Pathophysiological and therapeutic implications in patients with atrial fibrillation and heart failure

Development of a Nomogram That Predicts the Risk of Atrial Fibrillation in Patients with Coronary Heart Disease

Objective

To explore the risk factors of atrial fibrillation (AF) in patients with coronary heart disease (CHD), and to construct a risk prediction model.

Methods

The participants in this case-control study were from the cardiovascular Department of Changzhou Affiliated Hospital of Nanjing University of Chinese Medicine from June 2016 to June 2023, and they were divided into AF group and non-AF group according to whether AF occurred during hospitalization. The clinical data of the two groups were compared by retrospective analysis. Multivariate Logistic regression analysis was used to investigate the risk factors of AF occurrence in CHD patients. The nomogram model was constructed with R 4.2.6 language "rms" package, and the model's differentiation, calibration and effectiveness were evaluated by drawing ROC curve, calibration curve and decision curve.

Results

A total of 1258 patients with CHD were included, and they were divided into AF group (n=92) and non-AF group (n=1166) according to whether AF was complicated. Logistic regression analysis showed that age, coronary multiple branch lesion, history of heart failure, history of drinking, pulmonary hypertension, left atrial diameter, left ventricular end-diastolic diameter and diabetes mellitus were independent risk factors for the occurrence of AF in CHD patients (P < 0.05). The ROC curve showed that the AUC of this model was 0.956 (95% CI (0.916, 0.995)) and the consistency index was 0.966. The calibration curve of the model is close to the ideal curve. The analysis of decision curve shows that the prediction value of the model is better when the probability threshold of the model is 0.042~0.963.

Conclusion

The nomogram model established in this study for predicting the risk of AF in patients with CHD has better predictive performance and has certain reference value for clinical identification of high-risk groups prone to AF in patients with CHD.

Arrhythmias and cardiac MRI associations in patients with established cardiac dystrophinopathy

AIMS

Some patients with cardiac dystrophinopathy die suddenly. Whether such deaths are preventable by specific antiarrhythmic management or simply indicate heart failure overwhelming medical therapies is uncertain. The aim of this prospective, cohort study was to describe the occurrence and nature of cardiac arrhythmias recorded during prolonged continuous ECG rhythm surveillance in patients with established cardiac dystrophinopathy and relate them to abnormalities on cardiac MRI.

METHODS AND RESULTS

A cohort of 10 patients (36.3 years; 3 female) with LVEF<40% due to Duchenne (3) or Becker muscular (4) dystrophy or Duchenne muscular dystrophy-gene carrying effects in females (3) were recruited, had cardiac MRI, ECG signal-averaging and ECG loop-recorder implants. All were on standard of care heart medications and none had prior history of arrhythmias.No deaths or brady arrhythmias occurred during median follow-up 30 months (range 13-35). Self-limiting episodes of asymptomatic tachyarrhythmia (range 1-29) were confirmed in 8 (80%) patients (ventricular only 2; ventricular and atrial 6). Higher ventricular arrhythmia burden correlated with extent of myocardial fibrosis (extracellular volume%, p=0.029; native T1, p=0.49; late gadolinium enhancement, p=0.49), but not with LVEF% (p=1.0) on MRI and atrial arrhythmias with left atrial dilatation. Features of VT episodes suggested various underlying arrhythmia mechanisms.

CONCLUSIONS

The overall prevalence of arrhythmias was low. Even in such a small sample size, higher arrhythmia counts occurred in those with larger scar burden and greater ventricular volume, suggesting key roles for myocardial stretch as well as disease progression in arrhythmogenesis. These features overlap with the stage of left ventricular dysfunction when heart failure also becomes overt. The findings of this pilot study should help inform the design of a definitive study of specific antiarrhythmic management in dystrophinopathy.

TRIAL REGISTRATION NUMBER

ISRCTN15622536.

The Relationship Between Atrial Fibrillation and Parathyroid Hormone in Heart Failure Outpatients

Background    Atrial fibrillation (AF) is a common arrhythmia in heart failure (HF). Plasma concentrations of para-thyroid hormone (PTH) have been shown to increase in HF. The relationship between PTH concentrations and the presence of AF in HF is, however, unknown. This study analyzed the relationship between plasma PHT concentrations and AF in patients with systolic HF.Material and methods    131 consecutive, stable HF patients, who were admitted to the HF outpatient clinic, were included in this prospective, observational study. Patients were classified as those with AF (n = 36) and those in sinus rhythm (SR, n = 95).Results    PTH concentrations were markedly higher in patients with AF compared to the patients in SR [85 (15-320) vs. 112 (30-326) U / ml, p=0.007]. PTH, creatinine clearance, hemoglobin, creatinine, age, and left ventricular ejection fraction were found to be related to AF by univariate analysis; though, multivariate logistic regression analysis showed that only PTH concentration was independently related to AF.Conclusion    PTH concentrations can be used to indicate AF in patients with systolic HF.

Effectiveness of Catheter Ablation in Left Ventricular Ejection Fraction, Stroke, Quality of Life, All-Cause Mortality, Sinus Rhythm Maintenance, and Hospitalization Rates as Compared to Medical Therapy

Atrial fibrillation (AF) in the setting of heart failure (HF) accounts for a significant proportion of mortality. AF can be managed either with rate control or rhythm control strategies. Rate control involves the use of beta blockers or calcium channel blockers. Rhythm control methods use antiarrhythmic drugs or catheter ablation (CA) to abolish the rhythm. Articles from PubMed and Google Scholar were chosen for review. The literature was reviewed for data from the last 10 years to be chosen for interpretation. Clinical trials, meta-analyses, and systematic analysis were included in this study. Various health parameters such as all-cause mortality, hospitalization rates, sinus rhythm (SR) maintenance, quality of life improvement, stroke risk, left ventricular ejection fraction (LVEF) improvement, and healthcare costs were analyzed. We demonstrated that CA was superior to medical therapy in reducing all-cause mortality and hospitalization. It leads to significant improvement in LVEF as SR was maintained consistently. Overall, quality of life improved in those who underwent ablation as compared to those who did not. Stroke risk reduction was seen in observational studies only. We recommend CA as first-line therapy for treating patients with AF in the setting of HF. More clinical trials are needed to determine the effectiveness of ablation in reducing stroke risk.

