Cardiac and Metabolic Effects of Dapagliflozin in Heart Failure With Preserved Ejection Fraction: The CAMEO-DAPA Trial.

BACKGROUND: Sodium-glucose cotransporter-2 inhibitors reduce risk of hospitalization for heart failure in patients who have heart failure with preserved ejection fraction (HFpEF), but the hemodynamic mechanisms underlying these benefits remain unclear. This study sought to determine whether treatment with dapagliflozin affects pulmonary capillary wedge pressure (PCWP) at rest and during exercise in patients with HFpEF. METHODS: This was a single-center, double-blinded, randomized, placebo-controlled trial testing the effects of 10 mg of dapagliflozin once daily in patients with HFpEF. Patients with New York Heart Association class II or III heart failure, ejection fraction ≥50%, and elevated PCWP during exercise were recruited. Cardiac hemodynamics were measured at rest and during exercise using high-fidelity micromanometers at baseline and after 24 weeks of treatment. The primary end point was a change from baseline in rest and peak exercise PCWPs that incorporated both measurements, and was compared using a mixed-model likelihood ratio test. Key secondary end points included body weight and directly measured blood and plasma volumes. Expired gas analysis was performed evaluate oxygen transport in tandem with arterial lactate sampling. RESULTS: Among 38 patients completing baseline assessments (median age 68 years; 66% women; 71% obese), 37 completed the trial. Treatment with dapagliflozin resulted in reduction in the primary end point of change in PCWP at rest and during exercise at 24 weeks relative to treatment with placebo (likelihood ratio test for overall changes in PCWP; P<0.001), with lower PCWP at rest (estimated treatment difference [ETD], -3.5 mm Hg [95% CI, -6.6 to -0.4]; P=0.029) and maximal exercise (ETD, -5.7 mm Hg [95% CI, -10.8 to -0.7]; P=0.027). Body weight was reduced with dapagliflozin (ETD, -3.5 kg [95% CI, -5.9 to -1.1]; P=0.006), as was plasma volume (ETD, -285 mL [95% CI, -510 to -60]; P=0.014), but there was no significant effect on red blood cell volume. There were no differences in oxygen consumption at 20-W or peak exercise, but dapagliflozin decreased arterial lactate at 20 W (-0.70 ± 0.77 versus 0.37 ± 1.29 mM; P=0.006). CONCLUSIONS: In patients with HFpEF, treatment with dapagliflozin reduces resting and exercise PCWP, along with the favorable effects on plasma volume and body weight. These findings provide new insight into the hemodynamic mechanisms of benefit with sodium-glucose cotransporter-2 inhibitors in HFpEF. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04730947.

Racial Differences of Cardiac Structure and Function in Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Potential race differences in cardiac structure and function among patients with heart failure with preserved ejection fraction (HFpEF) are not well-understood, but may have pathophysiological and treatment implications. METHODS AND RESULTS: In this study, patients with HFpEF who self-identified as Asian (n = 360), White (n = 787), and Black (n = 171) from 3 institutions underwent comprehensive transthoracic echocardiography to evaluate for potential differences. The Asian HFpEF group was oldest and the Black HFpEF group was youngest (75 ± 12 years vs 73 ± 13 years vs 62 ± 12 years; P < .0001). Women constituted the lowest proportion of patients with HFpEF among Asian individuals, but were the largest among Black patients (49% vs 56% vs 73%; P < .0001). Body mass index and obesity prevalence were highest in Black patients with HFpEF and were lowest in Asian patients. Black individuals with HFpEF had greater left ventricular (LV) wall thickening and concentricity, smaller LV chamber size, leftward-shifted LV end-diastolic pressure-volume relationship, indicating greater LV stiffening, smallest left atrial volumes, and the most right ventricular dilatation. Asian individuals with HFpEF had greater LV and left atrial dilation, more rightward shifted LV end-diastolic pressure-volume relationship, and the highest arterial stiffness. CONCLUSIONS: In summary, we show that patients with HFpEF of Asian, Black, and White race display key differences in clinical, anthropometric, and cardiac structure-function indices, indicating that consideration of race-related differences might important to individualize treatment strategies in HFpEF.

