The Natural History of Atrial Functional Mitral Regurgitation.

BACKGROUND: The natural history of moderate/severe atrial functional mitral regurgitation (AFMR) is unknown. OBJECTIVES: The authors sought to study the incidence of left ventricular (LV) systolic dysfunction (LVSD), progression or regression of ≥mild-moderate AFMR, and impact on mortality. METHODS: Adults with left atrial (LA) volume index ≥40 mL/m2, ≥mild-moderate AFMR, and follow-up echocardiogram were followed for incident LVSD (ejection fraction <50% and ≥10% lower than baseline), progression of mild-moderate/moderate AFMR to severe, and persistent regression of AFMR to no/trivial. Relation of AFMR progression or regression as time-dependent covariates with all-cause mortality was studied. Incidence of LVSD was compared with patients with no/mild AFMR matched on age, sex, comorbidities and ejection fraction. Patients were followed until mitral intervention, myocardial infarction, or last follow-up. RESULTS: A total of 635 patients (median age 75 years, 51% female, 96% mild-moderate/moderate AFMR, 4% severe AFMR) were included. Over a median 2.2 years (Q1-Q3: 1.0-4.3 years), incidence rates per 100 person-years were 3.2 for LVSD (P = 0.52 vs patients with no/mild AFMR), 1.9 for progression of AFMR, and 3.9 for regression. Female sex and larger LA volume index were independently associated with progression, whereas younger age, male sex, absent atrial fibrillation, and higher LA emptying fraction were independently associated with regression. Neither AFMR progression nor regression was independently associated with mortality. Instead, independent risk factors for mortality included older age, concentric LV geometry, and higher estimated LV filling and pulmonary pressures. CONCLUSIONS: In patients with predominantly mild-moderate/moderate AFMR, regression of MR was more common than progression, but neither was associated with mortality. Instead, diastolic function abnormalities were more important. Over a median 2-year follow-up, LVSD risk was not increased.

Prevalence and risk factors for medication-refractory reflux esophagitis in patients with systemic sclerosis in Japan.

BACKGROUNDS: Patients with systemic sclerosis (SSc) often have esophageal motility abnormalities and weak esophago-gastric junction (EGJ) barrier function, which causes proton pump inhibitor (PPI)-refractory reflux esophagitis (RE). The aims of this study were to clarify the current management of RE and prevalence and risk factors of medication-refractory RE in patients with SSc in Japan. METHODS: A total of 188 consecutive patients with SSc who underwent both esophageal high-resolution manometry (HRM) and esophagogastroduodenoscopy (EGD) were reviewed. The presence of RE and grades of the gastroesophageal flap valve (GEFV) were assessed. Esophageal motility was assessed retrospectively according to the Chicago classification v3.0. When RE was seen on a standard dose of PPI or any dose of vonoprazan (VPZ), it was defined as medication-refractory RE. RESULTS: Approximately 80% of patients received maintenance therapy with acid secretion inhibitors regardless of esophageal motility abnormalities. Approximately 50% of patients received maintenance therapy with PPI, and approximately 30% of patients received VPZ. Medication-refractory RE was observed in 30 patients (16.0%). In multivariable analyses, the number of EGD and absent contractility were significant risk factors for medication-refractory RE. Furthermore, combined absent contractility and GEFV grade III or IV had higher odds ratios than did absent contractility alone. CONCLUSIONS: Patients with persistent reflux symptoms and those with absent contractility and GEFV grade III or IV should receive maintenance therapy with strong acid inhibition to prevent medication-refractory RE.

Pathophysiologic and prognostic importance of cardiac power output reserve in heart failure with preserved ejection fraction.