Midazolam versus morphine in acute cardiogenic pulmonary edema patients with and without atrial fibrillation: findings from the MIMO trial

BACKGROUND AND IMPORTANCE

The MIMO clinical trial showed that patients with acute cardiogenic pulmonary edema (ACPE) treated with midazolam had fewer serious adverse events than those treated with morphine. Atrial fibrillation (AF) is a common comorbidity in heart failure and affects patient's outcome.

OBJECTIVE

The primary endpoint of this substudy is to know if AF modified the reduced risk of serious adverse events in the midazolam arm compared to morphine. The first secondary endpoint is to know if AF modified the reduced risk of serious adverse events or death at 30 days in the midazolam arm. The second secondary objective of this substudy is to analyze whether AF modified the reduced risk of midazolam against morphine on the total number of serious adverse events per patient.

DESIGN

We conducted a secondary analysis of the MIMO trial. Patients more than 18 years old clinically diagnosed with ACPE and with dyspnea and anxiety were randomized (1:1) at emergency department arrival to receive either intravenous midazolam or morphine.

OUTCOME MEASURES AND ANALYSIS

In this post hoc analysis, we calculated the relative risk (RR) of serious adverse events in patients with and without AF. Calculating the Cochran-Mantel-Haenszel interaction test, we evaluated if AF modified the reduced risk of serious adverse events in the midazolam arm compared to morphine.

MAIN RESULTS

One hundred eleven patients (median = 78.9 years; IQR, 72.3-83.7; women, 52.2%) were randomized in the MIMO trial, 55 to receive midazolam and 56 to morphine. All randomized patients received the assigned drug and there were no losses to follow-up. Forty-four patients (39.6%) had AF. In the AF group, the RR for the incidence of serious adverse events in the midazolam versus morphine arm was 0.42 (95% CI, 0.14-1.3). In the group without AF, the RR was 0.46 (95% CI, 0.21-1). The presence of AF did not modify the reduced risk of serious adverse events in the midazolam arm compared with morphine ( P for interaction = 0.88).

CONCLUSION

This post hoc analysis of the MIMO trial suggests that the reduced risk of serious adverse events in the midazolam group compared to morphine is similar in patients with and without AF.

Long-term outcome of repaired tetralogy of Fallot: Survival, tachyarrhythmia, and impact of pulmonary valve replacement

BACKGROUND

Pulmonary valve replacement (PVR) is recommended for severe pulmonary regurgitation in repaired tetralogy of Fallot (rTOF).

OBJECTIVE

The purpose of this study was to investigate the event rate and effectiveness of PVR.

METHODS

A retrospective study of tetralogy of Fallot patients who survived total repair from 1970 to 2020 was conducted.

RESULTS

We identified 1744 rTOF patients; 86.6% with classic rTOF, 11.5% with pulmonary atresia, 0.8% with endocardial cushion defect, and 1.1% with absent pulmonary valve. Annual risks of tachyarrhythmia/sudden cardiac arrest (SCA) increased to 0.295% and 1.338% in patients aged 10-30 and 30-60 years, respectively, without sex predominance. PVR (223 surgical and 39 percutaneous) event rate was 34.7% ± 2.1% by 30 years after repair (annual risk: 1.57% between 10 and 30 years after repair). The second PVR rate was 9.9% ± 4.1% by 20 years after the first PVR. Tachyarrhythmia/SCA risk was higher in PVR patients than in No PVR patients and was reduced in PVR patients without tachyarrhythmia/SCA before PVR. However, survival in patients with ventricular tachyarrhythmia/SCA still was better after PVR. At PVR, 13% of patients had tachyarrhythmia/SCA, which was the major predictor of events after PVR. Before PVR, although the ventricular tachyarrhythmia/SCA risks included QRS duration >160 ms and New York Heart Association functional class III or IV, supraventricular tachyarrhythmia was associated with PVR age ≥28 years and N-terminal pro-brain natriuretic peptide >450 pg/mL.

CONCLUSION

Tachyarrhythmia/SCA occurrence and the need for PVR increased with age during young adulthood. PVR reduced subsequent arrhythmias only in those patients without arrhythmias before PVR.

Incidence and Determinants of Spontaneous Cardioversion of Early Onset Symptomatic Atrial Fibrillation

Atrial fibrillation (AF) is the most frequent chronic arrhythmia worldwide, and it is associated with significant morbidity and mortality, making it a considerable burden both to patients and the healthcare system. Nowadays, an early attempt to restore sinus rhythm in acute symptomatic AF through electrical or pharmacological cardioversion is the most common approach in the Emergency Department (ED). However, considering the high percentage of spontaneous cardioversion of paroxysmal AF reported by many studies, this approach may not be the ideal choice for all patients. In this manuscript we performed a review of the most relevant studies found in literature with the aim of identifying the main determinants of spontaneous cardioversion, focusing on those easy to detect in the ED. We have found that the most relevant predictors of spontaneous cardioversion are the absence of Heart Failure (HF), a small atrial size, recent-onset AF, rapid Atrial Fibrillatory Rate and the relationship between a previous AF episode and Heart Rate/Blood Pressure. A number of those are utilized, along with other easily determined parameters, in the recently developed "ReSinus" score which predicts the likelihood of AF spontaneous cardioversion. Such identification may help the physician decide whether immediate cardioversion is necessary, or whether to adopt a "watch-and-wait" strategy in the presence of spontaneous cardioversion determinants.

