Risk assessment for incident heart failure in individuals with atrial fibrillation

Appropriate strength of acceleration selective-motion sensitized gradient for non-triggered, non-contrast enhanced magnetic resonance angiography of the lower extremities

Non-contrast enhanced magnetic resonance angiography (MRA) is useful for diagnosing peripheral arterial disease, especially in patients with renal insufficiency. Recently, non-triggered, non-contrast enhanced MRA using acceleration selective-motion sensitized gradient (AS-MSG), known as enhanced acceleration-selective arterial spin labeling (eAccASL), has been introduced. We aimed to investigate the appropriate strength of the AS-MSG for this technique in the lower extremities. Non-triggered eAccASL with four acceleration encodings (AENCs; 0.17, 0.29, 0.58, and 0.87 m/s2) was compared with electrocardiography (ECG)-triggered eAccASL (AENC: 0.87 m/s2). In the flow phantom, signal intensities (SIs) were calculated. A higher SI was observed with a smaller AENC on non-triggered eAccASL. In eight volunteers, vessel-background contrasts (VBCs) were calculated, and arterial visibility and venous artifacts were assessed by two radiologists. A higher VBC was observed with a smaller AENC on non-triggered eAccASL. The VBCs of non-triggered eAccASL 0.87 were lower than those of ECG-triggered eAccASL 0.87 in the peroneal, and anterior and posterior tibial arteries (all p < 0.05). Subjective scores for arterial visibility did not differ, with median scores within acceptable levels. The venous artifacts score of non-triggered eAccASL 0.17 was lower than those of non-triggered eAccASL 0.29, 0.58, and 0.87 and ECG-triggered eAccASL 0.87 (p < 0.01, p < 0.05, p < 0.001, and p < 0.01, respectively). In two clinical patients, arterial visibility on non-triggered eAccASL 0.29 was comparable or superior to that on ECG-triggered eAccASL 0.87. An AENC of 0.29-0.58 m/s2 was considered appropriate for non-triggered, non-contrast enhanced lower-extremity MRA using eAccASL.

Heart Failure in Atrial Fibrillation Subtypes in Women and Men in the Tromsø Study

Background

Atrial fibrillation (AF) and heart failure (HF) often coexist and impact morbidity and mortality. There is limited knowledge on the association of AF subtypes with HF according to sex.

Objectives

The purpose of this study was to explore sex-specific associations between AF subtypes and subsequent HF, identifying HF risk factors in participants with AF, and exploring the combined impact on mortality.

Methods

14,790 women and 13,181 men from the Tromsø Study were enrolled between 1994 and 2008 and followed for incident AF and HF through 2016. Cox regression was conducted to provide HRs and 95% CIs.

Results

Those with AF had higher risk of subsequent HF in both sexes compared to those without AF. Women with permanent AF had higher relative risk of HF than men (HR: 10.52; 95% CI: 8.72-12.70, and HR: 7.65; 95% CI: 6.40-9.15, respectively). Risk factors for HF in participants with AF included smoking in all, higher diastolic blood pressure and hypertension in women, underweight, obesity, and low alcohol consumption in men. All-cause mortality was higher in women with both subtypes (paroxysmal/persistent: HR: 2.10; 95% CI: 1.78-2.48, permanent: HR: 1.40, 95% CI: 1.14-1.72) and in men with paroxysmal/persistent AF (HR: 1.66; 95% CI: 1.40-1.96). Subsequent HF increased risk of mortality in both sexes.

Conclusions

All AF subtypes were associated with increased risk of HF. Smoking was a shared risk factor, while diastolic blood pressure and hypertension were specific to women, and underweight, obesity, and low alcohol intake were specific to men. Subsequent HF increased mortality risk in all.

Incidence of atrial fibrillation and flutter in Denmark in relation to country of origin: a nationwide register-based study

BACKGROUND

Atrial fibrillation and flutter (AF) is the most common sustained arrhythmia with an increasing prevalence in Western countries. However, little is known about AF among immigrants compared to non-immigrants.

AIM

To examine the incidence of hospital-diagnosed AF according to country of origin.

METHOD

Immigrants were defined as individuals born outside Denmark by parents born outside Denmark. AF was defined as first-time diagnosis of AF. All individuals were followed from the age of 45 years from 1998 to 2017. The analyses were adjusted for sex, age, comorbidity, contact with the general practitioner and socioeconomic variables. Adjustment was conducted using standardised morbidity ratio weights, standardised to the Danish population in a marginal structural model.

RESULTS

The study population consisted of 3,489,730 Danish individuals free of AF and 108,914 immigrants free of AF who had emigrated from the 10 most represented countries. A total of 323,005 individuals of Danish origin had an incident hospital diagnosis of AF, among the immigrants 7,300 developed AF. Adjusted hazard rate ratios (HRRs) of AF for immigrants from Iran (0.48 [95%CI:0.35;0.64]), Turkey (0.74 [95%CI:0.67;0.82]) and Bosnia-Herzegovina (0.42 [95%CI:0.22;0.79]) were low compared with Danish individuals. Immigrants from Sweden, Germany and Norway had an adjusted HRR of 1.13 [95%CI:1.03;1.23], 1.12 [95%CI:1.05;1.18] and 1.11 [95%CI:1.03;1.21], respectively (Danish individuals as reference).

CONCLUSIONS

Substantial variation in the incidence of hospital-diagnosed AF according to country of origin was observed. The results may reflect true biological differences but could also reflect barriers to AF diagnosis for immigrants. Further efforts are warranted to determine the underlying mechanisms.

Fast interactive simulations of cardiac electrical activity in anatomically accurate heart structures by compressing sparse uniform cartesian grids

BACKGROUND AND OBJECTIVE

Numerical simulations are valuable tools for studying cardiac arrhythmias. Not only do they complement experimental studies, but there is also an increasing expectation for their use in clinical applications to guide patient-specific procedures. However, numerical studies that solve the reaction-diffusion equations describing cardiac electrical activity remain challenging to set up, are time-consuming, and in many cases, are prohibitively computationally expensive for long studies. The computational cost of cardiac simulations of complex models on anatomically accurate structures necessitates parallel computing. Graphics processing units (GPUs), which have thousands of cores, have been introduced as a viable technology for carrying out fast cardiac simulations, sometimes including real-time interactivity. Our main objective is to increase the performance and accuracy of such GPU implementations while conserving computational resources.

METHODS

In this work, we present a compression algorithm that can be used to conserve GPU memory and improve efficiency by managing the sparsity that is inherent in using Cartesian grids to represent cardiac structures directly obtained from high-resolution MRI and mCT scans. Furthermore, we present a discretization scheme that includes the cross-diagonal terms in the computational cell to increase numerical accuracy, which is especially important for simulating thin tissue sections without the need for costly mesh refinement.

RESULTS

Interactive WebGL simulations of atrial/ventricular structures (on PCs, laptops, tablets, and phones) demonstrate the algorithm's ability to reduce memory demand by an order of magnitude and achieve calculations up to 20x faster. We further showcase its superiority in slender tissues and validate results against experiments performed in live explanted human hearts.

CONCLUSIONS

In this work, we present a compression algorithm that accelerates electrical activity simulations on realistic anatomies by an order of magnitude (up to 20x), thereby allowing the use of finer grid resolutions while conserving GPU memory. Additionally, improved accuracy is achieved through cross-diagonal terms, which are essential for thin tissues, often found in heart structures such as pectinate muscles and trabeculae, as well as Purkinje fibers. Our method enables interactive simulations with even interactive domain boundary manipulation (unlike finite element/volume methods). Finally, agreement with experiments and ease of mesh import into WebGL paves the way for virtual cohorts and digital twins, aiding arrhythmia analysis and personalized therapies.

Incidence and prediction of hospitalization for heart failure in patients with atrial fibrillation: the REFLEJA scale

INTRODUCTION AND OBJECTIVES

Hospitalization for heart failure (HHF) is common in patients with atrial fibrillation (AF) and is associated with increased mortality. The aims of this study were to determine the incidence of HHF, identify the clinical predictors of its occurrence, and develop a new risk scale.

METHODS

The incidence of HHF was estimated using data from the prospective single-center REFLEJA registry of outpatients with AF (October 2017-October 2018). A multivariate Cox regression model was calculated to detect HHF predictors, and a nomogram was created for individual risk assessment.

RESULTS

Of the 1499 patients included (mean age 73.8±11.1 years, 48.1% women), 127 had HHF (incidence rate of 8.51 per 100 persons/y) and 319 died (rate of death from any cause of 21.1 per 100 persons/y) after a 3-year follow-up. The independent predictors of HHF were age, diabetes, chronic kidney disease, pulmonary hypertension, previous pacemaker implantation, baseline use of diuretics, and moderate-severe aortic regurgitation. The c-statistic for predicting the event was 0.762 (95%CI after boostrapping resampling, 0.753-0.791). The cumulative incidences of the main outcome for the risk scale quartiles were 1.613 (Q1), 3.815 (Q2), 8.378 (Q3), and 20.436 (Q4) cases per 100 persons/y (P <.001).

CONCLUSIONS

HHF was common in this AF cohort. The combination of certain clinical characteristics can identify patients with a very high risk of HHF.

