Impact of Atrial Fibrillation in Heart Failure With Normal Ejection Fraction: A Clinical and Echocardiographic Study

The Effects of Radiofrequency Catheter Ablation for Atrial Fibrillation on Right Ventricular Function

BACKGROUND AND OBJECTIVE

The effects of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) on right ventricular (RV) function are not well known.

METHODS

Patients who underwent RFCA for AF and underwent pre- and post-procedural echocardiography were enrolled consecutively. Fractional area change (FAC), RV free-wall longitudinal strain (RVFWSL), and RV 4-chamber strain including the ventricular septum (RV4CSL) were measured. Changes in FAC, RVFWSL, and RV4CSL before and after RFCA were compared among paroxysmal AF (PAF), persistent AF (PeAF), and long-standing persistent AF (LSPeAF) groups.

RESULTS

A total of 164 participants (74 PAF, 47 PeAF, and 43 LSPeAF; age, 60.8 ± 9.8 years; men, 74.4%) was enrolled. The patients with PeAF and LSPeAF had worse RV4CSL (p<0.001) and RVFWSL (p<0.001) than those with PAF and reference values. Improvements in RVFWSL and RV4CSL after RFCA were significant in the PeAF group compared with the PAF and LSPeAF groups (ΔRV4CSL, 8.4% [5.1, 11.6] in PeAF vs. 1.0% [-1.0, 4.1] in PAF, 1.9% [-0.2, 4.4] in LSPeAF, p<0.001; ΔRVFWSL, 9.0% [6.9, 11.5] in PeAF vs. 0.9% [-1.4, 4.9] in PAF, 1.0% [-1.0, 3.6] in LSPeAF, p<0.001). In patients without recurrence, improvements in RVFWSL and RV4CSL after RFCA were significant in the PeAF group compared to the LSPeAF group.

CONCLUSIONS

RV systolic function is more impaired in patients with PeAF and LSPeAF than in those with PAF. RV systolic function is more improved after RFCA in patients with PeAF than in those with PAF or LSPeAF.

Basal Septal Hypertrophy as the Early Imaging Biomarker for Adaptive Phase of Remodeling Prior to Heart Failure

Hypertension plays a dominant role in the development of left ventricular (LV) remodeling and heart failure, in addition to being the main risk factor for coronary artery disease. In this review, we focus on the focal geometric and functional tissue aspects of the LV septal base, since basal septal hypertrophy (BSH), as the early imaging biomarker of LV remodeling due to hypertensive heart disease, is detected in cross-sectional clinic studies. In addition, the validation of BSH by animal studies using third generation microimaging and relevant clinical observations are also discussed in the report. Finally, an evaluation of both human and animal quantitative imaging studies and the importance of combined cardiac imaging methods and stress-induction in the separation of adaptive and maladaptive phases of the LV remodeling are pointed out. As a result, BSH, as the early imaging biomarker and quantitative follow-up of functional analysis in hypertension, could possibly contribute to early treatment in a timely fashion in the prevention of hypertensive disease progression to heart failure. A variety of stress stimuli in etiopathogenesis and the difficulty of diagnosing pure hemodynamic overload mediated BSH lead to an absence of the certain prevalence of this particular finding in the population.

The Relationship of Dehydration and Body Mass Index With the Occurrence of Atrial Fibrillation in Heart Failure Patients

Purpose: The aim of the study was to assess the relationship of dehydration, body mass index (BMI) and other indices with the occurrence of atrial fibrillation (AF) in heart failure (HF) patients. Methods: The study included 113 patients [median age 64 years; 57.52% male] hospitalized due to HF. Baseline demographics, body mass analysis, echocardiographic results, key cardiopulmonary exercise test (CPET) parameters, 6 min walk distance (6MWD) and Kansas City Cardiomyopathy Questionnaire (KCCQ) score were assessed. Results: Of all patients, 23 (20.35%) had AF, and 90 (79.65%) had sinus rhythm (SR). Patients with AF were older (med. 66 vs. 64 years; p = 0.039), with higher BMI (32.02 vs. 28.51 kg/m2; p = 0.017) and percentage of fat content (37.0 vs. 27.9%, p = 0.014). They were more dehydrated, with a lower percentage of total body water (TBW%) (45.7 vs. 50.0%; p = 0.022). Clinically, patients with AF had more often higher New York Heart Association (NYHA) class (III vs. II; p < 0.001), shorter 6MWD (median 292.35 vs. 378.4 m; p = 0.001) and a lower KCCQ overall summary score (52.60 vs. 73.96 points; p = 0.002). Patients with AF had significantly lower exercise capacity as measured by peak oxygen consumption (peak VO2) (0.92 vs. 1.26 mL/min, p = 0.016), peak VO2/kg (11 vs. 15 mL/kg/min; p < 0.001), and percentage of predicted VO2max (pp-peak VO2) (62.5 vs 70.0; p=0.010). We also found VE/VCO2 (med. 33.85 vs. 32.20; p = 0.049) to be higher and peak oxygen pulse (8.5 vs. 11 mL/beat; p = 0.038) to be lower in patients with AF than in patients without AF. In a multiple logistic regression model higher BMI (OR 1.23 per unit increase, p < 0.001) and higher left atrial volume index (LAVI) (OR 1.07 per unit increase, p = 0.03), lower tricuspid annular plane systolic excursion (TAPSE) (OR 0.74 per unit increase, p =0.03) and lower TBW% in body mass analysis (OR 0.90 per unit increase, p =0.03) were independently related to AF in patients with HF. Conclusion: Increased volume of left atrium and right ventricular systolic dysfunction are well-known predictors of AF occurrence in patients with HF, but hydration status and increased body mass also seem to be important factors of AF in HF patients.