AIMS: Heart failure with preserved ejection fraction (HFpEF) is a syndrome characterized by multiple cardiac reserve limitations during exercise. Cardiac power output (CPO) is an index of global cardiac performance and can be estimated non-invasively by echocardiography. We hypothesized that CPO reserve during exercise would be associated with impaired cardiovascular reserve, exercise intolerance, and adverse outcomes in HFpEF. METHODS AND RESULTS: Exercise stress echocardiography was performed in 425 dyspnoeic patients [217 HFpEF and 208 non-heart failure (HF) controls] to estimate CPO at rest and during exercise. We classified patients with HFpEF based on the median value of changes in CPO from rest to peak exercise (ΔCPO >0.49 W/100 g). Patients with HFpEF and a lower CPO reserve had poorer biventricular systolic function, impaired chronotropic response during exercise, and worse aerobic capacity than controls and those with a higher CPO reserve. During a median follow-up of 358 days, a composite outcome of all-cause mortality or HF events occurred in 30 patients. Patients with a lower CPO reserve had four-fold and nearly 10-fold increased risks of the outcomes compared with those with a higher CPO reserve and controls, respectively [hazard ratio (HR) 4.05, 95% confidence interval (CI) 1.16-10.1, P = 0.003 and HR 9.61, 95% CI 3.58-25.8, P < 0.0001]. We further found that a lower CPO reserve had an incremental prognostic value over the H2FPEF score and exercise duration. In contrast, resting CPO did not predict clinical outcomes in patients with HFpEF. CONCLUSION: A lower CPO reserve was associated with biventricular systolic dysfunction, chronotropic incompetence, exercise intolerance, and adverse outcomes in patients with HFpEF.

Characterization and prognostic importance of chronotropic incompetence in heart failure with preserved ejection fraction.

BACKGROUND: Exercise intolerance is the primary symptom of patients with heart failure with preserved ejection fraction (HFpEF). Chronotropic incompetence has been considered to be common and contribute to poor exercise capacity in HFpEF. However, clinical characteristics, pathophysiology, and outcomes of chronotropic incompetence in HFpEF remain poorly understood. METHODS: Patients with HFpEF (n = 246) underwent ergometry exercise stress echocardiography with simultaneous expired gas analysis. The patients were divided into two groups based on the presence of chronotropic incompetence, which was defined by heart rate reserve <0.80. RESULTS: Chronotropic incompetence was common in HFpEF (n = 112, 41 %). Compared to HFpEF patients with a normal chronotropic response (n = 134), those with chronotropic incompetence had higher body mass index, a higher prevalence of diabetes, more frequent ß-blocker use, and worse New York Heart Association class. During peak exercise, patients with chronotropic incompetence demonstrated less increase in cardiac output and arterial oxygen delivery (cardiac output × saturation × hemoglobin × 1.34 × 10), higher metabolic work (peak oxygen consumption [VO2]/watt), an inability to increase arteriovenous oxygen difference, and poorer exercise capacity (lower peak VO2) than those without. Chronotropic incompetence was associated with higher rates of a composite of all-cause mortality or worsening HF events (hazard ratio, 2.66, 95 % confidence intervals, 1.16-6.09, p = 0.02). CONCLUSION: Chronotropic incompetence is common in HFpEF, and is associated with unique pathophysiologic characteristics during exercise and clinical outcomes.

Contributions of anemia to exercise intolerance in heart failure with preserved ejection fraction-An exercise stress echocardiographic study.

Aims: Anemia is common in patients with heart failure with preserved ejection fraction (HFpEF) and is associated with exercise intolerance. However, there are limited data on how anemia contributes to reduced exercise capacity in patients with HFpEF. We aimed to characterize exercise capacity, cardiovascular and ventilatory reserve, and the oxygen (O2) pathway in anemic patients with HFpEF. Methods: A total of 238 patients with HFpEF and 248 dyspneic patients without HF underwent ergometry exercise stress echocardiography with simultaneous expired gas analysis. Patients with HFpEF were classified into two groups based on the presence of anemia (hemoglobin < 13.0 g/dL in men and < 12.0 g/dL in women). Results: Anemic HFpEF patients (n = 112) had worse nutritional status and renal function, lower iron levels, and greater left ventricular (LV) remodeling and plasma volume expansion than those without anemia (n = 126). Exercise capacity, assessed by peak oxygen consumption, exercise intensity, and exercise duration, was lower in the anemic HFpEF group than in the other groups. Despite a similar cardiac output during exercise, anemic patients with HFpEF demonstrated limitations in arterial O2 delivery, lower arteriovenous O2 content difference, and ventilatory inefficiency (higher minute ventilation vs. carbon dioxide production slope) during peak exercise. Conclusion: Anemic HFpEF patients demonstrated unique pathophysiological features with greater LV remodeling and plasma volume expansion, limitations in arterial O2 delivery and peripheral O2 extraction, and ventilatory inefficiency, which may contribute to reduced exercise capacity. Further studies are needed to develop an optimal approach for treating anemia in patients with HFpEF.