Turbo spin-echo-based enhanced acceleration-selective arterial spin labeling without electrocardiography or peripheral pulse unit triggering and contrast enhancement for lower extremity MRA

PURPOSE

Lower extremity magnetic resonance angiography (MRA) without electrocardiography (ECG) or peripheral pulse unit (PPU) triggering and contrast enhancement is beneficial for diagnosing peripheral arterial disease (PAD) while avoiding synchronization failure and nephrogenic systemic fibrosis. This study aimed to compare the diagnostic performance of turbo spin-echo-based enhanced acceleration-selective arterial spin labeling (eAccASL) (TSE-Acc) of the lower extremities with that of turbo field-echo-based eAccASL (TFE-Acc) and triggered angiography non-contrast enhanced (TRANCE).

METHODS

Nine healthy volunteers and a patient with PAD were examined on a 3.0 Tesla magnetic resonance imaging (MRI) system. The artery-to-muscle signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) were calculated. The arterial visibility (1: poor, 4: excellent) and artifact contamination (1: severe, 4: no) were independently assessed by two radiologists. Phase-contrast MRI and digital subtraction angiography were referenced in a patient with PAD. Friedman's test and a post-hoc test according to the Bonferroni-adjusted Wilcoxon signed-rank test were used for the SIR, CNR, and visual assessment. p < 0.05 was considered statistically significant.

RESULTS

No significant differences in nearly all the SIRs were observed among the three MRA methods. Higher CNRs were observed with TSE-Acc than those with TFE-Acc (anterior tibial artery, p = 0.014; peroneal artery, p = 0.029; and posterior tibial artery, p = 0.014) in distal arterial segments; however, no significant differences were observed upon comparison with TRANCE (all p > 0.05). The arterial visibility scores exhibited similar trends as the CNRs. The artifact contamination scores with TSE-Acc were significantly lower (but within an acceptable level) compared to those with TFE-Acc. In the patient with PAD, the sluggish peripheral arteries were better visualized using TSE-Acc than those using TFE-Acc, and the collateral and stenosis arteries were better visualized using TSE-Acc than those using TRANCE.

CONCLUSION

Peripheral arterial visualization was better with TSE-Acc than that with TFE-Acc in lower extremity MRA without ECG or PPU triggering and contrast enhancement, which was comparable with TRANCE as the reference standard. Furthermore, TSE-Acc may propose satisfactory diagnostic performance for diagnosing PAD in patients with arrhythmia and chronic kidney disease.

Relationship between ω3 and ω6 polyunsaturated fatty acids and atrial fibrillation in acute ischemic stroke

BACKGROUND & AIMS

Some ω3 polyunsaturated fatty acids (PUFAs) are said to demonstrate a dose-related risk of atrial fibrillation (AF), conversely, some ω6 PUFAs might have AF protective potential. However, few investigated the relation among ischemic strokes. Primarily, we aimed to examine a relation between ω3 and ω6 PUFAs and the presence of AF in ischemic strokes. Further, since, some PUFAs are said to affect the cardiac load, we secondarily aimed to investigate the association between ω3 and ω6 PUFAs and brain natriuretic peptide (BNP) and the occurrence of cerebral large vessel occlusion (LVO) in ischemic strokes with AF.

METHODS

Consecutive patients with ischemic stroke admitted between 2012 and 2022 were retrospectively screened. Plasma levels of PUFAs, including eicosapentaenoic acid (EPA), docosahexaenoic acid, dihomo-γ-linolenic acid (DGLA) and arachidonic acid (AA), were assayed. Data were analyzed using a Poisson regression analysis with a robust variance estimator and a multiple linear regression analysis.

RESULTS

We screened 2112 consecutive ischemic strokes, including 1574 (1119 [71%] males, median age 69 years). Lower DGLA (prevalence ratio (PR) 0.885, 95% CI 0.811-0.966, p = 0.006), lower AA (PR 0.797, 95% CI 0.649-0.978, p = 0.030), and higher EPA/AA ratio (PR 1.353, 95% CI 1.036-1.767, p = 0.026) were associated with AF. Checking the linearity between AF and PUFAs, negative linear trends were observed between DGLA quartiles (Q1: PR 1.901, Q2: PR 1.550, Q3: PR 1.423, Q4: 1.000, p < 0.001 for trend) and AA quartiles (Q1: PR 1.499, Q2: PR 1.204, Q3: PR 1.125, Q4: 1.000, p = 0.004 for trend), with positive linear trends between EPA/AA ratio quartiles (Q1: 1.000, Q2: PR 1.555, Q3: PR 1.612, Q4: PR 1.797, p = 0.001 for trend). Among patients with AF, a negative association between AA and BNP (unstandardized coefficient -1.316, 95% CI -2.290∼-0.342, p = 0.008) was observed, and lower AA was associated with LVO (PR 0.707, 95% CI 0.527-0.950, p = 0.021).

CONCLUSION

Lower DGLA and AA and a higher EPA/AA ratio might be related to the development of AF in ischemic strokes. Further, AA might have a cardio-cerebrovascular protective role in ischemic strokes with AF.

Temporal trends in lifetime risks of atrial fibrillation and its complications between 2000 and 2022: Danish, nationwide, population based cohort study

OBJECTIVES

To examine how the lifetime risks of atrial fibrillation and of complications after atrial fibrillation changed over time.

DESIGN

Danish, nationwide, population based cohort study.

SETTING

Population of Denmark from 1 January 2000 to 31 December 2022.

PARTICIPANTS

3.5 million individuals (51.7% women and 48.3% men) who did not have atrial fibrillation at 45 years of age or older were followed up until incident atrial fibrillation, migration, death, or end of follow-up, whichever came first. All 362 721 individuals with incident atrial fibrillation (46.4% women and 53.6% men), but with no prevalent complication, were further followed up until incident heart failure, stroke, or myocardial infarction.

MAIN OUTCOME MEASURES

Lifetime risk of atrial fibrillation and lifetime risks of complications after atrial fibrillation over two prespecified periods (2000-10 v 2011-22).

RESULTS

The lifetime risk of atrial fibrillation increased from 24.2% in 2000-10 to 30.9% in 2011-22 (difference 6.7% (95% confidence interval 6.5% to 6.8%)). After atrial fibrillation, the most frequent complication was heart failure with a lifetime risk of 42.9% in 2000-10 and 42.1% in 2011-22 (-0.8% (-3.8% to 2.2%)). Individuals with atrial fibrillation lost 14.4 years with no heart failure. The lifetime risks of stroke and of myocardial infarction after atrial fibrillation decreased slightly between the two periods, from 22.4% to 19.9% for stroke (-2.5% (-4.2% to -0.7%)) and from 13.7% to 9.8% for myocardial infarction (-3.9% (-5.3% to -2.4%). No evidence was reported of a differential decrease between men and women.

CONCLUSION

Lifetime risk of atrial fibrillation increased over two decades of follow-up. In individuals with atrial fibrillation, about two in five developed heart failure and one in five had a stroke over their remaining lifetime after atrial fibrillation diagnosis, with no or only small improvement over time. Stroke risks and heart failure prevention strategies are needed for people with atrial fibrillation.

Association of insulin resistance and glycemic measures with major abnormal electrocardiogram in older Chinese: Cross-sectional analysis based on the Guangzhou Biobank Cohort study

AIMS

To examine whether insulin resistance (IR) and glycemic measures were associated with major abnormal electrocardiogram (MA-ECG) and its specific abnormalities in the general population.

METHODS

Twelve-lead ECG measurements were performed on 21,720 participants without cardiovascular disease (5,918 men) from the Guangzhou Biobank Cohort Study. The participants were aged 50 years or above (mean age 61.6, standard deviation 7.1 years). Logistic regression was used to assess the associations of IR and glycemic measures with MA-ECG and specific abnormalities.

RESULTS

Ln-fasting insulin was significantly associated with MA-ECG and ST-T abnormalities (adjusted odds ratio = 1.52, 95 % confidence interval = 1.15-2.02 and 1.83, 1.37-2.45, respectively, for per standard deviation), which were stronger than those of TyG index with MA-ECG (1.08, 1.04-1.13) and ST-T abnormalities (1.16, 1.11-1.22). Ln-fasting insulin had association with Q wave abnormalities (3.19, 1.52-6.67). The association of TyG index with prolonged QTc varied by sex and obesity (P for interaction ≤ 0.01). Participants with diabetes had stronger associations of ln-fasting plasma glucose with ECG abnormalities than those without.

CONCLUSIONS

IR and glycemic measures were associated with MA-ECG, ischemia and prolonged QTc in older Chinese, especially in women, those with obesity, and those with diabetes. These findings underscore the importance of regular evaluations for these groups.

Heart failure in older patients with atrial fibrillation: incidence and risk factors

INTRODUCTION AND OBJECTIVES

Atrial fibrillation (AF) is linked to heart failure (HF). However, little has been published on the factors that may precipitate the onset of HF in AF patients. We aimed to determine the incidence, predictors, and prognosis of incident HF in older patients with AF with no prior history of HF.

METHODS

Patients with AF older than 80 years and without prior HF were identified between 2014 and 2018.