Meta-Analysis of Atrial Fibrillation and Outcomes in Patients With Heart Failure and Preserved Ejection Fraction

BACKGROUND

Atrial fibrillation (AF) is common in heart failure with preserved ejection fraction (HFpEF); However, the prognostic impact of AF on HFpEF patients has not been fully elucidated.

METHODS

A literature search of the PubMed and EMBASE databases on literature published through April 2019 was undertaken. Combined hazard ratio (HR) estimates and 95% confidence intervals (CIs) were calculated using fixed-effects or random-effects models, depending on the heterogeneity. Subgroup analyses, sensitivity analysis and meta-regression analyses were also performed.

RESULTS

Fourteen (14) eligible studies with 1,948,923 patients with HFpEF were included in the analysis. Atrial fibrillation was associated with an 11% increased risk of all-cause mortality in patients with HFpEF (HR 1.11, 95% CI 1.09-1.12). Sensitivity analysis confirmed the stability of the results. The stratification of studies by controlled or uncontrolled confounding factors affected the final estimate (confounder-controlled HR 1.21, 95% CI 1.12-1.30; confounder-uncontrolled HR 1.13, 95% CI 0.96-1.31). In addition, AF was an independent predictor of hospitalisation for heart failure (HR 1.32, 95% CI 1.15-1.52), cardiovascular death (HR 1.38, 95% CI 1.01-1.89) and stroke (HR 1.87, 95% CI 1.54-2.27).

CONCLUSIONS

Atrial fibrillation was associated with worse clinical outcomes in patients with HFpEF. Further investigation is required to see whether AF is the primary offender in these patients or merely a bystander to worse diastolic function.

Obstructive sleep apnoea, intermittent hypoxia and heart failure with a preserved ejection fraction

Obstructive sleep apnoea (OSA) is recognised to be a potent risk factor for hypertension, coronary heart disease, strokes and heart failure with a reduced ejection fraction. However, the association between OSA and heart failure with a preserved ejection fraction (HFpEF) is less well recognised. Both conditions are very common globally.It appears that there are many similarities between the pathological effects of OSA and other known aetiologies of HFpEF and its postulated pathophysiology. Intermittent hypoxia induced by OSA leads to widespread stimulation of the sympathetic nervous system, renin-angiotensin-aldosterone system and more importantly a systemic inflammatory state associated with oxidative stress. This is similar to the consequences of hypertension, diabetes, obesity and ageing that are the common precursors to HFpEF. The final common pathway is probably via the development of myocardial fibrosis and structural changes in collagen and myocardial titin that cause myocardial stiffening. Thus, considering the pathophysiology of OSA and HFpEF, OSA is likely to be a significant risk factor for HFpEF and further trials of preventive treatment should be considered.

Prevalence of right ventricular dysfunction and prognostic significance in heart failure with preserved ejection fraction

There is a paucity of data characterizing right ventricular performance in heart failure with preserved ejection fraction (HFpEF) using the gold standard of cardiovascular magnetic resonance imaging (CMR). We aimed to assess the proportion of right ventricular systolic dysfunction (RVD) in HFpEF and the relation to clinical outcomes. As part of a single-centre, prospective, observational study, 183 subjects (135 HFpEF, and 48 age- and sex-matched controls) underwent extensive characterization with CMR. transthoracic echocardiography, blood sampling and six-minute walk testing. Patients were followed for the composite endpoint of death or HF hospitalization. RVD (defined as right ventricular ejection fraction < 47%) controls was present in 19% of HFpEF. Patients with RVD presented more frequently with lower systolic blood pressure, atrial fibrillation, radiographic evidence of pulmonary congestion and raised cardiothoracic ratio and larger right ventricular volumes. During median follow-up of 1429 days, 47% (n = 64) of HFpEF subjects experienced the composite endpoint of death (n = 22) or HF hospitalization (n = 42). RVD was associated with an increased risk of composite events (Log-Rank p = 0.001). In multivariable Cox regression analysis, RVD was an independent predictor of adverse outcomes (adjusted Hazard Ratio [HR] 3.946, 95% CI 1.878–8.290, p = 0.0001) along with indexed extracellular volume (HR 1.742, CI 1.176–2.579, p = 0.006) and E/E’ (HR 1.745, CI 1.230–2.477, p = 0.002). RVD as assessed by CMR is prevalent in nearly one-fifth of HFpEF patients and is independently associated with death and/or hospitalization with HF.