Prediction of herbal medicines based on immune cell infiltration and immune- and ferroptosis-related gene expression levels to treat valvular atrial fibrillation

Inflammatory immune response is apparently one of the determinants of progressive exacerbation of valvular atrial fibrillation(VAF). Ferroptosis, an iron-dependent modality of regulated cell death, is involved in the immune regulation of cardiovascular disease. However, the relevant regulatory mechanisms of immune infiltration and ferroptosis in VAF have been less studied. In the current study, a highly efficient system for screening immunity- and ferroptosis-related biomarkers and immunomodulatory ability of herbal ingredients has been developed with the integration of intelligent data acquisition, data mining, network pharmacology, and computer-assisted target fishing. VAF patients showed higher infiltration of neutrophils and resting stage dendritic cells, while VSR patients showed higher infiltration of follicular helper T cells. In addition, six (e.g., PCSK2) and 47 (e.g., TGFBR1) ImmDEGs and one (SLC38A1) and four (TGFBR1, HMGB1, CAV1, and CD44) FerDEGs were highly expressed in patients with valvular sinus rhythm (VSR) and VAF, respectively. We further identified a core subnetwork containing 34 hub genes, which were intersected with ImmDEGs and FerDEGs to obtain the key gene TGFBR1. Based on TGFBR1, 14 herbs (e.g., Fructus zizyphi jujubae, Semen Juglandis, and Polygonum cuspidatum) and six herbal ingredients (curcumin, curcumine, D-glucose, hexose, oleovitamin A, and resveratrol) were predicted. Finally, TGFBR1 was found to dock well with curcumin and resveratrol, and it was further verified that curcumin and resveratrol could significantly reduce myocardial fibrosis. We believe that herbs rich in curcumin and resveratrol such as Rhizoma curcumae longae and Curcuma kwangsiensis, mitigate myocardial fibrosis to improve VAF by modulating the TGFβ/Smad signaling pathway. This strategy provides a prospective approach systemically characterizing phenotype-target-herbs relationships based on the tissue-specific biological functions in VAF and brings us new insights into the searching lead compounds from Chinese herbs.

Putative protective effects of sodium-glucose cotransporter 2 inhibitors on atrial fibrillation through risk factor modulation and off-target actions: potential mechanisms and future directions

Atrial fibrillation, the most common cardiac arrhythmia, results in substantial morbidity and mortality related to its increased risks of stroke, heart failure, and impaired cognitive function. The incidence and prevalence of atrial fibrillation in the general population is rising, making atrial fibrillation treatment and management of its risk factors highly relevant clinical targets. One well-studied risk factor for the development of atrial fibrillation is diabetes mellitus. Inhibitors of sodium-glucose cotransporter 2 (SGLT2), common medications used to treat diabetes mellitus, have been observed to decrease the incidence of atrial fibrillation. This review discusses the SGLT2 and its role in glucose homeostasis, molecules inhibiting the transporter, possible physiological mechanisms responsible for the decreased incident atrial fibrillation in patients treated with SGLT2 inhibitors and proposes mechanistic studies to further our understanding of the biological processes involved.

Characteristics of the Dynamic Electrocardiogram in the Elderly with Nonvalvular Atrial Fibrillation Combined with Long R-R Intervals

Objective

To investigate the characteristics of dynamic electrocardiogram and their clinical implications in elderly patients with nonvalvular atrial fibrillation combined with long R-R intervals.

Methods

Elderly patients diagnosed with nonvalvular atrial fibrillation who were admitted as an inpatient or attended the outpatient department from January 2015 to January 2020 were selected. Patients were divided into two groups based on the presence of a long R-R interval. The characteristics and therapeutic significance of dynamic electrocardiogram between the two groups were compared.

Results

A total of 532 patients were included in our analyses. Of these, 399 patients were in the long R-R interval group and 133 in the nonlong R-R interval group. In 399 patients, there were 48,840 long R-R intervals manifested within 24 hours. The average, slowest, and fastest ventricular rates during sleep time were higher than those in nonsleep time, while the number of long R-R intervals in sleep time was significantly smaller than that in nonsleep time (P < 0.05). Clinical parameters including dizziness/syncope, cerebral infarction, ST-segment changes, platelet count, average hematocrit, prothrombin time (PT), left ventricular systolic function, end-diastolic diameter, pulmonary artery pressure, and left ventricular ejection fraction were comparable between the groups (P > 0.05). When compared with the nonlong R-R interval group, the level of C-reactive protein was slightly lower in the long R-R interval group (P < 0.05). In addition, the long R-R interval group had a higher incidence of atrial premature beats but a lower incidence of ventricular premature beats. Furthermore, the probability of long R-R interval combined with paroxysmal atrial tachycardia, transient ventricular arrest, second-degree atrioventricular block, and complete or incomplete right bundle branch block was higher than that of nonlong R-R interval (P < 0.05). In patients with long R-R interval >3 s, the risk of having second-degree atrioventricular block and complete or incomplete right bundle branch block was significantly lower, while the risk of having transient ventricular arrest was higher when compared to patients with long R-R intervals of 2-3 s (P < 0.05P).

Conclusions

Long R-R interval is a common electrocardiographic phenomenon among the elderly with nonvalvular atrial fibrillation. The long R-R interval mostly occurs in nonsleeping time. The average ventricular rate, slowest ventricular rate, and fastest ventricular rate of sleep time are higher than nonsleeping time. Analysis of the characteristics of the dynamic electrocardiogram of these patients may shed light on the mechanisms for long R-R intervals, including the likelihood of concealed conduction and physiological interference in the atrioventricular node, overspeed inhibition, increased vagus nerve tension, or pathological atrioventricular block.

Mendelian randomization study on atrial fibrillation and cardiovascular disease subtypes

Atrial fibrillation (AF) has been associated with numerous diseases. However, whether AF is a cause or consequence of these diseases is uncertain. To clarify, we assessed the causal role of AF on ischemic heart disease (IHD), stroke, other cardiovascular disease (CVD) subtypes, type 2 diabetes mellitus (T2DM), and late-onset AD using bi-directional two-sample Mendelian randomization (MR) among people primarily of European descent. Genetically predicted log odds of AF was associated with any stroke (odds ratio (OR) 1.22, 95% CI 1.18 to 1.27), particularly cardioembolic stroke and possibly subdural hemorrhage, with sensitivity analyses showing similar positive findings. Genetically predicted AF was also associated with arterial thromboembolism (1.32, 1.13 to 1.53), and heart failure (1.26, 1.21 to 1.30). No association of genetically predicted AF with IHD, T2DM, cognitive function, or late-onset AD was found. Conversely, genetically predicted IHD, heart failure and possibly ischemic stroke, particularly cardioembolic stroke, were positively associated with AF. Atrial fibrillation plays a role in any stroke, arterial thromboembolism, and heart failure, corroborating current clinical guidelines on the importance of preventing these complications by effective AF management. In addition, patients with IHD, heart failure or possibly ischemic stroke might be predisposed to developing AF, with implications for management.