RESULTS

A total of 5794 patients (mean age, 85.2±3.8 years; 63.2% women) were followed up for 3.7 years. Incident HF, predominantly with preserved left ventricular ejection fraction, developed in 33.3% (incidence rate, 11.5-100 people-year). Multivariate analysis identified 11 clinical risk factors for incident HF, irrespective of HF subtype: significant valvular heart disease (HR, 1.99; 95%CI, 1.73-2.28), reduced baseline left ventricular ejection fraction (HR, 1.92; 95%CI, 1.68-2.19), chronic pulmonary obstructive disease (HR, 1.59; 95%CI, 1.40-1.82), enlarged left atrium (HR 1.47, 95%CI 1.33-1.62), renal dysfunction (HR 1.36, 95%CI 1.24-1.49), malnutrition (HR, 1.33; 95%CI, 1.21-1.46), anemia (HR, 1.30; 95%CI, 1.17-1.44), permanent AF (HR, 1.15; 95%CI, 1.03-1.28), diabetes mellitus (HR, 1.13; 95%CI, 1.01-1.27), age per year (HR, 1.04; 95%CI, 1.02-1.05), and high body mass index for each kg/m2 (HR, 1.03; 95%CI, 1.02-1.04). The presence of incident HF nearly doubled the mortality risk (HR, 1.67; 95%CI, 1.53-1.81).

CONCLUSIONS

The presence of HF in this cohort was relatively frequent and nearly doubled the mortality risk. Eleven risk factors for HF were identified, expanding the scope for primary prevention among elderly patients with AF.

Statin Therapy Is Associated With a Lower Risk of Heart Failure in Patients With Atrial Fibrillation: A Population-Based Study

BACKGROUND

Whether statin use can reduce the risk of heart failure (HF) remains controversial. The present study evaluates the association between statin use and HF in patients with atrial fibrillation.

METHODS AND RESULTS

Patients with newly diagnosed atrial fibrillation from 2010 to 2018 were included. An inverse probability of treatment weighting was used to balance baseline covariates between statin users (n=23 239) and statin nonusers (n=29 251). The primary outcome was incident HF. Cox proportional hazard models with competing risk regression were used to evaluate the risk of HF between statin users and nonusers. The median age of the cohort was 74.7 years, and 47.3% were women. Over a median follow-up of 5.1 years, incident HF occurred in 3673 (15.8%) statin users and 5595 (19.1%) statin nonusers. Statin use was associated with a 19% lower risk of HF (adjusted subdistribution hazard ratio, 0.81 [95% CI, 0.78-0.85]). Restricted to the statin users, duration of statin use was measured during follow-up; compared with short-term use (3 months to <2 years), there was a stepwise reduction in the risk of incident HF among those with 2 to <4 years of statin use (subdistribution hazard ratio, 0.86 [95% CI, 0.84-0.88]), 4 to <6 years of statin use (subdistribution hazard ratio, 0.74 [95% CI, 0.72-0.76]), and ≥6 years of statin use (subdistribution hazard ratio, 0.71 [95% CI, 0.69-0.74]). Subgroup analysis showed consistent reductions in the risk of HF with statin use.

CONCLUSIONS

Statin use was associated with a decreased risk of incident HF in a duration-dependent manner among patients with atrial fibrillation.

Hypertrophic Cardiomyopathy Predicts Thromboembolism and Heart Failure in Patients With Nonvalvular Atrial Fibrillation - A Prospective Analysis From the Hokuriku-Plus AF Registry

BACKGROUND

The prognostic effect of concomitant hypertrophic cardiomyopathy (HCM) on adverse events in patients with atrial fibrillation (AF) has not been evaluated in a multicenter prospective cohort study in Japan.

METHODS AND RESULTS

Using the Hokuriku-Plus AF Registry, 1,396 patients with nonvalvular AF (1,018 men, 72.3±9.7 years old) were assessed prospectively; 72 (5.2%) had concomitant HCM. During a median follow-up of 5.0 years (interquartile range 3.5-5.3 years), 79 cases of thromboembolism (1.3 per 100 person-years) and 192 of heart failure (HF) (3.2 per 100 person-years) occurred. Kaplan-Meier analysis revealed that the HCM group had a significantly greater incidence of thromboembolism (P=0.002 by log-rank test) and HF (P<0.0001 by a log-rank test) than the non-HCM group. The Cox proportional hazards model demonstrated that persistent AF (adjusted hazard ratio 2.98, 95% confidence interval 1.56-6.21), the CHA2DS2-VASc score (1.35, 1.18-1.54), and concomitant HCM (2.48, 1.16-4.79) were significantly associated with thromboembolism. Conversely, concomitant HCM (2.81, 1.72-4.43), older age (1.07, 1.05-1.10), lower body mass index (0.95, 0.91-0.99), a history of HF (2.49, 1.77-3.52), and lower left ventricular ejection fraction (0.98, 0.97-0.99) were significantly associated with the development of HF.

CONCLUSIONS

Concomitant HCM predicts the incidence of thromboembolism and HF in AF patients.

Predicting new-onset heart failure hospitalization of patients with atrial fibrillation: development and external validations of a risk score

AIM

Atrial fibrillation (AF) is a well-known risk factor for heart failure (HF). We sought to develop and externally validate a risk model for new-onset HF admission in patients with AF and those without a history of HF.

METHODS AND RESULTS

Using two multicentre, prospective, observational AF registries, RAFFINE (2857 patients, derivation cohort) and SAKURA (2516 patients without a history of HF, validation cohort), we developed a risk model by selecting variables with regularized regression and weighing coefficients by Cox regression with the derivation cohort. External validity testing was used for the validation cohort. Overall, 148 (5.2%) and 104 (4.1%) patients in the derivation and validation cohorts, respectively, developed HF during median follow-ups of 1396 (interquartile range [IQR]: 1078-1820) and 1168 (IQR: 844-1309) days, respectively. In the derivation cohort, age, haemoglobin, serum creatinine, and log-transformed brain natriuretic peptide were identified as potential risk factors for HF development. The risk model showed good discrimination and calibration in both derivations (area under the curve [AUC]: 0.80 [95% confidence interval (CI) 0.76-0.84]; Hosmer-Lemeshow, P = 0.257) and validation cohorts (AUC: 0.78 [95%CI 0.74-0.83]; Hosmer-Lemeshow, P = 0.475).

CONCLUSION

The novel risk model with four readily available clinical characteristics and biomarkers performed well in predicting new-onset HF admission in patients with AF.

Predictive Value of Deep Learning-derived CT Pectoralis Muscle and Adipose Measurements for Incident Heart Failure: Multi-Ethnic Study of Atherosclerosis

Purpose

To develop a deep learning algorithm capable of extracting pectoralis muscle and adipose measurements and to longitudinally investigate associations between these measurements and incident heart failure (HF) in participants from the Multi-Ethnic Study of Atherosclerosis (MESA).

Materials and Methods

MESA is a prospective study of subclinical cardiovascular disease characteristics and risk factors for progression to clinically overt disease approved by institutional review boards of six participating centers (ClinicalTrials.gov identifier: NCT00005487). All participants with adequate imaging and clinical data from the fifth examination of MESA were included in this study. Hence, in this secondary analysis, manual segmentations of 600 chest CT examinations (between the years 2010 and 2012) were used to train and validate a convolutional neural network, which subsequently extracted pectoralis muscle and adipose (intermuscular adipose tissue (IMAT), perimuscular adipose tissue (PAT), extramyocellular lipids and subcutaneous adipose tissue) area measurements from 3031 CT examinations using individualized thresholds for adipose segmentation. Next, 1781 participants without baseline HF were longitudinally investigated for associations between baseline pectoralis muscle and adipose measurements and incident HF using crude and adjusted Cox proportional hazards models. The full models were adjusted for variables in categories of demographic (age, race, sex, income), clinical/laboratory (including physical activity, BMI, and smoking), CT (coronary artery calcium score), and cardiac MRI (left ventricular ejection fraction and mass (% of predicted)) data.

Results

In 1781 participants (median age, 68 (IQR,61, 75) years; 907 [51%] females), 41 incident HF events occurred over a median 6.5-year follow-up. IMAT predicted incident HF in unadjusted (hazard ratio [HR]:1.14; 95% CI: 1.03-1.26) and fully adjusted (HR:1.16, 95% CI: 1.03-1.31) models. PAT also predicted incident HF in crude (HR:1.19; 95% CI: 1.06-1.35) and fully adjusted (HR:1.25; 95% CI: 1.07-1.46) models.

Conclusion

The study demonstrates that fast and reliable deep learning-derived pectoralis muscle and adipose measurements are obtainable from conventional chest CT, which may be predictive of incident HF.©RSNA, 2023.

Predicting Heart Failure in Patients with Atrial Fibrillation: A Report from the Prospective COOL-AF Registry

BACKGROUND

This study aimed to determine risk factors and incidence rate and develop a predictive risk model for heart failure for Asian patients with atrial fibrillation (AF).

METHODS

This is a prospective multicenter registry of patients with non-valvular AF in Thailand conducted between 2014 and 2017. The primary outcome was the occurrence of an HF event. A predictive model was developed using a multivariable Cox-proportional model. The predictive model was assessed using C-index, D-statistics, Calibration plot, Brier test, and survival analysis.

RESULTS

There were a total of 3402 patients (average age 67.4 years, 58.2% male) with mean follow-up duration of 25.7 ± 10.6 months. Heart failure occurred in 218 patients during follow-up, representing an incidence rate of 3.03 (2.64-3.46) per 100 person-years. There were ten HF clinical factors in the model. The predictive model developed from these factors had a C-index and D-statistic of 0.756 (95% CI: 0.737-0.775) and 1.503 (95% CI: 1.372-1.634), respectively. The calibration plots showed a good agreement between the predicted and observed model with the calibration slope of 0.838. The internal validation was confirmed using the bootstrap method. The Brier score indicated that the model had a good prediction for HF.

CONCLUSIONS

We provide a validated clinical HF predictive model for patients with AF, with good prediction and discrimination values.