Effects of Mineralocorticoid Receptor Antagonists in Early-Stage Heart Failure With Preserved Ejection Fraction.

Background: Hospitalization with a first episode of heart failure (HF) is a serious event associated with poor clinical outcomes in HF with preserved ejection fraction (HFpEF). Identification of HFpEF via detection of elevated left ventricular filling pressure at rest or during exercise may allow early intervention. Benefits of treatment with mineralocorticoid receptor antagonists (MRAs) in established HFpEF have been reported, but use of MRAs is not well studied in early HFpEF without prior HF hospitalization. Methods: We retrospectively studied 197 patients with HFpEF who did not have prior hospitalization but had been diagnosed by exercise stress echocardiography or catheterization. We examined changes in natriuretic peptide levels and echocardiographic parameters reflecting diastolic function following MRA initiation. Results: Of the 197 patients with HFpEF, MRA treatment was initiated for 47 patients. After a median 3-month follow-up, reduction in N-terminal pro-B-type natriuretic peptide levels from baseline to follow-up was greater in patients treated with MRA than in those who were not (median, -200 pg/mL [interquartile range, -544 to -31] vs 67 pg/mL [interquartile range, -95 to 456], P < 0.0001 in 50 patients with paired data). Similar results were observed for the changes in B-type natriuretic peptide levels. Reduction in the left atrial volume index was also greater in the MRA-treated group than in the non-MRA-treated group after a median 7-month follow-up (77 patients with paired echocardiographic data). Patients with lower left ventricular global longitudinal strain experienced a greater reduction in N-terminal pro-B-type natriuretic peptide levels following MRA treatment. In the safety assessment, MRA modestly decreased renal function but did not change potassium levels. Conclusions: Our results suggest that MRA treatment has potential benefits for early-stage HFpEF.

Contexte: L'hospitalisation consécutive à un premier épisode d'insuffisance cardiaque (IC) est un événement grave associé à des résultats cliniques médiocres dans l'IC à fraction d'éjection préservée (ICFEP). Or, la détection d'une pression de remplissage ventriculaire gauche élevée au repos ou à l'effort peut permettre de déceler une ICFEP et d'intervenir de façon précoce. Par ailleurs, le recours à des antagonistes des récepteurs minéralocorticoïdes (ARM) serait bénéfique dans les cas d'ICFEP, mais leur utilisation n'a pas été bien étudiée dans l'ICFEP précoce sans hospitalisation préalable pour cause d'insuffisance cardiaque. Méthodologie: Nous avons étudié rétrospectivement 197 patients atteints d'ICFEP qui n'avaient pas été hospitalisés auparavant, mais dont la maladie avait été diagnostiquée par une échocardiographie de stress ou un cathétérisme. Après l'instauration des ARM, nous avons examiné les variations des taux de peptides natriurétiques et des paramètres échocardiographiques reflétant la fonction diastolique. Résultats: Sur les 197 patients atteints d'ICFEP, 47 ont entamé un traitement par des ARM. Après un suivi médian de trois mois, la réduction des taux de propeptides natriurétiques de type B N-terminal (NT-proBNP) entre la valeur initiale et le suivi était plus importante chez les patients traités par des ARM que chez ceux qui ne l'étaient pas (médiane : -200 pg/ml [écart interquartile : -544 à -31] contre 67 pg/ml [écart interquartile : -95 à 456], p < 0,0001 chez 50 patients ayant des données appariées). Des résultats similaires ont été observés pour la variation des taux de peptides natriurétiques de type B. La réduction du volume de l'oreillette gauche était également plus importante dans le groupe traité par des ARM que dans le groupe témoin après un suivi médian de sept mois (données échocardiographiques appariées pour 77 patients). Les patients présentant une déformation longitudinale globale du ventricule gauche plus faible ont connu une réduction plus importante des taux de NT-proBNP après le traitement par des ARM. Enfin, lors de l'évaluation de l'innocuité, les ARM ont légèrement altéré la fonction rénale, mais sans modifier les taux de potassium. Conclusions: Ces résultats semblent indiquer que le traitement par des ARM présente des avantages potentiels dans les cas d'ICFEP au stade précoce.

