratio [HR], 4.770; 95% CI, 1.175-19.363; p = 0.029) and reduced MBFR (HR, 2.496; 95% CI, 1.446-4.311; p = 0.001) were risk factors associated with composite endpoints in patients with elevated hs-TnI.

CONCLUSIONS

In patients with chest pain and without obstructive coronary artery disease, elevated hs-TnI is associated with decreased myocardial perfusion by contrast echocardiography as well as a higher incidence of cardiovascular events.

Prognostic Impact of Atrial Fibrillation in Patients with Heavily Calcified Coronary Artery Disease Receiving Rotational Atherectomy

Background and Objectives: Although both rotational atherectomy (RA) and atrial fibrillation (AF) have a high thrombotic risk, there have been no previous studies on the prognostic impact of AF in patients who undergo percutaneous coronary intervention (PCI) using RA. Thus, the aim of the present study was to determine the prognostic impact of AF in patients undergoing PCI using RA. Materials and Methods: A total of 540 patients who received PCI using RA were enrolled between January 2010 and October 2019. Patients were divided into AF and sinus rhythm groups according to the presence of AF. The primary endpoint was net adverse clinical events (NACEs) defined as a composite outcome of all-cause death, myocardial infarction, target vessel revascularization, cerebrovascular accident, or total bleeding. Results: Although in-hospital adverse events showed no difference between those with AF and those without AF (in-hospital events, 54 (11.0%) vs. 6 (12.2%), p = 0.791), AF was strongly associated with an increased risk of NACE at 3 years (NACE: hazard ratio, 1.880; 95% confidence interval, 1.096-3.227; p = 0.022). Conclusions: AF in patients who underwent PCI using RA was strongly associated with poor clinical outcomes. Thus, more attention should be paid to thrombotic and bleeding risks.

Risk of myocardial infarction and ischemic stroke in individuals with first-diagnosed paroxysmal vs. non-paroxysmal atrial fibrillation under anticoagulation

AIMS

There is conflicting evidence on whether the type of atrial fibrillation (AF) is associated with risk of cardiovascular events, including acute myocardial infarction (MI) and ischemic stroke. The aim of the present study was to investigate whether the risk of MI and ischemic stroke differs between individuals with first-diagnosed paroxysmal vs. non-paroxysmal AF treated with anticoagulants.

METHODS AND RESULTS

De-identified electronic medical records from the TriNetX federated research network were used. Individuals with a new diagnosis of paroxysmal AF who had no evidence of other types of AF in their records were 1:1 propensity score-matched with individuals with non-paroxysmal AF, defined as persistent or chronic AF, who had no evidence of other types of AF in their records. All patients were followed for three years for the outcomes of MI and ischemic stroke. Cox proportional hazard models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). In the propensity-matched cohort, among 24 848 well-matched AF individuals [mean age 74.4 ± 10.4; 10 101 (40.6%) female], 410 (1.7%) were diagnosed with acute MI and 875 (3.5%) with ischemic stroke during the three-year follow-up. Individuals with paroxysmal AF had significantly higher risk of acute MI (HR: 1.65, 95%CI: 1.35-2.01) compared to those with non-paroxysmal AF. First diagnosed paroxysmal AF was associated with higher risk of non-ST elevation MI (nSTEMI) (HR: 1.89, 95%CI: 1.44-2.46). No significant association was observed between the type of AF and risk of ischemic stroke (HR: 1.09, 95%CI: 0.95-1.25).

CONCLUSION

Patients with first-diagnosed paroxysmal AF had higher risk of acute MI compared to individuals with non-paroxysmal AF, attributed to the higher risk of nSTEMI among patients with first-diagnosed paroxysmal AF. There was no significant association between type of AF and risk of ischemic stroke.

Interaction of Cardiovascular Nonmodifiable Risk Factors, Comorbidities and Comedications With Ischemia/Reperfusion Injury and Cardioprotection by Pharmacological Treatments and Ischemic Conditioning

Preconditioning, postconditioning, and remote conditioning of the myocardium enhance the ability of the heart to withstand a prolonged ischemia/reperfusion insult and the potential to provide novel therapeutic paradigms for cardioprotection. While many signaling pathways leading to endogenous cardioprotection have been elucidated in experimental studies over the past 30 years, no cardioprotective drug is on the market yet for that indication. One likely major reason for this failure to translate cardioprotection into patient benefit is the lack of rigorous and systematic preclinical evaluation of promising cardioprotective therapies prior to their clinical evaluation, since ischemic heart disease in humans is a complex disorder caused by or associated with cardiovascular risk factors and comorbidities. These risk factors and comorbidities induce fundamental alterations in cellular signaling cascades that affect the development of ischemia/reperfusion injury and responses to cardioprotective interventions. Moreover, some of the medications used to treat these comorbidities may impact on cardioprotection by again modifying cellular signaling pathways. The aim of this article is to review the recent evidence that cardiovascular risk factors as well as comorbidities and their medications may modify the response to cardioprotective interventions. We emphasize the critical need for taking into account the presence of cardiovascular risk factors as well as comorbidities and their concomitant medications when designing preclinical studies for the identification and validation of cardioprotective drug targets and clinical studies. This will hopefully maximize the success rate of developing rational approaches to effective cardioprotective therapies for the majority of patients with multiple comorbidities. SIGNIFICANCE STATEMENT: Ischemic heart disease is a major cause of mortality; however, there are still no cardioprotective drugs on the market. Most studies on cardioprotection have been undertaken in animal models of ischemia/reperfusion in the absence of comorbidities; however, ischemic heart disease develops with other systemic disorders (e.g., hypertension, hyperlipidemia, diabetes, atherosclerosis). Here we focus on the preclinical and clinical evidence showing how these comorbidities and their routine medications affect ischemia/reperfusion injury and interfere with cardioprotective strategies.