Risks of Heart Failure, Stroke, and Bleeding in Atrial Fibrillation According to Heart Failure Phenotypes

BACKGROUND

The risks of heart failure (HF) events compared with stroke/systemic embolic events (SEE) or major bleeding (MB) in heart failure with reduced ejection fraction (HFrEF) vs heart failure with preserved ejection fraction (HFpEF) in a large atrial fibrillation (AF) population have not been well-studied.

OBJECTIVES

This study sought to assess HF outcomes, according to HF history and HF phenotypes (HFrEF vs HFpEF), and compare these events with SEE and MB, among patients with AF.

METHODS

We analyzed patients enrolled in the ENGAGE-AF TIMI 48 (Effective Anticoagulation with Factor Xa Next Generation in AF-Thrombolysis in Myocardial Infarction 48) trial. Cumulative incidence of heart failure hospitalization (HHF) or HF death was assessed and compared with the rates of fatal and nonfatal stroke/SEE and MB over a median follow-up of 2.8 years.

RESULTS

Overall, 12,124 (57.4%) had a history of HF (37.7% HFrEF, 40.1% HFpEF, 22.1% with unknown ejection fraction). The rate per 100 person-years (py) of HHF or HF death (4.95; 95% CI: 4.70-5.20) was higher than of fatal and nonfatal stroke/SEE (1.77; 95% CI: 1.63-1.92) and MB (2.66; 95% CI: 2.47-2.86) among patients with HF history. HFrEF patients experienced a higher rate of HHF or HF death compared with HFpEF patients (7.15 vs 3.65; P < 0.001), while the rates of fatal and nonfatal stroke/SEE and MB were similar by HF phenotype. Patients with HF history had a higher rate of mortality after a HHF (1.29; 95% CI: 1.17-1.42) than after a stroke/SEE (0.69; 95% CI: 0.60-0.78) or after MB (0.61; 95% CI: 0.53-0.70). Overall, patients with nonparoxysmal AF had a higher rate of HF and stroke/SEE events regardless of HF history.

CONCLUSIONS

Patients with AF and HF, regardless of ejection fraction, are at a higher risk of HF events with higher subsequent mortality rates than of stroke/SEE or MB. While HFrEF is associated with a higher risk of HF events than HFpEF, the risk of stroke/SEE and MB is similar between HFrEF and HFpEF.

Association between serum alkaline phosphatase and cardiovascular events in patients with atrial fibrillation

High alkaline phosphatase (ALP) levels are reported to be associated with an increased risk of cardiovascular events in patients with chronic kidney disease (CKD). Given the pathological link with CKD, a similar relationship may exist in patients with atrial fibrillation (AF). We retrospectively evaluated 1,719 patients with AF and normal hepatic function who were registered in the Shinken Database between November 2011 and March 2017. Study patients were divided into three groups according to ALP value tertiles with cut-offs of 175 and 227 IU/L (normal range: 95-350 IU/L). Each group's incidence rate was recorded, and the risks of cardiovascular events and each component for patients in the middle and high ALP tertiles were compared with those in the low tertile and evaluated using Cox regression models. The additional predictive value of the high ALP tertile over the existing risk scores for the components of cardiovascular events was evaluated via receiver operating characteristic (ROC) curve analysis. During the median follow-up of 731 days (IQR: 444-1095 days), 137 cardiovascular events occurred, with incidence rates of 2.94%, 3.44%, and 6.19%/person-year for the low, middle, and high ALP tertiles, respectively. Of these cardiovascular events, heart failure had the highest incidence rates (1.34%, 1.89%, and 4.29%/person-year for the low, middle, and high ALP tertiles, respectively) and the incidence rates of the other components of cardiovascular event were similar in each ALP groups. Multivariate Cox regression analysis yielded hazard ratios of 1.22 (95% confidence interval [CI] 0.70-1.96) and 1.62 (95% CI 1.06-2.48) for cardiovascular events and 1.66 (95% CI 0.87-3.15) and 2.50 (95% CI 1.39-4.48) for heart failure admission in the middle and high ALP tertiles, respectively. By ROC curve analysis for heart failure admission showed that the high ALP tertile lacked significant additive predictive value over the existing risk scores. High serum ALP levels, even those in the normal range, were significantly associated with an increased risk of cardiovascular events, especially heart failure admission in patients with AF.

Prediabetes Is Associated With Increased Risk of Heart Failure Among Patients With Atrial Fibrillation

OBJECTIVE

To evaluate the association between prediabetes and heart failure (HF) and the association of HF with changes in glycemic status.

RESEARCH DESIGN AND METHODS

Patients newly diagnosed with atrial fibrillation (AF) between 2015 and 2018 were divided into three groups (normoglycemia, prediabetes, and type 2 diabetes) according to their baseline glycemic status. The primary outcome was incident HF. The Fine and Gray competing risks model was applied, with death defined as the competing event.

RESULTS

Among 17,943 patients with AF (mean age 75.5 years, 47% female), 3,711 (20.7%) had prediabetes, and 10,127 (56.4%) had diabetes at baseline. Over a median follow-up of 4.7 years, HF developed in 518 (14%) patients with normoglycemia, 646 (15.7%) with prediabetes, and 1,795 (17.7%) with diabetes. Prediabetes was associated with an increased risk of HF compared with normoglycemia (subdistribution hazard ratio [SHR] 1.12, 95% CI 1.03-1.22). In patients with prediabetes at baseline, 403 (11.1%) progressed to diabetes, and 311 (8.6%) reversed to normoglycemia at 2 years. Compared with remaining prediabetic, progression to diabetes was associated with an increased risk of HF (SHR 1.50, 95% CI 1.13-1.97), whereas reversion to normoglycemia was associated with a decreased risk (SHR 0.61, 95% CI 0.42-0.94).

CONCLUSIONS

Prediabetes was associated with an increased risk of HF in patients with AF. Compared with patients who remained prediabetic, those who progressed to diabetes at 2 years experienced an increased risk of HF, whereas those who reversed to normoglycemia incurred a lower risk of HF.

Integration of proteomic and metabolomic characterization in atrial fibrillation-induced heart failure

BACKGROUND

The exact mechanism of atrial fibrillation (AF)-induced heart failure (HF) remains unclear. Proteomics and metabolomics were integrated to in this study, as to describe AF patients' dysregulated proteins and metabolites, comparing patients without HF to patients with HF.

METHODS

Plasma samples of 20 AF patients without HF and another 20 with HF were analyzed by multi-omics platforms. Proteomics was performed with data independent acquisition-based liquid chromatography-tandem mass spectrometry (LC-MS/MS), as metabolomics was performed with LC-MS/MS platform. Proteomic and metabolomic results were analyzed separately and integrated using univariate statistical methods, multivariate statistical methods or machine learning model.

RESULTS

We found 35 up-regulated and 15 down-regulated differentially expressed proteins (DEPs) in AF patients with HF compared to AF patients without HF. Moreover, 121 up-regulated and 14 down-regulated differentially expressed metabolites (DEMs) were discovered in HF patients compared to AF patients without HF. An integrated analysis of proteomics and metabolomics revealed several significantly enriched pathways, including Glycolysis or Gluconeogenesis, Tyrosine metabolism and Pentose phosphate pathway. A total of 10 DEPs and DEMs selected as potential biomarkers provided excellent predictive performance, with an AUC of 0.94. In addition, subgroup analysis of HF classification was performed based on metabolomics, which yielded 9 DEMs that can distinguish between AF and HF for HF classification.

CONCLUSIONS

This study provides novel insights to understanding the mechanisms of AF-induced HF progression and identifying novel biomarkers for prognosis of AF with HF by using metabolomics and proteomics analyses.

Atrial Fibrillation in Heart Failure with Preserved Left Ventricular Systolic Function: Distinct Elevated Risk for Cardiovascular Outcomes in Women Compared to Men

Background: Heart failure with preserved ejection fraction (HFpEF) is prevalent in women and is associated with atrial fibrillation (AF). However, sex associations in AF-related HFpEF are not well explored. Aim: We studied differences between men and women with and without AF-related HFpEF symptoms on left ventricular (LV) geometry and diastolic dysfunction (DD) and their effect on cardiovascular events. Methods: Retrospectively, HFpEF patients with and without a history of AF referred for echocardiography were studied. Echocardiographic assessments were focused on LV geometry and diastolic functions. Patients were followed for the occurrence of cardiac events defined as death and cardiac hospitalization. Results: We studied 556 patients [age: 66.7 ± 17 years, 320 (58%) women, 91 (16%) AF]. Compared to HFpEF without AF (HFpEF-AF), HFpEF with AF patients (HFpEF+AF) were older (76 ± 13.8 vs. 64.9 ± 17.3 years, p < 0.001), had more risk factors, comorbidities, left ventricular hypertrophy (32 vs. 13%, p < 0.001), higher relative wall thickness (0.50 ± 0.14 vs. 0.44 ± 0.15, p < 0.001), and DD (56 vs. 30%, all p < 0.001). HFpEF+AF women had the worst clinical, LV geometric, and diastolic functional profiles and highest rates of cardiovascular outcomes compared to HFpEF+AF men and were the only group to predict outcomes (HR: 2.7, 95%CI: 1.4−5.1), while HFpEF-AF women were a low-risk group; HFpEF+AF and HFpEF-AF men had intermediate cardiovascular outcomes which were confirmed after propensity score matching. Conclusions: Among patients with HFpEF, women with AF had more abnormal LV geometry and diastolic function and had an increased risk of adverse cardiovascular outcomes independent of traditional risk factors, comorbidities, and baseline diastolic function.