Prevalence, Mechanisms, and Management of Ischemic Stroke in Heart Failure Patients

Heart failure (HF) and stroke, two of the major causes of death worldwide, are closely associated. Although atrial fibrillation (AF), which occurs in more than half of patients with HF, is a major risk factor for stroke, there is a great deal of evidence that HF itself increases the risk of stroke independent of AF. The main mechanism of stroke appears to be thromboembolism. However, previous studies have failed to demonstrate the benefit of warfarin in patients with HF without AF, as the benefit of stroke prevention was counteracted by the increased incidence of major bleeding. Recently, researchers have identified patients with HF at a particularly high risk for stroke who may benefit from anticoagulation therapy. Based on stroke-risk prediction models, it may be possible to make better stroke prevention decisions for patients with HF. Moreover, non-vitamin K oral anticoagulants have emerged as anticoagulants with a more favorable risk-benefit profile than warfarin. Future studies on selecting high-risk patients and using more appropriate antithrombotics will lead to improved management of patients with HF.

Meta-analysis of the Usefulness of Catheter Ablation of Atrial Fibrillation in Patients With Heart Failure With Preserved Ejection Fraction

Catheter ablation improves clinical outcomes in atrial fibrillation (AF) patients with heart failure (HF) with reduced ejection fraction (HFrEF). However, the role of catheter ablation in HF with a preserved ejection fraction (HFpEF) is less clear. We performed a literature search and systematic review of studies that compared AF recurrence at one year after catheter ablation of AF in patients with HFpEF versus those with HFrEF. Risk ratio (RR; where a RR <1.0 favors the HFpEF group) and mean difference (MD; where MD <0 favors the HFpEF group) 95% confidence intervals (CI) were measured for dichotomous and continuous variables, respectively. Six studies with a total of 1,505 patients were included, of which 764 (51%) had HFpEF and 741 (49%) had HFrEF. Patients with HFpEF experienced similar recurrence of AF 1 year after ablation on or off antiarrhythmic drugs compared with those with HFrEF (RR 1.01; 95% CI 0.76, 1.35). Fluoroscopy time was significantly shorter in the HFpEF group (MD -5.42; 95% CI -8.51, -2.34), but there was no significant difference in procedure time (MD 1.74; 95% CI -11.89, 15.37) or periprocedural adverse events between groups (RR 0.84; 95% CI 0.54,1.32). There was no significant difference in hospitalizations between groups (MD 1.18; 95% CI 0.90, 1.55), but HFpEF patients experienced significantly less mortality (MD 0.41; 95% CI 0.18, 0.94). In conclusion, based on the results of this meta-analysis, catheter ablation of AF in patients with HFpEF appears as safe and efficacious in maintaining sinus rhythm as in those with HFrEF.

Diffuse myocardial fibrosis: mechanisms, diagnosis and therapeutic approaches

Diffuse myocardial fibrosis resulting from the excessive deposition of collagen fibres through the entire myocardium is encountered in a number of chronic cardiac diseases. This lesion results from alterations in the regulation of fibrillary collagen turnover by fibroblasts, facilitating the excessive deposition of type I and type III collagen fibres within the myocardial interstitium and around intramyocardial vessels. The available evidence suggests that, beyond the extent of fibrous deposits, collagen composition and the physicochemical properties of the fibres are also relevant in the detrimental effects of diffuse myocardial fibrosis on cardiac function and clinical outcomes in patients with heart failure. In this regard, findings from the past 20 years suggest that various clinicopathological phenotypes of diffuse myocardial fibrosis exist in patients with heart failure. In this Review, we summarize the current knowledge on the mechanisms and detrimental consequences of diffuse myocardial fibrosis in heart failure. Furthermore, we discuss the validity and usefulness of available imaging techniques and circulating biomarkers to assess the clinicopathological variation in this lesion and to track its clinical evolution. Finally, we highlight the currently available and potential future therapeutic strategies aimed at personalizing the prevention and reversal of diffuse myocardial fibrosis in patients with heart failure.

Characteristics, treatment, and outcomes of newly diagnosed atrial fibrillation patients with heart failure: GARFIELD-AF

Aims

Heart failure (HF) and atrial fibrillation (AF) may coexist and influence each other. However, characteristics, anticoagulant treatment, and outcomes of contemporary AF patients with concurrent HF are ill‐defined. This study analyses characteristics, treatment, and 2 year outcomes in newly diagnosed Global Anticoagulant Registry in the FIELD‐Atrial Fibrillation (GARFIELD‐AF) patients with vs. without HF.

Methods and results

GARFIELD‐AF is the world's largest observational AF patient study. At enrolment, 11 758 of 52 072 patients (22.6%) had HF; 76.3% were New York Heart Association class II–III. Patients with HF had comparable demographics, blood pressure, and heart rate but more likely had permanent (15.6% vs. 11.9%) or persistent AF (18.9% vs. 13.8%), acute coronary syndromes (16.7% vs. 8.9%), vascular disease (40.8% vs. 20.2%), and moderate‐to‐severe chronic kidney disease (14.6% vs. 9.0%) than those without. Anticoagulant prescription was similar between the two groups. At 2 year follow‐up, patients with HF showed a greater risk of all‐cause mortality [hazard ratio (HR), 2.06; 95% confidence interval (CI), 1.91–2.21; P < 0.0001], cardiovascular mortality (HR, 2.91; 95% CI, 2.58–3.29; P < 0.0001), acute coronary syndromes (HR, 1.25; 95% CI, 1.02–1.52; P = 0.03), and stroke/systemic embolism (HR, 1.24; 95% CI, 1.07–1.43; P = 0.0044). Major bleeding rate was comparable (adjusted HR, 1.00; 95% CI, 0.84–1.18; P = 0.968). Among patients without HF at baseline, incidence of new HF was low [0.69 (95% CI, 0.63–0.75) per 100 person‐years], whereas propensity to develop worsening HF was higher in those with HF [1.62 (95% CI, 1.45–1.80) per 100 person‐years].

Conclusions

Patients with AF and HF have a high risk of all‐cause and cardiovascular mortality and stroke/systemic embolism and may develop worsening HF.