The Impact of Cardiac Comorbidity Sequence at Baseline and Mortality Risk in Type 2 Diabetes Mellitus: A Retrospective Population-Based Cohort Study

Introduction: The presence of multiple comorbidities increases the risk of all-cause mortality, but the effects of the comorbidity sequence before the baseline date on mortality remain unexplored. This study investigated the relationship between coronary heart disease (CHD), atrial fibrillation (AF) and heart failure (HF) through their sequence of development and the effect on all-cause mortality risk in type 2 diabetes mellitus. Methods: This study included patients with type 2 diabetes mellitus prescribed antidiabetic/cardiovascular medications in public hospitals of Hong Kong between 1 January 2009 and 31 December 2009, with follow-up until death or 31 December 2019. The Cox regression was used to identify comorbidity sequences predicting all-cause mortality in patients with different medication subgroups. Results: A total of 249,291 patients (age: 66.0 ± 12.4 years, 47.4% male) were included. At baseline, 7564, 10,900 and 25,589 patients had AF, HF and CHD, respectively. Over follow-up (3524 ± 1218 days), 85,870 patients died (mortality rate: 35.7 per 1000 person-years). Sulphonylurea users with CHD developing later and insulin users with CHD developing earlier in the disease course had lower mortality risks. Amongst insulin users with two of the three comorbidities, those with CHD with preceding AF (hazard ratio (HR): 3.06, 95% CI: [2.60−3.61], p < 0.001) or HF (HR: 3.84 [3.47−4.24], p < 0.001) had a higher mortality. In users of lipid-lowering agents with all three comorbidities, those with preceding AF had a higher risk of mortality (AF-CHD-HF: HR: 3.22, [2.24−4.61], p < 0.001; AF-HF-CHD: HR: 3.71, [2.66−5.16], p < 0.001). Conclusions: The sequence of comorbidity development affects the risk of all-cause mortality to varying degrees in diabetic patients on different antidiabetic/cardiovascular medications.

Pathological Roles of Oxidative Stress in Cardiac Microvascular Injury

Cardiac microvascular injury can be a fundamental pathological process that causes high incidence cardiovascular diseases such heart failure, diabetic cardiomyopathy, and hypertension. It is also an independent risk factor for cardiovascular disease. Oxidative stress is a significant pathological process in which the body interferes with the balance of the endogenous antioxidant defense system by producing reactive oxygen species, leading to property changes and dysfunction. It has been demonstrated that oxidative stress is one of the major causes of cardiac microvascular disease. Therefore, additional investigation into the relationship between oxidative stress and cardiac microvascular injury will direct clinical management in the future. In order to give suggestions and support for future in-depth studies, we give a basic overview of the cardiac microvasculature in relation to physiopathology in this review. We also summarize the role of oxidative stress of mitochondrial and non-mitochondrial origin in cardiac microvascular injury and related drug studies.

Presenting Pattern of Atrial Fibrillation and Outcomes of Early Rhythm Control Therapy

BACKGROUND

Whether atrial fibrillation (AF) pattern or timing of AF therapy modifies the effectiveness of early rhythm control (ERC) is not known.

OBJECTIVES

This study sought to compare clinical characteristics and outcomes in patients presenting with different AF patterns on ERC vs usual care.

METHODS

The effects of ERC were compared in first-diagnosed AF (FDAF), paroxysmal AF (paroxAF), and persistent AF (persAF) in this prespecified analysis of the EAST-AFNET 4 (Early treatment of atrial fibrillation for stroke prevention) trial. Associations between AF pattern and primary outcomes (first primary outcome: cardiovascular death, stroke, and hospitalization for heart failure and acute coronary syndrome; second primary outcome: nights spent in hospital per year) were compared over a mean follow-up of 5.1 years. Changes in health-related quality of life were assessed by the EQ-5D.

RESULTS

FDAF patients (n = 1,048, enrolled 7 days after diagnosing AF) were slightly older (71 years of age, 48.0% female) than patients with paroxAF (n = 994, 70 years of age, 50.0% female) and persAF (n = 743, 70 years of age, 38.0% female). ERC reduced the primary outcome in all 3 AF patterns. Hospitalizations for acute coronary syndrome were highest in FDAF (incidence rate ratio [IRR]: 1.50; 95% CI: 0.83-2.69; P for interaction = 0.032) compared with paroxAF (IRR: 0.64; 95% CI: 0.32-1.25) and persAF (IRR: 0.50; 95% CI: 0.25-1.00). FDAF patients spent more nights in hospital (IRR: 1.38; 95% CI: 1.12-1.70; P for interaction = 0.004) than paroxAF (IRR: 0.84; 95% CI: 0.67-1.03), and persAF (IRR: 1.02; 95% CI: 0.80-1.30) patients. ERC improved health-related quality of life (EQ-5D score) in patients with paroxAF and persAF but not in patients with FDAF (P = 0.019).

CONCLUSIONS

ERC reduces the first primary composite outcome in all AF patterns. Patients with FDAF are at high risk for hospitalization and acute coronary syndrome, particularly on ERC. (Early treatment of atrial fibrillation for stroke prevention trial; ISRCTN04708680; Early Treatment of Atrial Fibrillation for Stroke Prevention Trial [EAST]; NCT01288352; Early treatment of Atrial fibrillation for Stroke prevention Trial [EAST]; EudraCT2010-021258-20).

Anemia and iron deficiency in patients with atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac tachyarrhythmia and has a rising global prevalence. Given the increasing burden of AF-related symptoms and complications, new approaches to management are required. Anemia and iron deficiency are common conditions in patients with AF. Furthermore, emerging evidence suggests that the presence of anemia may be associated with worse outcome in these patients. The role of anemia and iron deficiency has been extensively explored in other cardiovascular states, such as heart failure and ischemic heart disease. In particular, the role of iron repletion amongst patients with heart failure is now an established treatment modality. However, despite the strong bidirectional inter-relationship between AF and heart failure, the implications of anemia and iron-deficiency in AF have been scarcely studied. This area is of mechanistic and clinical relevance given the potential that treatment of these conditions may improve symptoms and prognosis in the increasing number of individuals with AF. In this review, we summarise the current published literature on anemia and iron deficiency in patients with AF. We discuss AF complications such as stroke, bleeding, and heart failure, in addition to AF-related symptoms such as exercise intolerance, and the potential impact of anemia and iron deficiency on these. Finally, we summarize current research gaps on anemia, iron deficiency, and AF, and underscore potential research directions.