Pathophysiologic Contributions of Visceral Adiposity to Left Ventricular Diastolic Dysfunction.

BACKGROUND: Visceral fat produces inflammatory cytokines and may play a major role in heart failure with preserved ejection fraction (HFpEF). However, little data exist regarding how qualitative and quantitative abnormalities of visceral fat would contribute to left ventricular diastolic dysfunction (LVDD). METHODS: We studied 77 participants who underwent open abdominal surgery for intra-abdominal tumors (LVDD, n = 44; controls without LVDD, n = 33). Visceral fat samples were obtained during the surgery, and mRNA levels of inflammatory cytokines were measured. Visceral and subcutaneous fat areas were measured using abdominal computed tomography. RESULTS: Patients with significant LVDD had greater LV remodeling and worse LVDD than controls. While body weight, body mass index, and subcutaneous fat area were similar in patients with LVDD and controls, the visceral fat area was larger in patients with LVDD than in controls. The visceral fat area was correlated with BNP levels, LV mass index, mitral e' velocity, and E/e' ratio. There were no significant differences in the mRNA expressions of visceral adipose tissue cytokines (IL-2, -6, -8, and -1ß, TNFα, CRP, TGFß, IFNγ, leptin, and adiponectin) between the groups. CONCLUSIONS: Our data may suggest the pathophysiological contribution of visceral adiposity to LVDD.

Epidemiology, Pathophysiology, Diagnosis, and Therapy of Heart Failure With Preserved Ejection Fraction in Japan.

Heart failure (HF) with preserved ejection fraction (HFpEF) is a global health care problem, with diagnostic difficulty, limited treatment options and high morbidity and mortality rates. The prevalence of HFpEF is increasing because of the aging population and the increasing burden of cardiac and metabolic comorbidities, such as systemic hypertension, diabetes, chronic kidney disease, and obesity. The knowledge base is derived primarily from the United States and Europe, and data from Asian countries, including Japan, remain limited. Given that phenotypic differences may exist between Japanese and Western patients with HFpEF, careful characterization may hold promise to deliver new therapy specific to the Japanese population. In this review, we summarize the current knowledge regarding the epidemiology, pathophysiology and diagnosis of and the potential therapies for HFpEF in Japan.

Diagnostic value of reduced left atrial compliance during ergometry exercise in heart failure with preserved ejection fraction.

AIMS: Diagnosis of heart failure with preserved ejection fraction (HFpEF) remains challenging in patients presenting with chronic dyspnoea. We sought to determine the diagnostic value of reduced left atrial (LA) compliance during exercise to diagnose HFpEF. METHODS AND RESULTS: Ergometry exercise stress echocardiography was performed in 225 patients with HFpEF and 262 non-heart failure controls (non-cardiac dyspnoea [NCD]) in Protocol 1, where the diagnosis of HFpEF was defined by the HFA-PEFF algorithm. In Protocol 2, the diagnosis of HFpEF was ascertained by exercise right heart catheterization in 67 participants (49 HFpEF and 18 NCD). Speckle-tracking echocardiography was performed at rest and during exercise to determine LA compliance (ratio of LA reservoir strain to E/e'). As compared with NCD, patients with HFpEF demonstrated decreased LA reservoir strain and compliance at rest, and these differences further increased during exercise in Protocol 1. Exercise LA compliance discriminated HFpEF from NCD (area under the curve 0.87, p < 0.0001), with a superior diagnostic ability to exercise E/e' ratio (DeLong p = 0.005). Exercise LA compliance demonstrated incremental diagnostic value over clinical factors (age, systemic hypertension, and atrial fibrillation) and resting LA compliance (χ2 212.4 vs. 166.2, p < 0.0001). These findings were confirmed in Protocol 2. CONCLUSION: Left atrial compliance during exercise demonstrated superior diagnostic ability to exercise E/e' ratio, with incremental diagnostic value over the resting LA compliance. Exercise LA compliance may enhance the diagnosis of HFpEF among patients with dyspnoea.