Dual SGLT-1 and SGLT-2 inhibition improves left atrial dysfunction in HFpEF

BACKGROUND

Sodium-glucose linked transporter type 2 (SGLT-2) inhibition has been shown to reduce cardiovascular mortality in heart failure independently of glycemic control and prevents the onset of atrial arrhythmias, a common co-morbidity in heart failure with preserved ejection fraction (HFpEF). The mechanism behind these effects is not fully understood, and it remains unclear if they could be further enhanced by additional SGLT-1 inhibition. We investigated the effects of chronic treatment with the dual SGLT-1&2 inhibitor sotagliflozin on left atrial (LA) remodeling and cellular arrhythmogenesis (i.e. atrial cardiomyopathy) in a metabolic syndrome-related rat model of HFpEF.

METHODS

17 week-old ZSF-1 obese rats, a metabolic syndrome-related model of HFpEF, and wild type rats (Wistar Kyoto), were fed 30 mg/kg/d sotagliflozin for 6 weeks. At 23 weeks, LA were imaged in-vivo by echocardiography. In-vitro, Ca2+ transients (CaT; electrically stimulated, caffeine-induced) and spontaneous Ca2+ release were recorded by ratiometric microscopy using Ca2+-sensitive fluorescent dyes (Fura-2) during various experimental protocols. Mitochondrial structure (dye: Mitotracker), Ca2+ buffer capacity (dye: Rhod-2), mitochondrial depolarization (dye: TMRE) and production of reactive oxygen species (dye: H2DCF) were visualized by confocal microscopy. Statistical analysis was performed with 2-way analysis of variance followed by post-hoc Bonferroni and student's t-test, as applicable.

RESULTS

Sotagliflozin ameliorated LA enlargement in HFpEF in-vivo. In-vitro, LA cardiomyocytes in HFpEF showed an increased incidence and amplitude of arrhythmic spontaneous Ca2+ release events (SCaEs). Sotagliflozin significantly reduced the magnitude of SCaEs, while their frequency was unaffected. Sotagliflozin lowered diastolic [Ca2+] of CaT at baseline and in response to glucose influx, possibly related to a ~ 50% increase of sodium sodium-calcium exchanger (NCX) forward-mode activity. Sotagliflozin prevented mitochondrial swelling and enhanced mitochondrial Ca2+ buffer capacity in HFpEF. Sotagliflozin improved mitochondrial fission and reactive oxygen species (ROS) production during glucose starvation and averted Ca2+ accumulation upon glycolytic inhibition.

CONCLUSION

The SGLT-1&2 inhibitor sotagliflozin ameliorated LA remodeling in metabolic HFpEF. It also improved distinct features of Ca2+-mediated cellular arrhythmogenesis in-vitro (i.e. magnitude of SCaEs, mitochondrial Ca2+ buffer capacity, diastolic Ca2+ accumulation, NCX activity). The safety and efficacy of combined SGLT-1&2 inhibition for the treatment and/or prevention of atrial cardiomyopathy associated arrhythmias should be further evaluated in clinical trials.

The Role of Sleep Disturbance, Depression and Anxiety in Frail Patients with AF-Gender Differences

The aim of the study was to assess the link between anxiety and depression and frailty syndrome (FS) in patients with atrial fibrillation (AF) with regard to gender differences.

MATERIAL AND METHODS

The study was conducted on 158 patients with AF (mean age 70.4 ± 7.6). The study used the hospital anxiety and depression scale (HADS-M), the Athens insomnia scale (AIS) and the Edmonton frailty scale to assess and compare anxiety, depression, and sleep disturbance between frail and non-frail patients with AF.

RESULTS

FS was diagnosed in 53.2% of patients. A comparative analysis showed a statistically significantly higher severity level of anxiety (12.0 ± 2.6 vs. 8.4 ± 2.5, p < 0.001) and depression (12.5 ± 2.5 vs. 7.2 ± 3.3, p < 0.001) in frail patients compared to non-frail patients. The analysis of the level of anxiety, depression and FS did not show any significant differences between the studied women and men. However, statistically, significant differences were observed when FS occurred, regardless of gender. Anxiety disorders were observed in 75.5% of patients with FS and in 16.7% without frailty, whereas depressive disorders were observed in 73.6% of frail patients and in 4.2% without frailty. In an analysis of the impact of cumulative variables on the level of frailty, the risk of FS in patients with anxiety/depression and sleep disturbance is almost 500 times higher compared to patients without anxiety/depression and sleep disturbance. The risk of frailty in patients with sleep disturbance only is thirteen times higher than in the reference group, i.e., in patients without depression/anxiety and sleep disturbances.

CONCLUSIONS

Patients with AF and FS show deeper anxiety, depression and sleep disturbances. Gender does not influence the risk of frailty in AF patients. Frailty in patients with AF is associated with a higher risk of depression, sleep disturbances and anxiety.

Impact of catheter ablation in patients with atrial flutter and concurrent heart failure

Background

No studies assessed impact of atrial flutter (AFL) ablation on outcomes in patients with AFL and concurrent heart failure (HF).

Objectives

To assess the effect of AFL ablation on mortality and HF readmissions in patients with AFL and HF.

Methods

This retrospective cohort study identified 15,952 patients with AFL and HF from the 2016–17 Nationwide Readmissions Database. The primary outcome was a composite of all-cause mortality and/or HF readmission at 1 year. Secondary outcomes included HF readmission, all-cause mortality, and atrial fibrillation (AF) readmission at 1 year. Propensity score match (1:2) algorithm was used to adjust for confounders. Cox proportional hazard regression was used to generate hazard ratios.

Results

Of the 15,952 patients, 9889 had heart failure with reduced ejection fraction (HFrEF) and 6063 had heart failure with preserved ejection fraction (HFpEF). In the matched HFrEF cohort (n = 5421), the primary outcome was significantly lower in patients undergoing ablation (HR 0.72, 95% CI 0.61–0.85, P < .001). HF readmission (HR 0.73, 95% CI 0.61–0.89, P = .001), all-cause mortality (HR 0.62, 95% CI 0.46–0.85, P = .003), and AF readmission (HR 0.63, 95% CI 0.48–0.82, P = .001) were also significantly reduced. In the matched HFpEF cohort (n = 2439), the primary outcome was lower in the group receiving ablation but was not statistically significant (HR 0.80, 95% CI 0.63–1.01, P = .065).