The trial was registered retrospectively on ClinicalTrials.gov (Identifier: NCT03050593). The date of registration was February 06, 2017.

Heart Failure With Preserved Ejection Fraction: A Comprehensive Review and Update of Diagnosis, Pathophysiology, Treatment, and Perioperative Implications

Almost three-quarters of all heart failure patients who are older than 65 have heart failure with preserved ejection fraction (HFpEF). The proportion and hospitalization rate of patients with HFpEF are increasing steadily relative to patients in whom heart failure occurs as result of reduced ejection fraction. The predominance of the HFpEF phenotype most likely is explained by the prevalence of medical conditions associated with an aging population. A multitude of age-related, medical, and lifestyle risk factors for HFpEF have been identified as potential causes for the sustained low-grade proinflammatory state that accelerates disease progression. Profound left ventricular (LV) systolic and diastolic stiffening, elevated LV filling pressures, reduced arterial compliance, left atrial hypertension, pulmonary venous congestion, and microvascular dysfunction characterize HFpEF, but pulmonary arterial hypertension, right ventricular dilation and dysfunction, and atrial fibrillation also frequently occur. These cardiovascular features make patients with HFpEF exquisitely sensitive to the development of hypotension in response to acute declines in LV preload or afterload that may occur during or after surgery. With the exception of symptom mitigation, lifestyle modifications, and rigorous control of comorbid conditions, few long-term treatment options exist for these unfortunate individuals. Patients with HFpEF present for surgery on a regular basis, and anesthesiologists need to be familiar with this heterogeneous and complex clinical syndrome to provide successful care. In this article, the authors review the diagnosis, pathophysiology, and treatment of HFpEF and also discuss its perioperative implications.

Impaired left atrial strain predicts abnormal exercise haemodynamics in heart failure with preserved ejection fraction

BACKGROUND

Elevated left atrial (LA) pressure, particularly during exercise, is associated with symptomatic status and survival in patients with heart failure with preserved ejection fraction (HFpEF). We aimed to characterize the contribution of abnormal LA mechanical properties to exercise haemodynamics in HFpEF.

METHODS AND RESULTS

Simultaneous echocardiography and right heart catheterization were performed in 71 subjects with left ventricular ejection fraction ≥ 50% referred for assessment of exertional dyspnoea. According to haemodynamic evaluation, 49 patients were diagnosed with HFpEF [pulmonary capillary wedge pressure (PCWP) ≥ 15 mmHg at rest and/or ≥ 25 mmHg at maximal exertion] and 22 as non-cardiac dyspnoea. Apical two- and four-chamber views were used for blinded two-dimensional LA speckle tracking analysis. HFpEF was characterized by impaired LA reservoir (24.3 ± 9.6 vs. 36.7 ± 8.4%, P < 0.001) and pump strain (-11.5 ± 3.2 vs. -17.0 ± 3.4%, P < 0.001); and increased stiffness (0.8 ± 0.7 vs. 0.2 ± 0.1 mmHg/%, P < 0.001). Reservoir and pump strain correlated with exercise PCWP (r = -0.64 and r = 0.72, P < 0.001), and remained independent predictors after adjusting for left ventricular mass index, LA volume index, mean E/e' and systolic blood pressure (B = -0.66 and B = 1.41, respectively, P < 0.001). LA stiffness was strongly related to B-type natriuretic peptide levels (r = 0.73, P < 0.001; B = 173.0, P < 0.001). Reservoir strain at cut-off of ≤ 33% predicted invasively verified HFpEF diagnosis with 88% sensitivity and 77% specificity, providing a net reclassification improvement of 12% in comparison to the 2016 European Society of Cardiology criteria for non-invasive diagnosis of HFpEF.

CONCLUSIONS

Impaired LA reservoir and pump function and increased stiffness are associated with abnormal exercise haemodynamics in HFpEF. These markers provide significant HFpEF diagnostic utility in elderly ambulatory patients with dyspnoea.

Heart Failure With Preserved Ejection Fraction and Atrial Fibrillation: Vicious Twins

Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are age-related conditions that are increasing in prevalence, commonly coexist, and share clinical features. This review provides a practical update on the epidemiology, pathophysiology, diagnosis, and management of patients with concomitant HFpEF and AF. Epidemiological studies highlight the close and complex links between HFpEF and AF, the shared risk factors, the high AF occurrence in the natural history of HFpEF, and the independent contribution of each condition to poor outcomes. Diagnosis of HFpEF in the setting of AF is challenging because the symptoms overlap. AF is associated with changes in echocardiographic parameters and circulating natriuretic peptides that confound HFpEF diagnosis. Symptomatic improvement with diuretic therapy supports the presence of HFpEF in patients with concomitant AF. Important knowledge gaps need to be addressed by a multidisciplinary and translational research approach to develop novel therapies that can improve prognosis.