Atrial Cardiomyopathy: Pathophysiology and Clinical Consequences

Around the world there are 33.5 million patients suffering from atrial fibrillation (AF) with an annual increase of 5 million cases. Most AF patients have an established form of an atrial cardiomyopathy. The concept of atrial cardiomyopathy was introduced in 2016. Thus, therapy of underlying diseases and atrial tissue changes appear as a cornerstone of AF therapy. Furthermore, therapy or prevention of atrial endocardial changes has the potential to reduce atrial thrombogenesis and thereby cerebral stroke. The present manuscript will summarize the underlying pathophysiology and remodeling processes observed in the development of an atrial cardiomyopathy, thrombogenesis, and atrial fibrillation. In particular, the impact of oxidative stress, inflammation, diabetes, and obesity will be addressed.

The relation between the atrial blood supply and the complexity of acute atrial fibrillation

Background

Patients with a history of myocardial infarction and coronary artery disease (CAD) have a higher risk of developing AF. Conversely, patients with atrial fibrillation (AF) have a higher risk of developing myocardial infarction, suggesting a link in underlying pathophysiology. The aim of this study was to assess whether coronary angiographic parameters are associated with a substrate for AF in patients without a history of AF.

Methods

During cardiac surgery in 62 patients (coronary artery bypass grafting (CABG;n = 47), aortic valve replacement (AVR;n = 9) or CABG + AVR (n = 6)) without a history of clinical AF (age 65.4 ± 8.5 years, 26.2% female), AF was induced by burst pacing. The preoperative coronary angiogram (CAG) was assessed for the severity of CAD, and the adequacy of atrial coronary blood supply as quantified by a novel scoring system including the location and severity of right coronary artery disease in relation to the right atrial branches. Epicardial mapping of the right atrium (256 unipolar electrodes) was used to assess the complexity of induced AF.

Results

There was no association between the adequacy of right atrial coronary blood supply on preoperative CAG and AF complexity parameters. Multivariable analysis revealed that only increasing age (B0.232 (0.030;0.433),p = 0.03) and the presence of 3VD (B3.602 (0.187;7.018),p = 0.04) were independently associated with an increased maximal activation time difference.

Conclusions

The adequacy of epicardial right atrial blood supply is not associated with increased complexity of induced atrial fibrillation in patients without a history of clinical AF, while age and the extent of ventricular coronary artery disease are.

New aspects of endocrine control of atrial fibrillation and possibilities for clinical translation

Hormones are potent endo-, para-, and autocrine endogenous regulators of the function of multiple organs, including the heart. Endocrine dysfunction promotes a number of cardiovascular diseases, including atrial fibrillation (AF). While the heart is a target for endocrine regulation, it is also an active endocrine organ itself, secreting a number of important bioactive hormones that convey significant endocrine effects, but also through para-/autocrine actions, actively participate in cardiac self-regulation. The hormones regulating heart-function work in concert to support myocardial performance. AF is a serious clinical problem associated with increased morbidity and mortality, mainly due to stroke and heart failure. Current therapies for AF remain inadequate. AF is characterized by altered atrial function and structure, including electrical and profibrotic remodelling in the atria and ventricles, which facilitates AF progression and hampers its treatment. Although features of this remodelling are well-established and its mechanisms are partly understood, important pathways pertinent to AF arrhythmogenesis are still unidentified. The discovery of these missing pathways has the potential to lead to therapeutic breakthroughs. Endocrine dysfunction is well-recognized to lead to AF. In this review, we discuss endocrine and cardiocrine signalling systems that directly, or as a consequence of an underlying cardiac pathology, contribute to AF pathogenesis. More specifically, we consider the roles of products from the hypothalamic-pituitary axis, the adrenal glands, adipose tissue, the renin–angiotensin system, atrial cardiomyocytes, and the thyroid gland in controlling atrial electrical and structural properties. The influence of endocrine/paracrine dysfunction on AF risk and mechanisms is evaluated and discussed. We focus on the most recent findings and reflect on the potential of translating them into clinical application.

Clinical risk predictors in atrial fibrillation patients following successful coronary stenting: ENTRUST-AF PCI sub-analysis

Aims

This subgroup analysis of the ENTRUST-AF PCI trial (ClinicalTrials.gov Identifier: NCT02866175; Date of registration: August 2016) evaluated type of AF, and CHA₂DS₂-VASc score parameters as predictors for clinical outcome.

Methods

Patients were randomly assigned after percutaneous coronary intervention (PCI) to either edoxaban (60 mg/30 mg once daily [OD]; n = 751) plus a P2Y₁₂ inhibitor for 12 months or a vitamin K antagonist [VKA] (n = 755) plus a P2Y₁₂ inhibitor and aspirin (100 mg OD, for 1–12 months). The primary outcome was a composite of major/clinically relevant non-major bleeding (CRNM) within 12 months. The composite efficacy endpoint consisted of cardiovascular death, stroke, systemic embolic events, myocardial infarction (MI), and definite stent thrombosis.

Results

Major/CRNM bleeding event rates were 20.7%/year and 25.6%/year with edoxaban and warfarin, respectively (HR [95% CI]: 0.83 [0.654–1.047]). The event rates of composite outcome were 7.26%/year and 6.86%/year, respectively (HR [95% CI]): 1.06 [0.711–1.587]), and of overall net clinical benefit were 12.48%/year and 12.80%/year, respectively (HR [(95% CI]: 0.99 [(0.730; 1.343]). Increasing CHA₂DS₂-VASc score was associated with increased rates of all outcomes. CHA₂DS₂-VASc score ≥ 5 was a marker for stent thrombosis. Paroxysmal AF was associated with a higher occurrence of MI (4.87% versus 2.01%, p = 0.0024).

Conclusion

After PCI in AF patients, increasing CHA₂DS₂-VASc score was associated with increased bleeding rates and CHA₂DS₂-VASc score (≥ 5) predicted the occurrence of stent thrombosis. Paroxysmal AF was associated with MI. These findings may have important clinical implications in AF patients.