Conclusion

In patients with AFL and HFrEF, AFL ablation was associated with lower mortality and HF readmissions at 1 year. Patients with AFL and HFpEF did not show a similar significant reduction in the primary outcome.

Effect of Amiodarone, Sotalol and Bisoprolol on Heart Rate Variability in Patients with Atrial Fibrillation

Aim. To study the effect of class III antiarrhythmic drugs (amiodarone and sotalol), and the β-blocker bisoprolol on the spectral parameters of heart rate variability in patients with different forms of atrial fibrillation (AF).

Material and methods. Spectral analysis of heart rate variability of 5-minute electrocardiography intervals was used. The study included patients with newly diagnosed AF and having a duration of the disease from 6 months to 8 years. Arterial hypertension, coronary artery disease, myocardial infarction (in history), conduction disorders and type 2 diabetes mellitus were diagnosed as comorbidities. The following parameters were calculated: the total power (TP) of the spectrum, the power of very low frequencies (VLF), low frequencies (LF) and high frequencies (HF).

Results. In the group of patients with newly diagnosed AF without concomitant diseases after administration of amiodarone, VLF prevails in the spectrum structure, which indicates a significant role of humoral factors in the regulation of heart rate. The power of LF, reflecting the activity of the sympathetic nervous system, prevails over HF power after administration of amiodarone. In patients with newly diagnosed AF, having concomitant diseases, sympathetic influences prevail over parasympathetic ones by 3.6 times after administration of amiodarone. In the group of patients who have reduced the number of comorbidities, the LF/HF decreases and is only 1.66 after administration of amiodarone. The decrease in the number of negative factors is also accompanied by an increase in the influence of the vagus nerve on the activity of the heart. In the study of the effects of sotalol, the LF/HF in this group was twice lower in the group of patients with long-term AF. In patients receiving bisoprolol as antiarrhythmic therapy, the proportion of LF in the group of patients with newly diagnosed AF is 2 times lower, and the proportion of HF is twice higher than in the group of patients with long-term AF.

Conclusion. The effect of antiarrhythmic drugs on the spectral parameters of heart rate variability depends on the duration AF. The presence of concomitant diseases of the cardiovascular system can significantly change the effect of antiarrhythmic drugs on the spectral parameters of heart rate variability and is accompanied by an increase in sympathetic activity. In patients with newly diagnosed AF, amiodarone and sotalol cause a similar effect – the predominance of sympathetic influence; when using bisoprolol, the predominant influence belongs to the vagus nerve. In patients with long-term AF, the opposite effect of drugs is observed: the use of amiodarone is accompanied by a more pronounced influence of the vagus nerve, and bisoprolol – the predominance of sympathetic influence. When using sotalol, sympathetic influences also prevail, more pronounced in patients with newly diagnosed AF.

Atrial fibrillation in patients with heart failure with preserved ejection fraction

PURPOSE OF REVIEW

To review the shared pathology of atrial fibrillation and heart failure with preserved ejection fraction (HFpEF) and the prognostic, diagnostic, and treatment challenges incurred by the co-occurrence of these increasingly prevalent diseases.

RECENT FINDINGS

Multiple risk factors and mechanisms have been proposed as potentially linking atrial fibrillation and HFpEF, with systemic inflammation more recently being invoked. Nonvitamin K oral anticoagulants, left atrial appendage occlusion devices, and catheter ablation have emerged as alternative treatment options. Other novel pharmacological agents, such as neprilysin inhibitors, need to be studied further in this patient population.

SUMMARY

Atrial fibrillation and HFpEF commonly co-occur because of their shared risk factors and pathophysiology and incur increased morbidity and mortality relative to either condition alone. Although the presence of both diseases can often make each diagnosis difficult, it is important to do so early in the disease course as there are now a variety of treatment options aimed at improving symptoms and quality of life, slowing disease progression, and improving prognosis. However, more research needs to be performed on the role of catheter ablation in this population. Novel pharmacologic and procedural treatment options appear promising and may further improve the treatment options available to this growing population.

Efficacy and safety of non-vitamin K anticoagulants and warfarin in patients with atrial fibrillation and heart failure: A network meta-analysis

BACKGROUND

To recommend the proper anticoagulant drug and its dose for patients with atrial fibrillation (AF) and heart failure (HF), we conducted a network meta-analysis (NMA) to make the comparisons among non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin with regard to efficacy (stroke or systemic embolism) and safety (major bleeding).

METHODS

We searched PubMed, EMBASE, Web of Science and Cochrane Library with the items: "dabigatran, edoxaban, apixaban, rivaroxaban, warfarin, atrial fibrillation and heart failure" through April 14, 2020, focusing on the RCTs comparing the effect of NOACs to warfarin in patients with AF and HF. The NMA was performed based on R (version3.5.1) recalling JAGS (version4.3.0) with gemtc package. Moreover, NetMetaXL (version1.6.1) and winBUGS (version1.4.3) were employed to obtain the cumulative ranking curve area (SUCRA) of the anticoagulants.

RESULT

There was a high probability that dabigatran150 (SUCRA 0.82) ranked the first for the most effective drug, followed by apixaban (SUCRA 0.81), edoxaban60 (SUCRA 0.57) and rivaroxaban (SUCRA 0.52). However, with respect to safety for preventing major bleeding, edoxaban30 (SUCRA 0.99) ranked as the safest drug, followed by apixaban (SUCRA 0.71), edoxaban 60 (SUCRA 0.59) and dabigatran150 (SUCRA 0.55).

CONCLUSION

Apixaban, edoxaban60 and dabigatran150 were more likely to become the choice for preventing stroke or systemic embolism and major bleeding in patients with AF and HF. Nevertheless, more trials need to be performed to focus on the effect of NOACs on the efficacy outcome due to the sparse data. In addition, caution should be excised over selecting the NOAC and its dose on account of the lacking head-to-head comparisons.

Hydrogen-rich saline mitigates pressure overload-induced cardiac hypertrophy and atrial fibrillation in rats via the JAK-STAT signalling pathway

Objective

To investigate if hydrogen-rich saline (HRS), which has been shown to have antioxidant and anti-inflammatory properties, could mitigate cardiac remodelling and reduce the incidence of atrial fibrillation (AF) in the rat model of cardiac hypertrophy.