Prognostic benefit of early diagnosis with exercise stress testing in heart failure with preserved ejection fraction.

BACKGROUND: Delayed diagnosis of heart failure (HF) with preserved ejection fraction (HFpEF) can lead to poor clinical outcomes. Exercise stress testing, especially exercise stress echocardiography, plays a primary role in the early detection of HFpEF among dyspnoeic patients, but its prognostic significance is unknown, as is whether initiation of guideline-directed therapy could improve clinical outcomes in such early-stage HFpEF. METHODS AND RESULTS: Ergometry exercise stress echocardiography was performed in 368 patients with exertional dyspnoea. Heart failure with preserved ejection fraction was diagnosed by a total score of HFA-PEFF algorithm Step 2 (resting assessments) and Step 3 (exercise testing) ≥ 5 or elevated pulmonary capillary wedge pressure at rest or during exercise. The primary endpoint comprised all-cause mortality and worsening HF events. Heart failure with preserved ejection fraction was diagnosed in 182 patients, while 186 had non-cardiac dyspnoea (controls). Patients diagnosed with HFpEF had a seven-fold increased risk of composite events than that of controls [hazard ratio (HR) 7.52; 95% confidential interval (CI), 2.24-25.2; P = 0.001]. Patients with an HFA-PEFF Step 2 < 5 points but had an HFA-PEFF ≥ 5 after exercise stress testing (Steps 2-3) had a higher risk of composite events than controls. Guideline-recommended therapies were initiated in 90 patients diagnosed with HFpEF after index exercise testing. Patients with early treatment experienced lower rates of composite outcomes than those without (HR 0.33; 95% CI, 0.12-0.91; P = 0.03). CONCLUSION: Identification of HFpEF by exercise stress testing may allow risk stratification in dyspnoeic patients. Furthermore, initiation of guideline-directed therapy may be associated with improved clinical outcomes in patients with early-stage HFpEF. LAY SUMMARY: Delayed diagnosis of heart failure (HF) with preserved ejection fraction (HFpEF) can lead to poor clinical outcomes. Exercise stress testing, especially exercise stress echocardiography, plays a primary role in the early identification of HFpEF among dyspnoeic patients, but its prognostic significance is unknown, as is whether initiation of guideline-directed therapy could improve clinical outcomes in such early-stage HFpEF. In the current study, ergometry exercise stress echocardiography was performed in 368 patients with exertional dyspnoea. Heart failure with preserved ejection fraction was diagnosed by the established algorithm consisting of Step 2 (resting assessments) and Step 3 (exercise echocardiography or exercise right heart catheterization). The primary endpoint comprised all-cause mortality and worsening HF events. Heart failure with preserved ejection fraction was diagnosed in 182 patients and non-cardiac dyspnoea (controls) in 186 patients. Patients newly diagnosed with HFpEF had a seven-fold increased risk of composite events than that of controls. Guideline-recommended therapies were initiated in 90 patients newly diagnosed with HFpEF after index exercise testing. Patients with early treatment experienced lower rates of composite outcomes than those without. In conclusion, identification of HFpEF by exercise stress testing may allow risk stratification in patients with chronic exertional dyspnoea. Furthermore, initiation of guideline-directed therapy may be associated with improved clinical outcomes in patients with early-stage HFpEF.

Disproportionate exercise-induced pulmonary hypertension in relation to cardiac output in heart failure with preserved ejection fraction: a non-invasive echocardiographic study.