Safety and efficacy outcomes of double vs. triple antithrombotic therapy in patients with atrial fibrillation following percutaneous coronary intervention: a systematic review and meta-analysis of non-vitamin K antagonist oral anticoagulant-based randomized clinical trials

AIMS

To investigate the safety and efficacy of double vs. triple antithrombotic therapy (DAT vs. TAT) in patients with atrial fibrillation (AF) and acute coronary syndrome or who underwent percutaneous coronary intervention (PCI).

METHODS AND RESULTS

A systematic review and meta-analysis was performed using PubMed to search for non-vitamin K antagonist oral anticoagulant (NOAC)-based randomized clinical trials comparing DAT vs. TAT in AF patients undergoing PCI. Four trials encompassing 10 234 patients (DAT = 5496 vs. TAT = 4738) were included. The primary safety endpoint (ISTH major or clinically relevant non-major bleeding) was significantly lower with DAT compared with TAT [risk ratio (RR) 0.66, 95% confidence interval (CI) 0.56-0.78; P < 0.0001; I2 = 69%], which was consistent across all available bleeding definitions. This benefit was counterbalanced by a significant increase of stent thrombosis (RR 1.59, 95% CI 1.01-2.50; P = 0.04; I2 = 0%) and a trend towards higher risk of myocardial infarction with DAT. There were no significant differences in all-cause and cardiovascular death, stroke and major adverse cardiovascular events. The comparison of NOAC-based DAT vs. vitamin K antagonist (VKA)-TAT yielded consistent results and a significant reduction of intracranial haemorrhage (RR 0.33, 95% CI 0.17-0.65; P = 0.001; I2 = 0%).

CONCLUSION

Double antithrombotic therapy, particularly if consisting of a NOAC instead of VKA and a P2Y12 inhibitor, is associated with a reduction of bleeding, including major and intracranial haemorrhages. This benefit is however counterbalanced by a higher risk of cardiac-mainly stent-related-but not cerebrovascular ischaemic occurrences.

Differences in Thromboembolic Complications Between Paroxysmal and Persistent Atrial Fibrillation Patients Following Electrical Cardioversion (From the ENSURE-AF Study)

It is unclear if patients with paroxysmal atrial fibrillation (AF) and persistent AF have different outcomes following electrical cardioversion (ECV). ENSURE-AF-a multicenter, prospective, randomized, open-label, blinded-endpoint evaluation trial-compared once-daily edoxaban 60 mg with enoxaparin-warfarin in 2,199 subjects undergoing ECV of nonvalvular AF (NCT02072434). Patients received ≥3 weeks of proper anticoagulation or transesophageal echocardiogram before ECV paroxysmal AF was defined as AF with spontaneous conversion of duration of <7 days; persistent AF was defined as AF lasting ≥7 days without spontaneous conversion. Clinical characteristics and outcomes were compared between subjects based on type of AF present at baseline. In total, 415 subjects had paroxysmal AF; 1,777 had persistent AF. Patients with paroxysmal AF were older (65.8 ± 10.3 vs 63.9 ± 10.5, p = 0.001) with more hypertension (82.7% vs 77.2%, p = 0.01) versus persistent AF patients. Congestive heart failure was more common in persistent AF (46.7%) versus paroxysmal AF (31.3%, p <0.0001). CHA₂DS₂-VASc (score >2: 52.0% vs 49.5%, p = 0.4375) and prior myocardial infarction (6.5% vs 6.8%, p = 0.91) did not significantly differ between groups. After ECV, primary endpoint events were numerically higher in paroxysmal AF versus persistent AF (1.5% vs 0.6%, p = 0.0571), approaching statistical significance. Of note, myocardial infarction was observed in paroxysmal AF (n = 4 vs 0), whereas persistent AF was accompanied by stroke (n = 0 vs 5; p <0.05). In conclusion, patients with paroxysmal AF had more frequent major cardiovascular events than patients with persistent AF. Composite event rates were driven mainly by myocardial infarction in patients with paroxysmal AF and by stroke in those with persistent AF. Overall, the absolute number of events was low after ECV under anticoagulation.

Cerebral Immunohistochemical Characterization of the H2S and the Oxytocin Systems in a Porcine Model of Acute Subdural Hematoma

The hydrogen sulfide (H₂S) and the oxytocin/oxytocin receptor (OT/OTR) systems interact in trauma and are implicated in vascular protection and regulation of fluid homeostasis. Acute brain injury is associated with pressure-induced edema formation, blood brain barrier disruption, and neuro-inflammation. The similarities in brain anatomy: size, gyrencephalic organization, skull structure, may render the pig a highly relevant model for translational medicine. Cerebral biomarkers for pigs for pathophysiological changes and neuro-inflammation are limited. The current study aims to characterize the localization of OT/OTR and the endogenous H₂S producing enzymes together with relevant neuro-inflammatory markers on available porcine brain tissue from an acute subdural hematoma (ASDH) model. In a recent pilot study, anesthetized pigs underwent ASDH by injection of 20 mL of autologous blood above the left parietal cortex and were resuscitated with neuro-intensive care measures. After 54 h of intensive care, the animals were sacrificed, the brain was removed and analyzed via immunohistochemistry. The endogenous H₂S producing enzymes cystathionine-ɤ-lyase (CSE) and cystathionine-β-synthase (CBS), the OTR, and OT were localized in neurons, vasculature and parenchyma at the base of sulci, where pressure-induced injury leads to maximal stress in the gyrencephalic brain. The pathophysiological changes in response to brain injury in humans and pigs, we show here, are comparable. We additionally identified modulators of brain injury to further characterize the pathophysiology of ASDH and which may indicate future therapeutic approaches.