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.

Heart failure with preserved ejection fraction in patients with normal natriuretic peptide levels is associated with increased morbidity and mortality.

BACKGROUND: A substantial proportion of patients with heart failure (HF) with preserved ejection fraction (HFpEF) present with normal natriuretic peptide (NP) levels. The pathophysiology and natural history for this phenotype remain unclear. METHODS AND RESULTS: Consecutive subjects undergoing invasive cardiopulmonary exercise testing for unexplained dyspnoea at Mayo Clinic in 2006-18 were studied. Heart failure with preserved ejection fraction was defined as a pulmonary arterial wedge pressure (PAWP) ≥15 mmHg (rest) or ≥25 mmHg (exercise). Patients with HFpEF and normal NP [N-terminal of the pro-hormone B-type natriuretic peptide (NT-proBNP) < 125 ng/L] were compared with HFpEF with high NP (NT-proBNP ≥ 125 ng/L) and controls with normal haemodynamics. Patients with HFpEF and normal (n = 157) vs. high NP (n = 263) were younger, yet older than controls (n = 161), with an intermediate comorbidity profile. Normal NP HFpEF was associated with more left ventricular hypertrophy and worse diastolic function compared with controls, but better diastolic function, lower left atrial volumes, superior right ventricular function, and less mitral/tricuspid regurgitation compared with high NP HFpEF. Cardiac output (CO) reserve with exercise was preserved in normal NP HFpEF [101% predicted, interquartile range (IQR): 75-124%], but this was achieved only at the cost of higher left ventricular transmural pressure (LVTMP) (14 ± 6 mmHg vs. 7 ± 4 mmHg in controls, P < 0.001). In contrast, CO reserve was decreased in high NP HFpEF (85% predicted, IQR: 59-109%), with lower LVTMP (10 ± 8 mmHg) compared with normal NP HFpEF (P < 0.001), despite similar PAWP. Patients with high NP HFpEF displayed the highest event rates, but normal NP HFpEF still had 2.7-fold higher risk for mortality or HF readmissions compared with controls (hazard ratio: 2.74, 95% confidence interval: 1.02-7.32) after adjusting for age, sex, and body mass index. CONCLUSION: Patients with HFpEF and normal NP display mild diastolic dysfunction and preserved CO reserve during exercise, despite marked elevation in filling pressures. While clinical outcomes are not as poor compared with patients with high NP, patients with normal NP HFpEF exhibit increased risk of death or HF readmissions compared with patients without HF, emphasizing the importance of this phenotype.

Pulmonary vascular disease in pulmonary hypertension due to left heart disease: pathophysiologic implications.

AIMS: Pulmonary hypertension (PH) and pulmonary vascular disease (PVD) are common and associated with adverse outcomes in left heart disease (LHD). This study sought to characterize the pathophysiology of PVD across the spectrum of PH in LHD. METHODS AND RESULTS: Patients with PH-LHD [mean pulmonary artery (PA) pressure >20 mmHg and PA wedge pressure (PAWP) ≥15 mmHg] and controls free of PH or LHD underwent invasive haemodynamic exercise testing with simultaneous echocardiography, expired air and blood gas analysis, and lung ultrasound in a prospective study. Patients with PH-LHD were divided into isolated post-capillary PH (IpcPH) and PVD [combined post- and pre-capillary PH (CpcPH)] based upon pulmonary vascular resistance (PVR <3.0 or ≥3.0 WU). As compared with controls (n = 69) and IpcPH-LHD (n = 55), participants with CpcPH-LHD (n = 40) displayed poorer left atrial function and more severe right ventricular (RV) dysfunction at rest. With exercise, patients with CpcPH-LHD displayed similar PAWP to IpcPH-LHD, but more severe RV-PA uncoupling, greater ventricular interaction, and more severe impairments in cardiac output, O2 delivery, and peak O2 consumption. Despite higher PVR, participants with CpcPH developed more severe lung congestion compared with both IpcPH-LHD and controls, which was associated lower arterial O2 tension, reduced alveolar ventilation, decreased pulmonary O2 diffusion, and greater ventilation-perfusion mismatch. CONCLUSIONS: Pulmonary vascular disease in LHD is associated with a distinct pathophysiologic signature marked by greater exercise-induced lung congestion, arterial hypoxaemia, RV-PA uncoupling, ventricular interdependence, and impairment in O2 delivery, impairing aerobic capacity. Further study is required to identify novel treatments targeting the pulmonary vasculature in PH-LHD.