Methods

Pressure overload was induced in rats by abdominal aortic constriction (AAC). The animals were separated into four groups: sham; AAC group; AAC plus low dose HRS (LHRS); AAC plus high dose HRS (HHRS). The sham and AAC groups received normal saline intraperitoneally and the LHRS and HHRS groups received 3 or 6 ml/kg HRS daily for six weeks, respectively. In vitro research was also performed using cardiotrophin-1 (CT-1)-induced hypertrophy of cultured neonatal rat cardiomyocytes.

Results

Cardiac hypertrophy was successfully induced by AAC and low and high dose HRS mitigated the pressure overload as shown by lower heart and atrial weights in these treatment groups. AF incidence and duration of the HRS groups were also significantly lower in the HRS groups compared with the AAC group. Atrial fibrosis was also reduced in the HRS groups and the JAK-STAT signalling pathway was down-regulated. In vitro experiments showed that hydrogen-rich medium mitigated the CT-1-induced cardiomyocyte hypertrophy with a similar effect as the JAK specific antagonists AG490.

Conclusions

HRS was found to mitigate cardiac hypertrophy induced by pressure overload in rats and reduce atrial fibrosis and AF which was possibly achieved via inhibition of the JAK-STAT signalling pathway.

The ABCs of atrial fibrillation

This article provides an outline of the diagnosis and pathogenesis of atrial fibrillation. It introduces a mnemonic for atrial fibrillation treatment guidelines based on recent evidence. Mnemonics use has been associated with improved learning and task organization. Articles using mnemonics to inform clinical practice have been well-received and implemented.

Atrial fibrillation in the elderly: a risk factor beyond stroke

Atrial fibrillation (AF) represents the most common arrhythmia worldwide and its prevalence exponentially increases with age. It is related to increased risk of ischemic stroke or systemic embolism, which determines a significant burden of morbidity and mortality, as widely documented in the literature. AF also constitutes a risk factor for other less investigated conditions, such as heart failure, pulmonary embolism, impairment in physical performance, reduced quality of life, development of disability, mood disorders and cognitive impairment up to dementia. In the elderly population, the management of AF and its complications is particularly complex due to the heterogeneity of the ageing process, the lack of specific evidence-based recommendations, as well as the high grade of comorbidity and disability characterizing the over 65 years aged people. In the present review, we aim to summarize the pieces of the most updated evidence on AF complications beyond stoke, mainly focusing on the elderly population.

Heart rhythm during episodes of collapse in boxers with frequent or complex ventricular ectopy

OBJECTIVES

To describe heart rhythm during collapse events in boxer dogs using ambulatory electrocardiogram and determine the predictive value of frequent or complex ventricular ectopy for collapse associated with ventricular tachycardia.

MATERIALS AND METHODS

A total of 659 ambulatory electrocardiogram recordings from 429 boxer dogs were identified from a database in the UK. Summary statistics described the frequency and complexity of ventricular ectopy during all recordings, recordings in which collapse occurred and associated boxer demographics. Positive predictive values were calculated to investigate whether frequent ventricular ectopy was useful to predict heart rhythm during episodes of collapse.

RESULTS

Of the 659 ambulatory electrocardiogram recordings, 250 recordings showed <50 single ventricular beats (Group 1), and frequent (≥50) or complex ventricular ectopy were observed in 409 recordings (Group 2). A total of 90 collapse events were observed in 72 ambulatory electrocardiograms from 68 dogs, comprising 30 dogs in Group 1 and 38 dogs in Group 2. In both groups, sinus rhythm was the most frequent collapse rhythm, followed by neurally mediated collapse and then ventricular tachycardia. The proportion of dogs that displayed ventricular tachycardia-associated episodic collapse given that they had frequent (≥50) or complex ventricular ectopy in the study population was 0.11 [95% confidence interval = 0.01 to 0.21].

CLINICAL SIGNIFICANCE

These results challenge the preconception that UK boxer dogs with collapse will have ventricular tachycardia and, consequently, the authors recommend definitive diagnosis of the cause of episodic collapse to guide selection of therapeutic drugs.

Analysis of Outcomes in Ischemic vs Nonischemic Cardiomyopathy in Patients With Atrial Fibrillation: A Report From the GARFIELD-AF Registry

Importance

Congestive heart failure (CHF) is commonly associated with nonvalvular atrial fibrillation (AF), and their combination may affect treatment strategies and outcomes.

Objective

To assess the treatment strategies and 1-year clinical outcomes of antithrombotic and CHF therapies for patients with newly diagnosed AF with concomitant CHF stratified by etiology (ischemic cardiomyopathy [ICM] vs nonischemic cardiomyopathy [NICM]).

Design, Setting, and Participants

The GARFIELD-AF registry is a prospective, noninterventional registry. A total of 52 014 patients with AF were enrolled between March 2010 and August 2016. A total of 11 738 patients 18 years and older with newly diagnosed AF (≤6 weeks' duration) and at least 1 investigator-determined stroke risk factor were included. Data were analyzed from December 2017 to September 2018.

Exposures

One-year follow-up rates of death, stroke/systemic embolism, and major bleeding were assessed.

Main Outcomes and Measures

Event rates per 100 person-years were estimated from the Poisson model and Cox hazard ratios (HRs) and 95% confidence intervals.

Results

The median age of the population was 71.0 years, 22 987 of 52 013 were women (44.2%) and 31 958 of 52 014 were white (61.4%). Of 11 738 patients with CHF, 4717 (40.2%) had ICM and 7021 (59.8%) had NICM. Prescription of oral anticoagulant and antiplatelet drugs was not balanced between groups. Oral anticoagulants with or without antiplatelet drugs were used in 2753 patients with ICM (60.1%) and 5082 patients with NICM (73.7%). Antiplatelets were prescribed alone in 1576 patients with ICM (34.4%) and 1071 patients with NICM (15.5%). Compared with patients with NICM, use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (72.6% [3439] vs 60.3% [4236]) and of β blockers (63.3% [2988] vs 53.2% [3737]) was higher in patients with ICM. Rates of all-cause and cardiovascular death per 100 patient-years were significantly higher in the ICM group (all-cause death: ICM, 10.2; 95% CI, 9.2-11.1; NICM, 7.0; 95% CI, 6.4-7.6; cardiovascular death: ICM, 5.1; 95% CI, 4.5-5.9; NICM, 2.9; 95% CI, 2.5-3.4). Stroke/systemic embolism rates tended to be higher in ICM groups compared with NICM groups (ICM, 2.0; 95% CI, 1.6-2.5; NICM, 1.5; 95% CI, 1.3-1.9). Major bleeding rates were significantly higher in the ICM group (1.1; 95% CI, 0.8-1.4) compared with the NICM group (0.7; 95% CI, 0.5-0.9).