Molecular Basis of Atrial Fibrillation Pathophysiology and Therapy: A Translational Perspective

Atrial fibrillation (AF) is a highly prevalent arrhythmia, with substantial associated morbidity and mortality. There have been significant management advances over the past 2 decades, but the burden of the disease continues to increase and there is certainly plenty of room for improvement in treatment options. A potential key to therapeutic innovation is a better understanding of underlying fundamental mechanisms. This article reviews recent advances in understanding the molecular basis for AF, with a particular emphasis on relating these new insights to opportunities for clinical translation. We first review the evidence relating basic electrophysiological mechanisms to the characteristics of clinical AF. We then discuss the molecular control of factors leading to some of the principal determinants, including abnormalities in impulse conduction (such as tissue fibrosis and other extra-cardiomyocyte alterations, connexin dysregulation and Na+-channel dysfunction), electrical refractoriness, and impulse generation. We then consider the molecular drivers of AF progression, including a range of Ca2+-dependent intracellular processes, microRNA changes, and inflammatory signaling. The concept of key interactome-related nodal points is then evaluated, dealing with systems like those associated with CaMKII (Ca2+/calmodulin-dependent protein kinase-II), NLRP3 (NACHT, LRR, and PYD domains-containing protein-3), and transcription-factors like TBX5 and PitX2c. We conclude with a critical discussion of therapeutic implications, knowledge gaps and future directions, dealing with such aspects as drug repurposing, biologicals, multispecific drugs, the targeting of cardiomyocyte inflammatory signaling and potential considerations in intervening at the level of interactomes and gene-regulation. The area of molecular intervention for AF management presents exciting new opportunities, along with substantial challenges.

[Control of ventricular rate in permanent atrial fibrillation: cardio-protec-tion and tissue hemodynamics]

Objective To evaluate myocardial injury and tissue hemodynamics in elderly patients with permanent atrial fibrillation (AF) based on the achieved range of ventricular contraction rate (VCR).Materials and Methods This prospective, randomized, blind study included 75 patients aged ≥60 with permanent AF. All patients were prescribed bisoprolol as a VCR-reducing therapy. Patients were randomized to two groups according to the permuted-block design based on the range of resting VCR goal: group 1, 60-79 bpm (n=38) and group 2, 80-100 bpm (n=37). All patients also received perindopril and apixaban. Troponin I concentration was measured using the high-sensitivity assay (hsTn); parameters of tissue hemodynamics, including the mean blood flow velocity (Vm) and pulsatility index (PI), were measured using high-frequency ultrasound doppler flowmetry; echocardiographic indexes of left heart remodeling were recorded at baseline and after 6 month of VCR monitoring.Results Mean age of patients was 74±7 years. Medians [25th percentile; 75th percentile] of baseline hsTn concentrations were 10.2 [5.25; 21.2] ng / l in group 1 and 10.3 [5.4; 20.4] ng / ml in group 2 (p=0.91). 89.5 % of patients in group 1 and 100 % of patients in group 2 achieved the VCR range goal. At 6 month, resting VCRs were 70±4 bpm in group 1 (n=34) and 88±5 bpm in group 2 (n=37) (p1, p2&lt;0.001). According to echocardiographic data significant progression of myocardial remodeling was not observed. Concentrations of hsTn significantly decreased in both groups but the decrease was more pronounced in group 1, to 8.0 [4.13; 17.23; p1&lt;0.001] ng / l vs. 9.2 [4.8, 17.5] ng / l in group 2 (р1, p2&lt;0.001). A weak direct correlation was found between the VCR decrease and hsTn concentration (rs=0.44; p=0.009 in group 1, and rs=0.41; p=0.01 in group 2); regression coefficient was 0.78 at 95 % confidence interval (CI), from 0.21 to 1.3 (p=0.009) in group 1, and 0.14 at 95 % CI, from 0.04 to 0.24 (p=0.007) in group 2. Vm values were increased to 2.93±0.10 (p&lt;0.001) and 3.21±0.09 cm / sec (p&lt;0.001) and PIs were decreased to 1.42±0.03 conv. units (p&lt;0.01) and to 1.34±0.02 conv. units (p&lt;0.001) in groups 1 and 2, respectively.Conclusion The treatment aimed at VCR control in patients older than 60 with permanent AF was associated with a positive dynamics of myocardial injury (hsTn) and tissue hemodynamics indexes (Vm и РI). This indicates a possibility for using these indexes for further improvement of managing such patients.

Intense sport practices and cardiac biomarkers

Biomarkers are well established for the diagnosis of myocardial infarction, heart failure and cardiac fibrosis. Different papers on cardiac biomarker evolution during exercise have been published in the literature and generally show mild to moderate elevations. However, the mechanism responsible for these elevations, reflecting physiological or even pathophysiological changes, still has to be clearly elucidated. There are also indications of higher cardiac risk in poorly trained athletes than in well-trained athletes. Whether regular repetition of intensive exercise might lead, in the longer term, to fibrosis and heart failure remains to be determined. In this review, we summarized the main research about the effects of intense exercise (in particular, running) on cardiac biomarkers (including troponins, natriuretic peptides, etc.). We found that cardiac fibrosis biomarkers seemed to be the most informative regarding the biological impact of intense physical activity.

[Risk of Coronary Events in Atrial Fibrillation]

It has been established that cardiovascular events due to coronary heart disease are highly prevalent in the population of patients with atrial fibrillation. In this review, pathophysiologic mechanisms explaining this association are detailed along with supporting epidemiological evidence. Various methods for the prediction and prevention of coronary events in atrial fibrillation are iscussed, including modification of shared risk factors, antithrombotic therapy and selection of the optimal direct oral anticoagulant in terms of favourable influence on ischemic cardiac outcomes.

Hypertension and Arrhythmias

Hypertension is the most common cardiovascular risk factor and underlies heart failure, coronary artery disease, stroke, and chronic kidney disease. Hypertensive heart disease can manifest as cardiac arrhythmias. Supraventricular and ventricular arrhythmias may occur in the hypertensive patients. Atrial fibrillation and hypertension contribute to an increased risk of stroke. Some antihypertensive drugs predispose to electrolyte abnormalities, which may result in atrial and ventricular arrhythmias. A multipronged strategy involving appropriate screening, aggressive lifestyle modifications, and optimal pharmacotherapy can result in improved blood pressure control and prevent the onset or delay progression of heart failure, coronary artery disease, and cardiac arrhythmias.

Ischemic Heart Disease Modifies the Association of Atrial Fibrillation With Mortality in Heart Failure With Reduced Ejection Fraction

Background

The CASTLE‐AF (Catheter Ablation versus Standard Conventional Therapy in Patients With Left Ventricular Dysfunction and Atrial Fibrillation) trial recently reported that catheter ablation of atrial fibrillation (AF) improves survival in heart failure (HF) with reduced ejection fraction (HFrEF). However, established AF was not associated with mortality in trials of contemporary HFrEF pharmacotherapies. We investigated whether HFrEF pathogenesis may influence the conclusions of studies evaluating the prognostic impact of AF.