Pathophysiologic importance of visceral adipose tissue in women with heart failure and preserved ejection fraction.

AIMS: Central obesity is a major risk factor for heart failure with preserved ejection fraction (HFpEF), particularly in women, but the mechanisms remain unclear. We hypothesized that sex-specific differences in visceral adipose tissue (VAT) content would differentially relate to haemodynamic severity of HFpEF in women and men. METHODS AND RESULTS: Abdominal computed tomography (CT) and invasive haemodynamic exercise testing were performed in 105 subjects with HFpEF (63 women) and 105 age-, sex-, and body mass index-matched controls. Visceral adipose tissue area was quantified by CT. As compared with control women, VAT area was 34% higher in women with HFpEF (186 ± 112 vs. 139 ± 72 cm2, P = 0.006), while VAT area was not significantly different in men with or without HFpEF (294 ± 158 vs. 252 ± 92 cm2, P = 0.1). During exercise, pulmonary capillary wedge pressure (PCWP) increased markedly and to similar extent in both men and women with HFpEF. Women with increased VAT area displayed 33% higher PCWP during exercise compared with women with normal VAT area (28 ± 10 vs. 21 ± 10 mmHg, P = 0.001), whereas exercise PCWP was similar in men with or without excess VAT (24 ± 9 vs. 25 ± 6, P = 0.89). In women, each 100 cm2 increase in VAT area was associated with a 4.0 mmHg higher PCWP (95% CI 2.1, 6.0 mmHg; P < 0.0001), but there was no such relationship in men (interaction P = 0.009). CONCLUSIONS: These data suggest that accumulation of excess VAT plays a distinct and important role in the pathophysiology of HFpEF preferentially in women. Further research is needed to better understand the mechanisms and treatment implications for visceral fat in HFpEF.

Impact of Right Atrial Remodeling in Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Few studies have investigated right atrial (RA) remodeling in heart failure (HF) with preserved ejection fraction (HFpEF). This study sought to characterize the RA remodeling in HFpEF and to determine its prognostic significance. METHODS AND RESULTS: Patients with HFpEF were classified based on the presence of RA enlargement (RA volume index >39 mL/m2 in men and >33 mL/m2 in women). Compared with patients with normal RA size (n = 234), patients with RA dilation (n = 67) showed a higher prevalence of atrial fibrillation (AF), worse right ventricular systolic function, more severe pulmonary hypertension, and a greater prevalence of mild tricuspid regurgitation, as well as impaired RA reservoir function, with increased hepatobiliary enzyme levels. AF was strongly associated with the presence of RA dilation (odds ratio [OR] 10.2, 95% confidence interval [CI] 4.00-26.1 in current AF vs no AF and odds ratio 3.38, 95% CI 1.26-9.07, earlier AF vs no AF). Patients with RA dilation had more than a two-fold increased risk of composite outcomes of all-cause mortality or HF hospitalization (adjusted hazard ratio 2.01, 95% CI 1.09-3.70, P = .02). The presence of RA dilation also displayed an additive prognostic value over left atrial dilation alone. CONCLUSIONS: These data demonstrate that HFpEF with RA remodeling is associated with distinct echocardiographic features characterizing advanced right heart dysfunction with an increased risk of adverse outcomes.

Pulmonary Vascular Alterations on Computed Tomography Imaging and Outcomes in Heart Failure With Preserved Ejection Fraction: a Preliminary Data.