Machine Learning Risk Prediction for Incident Heart Failure in Patients With Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) increases the risk of heart failure (HF); however, little focus is placed on the risk stratification for, and prevention of, incident HF in patients with AF.

OBJECTIVES

This study aimed to construct and validate a machine learning (ML) prediction model for HF hospitalization in patients with AF.

METHODS

The Fushimi AF Registry is a community-based prospective survey of patients with AF in Fushimi-ku, Kyoto, Japan. We divided the data set of the registry into derivation (n = 2,383) and validation (n = 2,011) cohorts. An ML model was built to predict the incidence of HF hospitalization using the derivation cohort, and predictive ability was examined using the validation cohort.

RESULTS

HF hospitalization occurred in 606 patients (14%) during a median follow-up period of 4.4 years in the entire registry. Data of transthoracic echocardiography and biomarkers were frequently nominated as important predictive variables across all 6 ML models. The ML model based on a random forest algorithm using 7 variables (age, history of HF, creatinine clearance, cardiothoracic ratio on x-ray, left ventricular [LV] ejection fraction, LV end-systolic diameter, and LV asynergy) had high prediction performance (area under the receiver operating characteristics curve [AUC]: 0.75) and was significantly superior to the Framingham HF risk model (AUC: 0.67; P < 0.001). Based on Kaplan-Meier curves, the ML model could stratify the risk of HF hospitalization during the follow-up period (log-rank; P < 0.001).

CONCLUSIONS

The ML model revealed important predictors and helped us to stratify the risk of HF, providing opportunities for the prevention of HF in patients with AF.

Machine learning prediction of atrial fibrillation in cardiovascular patients using cardiac magnetic resonance and electronic health information

Background

Atrial fibrillation (AF) is a commonly encountered cardiac arrhythmia associated with morbidity and substantial healthcare costs. While patients with cardiovascular disease experience the greatest risk of new-onset AF, no risk model has been developed to predict AF occurrence in this population. We hypothesized that a patient-specific model could be delivered using cardiovascular magnetic resonance (CMR) disease phenotyping, contextual patient health information, and machine learning.

Methods

Nine thousand four hundred forty-eight patients referred for CMR imaging were enrolled and followed over a 5-year period. Seven thousand, six hundred thirty-nine had no prior history of AF and were eligible to train and validate machine learning algorithms. Random survival forests (RSFs) were used to predict new-onset AF and compared to Cox proportional-hazard (CPH) models. The best performing features were identified from 115 variables sourced from three data domains: (i) CMR-based disease phenotype, (ii) patient health questionnaire, and (iii) electronic health records. We evaluated discriminative performance of optimized models using C-index and time-dependent AUC (tAUC).

Results

A RSF-based model of 20 variables (CIROC-AF-20) delivered an overall C-index of 0.78 for the prediction of new-onset AF with respective tAUCs of 0.80, 0.79, and 0.78 at 1-, 2- and 3-years. This outperformed a novel CPH-based model and historic AF risk scores. At 1-year of follow-up, validation cohort patients classified as high-risk of future AF by CIROC-AF-20 went on to experience a 17.3% incidence of new-onset AF, being 24.7-fold higher risk than low risk patients.

Conclusions

Using phenotypic data available at time of CMR imaging we developed and validated the first described risk model for the prediction of new-onset AF in patients with cardiovascular disease. Complementary value was provided by variables from patient-reported measures of health and the electronic health record, illustrating the value of multi-domain phenotypic data for the prediction of AF.

Relationship of diabetes, heart failure, and N-terminal pro-B-type natriuretic peptide with cardiovascular outcomes in patients with atrial fibrillation

AIMS

We aim to explore the relationship of heart failure (HF) and diabetes with cardiovascular (CV) death or hospitalization for HF (HHF) and to study the clinical utility of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in an unselected patient population with atrial fibrillation (AF).

METHODS AND RESULTS

Patients with AF admitted to a tertiary academic center between January 2005 and July 2019 were identified through a search of electronic health records. We used Cox regression models adjusted for age, sex, estimated glomerular filtration rate, diabetes, HF, body mass index, prior myocardial infarction, coronary artery disease, hypertension, smoking, C-reactive protein, and low-density lipoprotein cholesterol. To select the most informative variables, we performed a least absolute shrinkage and selection operator Cox regression with 10-fold cross-validation. In total, 7412 patients (median age 70 years, 39.7% female) were included in this analysis and followed over a median of 4.5 years. Both diabetes [adjusted (Adj.) HR 1.87, 95% CI 1.55-2.25] and HF (Adj. HR 2.57, 95% CI 2.22-2.98) were significantly associated with CV death/HHF after multivariable adjustment. Compared with patients with diabetes, HF patients had a higher risk of HHF but a similar risk of CV and all-cause death. NT-proBNP showed good discriminatory performance (area under the curve 0.78, 95% CI 0.77-0.80) and the addition of NT-proBNP to the covariates used for adjustment resulted in a significant area under the curve improvement (Δ = 0.04, P < 0.001). With least absolute shrinkage and selection operator, the strongest associations for CV death/HHF were obtained for NT-proBNP [HR 1.91 per 1-SD in log-transformed biomarker], HF (HR 1.72), and diabetes (HR 1.56).

CONCLUSIONS

Diabetes and HF were independently associated with an increased risk of CV death/HHF in an unselected AF patient population, and NT-proBNP improved risk assessment. These findings suggest that AF patients with diabetes and/or HF should be managed not only for their risk of stroke and systemic embolic events but also for CV death/HHF.

Association of body mass index with outcomes in patients with newly diagnosed atrial fibrillation: GARFIELD-AF

Objective

While greater body mass index (BMI) is associated with increased risk of developing atrial fibrillation (AF), the impact of BMI on outcomes in newly diagnosed AF is unclear. We examine the influence of BMI on outcomes and whether this is modified by sex and evaluate the effect of non-vitamin K oral anticoagulants (NOACs) in patients with high BMI.

Methods

GARFIELD-AF is a prospective registry of 52 057 newly diagnosed AF patients. The study population comprised 40 482 participants: 703 underweight (BMI <18.5 kg/m²), 13 095 normal (BMI=18.5–24.9 kg/m²), 15 043 overweight (BMI=25.0–29.9 kg/m²), 7560 obese (BMI=30.0–34.9 kg/m²) and 4081 extremely obese (BMI ≥35.0 kg/m²). Restricted cubic splines quantified the association of BMI with outcomes. Comparative effectiveness of NOACs and vitamin K antagonists (VKAs) by BMI was performed using propensity score overlap-weighted Cox models.

Results

The median age of participants was 71.0 years (Q1; Q3 62.0; 78.0), and 55.6% were male. Those with high BMI were younger, more often had vascular disease, hypertension and diabetes. Within 2-year follow-up, a U-shaped relationship between BMI and all-cause mortality was observed, with BMI of ~30 kg/m² associated with the lowest risk. The association with new/worsening heart failure was similar. Only low BMI was associated with major bleeding and no association emerged for non-haemorrhagic stroke. BMI was similarly associated with outcomes in men and women. BMI did not impact the lower rate of all-cause mortality of NOACs compared with VKAs.

Conclusions

In the GARFIELD-AF registry, underweight and extremely obese AF patients have increased risk of mortality and new/worsening heart failure compared with normal or obese patients.

Development and Validation of a Risk Score in Chinese Patients With Chronic Heart Failure

Background

Acute exacerbation of chronic heart failure contributes to substantial increases in major adverse cardiovascular events (MACE). The study developed a risk score to evaluate the severity of heart failure which was related to the risk of MACE.

Methods

This single-center retrospective observational study included 5,777 patients with heart failure. A credible random split-sample method was used to divide data into training and validation dataset (split ratio = 0.7:0.3). Least absolute shrinkage and selection operator (Lasso) logistic regression was applied to select predictors and develop the risk score to predict the severity category of heart failure. Receiver operating characteristic (ROC) curves, and calibration curves were used to assess the model’s discrimination and accuracy.

Results

Body-mass index (BMI), ejection fraction (EF), serum creatinine, hemoglobin, C-reactive protein (CRP), and neutrophil lymphocyte ratio (NLR) were identified as predictors and assembled into the risk score (P &lt; 0.05), which showed good discrimination with AUC in the training dataset (0.770, 95% CI:0.746–0.794) and validation dataset (0.756, 95% CI:0.717–0.795) and was well calibrated in both datasets (all P &gt; 0.05). As the severity of heart failure worsened according to risk score, the incidence of MACE, length of hospital stay, and treatment cost increased (P &lt; 0.001).

Conclusion

A risk score incorporating BMI, EF, serum creatinine, hemoglobin, CRP, and NLR, was developed and validated. It effectively evaluated individuals’ severity classification of heart failure, closely related to MACE.

Nationwide study of sex differences in incident heart failure in newly diagnosed nonvalvular atrial fibrillation

Background

Heart failure (HF) is a leading complication of nonvalvular atrial fibrillation (NVAF), and the presence of both conditions worsens prognosis. Sex-specific associations between NVAF and outcomes focus on stroke; less is known about HF. We evaluated sex differences in incident HF in NVAF.

Methods

We identified adults age ≥ 65 years hospitalized for incident NVAF without prior HF from April 2010 to March 2018 in Canada. The primary outcome was incident HF hospitalization, with a secondary composite outcome of incident HF hospitalization or all-cause mortality at 1 year. Cox proportional hazard regression models were constructed for the association between sex and outcomes, adjusting for age, comorbidities, socioeconomic status, cardioversion, and medications.