Methods and Results

Using a prospective cohort study of 791 patients with HFrEF, with AF determined using 24‐hour ambulatory ECG monitoring, univariable and multivariable Cox regression analyses were used to define the association between AF and mode‐specific mortality (mean follow‐up of 5.4 years). One‐year HF‐related hospitalization was assessed with binary logistic regression analysis. One‐year cardiac remodeling was assessed in a subgroup (n=378) using echocardiography. AF was present in 28.2% of patients, with 9.4% of these being paroxysmal. While AF was associated with increased risk of all‐cause mortality (hazard ratio, 1.27; 95% confidence interval 1.03–1.57), with diverging survival curves after 1 year of follow‐up, this association was lost in age‐sex–adjusted analyses. However, AF was associated with increased risk of age‐sex–adjusted all‐cause mortality in people with ischemic pathogenesis, with a statistically significant interaction between pathogenesis and AF. This was predominantly attributed to progressive HF deaths. After 1 year, HF hospitalization and cardiac remodeling were not associated with AF, even in people with ischemic pathogenesis.

Conclusions

AF is associated with increased risk of death in HFrEF of ischemic pathogenesis, predominantly due to progressive HF deaths during long‐term follow‐up. HFrEF pathogenesis should be considered in trial design and interpretation.

Effect of sepsis on the action potential and cardiac serotonin response in rats

The current study aimed to investigate the effect of sepsis on rat serotonin (5-HT) responses and cardiac action potentials. A total of 20 rats were randomly divided into a sepsis and control group (each, n=10). Rat hearts were harvested and perfused using the Langendorff method 18-h after the induction of sepsis, which was assessed using cecal puncture. Cardiac action potential was subsequently measured using a multichannel electrophysiology instrument. Immunohistochemistry and quantitative analysis were performed to identify the effect of sepsis on myocardial 5-HT expression. The results revealed that mitochondrial changes were present in septic rat hearts. Heart rate (361.10±12.29 bpm vs. 348.60±12.38 bpm; P<0.05) was significantly higher, atrial action potential duration (106.40±2.95 ms vs. 86.60±4.12 ms; P<0.01) was significantly longer and the area (0.62±0.06 µm² vs. 0.39±0.05 µm²; P<0.05) and number (0.92±0.02/field vs. 0.46±0.01/field; P<0.01) of myocardial cells were significantly higher in the septic compared with the control group. These results demonstrated that 5-HT prolongs the atrial action potential, increases heart rate and aggravates myocardial injury, indicating that it may therefore be one of the factors that leads to cardiac dysfunction in sepsis.

Prognostic implications of troponin I elevation in emergency department patients with tachyarrhythmia

Background

Tachyarrhythmias are very common in emergency medicine, and little is known about the long‐term prognostic implications of troponin I levels in these patients.

Hypothesis

This study aimed to investigate the correlation of cardiac troponin I (cTnI) levels and long‐term prognosis in patients admitted to the emergency department (ED) with a primary diagnosis of tachyarrhythmia.

Methods

A retrospective cohort study was conducted between January 2012 and December 2013, enrolling patients admitted to the ED with a primary diagnosis of tachyarrhythmia and having documented cTnI measurements. Clinical characteristics and 5‐year all‐cause mortality were analyzed.

Results

Of a total of 222 subjects with a primary diagnosis of tachyarrhythmia, 73 patients had elevated levels of cTnI (32.9%). Patients with elevated cTnI levels were older and presented significantly more cardiovascular risk factors. At the 5‐year follow‐up, mortality was higher among patients with elevated cTnI levels (log‐rank test P < 0.001). In the multivariable Cox regression analysis, elevated cTnI was an independent predictor of all‐cause death (hazard ratio, 1.95, 95% confidence interval: 1.08‐3.50, P = 0.026), in addition to age and prior heart failure.

Conclusion

Patients admitted to the ED with a primary diagnosis of tachyarrhythmia and high cTnI levels have higher long‐term mortality rates than patients with low cTnI levels. cTnI is thus a biomarker with predictive capacity for mortality in late follow‐up, conferring utility in the risk stratification of this population.

Biomarkers of Atrial Fibrillation: Which One Is a True Marker?

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmias and associated with the risk of stroke and death. Continuous development of the diagnostic tool and prognostic stratification may lead to optimal management of AF. The use of biomarkers in the management of AF has been grown as an interesting topic. However, the AF biomarkers are not yet well established in the major guidelines. Among these biomarkers, a lot of data show troponin and brain natriuretic peptides are promising for the prediction of future events. The troponin elevation in AF patients may not necessarily be diagnosed as myocardial infarction or significant coronary artery stenosis, and brain natriuretic peptide elevation may not necessarily confirm heart failure. Troponin T and troponin I may predict postoperative AF. Furthermore, troponin and brain natriuretic peptide gave better prognostic performance when compared with the risk score available today.

Hypertension and cardiac arrhythmias: a consensus document from the European Heart Rhythm Association (EHRA) and ESC Council on Hypertension, endorsed by the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS) and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE)

Hypertension is a common cardiovascular risk factor leading to heart failure (HF), coronary artery disease, stroke, peripheral artery disease and chronic renal insufficiency. Hypertensive heart disease can manifest as many cardiac arrhythmias, most commonly being atrial fibrillation (AF). Both supraventricular and ventricular arrhythmias may occur in hypertensive patients, especially in those with left ventricular hypertrophy (LVH) or HF. Also, some of the antihypertensive drugs commonly used to reduce blood pressure, such as thiazide diuretics, may result in electrolyte abnormalities (e.g. hypokalaemia, hypomagnesemia), further contributing to arrhythmias, whereas effective control of blood pressure may prevent the development of the arrhythmias such as AF. In recognizing this close relationship between hypertension and arrhythmias, the European Heart Rhythm Association (EHRA) and the European Society of Cardiology (ESC) Council on Hypertension convened a Task Force, with representation from the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE), with the remit to comprehensively review the available evidence to publish a joint consensus document on hypertension and cardiac arrhythmias, and to provide up-to-date consensus recommendations for use in clinical practice. The ultimate judgment regarding care of a particular patient must be made by the healthcare provider and the patient in light of all of the circumstances presented by that patient.