BACKGROUND: Pulmonary vascular disease may play an important role in the pathophysiology of heart failure (HF) with preserved ejection fraction (HFpEF). However, no study has demonstrated noninvasive quantification of pulmonary vascular alterations in HFpEF. This study sought to determine the association between pulmonary vascular alterations quantified by chest computed tomography scan and clinical outcomes in HFpEF. METHODS AND RESULTS: Pulmonary vascular alterations were quantified in 151 patients with HFpEF who underwent noncontrast chest computed tomography scan by measuring the percentage of total cross-sectional area (CSA) of pulmonary vessels less than 5 mm2 to the total lung area (%CSA<5). We divided the patients by the median value of %CSA<5 (=1.45%) and examined the association between %CSA<5 and a composite outcome of all-cause mortality or HF hospitalization. During a median follow-up of 17.3 months, there were 44 (29%) composite outcomes. Event rates were significantly higher in patients with higher %CSA<5 than those with lower %CSA<5 (log-rank P = .02). %CSA<5 was associated with an increased risk of the outcome (hazard ratio per 1.0% increment, 1.46; 95% confidence interval 1.06-1.98; P = .02) in an unadjusted Cox model, and was independently and incrementally associated with the outcome over age, the presence of atrial fibrillation, E/e' ratio, and estimated pulmonary artery systolic pressure (global χ2 17.3 vs 11.5, P = .02). CONCLUSIONS: A higher %CSA<5 was associated with an increased risk of all-cause mortality or HF hospitalization in patients with HFpEF, with an incremental prognostic value over age, atrial fibrillation, E/e' ratio, and pulmonary artery systolic pressure.

Clinical Phenogroups in Heart Failure with Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) accounts for more than one-half of patients with heart failure. Effective treatment of HFpEF has not been established, largely because of the complexities and heterogeneity in the phenotypes of HFpEF. Categorizing patients based on clinical and pathophysiologic phenotype may provide more targeted and efficacious therapies. Despite this clinical need, there is no consensus on how to categorize patients with HFpEF into phenogroups. Possible metrics include the presence or absence of specific comorbidities that influence pathophysiology, imaging, hemodynamics, or other biomarkers. This article describes currently recognized phenotypes of HFpEF and potential treatment strategies.

Noninvasive evaluation of pulmonary artery pressure during exercise: the importance of right atrial hypertension.

INTRODUCTION: Identification of elevated pulmonary artery pressures during exercise has important diagnostic, prognostic and therapeutic implications. Stress echocardiography is frequently used to estimate pulmonary artery pressures during exercise testing, but data supporting this practice are limited. This study examined the accuracy of Doppler echocardiography for the estimation of pulmonary artery pressures at rest and during exercise. METHODS: Simultaneous cardiac catheterisation-echocardiographic studies were performed at rest and during exercise in 97 subjects with dyspnoea. Echocardiography-estimated pulmonary artery systolic pressure (ePASP) was calculated from the right ventricular (RV) to right atrial (RA) pressure gradient and estimated RA pressure (eRAP), and then compared with directly measured PASP and RAP. RESULTS: Estimated PASP was obtainable in 57% of subjects at rest, but feasibility decreased to 15-16% during exercise, due mainly to an inability to obtain eRAP during stress. Estimated PASP correlated well with direct PASP at rest (r=0.76, p<0.0001; bias -1 mmHg) and during exercise (r=0.76, p=0.001; bias +3 mmHg). When assuming eRAP of 10 mmHg, ePASP correlated with direct PASP (r=0.70, p<0.0001), but substantially underestimated true values (bias +9 mmHg), with the greatest underestimation among patients with severe exercise-induced pulmonary hypertension (EIPH). Estimation of eRAP during exercise from resting eRAP improved discrimination of patients with or without EIPH (area under the curve 0.81), with minimal bias (5 mmHg), but wide limits of agreement (-14-25 mmHg). CONCLUSIONS: The RV-RA pressure gradient can be estimated with reasonable accuracy during exercise when measurable. However, RA hypertension frequently develops in patients with EIPH, and the inability to noninvasively account for this leads to substantial underestimation of exercise pulmonary artery pressures.

[Left Atrial Strain Independently and Incrementally Predicts High Risk Thromboembolic Findings Over CHA2DS2-VASc Score and BNP].