Results

Of 68,909 NVAF patients, 53.8% were women. Women had a higher rate of the primary outcome (30.0% vs 25.6%, P < 0.001) and the composite outcome (39.5% vs 36.6%, P < 0.001) than men. In multivariable analysis without adjusting for medications, there was an 8% increase risk of HF (95% confidence interval [CI] 1.05-1.11, P < 0.001) for women, which was attenuated when accounting for medication (hazard ratio [HR] 1.01, 95% CI 0.98-1.04). After full adjustment, women age ≥ 75 years were at higher risk of the primary outcome (HR 1.10, 95% CI 1.06-1.13, P < 0.001) and the composite outcome (HR 1.04, 95% CI 1.01-1.07, P < 0.001), compared with men, whereas there was a significantly lower risk for those age 65-75 years.

Conclusions

In this nationwide study of incident NVAF without HF, women age ≥ 75 years were more likely to develop HF or die than men. Strategies to prevent HF in older women with NVAF are needed.

Team-based strategies to prevent heart failure

PURPOSE OF REVIEW

The burden of heart failure (HF) in the United States and worldwide is projected to rise. Prevention of HF can curb the burden of this chronic syndrome, but current approaches are limited. This review discusses team-based strategies aimed to prevent HF.

RECENT FINDINGS

Individuals at high risk for developing HF can be identified using HF risk scores, biomarkers, and cardiac imaging. Electronic medical records (EMR) can integrate clinical data to estimate HF risk and identify individuals who may benefit most from preventive therapies. Team-based interventions can lead to enhanced adherence to medications, optimization of medical management, and control of risk factors. Multifaceted interventions involve EMR-based strategies, pharmacist- and nurse-led initiatives, involvement of community personnel, polypills, and digital solutions.

SUMMARY

Team-based strategies aimed to prevent HF incorporate a broad group of personnel and tools. Despite implementation challenges, existing resources can be efficiently utilized to facilitate team-based approaches to potentially reduce the burden of HF.

Interactions Between Atrial Fibrillation and Natriuretic Peptide in Predicting Heart Failure Hospitalization or Cardiovascular Death

Background Natriuretic peptides are routinely quantified to diagnose heart failure (HF). Their concentrations are also elevated in atrial fibrillation (AF). To clarify their value in predicting future cardiovascular events, we measured natriuretic peptides in unselected patients with cardiovascular conditions and related their concentrations to AF and HF status and outcomes. Methods and Results Consecutive patients with cardiovascular conditions presenting to a large teaching hospital underwent clinical assessment, 7-day ECG monitoring, and echocardiography to diagnose AF and HF. NT-proBNP (N-terminal pro-B-type natriuretic peptide) was centrally quantified. Based on a literature review, four NT-proBNP groups were defined (<300, 300-999, 1000-1999, and ≥2000 pg/mL). Clinical characteristics and NT-proBNP concentrations were related to HF hospitalization or cardiovascular death. Follow-up data were available in 1616 of 1621 patients (99.7%) and analysis performed at 2.5 years (median age, 70 [interquartile range, 60-78] years; 40% women). HF hospitalization or cardiovascular death increased from 36 of 488 (3.2/100 person-years) in patients with neither AF nor HF, to 55 of 354 (7.1/100 person-years) in patients with AF only, 92 of 369 (12.1/100 person-years) in patients with HF only, and 128 of 405 (17.7/100 person-years) in patients with AF plus HF (P<0.001). Higher NT-proBNP concentrations predicted the outcome in patients with AF only (C-statistic, 0.82; 95% CI, 0.77-0.86; P <0.001) and in other phenotype groups (C-statistic in AF plus HF, 0.66; [95% CI, 0.61-0.70]; P <0.001). Conclusions Elevated NT-proBNP concentrations predict future HF events in patients with AF irrespective of the presence of HF, encouraging routine quantification of NT-proBNP in the assessment of patients with AF.

Incidence and Predictors of Heart Failure in Patients With Atrial Fibrillation

BACKGROUND

Heart failure (HF) is a frequent cause of hospitalization and death in patients with atrial fibrillation (AF). Identifying AF patients at risk of HF hospitalization could help select individuals for intensive follow-up and treatment.

METHODS

We pooled data from 3 randomized trials (ACTIVE-A, RE-LY, AVERROES) of AF patients, for derivation and internal validation of a risk score for first HF hospitalization. Secondary endpoints were cardiovascular death and a composite of HF hospitalizations and cardiovascular death.

RESULTS

In 23,503 patients, the mean age was 71.3 years, and 62% were male. Over a mean follow-up of 2.0 years, 875 patients (3.7%) experienced their first HF hospitalization, and 1037 patients (4.4%) died from cardiovascular causes. Incidence rates per 100 patient-years were 1.85 for HF hospitalizations, 2.15 for cardiovascular death, and 3.71 for the composite. Independent predictors for HF hospitalizations included the following: increased age, weight, heart rate and serum creatinine level, lower height and systolic blood pressure, diabetes, vascular disease, valvular disease, heart rhythm, left ventricular hypertrophy, and intraventricular conduction delay. The C-statistic (95% confidence intervals by bootstrap simulations) was 0.717 (0.705-0.732). At 2 years of follow-up, the incidence rate of the primary outcome increased across risk-score quintiles: 0.49, 0.87, 1.29, 2.44, and 4.51 per 100 patient-years, respectively. Patients in the highest quintile had an absolute risk of 6.8% for the primary endpoint at 2 years.

CONCLUSIONS

In a large AF population, new-onset HF was common. A combination of characteristics can identify high-risk patients for whom strategies to prevent HF should be considered.

LVS-HARMED Risk Score for Incident Heart Failure in Patients With Atrial Fibrillation Who Present to the Emergency Department: Data from a World-Wide Registry

Background Heart failure (HF) is a common complication to atrial fibrillation (AF), leading to rehospitalization and death. Early identification of patients with AF at risk for HF might improve outcomes. We aimed to derive a score to predict 1-year risk of new-onset HF after an emergency department (ED) visit with AF. Methods and Results The RE-LY AF (Randomized Evaluation of Long-Term Anticoagulant Therapy) registry enrolled patients with AF presenting to an ED in 47 countries, and followed them for a year. The end point was HF hospitalization and/or HF death. Among 15 400 ED patients, 9765 had no prior HF (mean age, 64.9±14.9 years). Within 1 year, new-onset HF developed in 6.8% of patients, of whom 21% died of HF. Independent predictors of HF included left ventricular hypertrophy (odds ratio [OR], 1.47; 95% CI, 1.19-1.82), valvular heart disease (OR, 1.55; 95% CI, 1.18-2.04), smoking (OR, 1.42; 95% CI, 1.12-1.78), height (OR, 0.93; 95% CI, 0.90-0.95 per 3 cm), age (OR, 1.11; 95% CI, 1.07-1.15 per 5 years), rheumatic heart disease (OR, 1.77, 95% CI, 1.24-2.51), prior myocardial infarction (OR, 1.85; 95% CI, 1.45-2.36), remaining in AF at ED discharge (OR, 1.86; 95% CI, 1.46-2.36), and diabetes (OR, 1.33; 95% CI, 1.09-1.64). A continuous risk prediction score (LVS-HARMED [left ventricular, valvular heart disease, smoking or other tobacco use, height, age, rheumatic heart disease, myocardial infarction, emergency department discharge rhythm, and diabetes]) had good discrimination (C statistic, 0.735; 95% CI, 0.716-0.755). Validation was conducted internally using bootstrapping (optimism-corrected C statistic, 0.705) and externally (C statistic, 0.699). The 1-year incidence of HF hospitalization and/or HF death across quartile groups of the score was 1.1%, 4.5%, 6.9%, and 14.4%, respectively. LVS-HARMED also predicted incident stroke (C statistic, 0.753; 95% CI, 0.728-0.778). Conclusions The LVS-HARMED score predicts new-onset HF after an ED visit for AF. Preventative strategies should be considered in patients with high LVS-HARMED HF risk.

Refined atrial fibrillation screening and cost-effectiveness in the German population

OBJECTIVE

Little is known on optimal screening population for detecting new atrial fibrillation (AF) in the community. We describe characteristics and estimate cost-effectiveness for a single timepoint electrocardiographic screening.

METHODS

We performed a 12-lead ECG in the German population-based Gutenberg Health Study between 2007 and 2012 (n=15 010), mean age 55±11 years, 51% men and collected more than 120 clinical and biomarker variables, including N-terminal pro B-type natriuretic peptide (Nt-proBNP), risk factors, disease symptoms and echocardiographic variables.

RESULTS

Of 15 010 individuals, 466 (3.1%) had AF. New AF was found in 32 individuals, 0.2% of the total sample, 0.5% of individuals aged 65-74 years and predominantly men (86%). The classical risk factor burden was high in individuals with new AF. The median estimated stroke risk was 2.2%/year, while risk of developing heart failure was 21% over 10 years. In the 65-74 year age group, the cost per quality-adjusted life-year gained resulting from a single timepoint screening was €30 361. In simulations, the costs were highly sensitive to AF detection rates, proportion of treatment and type of oral anticoagulant. Prescreening by Nt-proBNP measurements was not cost-effective in the current setting.

CONCLUSIONS

In our middle-aged population cohort, we identified 0.2% new AF by single timepoint screening. There was a significant estimated risk of stroke and heart failure in these individuals. Cost-effectiveness for screening may be reached in individuals aged 65 years and older. The simple age cut-off is not improved by using Nt-proBNP as a biomarker to guide a screening programme.