AIMS: Pulmonary hypertension (PH) and pulmonary vascular remodelling are common in patients with heart failure with preserved ejection fraction (HFpEF). Many patients with HFpEF demonstrate an abnormal pulmonary haemodynamic response to exercise that is not identifiable at rest. This can be estimated non-invasively by the mean pulmonary artery pressure-cardiac output relationship (mPAP/CO slope). We sought to characterize the pathophysiology of disproportionate exercise-induced PH in relation to CO (DEi-PH) and its prognostic impact in patients with HFpEF. METHODS AND RESULTS: A total of 345 patients (166 HFpEF and 179 controls) underwent ergometry exercise stress echocardiography with simultaneous expired gas analysis. DEi-PH was defined as the mPAP/CO slope >5.2 mmHg/L/min (median value). At rest, there were no differences in right ventricular (RV) function and severity of PH between HFpEF patients with and without DEi-PH. Compared with controls (n = 179) and HFpEF without DEi-PH (n = 83), HFpEF with DEi-PH (n = 83) demonstrated worse exercise capacity (lower peak oxygen consumption), depressed RV systolic function, impaired RV-pulmonary artery coupling, limitation in CO augmentation, more right-sided congestion, and worse ventilatory efficiency (higher minute ventilation vs. carbon dioxide volume) during peak exercise. Kaplan-Meier analyses showed that HFpEF patients with DEi-PH had higher rates of composite outcomes of all-cause mortality or heart failure events than those without (log-rank p = 0.0002). CONCLUSION: Patients with HFpEF and DEi-PH demonstrated distinct pathophysiologic features that become apparent only during exercise. These data suggest that DEi-PH is a pathophysiologic phenotype of HFpEF and reinforce the importance of exercise stress echocardiography for detailed characterization of HFpEF.

Diagnostic value of expired gas analysis in heart failure with preserved ejection fraction.

Cardiopulmonary exercise testing (CPET) may potentially differentiate heart failure (HF) with preserved ejection fraction (HFpEF) from noncardiac causes of dyspnea (NCD). While contemporary guidelines for HF recommend using CPET for identifying causes of unexplained dyspnea, data supporting this practice are limited. This study aimed to determine the diagnostic value of expired gas analysis to distinguish HFpEF from NCD. Exercise stress echocardiography with simultaneous expired gas analysis was performed in patients with HFpEF (n = 116) and those with NCD (n = 112). Participants without dyspnea symptoms were also enrolled as controls (n = 26). Exercise capacity was impaired in patients with HFpEF than in controls and those with NCD, evidenced by lower oxygen consumption (VO2), but there was a substantial overlap between HFpEF and NCD. Receiver operating characteristic curve analyses showed modest diagnostic abilities of expired gas analysis data in differentiating individuals with HFpEF from the controls; however, none of these variables clearly differentiated between HFpEF and NCD (all areas under the curve < 0.61). Expired gas analysis provided objective assessments of exercise capacity; however, its diagnostic value in identifying HFpEF among patients with symptoms of exertional dyspnea was modest.

Incremental diagnostic value of post-exercise lung congestion in heart failure with preserved ejection fraction.

AIMS: Lung ultrasound (LUS) may unmask occult heart failure with preserved ejection fraction (HFpEF) by demonstrating an increase in extravascular lung water (EVLW) during exercise. Here, we sought to examine the dynamic changes in ultrasound B-lines during exercise to identify the optimal timeframe for HFpEF diagnosis. METHODS AND RESULTS: Patients with HFpEF (n = 134) and those without HF (controls, n = 121) underwent a combination of exercise stress echocardiography and LUS with simultaneous expired gas analysis to identify exercise EVLW. Exercise EVLW was defined by B-lines that were newly developed or increased during exercise. The E/e' ratio peaked during maximal exercise and immediately decreased during the recovery period in patients with HFpEF. Exercise EVLW was most prominent during the recovery period in patients with HFpEF, while its prevalence did not increase from peak exercise to the recovery period in controls. Exercise EVLW was associated with a higher E/e' ratio and pulmonary artery pressure, lower right ventricular systolic function, and elevated minute ventilation to carbon dioxide production (VE vs. VCO2) slope during peak exercise. Increases in B-lines from rest to the recovery period provided an incremental diagnostic value to identify HFpEF over the H2FPEF score and resting left atrial reservoir strain. CONCLUSION: Exercise EVLW was most prominent early during the recovery period; this may be the optimal timeframe for imaging ultrasound B-lines. Exercise stress echocardiography with assessments of recovery EVLW may enhance the diagnosis of HFpEF.

Adiposity and clinical outcomes in East Asian patients with heart failure and preserved ejection fraction.