BACKGROUND: Left atrial longitudinal strain(LAs) is a novel and useful parameter of LA function and reflecting thromboembolic risk. CHA2DS2-VASc score and brain natriuretic protein (BNP) are also used for risk stratifica- tion. However, little is known about the impact of LAs on stroke risk stratification over these parameters. In this study, we aimed to examine whether LAs has independent and incremental risk stratification over them. METHODS: We studied 97 consecutive patients (age: 66 ± 12, 70 males) who underwent transesophageal echocardi- ography for evaluation of left atrial appendage (LAA) thrombus with persistent or paroxysmal atrial fibrillation. We assessed whether patients had spontaneous echo contrast (SEC) or not. Patients with LAA thrombus or sponta- neous echo contrast (SEC) were defined as high risk. LAs was assessed by averaging the segments measured in the 4- and 2-chamber views by transthoracic echocardiography. RESULTS: Among the 97 patients, 51(53%) patients had sinus rhythm and 36 were with SEC. Although LAs (21.0 ?9.0%), CHA2DS2-VASc score (2.7± 1.7) and BNP were mutually associated, only LAs and CHA2DS2-VASc score were independent predictors of high thromboembolic risk but BNP not. In nested logistic regression model anal- yses, predictive ability of a model with CHA2DS2-VASc score was improved by the addition of BNP (p =0.004) and further by adding LAs (p =0.027). CONCLUSION: LAs predicts independently and incrementally LAA thrombus or SEC over CHA2DS2-VASc score and BNP, suggesting that LAs serves as a functional predictor for future thromboembolism. [Original].

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.

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.

Dapagliflozin and Right Ventricular-Pulmonary Vascular Interaction in Heart Failure With Preserved Ejection Fraction: A Secondary Analysis of a Randomized Clinical Trial.

Importance: Increases in pulmonary capillary wedge pressure (PCWP) during exercise reduce pulmonary artery (PA) compliance, increase pulsatile right ventricular (RV) afterload, and impair RV-PA coupling in patients with heart failure with preserved ejection fraction (HFpEF). The effects of the sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin on pulmonary vascular properties and RV-PA coupling are unknown. Objective: To test the effect of dapagliflozin on right ventricular performance and pulmonary vascular load during exertion in HFpEF. Design, Setting, and Participants: Evaluation of the Cardiac and Metabolic Effects of Dapagliflozin in Heart Failure With Preserved Ejection Fraction (CAMEO-DAPA) randomized clinical trial demonstrated improvement in PCWP at rest and exercise over 24 weeks with dapagliflozin compared with placebo with participants recruited between February 2021 and May 2022. This secondary analysis evaluates the effects of dapagliflozin on pulsatile pulmonary vascular load and RV-PA coupling using simultaneous echocardiography and high-fidelity invasive hemodynamic testing with exercise. This was a single-center study including patients with hemodynamically confirmed HFpEF with exercise PCWP of 25 mm Hg or greater. Interventions: Dapagliflozin or placebo for 24 weeks. Main Outcomes and Measures: Pulsatile pulmonary vascular load (PA compliance and elastance) and right ventricular performance (PA pulsatility index, RV systolic velocity [s']/PA mean) during rest and exercise. Results: Among 37 randomized participants (mean [SD] age, 67.4 [8.5] years; 25 female [65%]; mean [SD] body mass index, 34.9 [6.7]; calculated as weight in kilograms divided by height in meters squared), there was no effect of dapagliflozin on PA loading or RV-PA interaction at rest. However, with exercise, dapagliflozin improved PA compliance (placebo-corrected mean difference, 0.57 mL/mm Hg; 95% CI, 0.11-1.03 mL/mm Hg; P = .02) and decreased PA elastance (stiffness; -0.17 mm Hg/mL; 95% CI, -0.28 to -0.07 mm Hg/mL; P = .001). RV function during exercise improved, with increase in PA pulsatility index (0.33; 95% CI, 0.08-0.59; P = .01) and increase in exercise RV s' indexed to PA pressure (0.09 cm·s-1/mm Hg; 95% CI, 0.02-0.16 cm·s-1/mm Hg; P = .01). Improvements in pulsatile RV load and RV-PA coupling were correlated with reduction in right atrial (RA) pressure (PA elastance Pearson r = 0.55; P =.008; RV s'/PA elastance Pearson r = -0.60; P =.002) and PCWP (PA elastance Pearson r = 0.58; P <.001; RV s'/PA elastance Pearson r = -0.47; P = .02). Dapagliflozin increased resistance-compliance time (dapagliflozin, median [IQR] change, 0.06 [0.03-0.15] seconds; placebo, median [IQR] change, 0.01 [-0.02 to 0.05] seconds; P =.046), resulting in higher PA compliance for any exercise pulmonary vascular resistance. Conclusions and Relevance: Results of this randomized clinical trial reveal that treatment with dapagliflozin for 24 weeks reduced pulsatile pulmonary vascular load and enhanced dynamic RV-PA interaction during exercise in patients with HFpEF, findings that are related to the magnitude of PCWP reduction. Benefits on dynamic right ventricular-pulmonary vascular coupling may partially explain the benefits of SGLT2 inhibitors in HFpEF. Trial Registration: ClinicalTrials.gov Identifier: NCT04730947.