Atrial fibrillation and the risk of cardiovascular disease and mortality in the Hypertension in the Very Elderly Trial

OBJECTIVE

To assess the prognostic value of electrocardiographic atrial fibrillation in older hypertensive people in the randomized, placebo-controlled Hypertension in the Very Elderly Trial.

METHODS

Hypertension in the Very Elderly Trial randomized 3845 hypertensive people aged 80 years and over, 3273 with electrographic data on the presence or absence of atrial fibrillation at baseline and without established cardiovascular disease. Multivariate Cox proportional hazard models were used to estimate hazard ratios with 95% confidence intervals (CIs) for all-cause mortality, incident fatal and nonfatal major cardiovascular events, all-stroke and all-heart failure. The mean follow-up time was 2.1 years.

RESULTS

Baseline prevalence of atrial fibrillation was 5.8%. Compared with people without atrial fibrillation at baseline, after adjustments the presence of atrial fibrillation was associated with increased risk of mortality (hazard ratio = 2.49, 95% CI = 1.80-3.44, P < 0.001), of nonfatal and fatal cardiovascular events (hazard ratio = 2.47, 95% CI = 1.71-3.55, P < 0.001), all-stroke (hazard ratio = 2.47, 95% CI = 1.34-4.56, P = 0.004) and all-heart failure (hazard ratio 2.33, 95% CI = 1.10-4.93, P = 0.027).

CONCLUSION

Atrial fibrillation is an important risk factor to consider when assessing older hypertensive adults as it is associated with increased risk of mortality, nonfatal and fatal cardiovascular events, stroke and heart failure.

Refocusing on the Primary Prevention of Heart Failure

Purpose of review

The burden of heart failure (HF) is a significant national and global public health problem, with prevalence rates on the rise. Given the significant morbidity, mortality, and healthcare costs attributable to HF, it is of utmost importance to utilize preventive strategies to prevent the development of HF. Therefore, we sought to address how a multi-modal risk assessment approach can be used to stratify patients for HF risk and guide implementation of therapeutic strategies to prevent HF.

Recent findings

New externally validated, multivariate prediction models for incident HF can be applied in the general population and may be used to aide clinicians in assessing individualized HF risk and screening for HF. Recent clinical trial data suggest a natriuretic peptide biomarker-based screening approach coupled with team-based cardiovascular care to focus on optimization of guideline-directed medical therapy may help prevent new-onset HF. However, widespread implementation of clinical risk scores and/or biomarkers is needed.

Summary

In addition to promoting a heart healthy lifestyle, prevention and management of modifiable risk factors, including intensive blood pressure lowering and use of sodium-glucose cotransporter-2 inhibitors, can prevent incident HF.

Incidence, predictors and mortality risk of new heart failure in patients hospitalised with atrial fibrillation

OBJECTIVE

To determine the incidence, risk predictors and relative mortality risk of incident heart failure (HF) in patients following atrial fibrillation (AF) hospitalisation.

METHODS

The Western Australian Hospitalisation Morbidity Data Collection was used to identify patients aged 25-94 years with index (first-in-period) AF hospitalisation, but without a prior HF admission, between 2000 and 2013. We evaluated the risk of incident HF hospitalisation within 3 years after AF admission, and the impact of HF hospitalisation on all-cause mortality.

RESULTS

The cohort comprised 52 447 patients, 57.5% men, with a median age of 73.1 (IQR 63.2-80.8) years. At 3 years after AF discharge, the cumulative incidence of HF (n=6153) was 11.7% (95% CI 11.5% to 12.0%) and all-cause death (n=9702) was 18.5% (95% CI 18.2% to 18.8%). Independent predictors of incident HF included advancing age, any history of myocardial infarction (MI), peripheral vascular disease, valvular heart disease, chronic kidney disease, chronic obstructive pulmonary disease, hypertension, diabetes, obesity and excessive alcohol use (all p<0.001). Patients hospitalised for first-ever HF compared with those without HF hospitalisation had an adjusted HR of 3.3 (95% CI 3.1 to 3.4) for all-cause mortality (p<0.001). Independent predictors of HF were also shared with those for mortality, with the exception of hypertension.

CONCLUSION

Hospitalisation for new HF is common in patients with AF and independently associated with a 3-fold hazard for death. The clinical predictors of incident HF emphasise the importance of integrated management of common comorbid conditions and lifestyle risk factors in patients with AF to reduce their morbidity and mortality.

Prognostic significance of present atrial fibrillation on a single office electrocardiogram in patients with atrial fibrillation

BACKGROUND

Evidence for the association of atrial fibrillation (AF) present on the ECG and cardiovascular outcomes in AF patients is limited.

OBJECTIVE

To investigate the prognostic significance of AF on a single surface ECG for cardiovascular outcomes in AF patients.

METHODS

A total of 3642 AF patients were prospectively enrolled. Main exclusion criteria were rhythms other than sinus rhythm (SR) or AF. The primary end-point was a composite of all-cause death and hospitalizations for congestive heart failure (CHF). Secondary end-points were all-cause death, CHF hospitalizations, cardiovascular death, myocardial infarction, any stroke and stroke subtypes. Associations were assessed with multivariable Cox proportional hazards models.

RESULTS

Mean age was 71 years, 28% were female, and mean follow-up was 3.4 years. Patients with SR on the ECG at study enrolment (56%) were younger (69 vs. 74 years, P < 0.0001), had more often paroxysmal AF (73 vs. 18%, P < 0.0001) and fewer comorbidities. The incidence of the primary end-point was 1.8 and 3.1 per 100 person-years in patients with SR and AF, respectively. The multivariable-adjusted hazard ratio was 1.4 (95% confidence intervals 1.1; 1.7; P = 0.001) for patients with AF on the ECG compared to patients with SR. The hazard ratios (95% confidence intervals) were 1.4 (1.1; 1.8; P = 0.006) for all-cause death, 1.5 (1.2; 1.9; P = 0.001) for CHF and 1.6 (1.1; 2.2; P = 0.006) for cardiovascular death. None of the other associations were statistically significant.

CONCLUSIONS

The presence of AF in a single office ECG had significant prognostic implications with regard to mortality and CHF hospitalizations in patients with AF. These patients present a high-risk group and might benefit from intensified treatment.

Stage A Heart Failure: Modern Strategies for an Effective Prevention

Stage A heart failure (HF) patients do not show HF symptoms or any structural heart disease but are at risk of HF development. Cardiovascular risk factors (hypertension, diabetes, metabolic syndrome, sedentary lifestyle, poor diet, and exposure to cardiotoxic agents) characterize subjects affected by stage A HF. It is essential to identify these subjects early and ensure that, despite being asymptomatic, they grasp the importance of undertaking correct lifestyle and therapeutic interventions. A careful stratification of asymptomatic subject's risk profile is needed to adopt proper preventive strategies and to set individualized therapeutic targets that avoid progression to advanced stages of HF.

Choline Metabolism and Risk of Atrial Fibrillation and Heart Failure in the PREDIMED Study

BACKGROUND

Few studies have examined the associations of trimethylamine-N-oxide (TMAO) and its precursors (choline, betaine, dimethylglycine, and L-carnitine) with the risk of atrial fibrillation (AF) and heart failure (HF). This study sought to investigate these associations.

METHODS

Prospective associations of these metabolites with incident AF and HF were examined among participants at high cardiovascular risk in the PREDIMED study (PREvención con DIeta MEDiterránea) after follow-up for about 10 years. Two nested case-control studies were conducted, including 509 AF incident cases matched to 618 controls and 326 HF incident cases matched to 426 controls. Plasma levels of TMAO and its precursors were semi-quantitatively profiled with liquid chromatography tandem mass spectrometry. Odds ratios were estimated with multivariable conditional logistic regression models.

RESULTS

After adjustment for classical risk factors and accounting for multiple testing, participants in the highest quartile vs. the lowest quartile of baseline choline and betaine levels had a higher risk of AF [OR (95% CI): 1.85 (1.30-2.63) and 1.57 (1.09-2.24), respectively]. The corresponding OR for AF for extreme quartiles of dimethylglycine was 1.39 (0.99-1.96). One SD increase in log-transformed dimethylglycine was positively associated with AF risk (OR, 1.17; 1.03-1.33). The corresponding ORs for HF for extreme quartiles of choline, betaine, and dimethylglycine were 2.51 (1.57-4.03), 1.65 (1.00-2.71) and 1.65 (1.04-2.61), respectively. TMAO and L-carnitine levels were not associated with AF or HF.

CONCLUSIONS

Our findings support the role of the choline metabolic pathway in the pathogenesis of AF and HF.

High Plasma Glutamate and a Low Glutamine-to-Glutamate Ratio Are Associated with Increased Risk of Heart Failure but Not Atrial Fibrillation in the Prevención con Dieta Mediterránea (PREDIMED) Study

BACKGROUND

Although the association between glutamate and glutamine in relation to cardiometabolic disorders has been evaluated, the role of these metabolites in the development of atrial fibrillation (AF) and heart failure (HF) remains unknown.

OBJECTIVES

We examined associations of glutamate, glutamine, and the glutamine-to-glutamate ratio with AF and HF incidence in a Mediterranean population at high cardiovascular disease (CVD) risk.