Background: Despite the obesity paradox, visceral adiposity is associated with poor clinical outcomes in patients with heart failure with preserved ejection fraction (HFpEF). However, it remains unclear whether a relationship between visceral fat and clinical outcomes exists in Asian patients with HFpEF, in whom obesity is rare. Methods: Visceral and subcutaneous adipose tissue (VAT and SAT) volume and area were measured using computed tomography (CT) in 196 HFpEF patients. The primary endpoint was a composite of all-cause mortality or HF hospitalization. Results: Participants had a normal body mass index (BMI) (22.5 ± 4.4 kg/m2), and obesity (BMI > 30 kg/m2) was rare (4.6 %). The primary outcome was observed in 64 patients during a median follow-up of 11.6 months. Lower VAT and SAT volumes were associated with underweight and malnutrition. Composite outcomes increased as body weight, BMI, and height-indexed SAT volume and area decreased. Lower height-indexed VAT volume and area were also associated with the outcomes. The height-indexed SAT area provided independent and incremental prognostic value over age, BMI, blood pressure, and creatinine and albumin levels. Conclusions: In lean East Asian patients with HFpEF, a lower VAT volume was associated with poorer clinical outcomes. CT-based assessments of adiposity may provide incremental prognostic value over simple anthropometric indices in lean HFpEF patients.

Key Phenotypes of Heart Failure with Preserved Ejection Fraction: Pathophysiologic Mechanisms and Potential Treatment Strategies.

Pathophysiological heterogeneity is considered the primary reason for the limited effective treatment options for patients with heart failure with preserved ejection fraction (HFpEF). Recent studies have focused on HFpEF phenotyping that categorizes patients as pathophysiologically homogeneous groups to develop personalized treatment strategies. This approach relies on comorbidities, cardiac structure and function, central hemodynamics at rest and during exercise, or machine learning techniques. Although some phenotypes have been successfully identified, efforts are still ongoing. This review summarizes the current understanding of phenotyping approaches in patients with HFpEF, highlighting its pathophysiology and potential treatment strategies."

Diastolic Filling Time, Chronotropic Response, and Exercise Capacity in Heart Failure and Preserved Ejection Fraction With Sinus Rhythm.

Background Exercise-induced high heart rate may impair exercise tolerance by reducing diastolic filling time and ventricular filling in heart failure with preserved ejection fraction (HFpEF). Given the importance of chronotropic response, we hypothesized that reduction in diastolic filling time because of exercise-induced increased heart rate would not impair cardiac output reserve and exercise capacity. We sought to determine the association between heart rate, diastolic filling time, hemodynamics, and exercise capacity in HFpEF. Methods and Results Patients with HFpEF (n=66) and controls without HF (n=107) underwent bicycle exercise echocardiography with simultaneous expired gas analysis to measure oxygen consumption. Diastolic filling time was assessed by the overlap time between mitral E- and A-waves (longer overlap time indicates shorter diastolic filling duration). Overlap time increased (ie, diastolic filling time shortened) in HFpEF and controls as heart rate increased with exercise, and the relationship was similar between the groups. Greater heart rate response correlated with higher cardiac output (r=0.51, P<0.0001) and oxygen consumption (r=0.50, P<0.0001) during peak exercise. Shorter diastolic filling time, as assessed by longer overlap time, was correlated with higher cardiac output (r=0.47, P<0.0001) and peak oxygen consumption (r=0.38, P=0.007), not with E/e' or right ventricular-pulmonary artery uncoupling. Longer overlap time was associated with mitral A velocity (r=0.53, P<0.0001) and left atrial booster pump strain (r=0.42, P<0.0001). Conclusions Shortening of diastolic filling interval in tandem with increased heart rate during exercise does not limit cardiac output reserve or exercise capacity in HFpEF.

Ketone body and FGF21 coordinately regulate fasting-induced oxidative stress response in the heart.