Biatrial myopathy in heart failure with preserved ejection fraction.

AIM: Left atrial (LA) myopathy is increasingly recognized as an important phenotypic trait in heart failure (HF) with preserved ejection fraction (HFpEF). Right atrial (RA) remodelling and dysfunction also develop in HFpEF, but little data are available regarding the clinical characteristics and pathophysiology among patients with isolated LA, RA, or biatrial myopathy. METHODS AND RESULTS: Patients with HFpEF underwent invasive haemodynamic exercise testing, comprehensive imaging including speckle tracking strain echocardiography, and clinical follow-up at Mayo Clinic between 2006 and 2018. LA myopathy was defined as LA volume index >34 ml/m2 and/or LA reservoir strain ≤24% and RA myopathy by RA volume index >39 ml/m2 in men and >33 ml/m2 in women and/or RA reservoir strain ≤19.8%. Of 476 consecutively evaluated patients with HFpEF defined by invasive exercise testing with evaluable atrial structure/function, 125 (26%) had no atrial myopathy, 147 (31%) had isolated LA myopathy, 184 (39%) had biatrial myopathy, and 20 (4%) had isolated RA myopathy. Patients with HFpEF and biatrial myopathy had more atrial fibrillation, poorer left ventricular systolic and diastolic function, more severe pulmonary vascular disease, tricuspid regurgitation, ventricular interdependence and right ventricular dysfunction, and poorer cardiac output reserve with exercise. There were 94 patients with events over a median follow-up of 2.9 (interquartile range 1.4-4.6) years. Individuals with biatrial myopathy had an 84% higher risk of HF hospitalization or death as compared to those with isolated LA myopathy (hazard ratio 1.84; 95% confidence interval 1.16-2.92, p = 0.01). CONCLUSIONS: Biatrial myopathy identifies patients with more advanced HFpEF characterized by more severe pulmonary vascular disease, right HF, poorer cardiac reserve, and a greater risk for adverse outcomes. Further study is required to define optimal strategies to treat and prevent biatrial myopathy in HFpEF.

Impaired Left Atrial Reserve Function in Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Left atrial (LA) dysfunction is common in heart failure (HF) with preserved ejection fraction. However, data on the pathophysiologic impacts of impaired LA functional reserve remained limited. We sought to determine the association of abnormal LA dynamics during exercise with cardiovascular reserve, exercise capacity, and clinical outcomes. METHODS: Patients with HF with preserved ejection fraction (n=231) and controls without HF (n=219) underwent exercise stress echocardiography with simultaneous expired gas analysis. LA function was assessed at rest and during exercise using speckle-tracking echocardiography. RESULTS: Patients with HF with preserved ejection fraction demonstrated less increase in LA reservoir and booster pump strain during exercise than those in controls. The degree of LA dilation was more closely related to exercise LA reservoir strain than to resting LA strain (Meng test, P=0.002). The presence of impaired LA reservoir strain during exercise was associated with poorer biventricular systolic reserve and cardiac output augmentation, more severe right ventricular-pulmonary artery uncoupling, and lower peak oxygen consumption. Patients with a lower exercise LA reservoir strain had a 2.7-fold increased risk of HF events (hazard ratio, 2.66 [95% CI, 1.32-5.38]; P=0.006). Among patients with follow-up echocardiography, initiation of guideline-directed medical therapy or atrial fibrillation ablation showed significant improvements in LA reservoir (P<0.001 and P=0.022) and booster pump strain (P=0.011 and 0.028) at rest and during exercise, respectively. CONCLUSIONS: Impaired LA reservoir function during exercise in HF with preserved ejection fraction is associated with biventricular reserve limitations, exercise intolerance, and increased risks of HF events.