The prognostic significance of atrial fibrillation in heart failure with preserved ejection function: insights from KaRen, a prospective and multicenter study

The prognostic value of atrial fibrillation (AF) in heart failure with preserved ejection fraction (HFPEF) remains controversial. We sought to study the prognostic value of AF in a prospective cohort and to characterize the HFPEF patients with AF. KaRen was a prospective, multicenter, international, observational study intended to characterize HFPEF; 538 patients presenting with an acute decompensated cardiac failure and a left ventricular EF > 45% were included. EKG and echocardiogram performed 4-8 week following the index hospitalization were analyzed in core centers. Clinical and echocardiographic characteristics of patients in sinus rhythm vs. with documented AF at enrolment (decompensated HF), upon their 4-8-week visit (in presumed stable clinical condition) and according to patients' cardiac history, were compared. The primary study endpoint was death from any cause or first hospitalization for decompensated heart failure (HF). A total of 413 patients (32% in AF) were analyzed, with a mean follow-up period of 28 months. The patients were primarily elderly individuals (mean age: 76.2 years), with a slight female predominance and a high prevalence of non-cardiovascular comorbidities. The baseline echocardiographic characteristics and the natriuretic peptide levels were indicative of a more severe heart condition among the patients with AF. However, the patients with AF exhibited a similar survival-free interval compared with the patients in sinus rhythm. In this elderly HFPEF population with a high prevalence of non-cardiovascular comorbidities, the presence of AF was not associated with a worse prognosis despite impaired clinical and echocardiographic features.ClinicalTrials.gov: NCT00774709.

IMproved exercise tolerance in patients with PReserved Ejection fraction by Spironolactone on myocardial fibrosiS in Atrial Fibrillation rationale and design of the IMPRESS-AF randomised controlled trial

INTRODUCTION

Patients with atrial fibrillation frequently suffer from heart failure with preserved ejection fraction. At present there is no proven therapy to improve physical capacity and quality of life in participants with permanent atrial fibrillation with preserved left ventricular contractility.

OBJECTIVE

The single-centre IMproved exercise tolerance In heart failure With PReserved Ejection fraction by Spironolactone On myocardial fibrosiS In Atrial Fibrillation (IMPRESS-AF) trial aims to establish whether treatment with spironolactone as compared with placebo improves exercise tolerance (cardiopulmonary exercise testing), quality of life and diastolic function in patients with permanent atrial fibrillation.

METHODS AND ANALYSIS

A total of 250 patients have been randomised in this double-blinded trial for 2-year treatment with 25 mg daily dose of spironolactone or matched placebo. Included participants are 50 years old or older, have permanent atrial fibrillation and ejection fraction >55%. Exclusion criteria include contraindications to spironolactone, poorly controlled hypertension and presence of severe comorbidities with life expectancy <2 years. The primary outcome is improvement in exercise tolerance at 2 years and key secondary outcomes include quality of life (assessed using the EuroQol EQ-5D-5L (EQ-5D) and Minnesota Living with Heart Failure (MLWHF) questionnaires), diastolic function and all-cause hospitalisation.

ETHICS AND DISSEMINATION

The study has been approved by the National Research and Ethics Committee West Midlands-Coventry and Warwickshire (REC reference number 14/WM/1211). The results of the trial will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBERS

EudraCT2014-003702-33; NCT02673463; Pre-results.

Baroreflex failure increases the risk of pulmonary edema in conscious rats with normal left ventricular function

In heart failure with preserved ejection fraction (HFpEF), the complex pathogenesis hinders development of effective therapies. Since HFpEF and arteriosclerosis share common risk factors, it is conceivable that stiffened arterial wall in HFpEF impairs baroreflex function. Previous investigations have indicated that the baroreflex regulates intravascular stressed volume and arterial resistance in addition to cardiac contractility and heart rate. We hypothesized that baroreflex dysfunction impairs regulation of left atrial pressure (LAP) and increases the risk of pulmonary edema in freely moving rats. In 15-wk Sprague-Dawley male rats, we conducted sinoaortic denervation (SAD, n = 6) or sham surgery (Sham, n = 9), and telemetrically monitored ambulatory arterial pressure (AP) and LAP. We compared the mean and SD (lability) of AP and LAP between SAD and Sham under normal-salt diet (NS) or high-salt diet (HS). SAD did not increase mean AP but significantly increased AP lability under both NS (P = 0.001) and HS (P = 0.001). SAD did not change mean LAP but significantly increased LAP lability under both NS (SAD: 2.57 ± 0.43 vs. Sham: 1.73 ± 0.30 mmHg, P = 0.01) and HS (4.13 ± 1.18 vs. 2.45 ± 0.33 mmHg, P = 0.02). SAD markedly increased the frequency of high LAP, and SAD with HS prolonged the duration of LAP > 18 mmHg by nearly 20-fold compared with Sham (SAD + HS: 2,831 ± 2,366 vs. Sham + HS: 148 ± 248 s, P = 0.01). We conclude that baroreflex failure impairs volume tolerance and together with salt loading increases the risk of pulmonary edema even in the absence of left ventricular dysfunction. Baroreflex failure may contribute in part to the pathogenesis of HFpEF.