Ketone body ß-hydroxybutyrate (ßOHB) and fibroblast growth factor-21 (FGF21) have been proposed to mediate systemic metabolic response to fasting. However, it remains elusive about the signaling elicited by ketone and FGF21 in the heart. Stimulation of neonatal rat cardiomyocytes with ßOHB and FGF21 induced peroxisome proliferator-activated receptor α (PPARα) and PGC1α expression along with the phosphorylation of LKB1 and AMPK. ßOHB and FGF21 induced transcription of peroxisome proliferator-activated receptor response element (PPRE)-containing genes through an activation of PPARα. Additionally, ßOHB and FGF21 induced the expression of Nrf2, a master regulator for oxidative stress response, and catalase and Ucp2 genes. We evaluated the oxidative stress response gene expression after 24 h fast in global Fgf21-null (Fgf21-/-) mice, cardiomyocyte-specific FGF21-null (cmFgf21-/-) mice, wild-type (WT), and Fgf21fl/fl littermates. Fgf21-/- mice but not cmFgf21-/- mice had unexpectedly higher serum ßOHB levels, and higher expression levels of PPARα and oxidative stress response genes than WT mice or Fgf21fl/fl littermates. Notably, expression levels of oxidative stress response genes were significantly correlated with serum ßOHB and PGC1α levels in both WT and Fgf21-/- mice. These findings suggest that fasting-induced ßOHB and circulating FGF21 coordinately regulate oxidative stress response gene expression in the heart.

Exercise Stress Echocardiography in the Diagnostic Evaluation of Heart Failure with Preserved Ejection Fraction.

More than half of patients with heart failure have a preserved ejection fraction (HFpEF). The prevalence of HFpEF has been increasing worldwide and is expected to increase further, making it an important health-care problem. The diagnosis of HFpEF is straightforward in the presence of obvious objective signs of congestion; however, it is challenging in patients presenting with a low degree of congestion because abnormal elevation in intracardiac pressures may occur only during physiological stress conditions, such as during exercise. On the basis of this hemodynamic background, current consensus guidelines have emphasized the importance of exercise stress testing to reveal abnormalities during exercise, and exercise stress echocardiography (i.e., diastolic stress echocardiography) may be used as an initial diagnostic approach to HFpEF owing to its noninvasive nature and wide availability. However, evidence supporting the use of this method remains limited and many knowledge gaps exist with respect to diastolic stress echocardiography. This review summarizes the current understanding of the use of diastolic stress echocardiography in the diagnostic evaluation of HFpEF and discusses its strengths and limitations to encourage future studies on this subject.

Impaired Right Atrial Reserve Function in Heart Failure with Preserved Ejection Fraction.

BACKGROUND: Patients with heart failure with preserved ejection fraction (HFpEF) have multiple cardiac reserve limitations during exercise. However, no data are available regarding right atrial (RA) reserve capacity in HFpEF. The aim of this study was to determine the association of RA reserve impairments with right ventricular function and exercise capacity in HFpEF and to explore its diagnostic value. METHODS: Patients with HFpEF (n = 89) and control subjects without heart failure (n = 108) underwent bicycle exercise echocardiography. RA reservoir, conduit, and booster pump strain at rest and during exercise were measured using speckle-tracking echocardiography. In a subset, simultaneous expired gas analysis was performed to measure peak oxygen consumption. RESULTS: At rest, RA reservoir strain was lower in patients with HFpEF than control subjects (27.0 ± 17.1% vs 38.6 ± 17.1%, P < .0001), while RA conduit and booster pump strain were similar between groups. During peak exercise, patients with HFpEF displayed marked reserve limitations in RA reservoir and booster pump function compared with control subjects, and the differences remained significant even after adjusting for confounding factors. During peak exercise, RA reservoir and booster pump strain were correlated with right ventricular systolic function. Lower RA booster pump strain during exercise was also weakly associated with lower cardiac output (r = 0.34, P < .0001) and reduced peak oxygen consumption (r = 0.47, P < .0001). RA reservoir strain during exercise had incremental diagnostic value to differentiate patients with HFpEF from control subjects over the established HFpEF diagnostic algorithms and left-sided strain parameters. CONCLUSIONS: Limitations in RA reservoir and booster pump function during exercise are present in patients with HFpEF, and the severity is associated with right ventricular systolic reserve, poor cardiac output, and depressed exercise capacity. Exercise RA strain assessment may help in the diagnosis of HFpEF.