Review article: The utility of troponin and other investigations in patients presenting to the emergency department with supraventricular tachycardia

Patients with supraventricular tachycardia commonly present to the ED. There is a lack of consensus regarding assessment of these patients. Our aim was to determine the utility of troponin and four other investigations (full blood examination, electrolyte levels, thyroid function tests and chest X-rays) commonly requested for these patients. MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials (January 1992-March 2017) were searched for randomised controlled trials and observational studies (of sample size greater than 10). Our search strategy yielded no randomised controlled trials and seven observational studies with significant statistical heterogeneity among selected studies (I² 87.3%, P < 0.001). Included studies investigated a total of 1155 patients. All studies reported on the utility of troponin testing in this patient population. The pooled proportion of patients investigated with troponin was 0.66 (95% confidence interval 0.44-0.88). The pooled proportion of positive troponin tests was 0.32 (95% confidence interval 0.23-0.41). Only one study reported on the utility of the remaining four investigations with abnormal results as follows: thyroid stimulating hormone 14%, haemoglobin 6%, white cell count 19% and chest X-ray 22%. Investigations are commonly requested for patients presenting with supraventricular tachycardia. Troponin testing is commonly performed with a high proportion of positive findings although these results did not appear to be associated with major adverse cardiac events. Heterogeneity among studies and low levels of evidence precluded conclusions on full blood examinations, electrolyte levels, thyroid testing and utility of chest X-rays in this patient population.

High Cardiac Troponin I Is Associated With Transesophageal Echocardiographic Risk of Thromboembolism and Ischemic Stroke Events in Non-Valvular Atrial Fibrillation Patients

BACKGROUND

Abnormalities in the left atrium (LA) detected on transesophageal echocardiography (TEE) are reliable predictors of thromboembolism in patients with atrial fibrillation (AF). Cardiac troponin I, a marker of subclinical myocardial damage, may also be a predictor of thromboembolic events in patients with AF. The relationship between cardiac troponin I and thromboembolic risk on TEE, however, remains unclear.Methods and Results:TEE and laboratory data, including high sensitivity cardiac troponin I (hs-cTnI) and CHA₂DS₂-VASc score, were analyzed in 199 patients with non-valvular AF (NVAF). Patients were stratified into those with or without LA abnormality, defined as LA appendage flow velocity <20 cm/s or dense spontaneous echo contrast. On multiple logistic analysis of the clinical variables, hs-cTnI was associated with LA abnormality (95% CI: 1.0003-1.020, P=0.034). The area under the curve for LA abnormality increased on addition of hs-cTnI to CHA₂DS₂-VASc score. The incidence rate of ischemic stroke was higher in the high hs-cTnI group than in the low-hs-cTnI group (log-rank test, P<0.05).

CONCLUSIONS

Elevated hs-cTnI was independently associated with LA abnormality in NVAF patients. hs-cTnI level may be a useful biomarker for risk stratification of thromboembolism in NVAF patients.

Integrating new approaches to atrial fibrillation management: the 6th AFNET/EHRA Consensus Conference

There are major challenges ahead for clinicians treating patients with atrial fibrillation (AF). The population with AF is expected to expand considerably and yet, apart from anticoagulation, therapies used in AF have not been shown to consistently impact on mortality or reduce adverse cardiovascular events. New approaches to AF management, including the use of novel technologies and structured, integrated care, have the potential to enhance clinical phenotyping or result in better treatment selection and stratified therapy. Here, we report the outcomes of the 6th Consensus Conference of the Atrial Fibrillation Network (AFNET) and the European Heart Rhythm Association (EHRA), held at the European Society of Cardiology Heart House in Sophia Antipolis, France, 17-19 January 2017. Sixty-two global specialists in AF and 13 industry partners met to develop innovative solutions based on new approaches to screening and diagnosis, enhancing integration of AF care, developing clinical pathways for treating complex patients, improving stroke prevention strategies, and better patient selection for heart rate and rhythm control. Ultimately, these approaches can lead to better outcomes for patients with AF.

Human electronegative low-density lipoprotein modulates cardiac repolarization via LOX-1-mediated alteration of sarcolemmal ion channels

Dyslipidemia is associated with greater risk of ventricular tachyarrhythmias in patients with cardiovascular diseases. We aimed to examine whether the most electronegative subfraction of low-density lipoprotein (LDL), L5, is correlated with QTc prolongation in patients with coronary artery disease (CAD) and investigate the effects of human L5 on the electrophysiological properties of cardiomyocytes in relation to the lectin-like oxidized LDL receptor (LOX-1). L5 was isolated from the plasma of 40 patients with angiography documented CAD and 13 patients with no CAD to correlate the QTc interval respectively. The mean concentration of L5 was higher and correlated with QTc in patients with CAD compared to controls. To examine the direct effect of L5 on QTc, mice were intravenously injected with L5 or L1. L5-injected wild-type but not LOX-1^−/− mice showed longer QTc compared to L1-injected animals in vivo with corresponding longer action potential duration (APD) in cardiomyocytes incubated with L5 in vitro. The APD prolongation was mediated by an increase of L-type calcium current and a decrease of transient outward potassium current. We show that L5 was positively correlated with QTc prolongation in patients with ischemic heart disease. L5 can modulate cardiac repolarization via LOX-1-mediated alteration sarcolemmal ionic currents.

Dynamic high-sensitivity troponin elevations in atrial fibrillation patients might not be associated with significant coronary artery disease

Background

Since the introduction of high-sensitivity troponin assays a greater proportion of atrial fibrillation (AF) patients present with dynamic troponin elevations. We hypothesize that significant coronary artery disease (CAD) causes relative ischemia in the setting of a rapid heart rate resulting in dynamic troponin elevation. The aim of this study was to examine if patients without known CAD who present with AF, tachycardia and dynamic high-sensitivity troponin T (hsTnT) change have an increased risk of cardiac events.

Methods

We retrospectively included AF patients presenting with tachycardia during one year. The primary endpoint was acute coronary syndrome, revascularization or death due to ischemic heart disease during 30 months follow-up.