Preventing Thrombosis to Improve Outcomes in Heart Failure Patients

Heart failure (HF) is associated with an increased risk of thrombotic events, particularly if this condition is accompanied by atrial fibrillation (AF). Many HF patients have background coronary artery disease (CAD) making them prone to coronary thrombosis resulting in myocardial infarction or sudden death. Oral anticoagulation is essential in the vast majority of HF patients with AF with non-vitamin K based anticoagulants being a suitable alternative to warfarin. In contrast, aspirin alone does not provide adequate stroke prevention in such patients. In HF without AF, oral anticoagulation should not be routinely used, and antiplatelet agents should be prescribed in patients with background CAD. This review provides an overview of prothrombotic factors and antithrombotic management of patients with HF.

Heart failure with preserved ejection fraction in the elderly: scope of the problem

Heart failure with preserved ejection fraction (HFpEF) is the most common form of heart failure (HF) in older adults, particularly women, and is increasing in prevalence as the population ages. With morbidity and mortality on par with HF with reduced ejection fraction, it remains a most challenging clinical syndrome for the practicing clinician and basic research scientist. Originally considered to be predominantly caused by diastolic dysfunction, more recent insights indicate that HFpEF in older persons is typified by a broad range of cardiac and non-cardiac abnormalities and reduced reserve capacity in multiple organ systems. The globally reduced reserve capacity is driven by: 1) inherent age-related changes; 2) multiple, concomitant co-morbidities; 3) HFpEF itself, which is likely a systemic disorder. These insights help explain why: 1) co-morbidities are among the strongest predictors of outcomes; 2) approximately 50% of clinical events in HFpEF patients are non-cardiovascular; 3) clinical drug trials in HFpEF have been negative on their primary outcomes. Embracing HFpEF as a true geriatric syndrome, with complex, multi-factorial pathophysiology and clinical heterogeneity could provide new mechanistic insights and opportunities for progress in management. This article is part of a Special Issue entitled CV Aging.

Left atrial dysfunction relates to symptom onset in patients with heart failure and preserved left ventricular ejection fraction

AIMS

Pathophysiology of heart failure (HF) with preserved ejection fraction (HFPEF) remains unclear. Left atrial (LA) function has been related to HF symptoms. Our purpose is to analyse LA function in outpatients with new onset symptoms of HF.

METHODS AND RESULTS

An observational study was performed including 138 consecutive outpatients with suspected HF referred to a one-stop clinic. Final diagnosis [HF with reduced EF (HFREF), HFPEF, or non-HF] was established according to current recommendations. Echocardiography was performed in all patients. LA function was analysed using strain derived from speckle tracking in sinus rhythm patients (n = 83). Results were analysed with ANOVA and Bonferroni statistical tests. Receiver operating characteristic (ROC) curves were constructed to investigate the predictive ability of LA parameters for the final diagnosis of HF. Patients were 75 ± 9 years and 63% women. Final diagnosis was 23.2% HFREF, 45.7% HFPEF, and 31.2% non-HF. Left ventricular strain rate showed no differences between non-HF and HFPEF groups, but both groups showed differences with the HFREF group. LA strain rate (A- and S-waves) was significantly reduced in both HF groups (without differences among them) when compared with the non-HF group. LA strain rate and indexed volume showed significant accuracy for HF diagnosis in ROC curves.

CONCLUSIONS

In outpatients with new-onset symptoms of HF, LA dysfunction was observed. It might be the initial mechanism in the development of symptoms in HFPEF patients. These findings support the relationship of LA dysfunction with HFPEF, suggesting that the analysis of LA function may be useful in sinus rhythm patients with new-onset dyspnoea.

Stroke prevention in atrial fibrillation in heart failure

Heart failure and atrial fibrillation are major problems of modern cardiology with important clinical, prognostic, and socioeconomic implications. The risks are high morbidity, impaired quality of life, poor outcome, and increased risk of stroke. Oral anticoagulation with vitamin K antagonists or novel licensed medicines should be considered unless contraindicated. Possible benefits of sinus rhythm maintenance are not entirely clear and need to be explored further. Relatively scarce data are available on stroke prevention in atrial fibrillation in heart failure with preserved ejection fraction; this requires further research.

How much atrial fibrillation causes symptoms of heart failure?