Cardiac function, haemodynamics, and valve competence with exercise in patients with heart failure with preserved ejection fraction and mild to moderate secondary mitral regurgitation.

AIMS: This study aimed to evaluate the clinical significance of secondary mitral regurgitation (MR) in patients with heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: We conducted a prospective study enrolling consecutively evaluated patients with HFpEF undergoing invasive haemodynamic exercise testing with simultaneous echocardiography. Compared to HFpEF without MR (n = 145, 79.7%), those with mild or moderate MR (n = 37, 20.3%) were older, more likely to be women, had more left ventricular (LV) systolic dysfunction, and more likely to have left atrial (LA) myopathy reflected by greater burden of atrial fibrillation, more LA dilatation, and poorer LA function. Pulmonary artery (PA) wedge pressure was higher at rest in HFpEF with MR (17 ± 5 mmHg vs. 20 ± 5 mmHg, p = 0.005), but there was no difference with exercise. At rest, only 2 (1.1%) patients had moderate MR, and none developed severe MR. Pulmonary vascular resistance was higher, and right ventricular (RV)-PA coupling was more impaired in patients with HFpEF and MR at rest and exercise. LV and LA myocardial dysfunction remained more severe in patients with MR during stress compared to those without MR, characterized by greater LA dilatation during all stages of exertion, lower LA emptying fraction and compliance, steeper and rightward-shifted LA pressure-volume relationships, and reduced LV longitudinal contractile function. CONCLUSIONS: Patients with HFpEF and mild or moderate MR have more severe LV systolic dysfunction, LA myopathy, RV-PA uncoupling, and more severe pulmonary vascular disease. Mitral valve incompetence in this setting is a phenotypic marker of more advanced disease but is not a causal factor in development of HFpEF.

Exercise Stress Echocardiography-Based Phenotyping of Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome requiring improved phenotypic classification. Previous studies have identified subphenotypes of HFpEF, but the lack of exercise assessment is a major limitation. The aim of this study was to identify distinct pathophysiologic clusters of HFpEF based on clinical characteristics, and resting and exercise assessments. METHODS: A total of 265 patients with HFpEF underwent ergometry exercise stress echocardiography with simultaneous expired gas analysis. Cluster analysis was performed by the K-prototype method with 21 variables (10 clinical and resting echocardiographic variables and 11 exercise echocardiographic parameters). Pathophysiologic features, exercise tolerance, and prognosis were compared among phenogroups. RESULTS: Three distinct phenogroups were identified. Phenogroup 1 (n = 112 [42%]) was characterized by preserved biventricular systolic reserve and cardiac output augmentation. Phenogroup 2 (n = 58 [22%]) was characterized by a high prevalence of atrial fibrillation, increased pulmonary arterial and right atrial pressures, depressed right ventricular systolic functional reserve, and impaired right ventricular-pulmonary artery coupling during exercise. Phenogroup 3 (n = 95 [36%]) was characterized by the smallest body mass index, ventricular and vascular stiffening, impaired left ventricular diastolic reserve, and worse exercise capacity. Phenogroups 2 and 3 had higher rates of composite outcomes of all-cause mortality or heart failure events than phenogroup 1 (log-rank P = .02). CONCLUSION: Exercise echocardiography-based cluster analysis identified three distinct phenogroups of HFpEF, with unique exercise pathophysiologic features, exercise capacity, and clinical outcomes.