Conclusions and Relevance

Patients with ICM received oral anticoagulants with or without antiplatelet drugs less frequently and antiplatelets alone more frequently than patients with NICM, but they received angiotensin-converting enzyme inhibitors/angiotensin receptor blockers more often than patients with NICM. All-cause and cardiovascular death rates were higher in patients with ICM than patients with NICM.

Trial Registration

ClinicalTrials.gov Identifier: NCT01090362.

Triggered Ca2+ Waves Induce Depolarization of Maximum Diastolic Potential and Action Potential Prolongation in Dog Atrial Myocytes

BACKGROUND

We have identified a novel form of abnormal Ca2+ wave activity in normal and failing dog atrial myocytes which occurs during the action potential (AP) and is absent during diastole. The goal of this study was to determine if triggered Ca2+ waves affect cellular electrophysiological properties.

METHODS

Simultaneous recordings of intracellular Ca2+ and APs allowed measurements of maximum diastolic potential and AP duration during triggered calcium waves (TCWs) in isolated dog atrial myocytes. Computer simulations then explored electrophysiological behavior arising from TCWs at the tissue scale.

RESULTS

At 3.3 to 5 Hz, TCWs occurred during the AP and often outlasted several AP cycles. Maximum diastolic potential was reduced, and AP duration was significantly prolonged during TCWs. All electrophysiological responses to TCWs were abolished by SEA0400 and ORM10103, indicating that Na-Ca exchange current caused depolarization. The time constant of recovery from inactivation of Ca2+ current was 40 to 70 ms in atrial myocytes (depending on holding potential) so this current could be responsible for AP activation during depolarization induced by TCWs. Modeling studies demonstrated that the characteristic properties of TCWs are potentially arrhythmogenic by promoting both conduction block and reentry arising from the depolarization induced by TCWs.

CONCLUSIONS

Triggered Ca2+ waves activate inward NCX and dramatically reduce atrial maximum diastolic potential and prolong AP duration, establishing the substrate for reentry which could contribute to the initiation and maintenance of atrial arrhythmias.

Catheter ablation of atrial fibrillation in heart failure: clinical, prognostic, and echocardiographic outcome

PURPOSE

Catheter ablation (CA) for atrial fibrillation (AF) in heart failure (HF) patients is associated with a lower rate of cardiac events compared with medical therapy. This study deals with the clinical, echocardiographic, and prognostic outcomes in these patients. Prognostic scores, as MAGGIC (Meta-analysis Global Group in Chronic Heart Failure) score, may help to predict the outcomes.

METHODS

From a single center, 47 patients with AF, HF, and left ventricular ejection fraction (LVEF) < 50% underwent CA. The primary endpoints were NYHA functional class, LVEF, and MAGGIC score.

RESULTS

The median age of patients was 59 years; 49% had paroxysmal AF. At 12 months, a significant improvement of NYHA class (median before II [interquartile range (IQR) II-III] vs median after I [IQR I-II]) and of LVEF (median before 44% [IQR 37-47] vs median after 55% [IQR49-57]) was observed (p value < 0.001). The MAGGIC 1-year and 3-year probability of death was estimated before (mean score 13 [IQR 11-17]) and at 12-month (mean score 11 [IQR 8-13]), showing a significant decrease in the probability of death (p value <0.001). At 12-month, a lower LVEF was associated with more HF hospitalizations (p value 0.035). Coronary artery disease (CAD) (HR 5, p value 0.035) and MAGGIC score (HR 1.2, p value 0.030) were predictors of HF hospitalization.

CONCLUSIONS

CA for AF in HF patients was associated with a significant improvement of NYHA functional class and LVEF and a higher life expectation. CAD history, LVEF < 40%, and MAGGIC score before ablation were predictors of HF hospitalization.

Na/Ca exchange in the atrium: Role in sinoatrial node pacemaking and excitation-contraction coupling

Na/Ca exchange is the dominant calcium (Ca) efflux mechanism in cardiac myocytes. Although our knowledge of exchanger function (NCX1 in the heart) was originally established using biochemical and electrophysiological tools such as cardiac sarcolemmal vesicles and the giant patch technique [1-4], many advances in our understanding of the physiological/pathophysiological roles of NCX1 in the heart have been obtained using a suite of genetically modified mice. Early mouse studies focused on modification of expression levels of NCX1 in the ventricles, with transgenic overexpressors, global NCX1 knockout (KO) mice (which were embryonic lethal if homozygous), and finally ventricular-specific NCX1 KO [5-12]. We found, to our surprise, that ventricular cardiomyocytes lacking NCX1 can survive and function by engaging a clever set of adaptations to minimize Ca entry, while maintaining contractile function through an increase in excitation-contraction (EC) coupling gain [5,6,13]. Having studied ventricular NCX1 ablation in detail, we more recently focused on elucidating the role of NCX1 in the atria through altering NCX1 expression. Using a novel atrial-specific NCX1 KO mouse, we found unexpected changes in atrial cell morphology and calcium handling, together with dramatic alterations in the function of sinoatrial node (SAN) pacemaker activity. In this review, we will discuss these findings and their implications for cardiac disease.

Heart Failure as a Risk Factor for Stroke

Heart failure (HF) is one of the major causes of death worldwide. Despite the high incidence of stroke in patients with HF, there has been a controversy as to whether HF itself is a risk factor for stroke. Recently, there is a great deal of evidence that HF itself increases the risk of stroke. In previous studies, the benefit of warfarin for stroke prevention in patients with HF was offset by the risk of bleeding. In the era of non-vitamin K antagonist oral anticoagulants with low bleeding profiles, we can expect a more effective stroke prevention in patients with HF by selective anticoagulation. The purpose of this review is to describe the relationship between stroke and HF, which could be an unconventional risk factor and a potential intervention target for stroke prevention.