INTRODUCTION

Patients with atrial fibrillation (AF) are more symptomatic than patients with sinus rhythm. However, it is unknown what per cent of time spent in AF is associated with symptoms.

METHODS

We used a limited access dataset from the Atrial Fibrillation Follow-up Investigation of Rhythm Management trial. Patients had their current rhythm and New York Heart Association (NYHA) class recorded at baseline and at every follow-up visit. The ratio of number of visits when patients were in AF to the total number of visits was used as a surrogate measure of AF burden. The median number of visits was 12 per patient. We grouped patients labelled as class 0 and I by NYHA as having no symptoms and NYHA II or III as having symptoms. Furthermore, we calculated mortality and the prevalence of symptoms depending on the per cent of visits when they had AF.

RESULTS

Of 4060 patients enrolled in the trial, 74 had no follow-up visits and were excluded; the remaining 3986 patients were analysed. Patients who had no or little AF throughout the study (0-20%) had the lowest prevalence of symptoms. Prevalence of symptoms increased with greater per cent of time spent in AF. Specifically, symptoms became more prevalent when AF burden reached 20-40%. Mortality was similar regardless of proportion of visits when patients were in AF.

CONCLUSIONS

Higher AF burden is associated with higher prevalence of symptoms. The increment became significant when patients were in AF at 20-40% of visits.

Outcomes in atrial fibrillation patients with and without left ventricular hypertrophy when treated with a lenient rate-control or rhythm-control strategy

Although left ventricular (LV) hypertrophy has been proposed as a factor predisposing to atrial fibrillation (AF), its relevance to prognosis and selection of therapeutic strategies is unclear. We identified 2,105 patients with echocardiographic data on LV mass enrolled in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial. LV hypertrophy was defined as increased LV mass, stratified by American Society of Echocardiography criteria. The primary end point was all-cause mortality, secondary end point was as per AFFIRM trial definition, and tertiary end point was cardiovascular hospitalizations. We compared "strict" versus "lenient" rate control in patients with increased LV mass, and studied association of heart failure (HF) with preserved and decreased systolic function in patients with increased LV mass. Over 6 years, 332 deaths (15.7%) were reported. Adjusted hazard ratio (HR) of severely increased LV mass for all-cause mortality was 1.34 (95% confidence interval [CI] 1.01 to 1.79, p=0.045) for the overall population and 1.61 (95% CI 1.09 to 2.37, p=0.016) for the rhythm-control arm. Increased LV mass was a predictor of cardiovascular hospitalizations in the lenient rate-control group (HR 1.72, 95% CI 1.05 to 2.82, p=0.03) but not in the strict rate-control group. Severely increased LV mass was predictive of cardiovascular hospitalizations in patients with HF with preserved (HR 1.8, 95% CI 1.0 to 3.2, p=0.03) and decreased LV systolic function (HR 2.4, 95% CI 1.1 to 5.2, p=0.02). Thus, LV hypertrophy is a significant independent predictor of mortality in patients with AF, especially those managed with rhythm control. In patients with LV hypertrophy, strict rate control may be associated with better outcomes than lenient rate control. LV hypertrophy portends higher cardiovascular morbidity in patients with AF and HF.

Impact of atrial fibrillation on exercise capacity in heart failure with preserved ejection fraction: a RELAX trial ancillary study

BACKGROUND

Atrial fibrillation (AF) is common among patients with heart failure and preserved ejection fraction (HFpEF), but its clinical profile and impact on exercise capacity remain unclear. RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in HFpEF) was a multicenter randomized trial testing the impact of sildenafil on peak VO2 in stable outpatients with chronic HFpEF. We sought to compare clinical features and exercise capacity among patients with HFpEF who were in sinus rhythm (SR) or AF.

METHODS AND RESULTS

RELAX enrolled 216 patients with HFpEF, of whom 79 (37%) were in AF, 124 (57%) in SR, and 13 in other rhythms. Participants underwent baseline cardiopulmonary exercise testing, echocardiogram, biomarker assessment, and rhythm status assessment before randomization. Patients with AF were older than those in SR but had similar symptom severity, comorbidities, and renal function. β-blocker use and chronotropic indices were also similar. Despite comparable left ventricular size and mass, AF was associated with worse systolic (lower EF, stroke volume, and cardiac index) and diastolic (shorter deceleration time and larger left atria) function compared with SR. Pulmonary artery systolic pressure was higher in AF. Patients with AF had higher N-terminal pro-B-type natriuretic peptide, aldosterone, endothelin-1, troponin I, and C-telopeptide for type I collagen levels, suggesting more severe neurohumoral activation, myocyte necrosis, and fibrosis. Peak VO2 was lower in AF, even after adjustment for age, sex, and chronotropic response, and VE/VCO2 was higher.