Results

Five hundred twenty-two patients without known CAD were included, 300 (57%) had normal hsTnT and 49 (9.5%) had dynamic hsTnT elevation. During follow-up 12 (4%) patients with normal hsTnT reached the primary endpoint and a total of 14 (4.7%) patients died. In the group with dynamic hsTnT the results were 4 (8.2%) and 12 (25%) respectively. The age-adjusted hazard ratio (HR) for the primary endpoint in patients with dynamic hsTnT was 1.9 (95% CI: 0.6 to 6.2; p = 0.28) and for all-cause mortality 3.8 (95% CI: 1.7 to 8.5; p = 0.001).

Conclusions

Dynamic hsTnT elevation in connection with AF might not be associated with any major increased risk of coronary events, but indicates increased all-cause mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-017-0601-7) contains supplementary material, which is available to authorized users.

Atrial fibrillation as a prognostic indicator of myocardial infarction and cardiovascular death: a systematic review and meta-analysis

This study aimed to investigate whether atrial fibrillation (AF) predicts myocardial infarction (MI) or cardiovascular (CV) death. AF is a well-established risk factor for thrombotic stroke and all-cause mortality. PubMed, EmBase, and Cochrane Central were searched for articles comparing the incidence rates of MI, CV death, or CV events between AF and non-AF patients. Relative risk ratio (RR) was used as effect estimate. Crude and adjusted RRs were calculated. Data were pooled using a random-effects model. The meta-analysis included 27 studies. In the unadjusted analysis, AF patients had a nonsignificant trend toward a higher risk of MI compared with non-AF patients; however, a significant association was found. The crude data analysis showed that AF was associated with increased risk of CV death (P < 0.05) and CV events (P < 0.05). These associations remained significant after pooling data from adjusted models (CV death: RR = 1.95, 95% CI 1.51–2.51, P < 0.05; CV events: RR = 2.10, 95% CI 1.50–2.95, P < 0.05). These results showed that AF is an independent risk factor for MI, CV death, and CV events.

Characteristics of coronary artery disease among patients with atrial fibrillation compared to patients with sinus rhythm

BACKGROUND

With a high prevalence of coronary artery disease (CAD) among patients with atrial fibrillation (AF), CAD is one of the main risk factors for AF. However, little is known about the characteristics of CAD in AF patients, especially whether a specific anatomical distribution of coronary artery stenoses might predispose an individual to AF via atrial ischemia remains speculative. To address this issue, we evaluated the potential associations between angiographic characteristics of CAD and AF.

METHODS

In this single-center retrospective analysis, 796 consecutive patients with confirmed CAD and AF (CAD-AF) and 785 patients with CAD and sinus rhythm (CAD-SR) were enrolled. Clinical characteristics and angiographic findings were compared between groups in stable CAD and during acute myocardial infarction (MI).

RESULTS

Mitral valve disease and chronic heart failure were significantly more common in CAD-AF than in CAD-SR. Clinical condition in CAD-AF was significantly more severe as indicated by New York Heart Association/World Health Organization functional class. Left ventricular ejection fraction was reduced in CAD-AF, reflecting the marked fraction of patients with ischemic cardiomyopathy. No association between anatomical characteristics of CAD and AF was found. However, CAD-AF seemed to be associated with a higher CAD severity (p = 0.06). Additionally, CAD-AF with MI showed a significantly higher number of diseased coronary vessels.

CONCLUSION

The anatomical distribution of coronary artery stenoses does not contribute to AF in CAD patients. However, AF is linked to a higher CAD severity, which might predispose individuals to AF by driving ischemic heart disease and changes in left ventricular function.

Atrial fibrillation, progression of coronary atherosclerosis and myocardial infarction

Background Despite atrial fibrillation representing an established risk factor for stroke, the association between atrial fibrillation and both progression of coronary atherosclerosis and major adverse cardiovascular events is not well characterized. We assessed the serial measures of coronary atheroma burden and cardiovascular outcomes in patients with and without atrial fibrillation. Methods Data were analyzed from nine clinical trials involving 4966 patients with coronary artery disease undergoing serial intravascular ultrasonography at 18-24 month intervals to assess changes in percent atheroma volume (PAV). Using a propensity weighted analysis, and following adjustment for baseline variables, patients with ( n = 190) or without ( n = 4776) atrial fibrillation were compared with regard to coronary plaque volume and major adverse cardiovascular events (death, myocardial infarction, and stroke). Results Atrial fibrillation patients demonstrated lower baseline PAV (36.0 ± 8.9 vs. 38.1 ± 8.9%, p = 0.002) and less PAV progression (-0.07 ± 0.34 vs. + 0.23 ± 0.34%, p = 0.001) compared with the non-atrial fibrillation group. Multivariable analysis revealed atrial fibrillation to independently predict both myocardial infarction [HR, 2.41 (1.74,3.35), p<0.001] 2.41 (1.74, 3.35), p < 0.00) and major adverse cardiovascular events [HR, 2.2, (1.66, 2.92), p<0.001] 2.20 (1.66, 2.92), p < 0.001]. Kaplan-Meier analysis showed that atrial fibrillation compared with non-atrial fibrillation patients had a significantly higher two-year cumulative incidence of overall major adverse cardiovascular events (4.4 vs. 2.0%, log-rank p = 0.02) and myocardial infarction (3.3 vs. 1.5%, log-rank p = 0.05). Conclusions The presence of atrial fibrillation independently associates with a heightened risk of myocardial infarction despite a lower baseline burden and progression rate of coronary atheroma. Further studies are necessary to define the pathogenesis of myocardial infarction in the setting of atrial fibrillation.

Lone Atrial Fibrillation Is Associated With Impaired Left Ventricular Energetics That Persists Despite Successful Catheter Ablation

Supplemental Digital Content is available in the text.

Lone atrial fibrillation (AF) may reflect a subclinical cardiomyopathy that persists after sinus rhythm (SR) restoration, providing a substrate for AF recurrence. To test this hypothesis, we investigated the effect of restoring SR by catheter ablation on left ventricular (LV) function and energetics in patients with AF but no significant comorbidities.