METHODS

The present study used 2 nested case-control studies within the PREDIMED (Prevención con Dieta Mediterránea) study. During ∼10 y of follow-up, there were 509 AF incident cases matched to 618 controls and 326 HF incident cases matched to 426 controls. Plasma concentrations of glutamate and glutamine were semiquantitatively profiled with LC-tandem MS. ORs were estimated with multivariable conditional logistic regression models.

RESULTS

In fully adjusted models, per 1-SD increment, glutamate was associated with a 29% (95% CI: 1.08, 1.54) increased risk of HF and glutamine-to-glutamate ratio with a 20% (95% CI: 0.67, 0.94) decreased risk. Glutamine-to-glutamate ratio was also inversely associated with HF risk (OR per 1-SD increment: 0.80; 95% CI: 0.67, 0.94) when comparing extreme quartiles. Higher glutamate concentrations were associated with a worse cardiometabolic risk profile, whereas a higher glutamine-to-glutamate ratio was associated with a better cardiometabolic risk profile. No associations between the concentrations of these metabolites and AF were observed.

CONCLUSIONS

Our findings suggest that high plasma glutamate concentrations possibly resulting from alterations in the glutamate-glutamine cycle may contribute to the development of HF in Mediterranean individuals at high CVD risk.This trial was registered at www.isrctn.com as ISRCTN35739639.

Association of Multimorbidity with Cardiovascular Endpoints and Treatment Effectiveness in Patients 75 Years and Older with Atrial Fibrillation

BACKGROUND

The burden imposed by multimorbidity on outcomes and on the effectiveness of atrial fibrillation therapies in elderly adults with atrial fibrillation is unknown.

METHODS

Patients with nonvalvular atrial fibrillation ages ≥75 years in the MarketScan Medicare Supplemental database from 2007-2015. Prevalence of 14 chronic conditions at the time of atrial fibrillation diagnosis were obtained and classified as cardiometabolic or noncardiometabolic. Cox regression estimated the associations of the number and type of conditions with stroke, severe bleeding, and heart failure hospitalizations. Tests for interaction were assessed between atrial fibrillation treatments and multimorbidity.

RESULTS

Among 275,617 patients with atrial fibrillation (mean age 83 years, 51% women), the mean (SD) number of conditions per participant was 3.0 (2.1). Over a mean follow-up of 23 months, 7814 strokes, 13,622 severe bleeds, and 19,252 heart failure events occurred. After adjustment, an increase in the number of cardiometabolic conditions was associated with greater risk of stroke (hazard ratio [HR] 1.07; 95% confidence interval [CI], 1.05-1.10), severe bleeding (HR 1.09; 95% CI, 1.07-1.11), and heart failure (HR 1.19, 95% CI, 1.18-1.20). In contrast, number of noncardiometabolic conditions had weak or null associations with risk of cardiovascular endpoints. Overall, the effectiveness of atrial fibrillation treatment on stroke and heart failure were similar across multimorbidity status, but bleeding risk associated with atrial fibrillation treatments was higher in patients with overall and subgroup multimorbidity.

CONCLUSION

Cardiometabolic multimorbidity was associated with worse outcomes and modified bleeding risk in atrial fibrillation patients. These findings underscore the impact of cardiometabolic conditions on atrial fibrillation outcomes and highlights the need to incorporate multimorbidity management in atrial fibrillation treatment guidelines.

A Stepwise Approach to the Management of Heart Failure and its Comorbidities

Modern medical and technological advances provide highly effective management for the treatment of patients with heart failure with reduced ejection fraction (HFrEF). In this review, the authors propose a 2-step approach to treatment that is straightforward, practical, and thorough. For the patient whose life now includes HFrEF, the physician's first step is to ensure that the patient is taking the 3 key medications ([1] renin-angiotensin inhibitors (angiotensin receptor/neprilysin inhibitors, angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers), [2] β-blockers, and [3] mineralocorticoid receptor antagonists) recommended in guideline-directed doses to attain comprehensive receptor blockade. Significant coexisting medical issues are also characteristic in patients with HFrEF. Therefore, the physician's second step is to address the comorbidities of heart failure to fulfill comprehensive patient care. This review presents evidence to implement the management of HFrEF and heart failure comorbidities that will reduce cardiac mortality and hospitalization and to avoid treatments that are of no benefit or may cause harm.

Heart Failure in Atrial Fibrillation - An Update on Clinical and Echocardiographic Implications

Atrial fibrillation (AF) is the most common sustained arrhythmia in adults and has unfavorable consequences such as stroke, heart failure (HF), and death. HF is the most common adverse event following AF and the leading cause of death. Therefore, identifying the association between AF and HF is important to establish risk stratification for HF in AF. Recent studies suggested that left atrial and ventricular fibrosis is an important link between AF and HF, and the prognostic impact may differ with respect to HF subtype, stratified with left ventricular ejection fraction (EF). Mortality risk in patients with concurrent AF and HF with reduced EF (HFrEF) appears slightly higher compared with those with concurrent AF and HF with preserved EF (HFpEF). On the other hand, the prognostic impact of HF in AF is similar between HFrEF and HFpEF. Further, left atrial size, as well as left atrial and left ventricular functional assessment, are reported to be useful for the prediction of HF in AF, incremental to the conventional risk factors. In this review, we focus on the epidemiological, pathophysiological, and prognostic associations between AF and HF, and review the clinical and echocardiographic predictors for HF in AF.

Advancing Research on the Complex Interrelations Between Atrial Fibrillation and Heart Failure: A Report From a US National Heart, Lung, and Blood Institute Virtual Workshop

The interrelationships between atrial fibrillation (AF) and heart failure (HF) are complex and poorly understood, yet the number of patients with AF and HF continues to increase worldwide. Thus, there is a need for initiatives that prioritize research on the intersection between AF and HF. This article summarizes the proceedings of a virtual workshop convened by the US National Heart, Lung, and Blood Institute to identify important research opportunities in AF and HF. Key knowledge gaps were reviewed and research priorities were proposed for characterizing the pathophysiological overlap and deleterious interactions between AF and HF; preventing HF in people with AF; preventing AF in individuals with HF; and addressing symptom burden and health status outcomes in AF and HF. These research priorities will hopefully help inform, encourage, and stimulate innovative, cost-efficient, and transformative studies to enhance the outcomes of patients with AF and HF.

The association of hypertension, hypertension duration, and control with incident heart failure in black and white adults

Associations between hypertension and some cardiovascular diseases are stronger in black vs white adults. We examined associations of hypertension, hypertension duration, and control with incident heart failure (HF) in black and white REasons for Geographic And Racial Differences in Stroke study participants (n = 25 770) who were followed for incident HF hospitalization (n = 947) from enrollment in 2003-2007 through 2015. Hypertension was defined, using updated US guidelines, as systolic or diastolic blood pressure (BP) ≥130/80 mm Hg or antihypertensive medication use. Duration was assessed at baseline, and control was defined as treated BP < 130/80 mm Hg. Compared with no hypertension, hypertension was associated with higher risk of incident HF (HRwhites 1.90 [95% CI 1.49, 2.41], HRblacks 2.36 [95% CI 1.53, 3.65]), HF with preserved ejection fraction (HRwhites 2.01 [95% CI 1.34, 3.01], HRblacks 2.70 [95% CI 1.25, 2.53]), and HF with reduced/mid-range ejection fraction (HRwhites 1.69 [95% CI 1.23, 2.33], HRblacks 2.29 [95% CI 1.26, 4.15]). Hypertension duration <10 years and ≥10 years were associated with higher risk for incident HF compared with no hypertension. Although risk of incident HF was highest among participants with uncontrolled BP, even controlled BP vs no hypertension was associated with increased risk of HF (HRwhites 1.93 [95% CI 1.44, 2.58], HRblacks 2.01 [95% CI 1.22, 3.29]). Interactions with race were not statistically significant. The risk of HF associated with hypertension, even with shorter duration or controlled BP, suggests that both prevention and therapeutic management of hypertension are important in reducing HF risk.

Correlation between increased atrial expression of genes related to fatty acid metabolism and autophagy in patients with chronic atrial fibrillation

Atrial metabolic disturbance contributes to the onset and development of atrial fibrillation (AF). Autophagy plays a role in maintaining the cellular energy balance. We examined whether atrial gene expressions related to fatty acid metabolism and autophagy are altered in chronic AF and whether they are related to each other. Right atrial tissue was obtained during heart surgery from 51 patients with sinus rhythm (SR, n = 38) or chronic AF (n = 13). Preoperative fasting serum free-fatty-acid levels were significantly higher in the AF patients. The atrial gene expression of fatty acid binding protein 3 (FABP3), which is involved in the cells' fatty acid uptake and intracellular fatty acid transport, was significantly increased in AF patients compared to SR patients; in the SR patients it was positively correlated with the right atrial diameter and intra-atrial electromechanical delay (EMD), parameters of structural and electrical atrial remodeling that were evaluated by an echocardiography. In contrast, the two groups' atrial contents of diacylglycerol (DAG), a toxic fatty acid metabolite, were comparable. Importantly, the atrial gene expression of microtubule-associated protein light chain 3 (LC3) was significantly increased in AF patients, and autophagy-related genes including LC3 were positively correlated with the atrial expression of FABP3. In conclusion, in chronic AF patients, the atrial expression of FABP3 was upregulated in association with autophagy-related genes without altered atrial DAG content. Our findings may support the hypothesis that dysregulated cardiac fatty acid metabolism contributes to the progression of AF and induction of autophagy has a cardioprotective effect against cardiac lipotoxicity in chronic AF.