CONCLUSIONS

AF identifies an HFpEF cohort with more advanced disease and significantly reduced exercise capacity. These data suggest that evaluation of the impact of different rate or rhythm control strategies on exercise tolerance in patients with HFpEF and AF is warranted.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00763867.

Atrial fibrillation and heart failure: beyond the heart rate

PURPOSE OF REVIEW

Atrial fibrillation and heart failure are two of the most prevalent cardiovascular disease conditions. They often coexist and lead to significant morbidity and mortality. Adequate management strategies for this dual epidemic continue to be the subject of many research studies.

RECENT FINDINGS

Recent clinical trials suggest that a rhythm control strategy for atrial fibrillation does not offer a survival advantage over rate control in heart failure patients with reduced systolic function. Rhythm control in these trials was achieved using antiarrhythmic drugs, with evidence of increased mortality associated with certain agents. Catheter ablation is a more effective and increasingly used approach to maintain sinus rhythm in atrial fibrillation patients, with promising results in the heart failure population. Late-gadolinium-enhancement cardiac MRI (LGE-MRI) assessment of atrial fibrosis helps in selecting the better candidates for atrial fibrillation ablation. AV nodal ablation and bi-ventricular pacing remains another viable option. Atrial fibrillation patients with heart failure and preserved systolic function are another group in whom maintenance of sinus rhythm is thought to be advantageous.

SUMMARY

Patients with atrial fibrillation and heart failure are a heterogeneous group and require a personalized treatment approach. Catheter ablation to restore and maintain sinus rhythm is a modality that promises to be advantageous beyond rate control.

Update on diastolic heart failure or heart failure with preserved ejection fraction in the older adults

Nearly half of all heart failure (HF) patients have diastolic HF (DHF) or clinical HF with normal or near-normal left ventricular ejection fraction (LVEF). Although the terminology has not been clearly defined, it is increasingly being referred to as HF with preserved ejection fraction (HFPEF). The prevalence of HFPEF increases with age, especially among older women. Identifying HFPEF is important because the etiology, pathogenesis, prognosis, and optimal management may differ from that for systolic HF (SHF) or HF with reduced ejection fraction. The clinical presentation of HF is similar for both SHF and HFPEF. As in SHF, HFPEF is a clinical diagnosis. Once a clinical diagnosis of HF has been made, the presence of HFPEF can be established by confirming a normal or near-normal LVEF, often by an echocardiogram. HFPEF is often associated with a history of hypertension, concentric left ventricular hypertrophy, vascular stiffness, and left ventricular diastolic dysfunction. As in SHF, HFPEF is also associated with poor outcomes. While therapies with angiotensin-converting enzyme inhibitors and beta-blockers improve outcomes in SHF, there is currently no such evidence of their benefits in older HFPEF patients. In this review recent advances in the diagnosis and management of HFPEF in older adults are discussed.

Comparison of mortality and morbidity in patients with atrial fibrillation and heart failure with preserved versus decreased left ventricular ejection fraction

Almost 50% of patients with congestive heart failure (HF) have preserved ejection fraction (PEF). Data on the effect of HF-PEF on atrial fibrillation outcomes are lacking. We assessed the prognostic significance of HF-PEF in an atrial fibrillation population compared to a systolic heart failure (SHF) population. A post hoc analysis of the National Heart, Lung, and Blood Institute-limited access data set of the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial was carried out. The patients with a history of congestive HF and a preserved ejection fraction (EF >50%) were classified as having HF-PEF (n = 320). The patients with congestive HF and a qualitatively depressed EF (EF <50%) were classified as having SHF (n = 402). Cox proportional hazards analysis was performed. The mean follow-up duration was 1,181 ± 534 days/patient. The patients with HF-PEF had lower all-cause mortality (hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.46 to 0.85, p = 0.003) and cardiovascular mortality (HR 0.56, 95% CI 0.38 to 0.84, p = 0.006), with a possible decreased arrhythmic end point (HR 0.39, 95% CI 0.16 to 1.006, p = 0.052) than did the patients with SHF. No differences were observed for ischemic stroke (HR 1.08, 95% CI 0.48 to 2.39, p = 0.86), rehospitalization (HR 0.89, 95% CI 0.75 to 1.07, p = 0.24), or progression to New York Heart Association class III-IV (odds ratio 0.80, 95% CI 0.42 to 1.54, p = 0.522). In conclusion, although patients with HF-PEF have better mortality outcomes than those with SHF, the morbidity appears to be similar.

Characterization of static and dynamic left ventricular diastolic function in patients with heart failure with a preserved ejection fraction

BACKGROUND

Congestive heart failure in the setting of a preserved left ventricular (LV) ejection fraction is increasing in prevalence among the senior population. The underlying pathophysiologic abnormalities in ventricular function and structure remain unclear for this disorder. We hypothesized that patients with heart failure with preserved ejection fraction (HFPEF) would have marked abnormalities in LV diastolic function with increased static diastolic stiffness and slowed myocardial relaxation compared with age-matched healthy controls.

METHODS AND RESULTS

Eleven highly screened patients (4 men, 7 women) aged 73±7 years with HFPEF were recruited to participate in this study. Thirteen sedentary healthy controls (7 men, 6 women) aged 70±4 years also were recruited. All subjects underwent pulmonary artery catheterization with measurement of cardiac output, end-diastolic volumes, and pulmonary capillary wedge pressures at baseline; cardiac unloading (lower-body negative pressure or upright tilt); and cardiac loading (rapid saline infusion). The data were used to define the Frank-Starling and LV end-diastolic pressure-volume relationships. Doppler echocardiographic data (tissue Doppler velocities, isovolumic relaxation time, propagation velocity of early mitral inflow , E/A-wave ratio) were obtained at each level of cardiac preload. Compared with healthy controls, patients with HFPEF had similar LV contractile function and static LV compliance but reduced LV chamber distensibility with elevated filling pressures and slower myocardial relaxation as assessed by tissue Doppler imaging.

CONCLUSIONS

In this small, highly screened patient population with hemodynamically confirmed HFPEF, increased end-diastolic static ventricular stiffness relative to age-matched controls was not a universal finding. Nevertheless, patients with HFPEF, even when well compensated, had elevated filling pressures, reduced distensibility, and increased diastolic wall stress compared with controls. In contrast, LV relaxation as assessed by tissue Doppler variables appeared consistently impaired in patients with HFPEF.

Epidemiology and clinical course of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFPEF) is increasingly recognized as a major public health problem worldwide. Significant advances have been made in our understanding of the epidemiology of HFPEF over the past two decades, with the publication of numerous population-based epidemiological studies, large heart failure registries, and randomized clinical trials. These recent studies have provided detailed characterization of larger numbers of patients with HFPEF than ever before. This review summarizes the state of current knowledge with regards to the disease burden, patient characteristics, clinical course, and outcomes of HFPEF. Despite the wealth of available data, substantive gaps in knowledge were identified. These gaps represent opportunities for further research in HFPEF, a syndrome that is clearly a rising societal burden and that is associated with substantial morbidity and mortality.

Heart failure with preserved ejection fraction: pathophysiology and emerging therapies

Approximately half of patients with heart failure (HF) have a preserved ejection fraction (HFpEF). Morbidity and mortality are similar to HF with reduced EF (HFrEF), yet therapies with unequivocal benefit in HFrEF have not been shown to be effective in HFpEF. Recent studies have shown that the pathophysiology of HFpEF, initially believed to be due principally to diastolic dysfunction, is more complex. Appreciation of this complexity has shed new light into how HFpEF patients might respond to traditional HF treatments, while also suggesting new applications for novel therapies and strategies. In this review, we shall briefly review the pathophysiologic mechanisms in HFpEF, currently available clinical trial data, and finally explore new investigational therapies that are being developed and tested in ongoing and forthcoming trials.

Current controversies in heart failure with a preserved ejection fraction

Heart failure with a preserved ejection fraction is a fascinating and multifaceted condition that has provoked enormous debate and a wealth of mechanistic studies. Controversies exist with regard to its nomenclature. If its nomenclature is questioned, one can be certain the pathogenesis is ill understood. If the pathogenesis is disputed, the diagnosis becomes difficult and inconsistent. These diagnostic challenges result in inappropriate recruitment to clinical trials. Therefore, the trials may be underpowered and difficult to interpret. This paper examines contemporary theories of heart failure with a preserved ejection fraction, clarifies the controversies and attempts to resolve the divergences of opinion.

Hypertension and heart failure: a dysfunction of systole, diastole or both?

The pathological myocardial hypertrophy associated with hypertension contains the seed for further maladaptive development. Increased myocardial oxygen consumption, impaired epicardial coronary perfusion, ventricular fibrosis and remodelling, abnormalities in long-axis function and torsion, cause, to a varying degree, a mixture of systolic and diastolic abnormalities. In addition, chronotropic incompetence and peripheral factors such as lack of vasodilator reserve and reduced arterial compliance further affect cardiac output particularly on exercise. Many of these factors are common to hypertensive heart failure with a normal ejection fraction as well as systolic heart failure. There is increasing evidence that these apparently separate phenotypes are part of a spectrum of heart failure differing only in the degree of ventricular remodelling and volume changes. Furthermore, dichotomizing heart failure into systolic and diastolic clinical entities has led to a paucity of clinical trials of therapies for heart failure with a normal ejection fraction. Therapies aimed at reversing myocardial fibrosis, and targets outside the heart such as enhancing vasodilator reserve and improving chronotropic incompetence deserve further study and may improve the exercise capacity of hypertensive heart failure patients. Hypertension heart disease with heart failure is simply not a dysfunction of systole and diastole. Other peripheral factors including heart rate and vasodilator response with exercise may deserve equal attention in an attempt to develop more effective treatments for this disorder.