Heart failure with preserved ejection fraction: a heterogenous disorder with multifactorial pathophysiology

The clinical burden of newly diagnosed Heart failure among patients with Reduced, mildly Reduced, and preserved ejection fraction

Background

Contemporary analyses of the distribution of heart failure (HF) patients by groups of ejection fraction are not available or are limited to hospitalized patients. Our objective was to quantify the per-person and system level clinical burden of a broad population of HF patients.

Methods

We studied 16,516 patients with a new HF diagnosis recorded in the electronic medical record of a U.S. integrated delivery system between 2005 and 2017. We used the diagnosis date as the index date and the nearest echocardiogram result to classify patients as HFrEF (n = 2,430), HFmrEF (n = 1,646), HFpEF (n = 12,440) and followed them through 2019 for major clinical outcomes (all-cause mortality, HF hospitalizations [HHF], all-cause hospitalizations, incident chronic kidney disease [CKD], progression of eGFR category, progression of CKD, incident type 2 diabetes [T2D], and progression to insulin use). We compared age and sex adjusted incidence rates and rate ratios of the outcomes between the HF types.

Results

Incidence rates for most outcomes were significantly higher among patients with HFrEF compared with HFpEF. HHF was 59 % greater, mortality 31 % greater, and CKD incidence 55 % greater, (p < 0.001 for all comparisons). However, the larger size of the HFpEF group generated 4.7-6.7 times as many total outcomes.

Conclusions

Regardless of subtype, the presence of HF was associated with poor clinical outcomes. Incidence rates were higher for HFrEF than HFpEF, but as the latter represented 75% of the study population, HFpEF caused a greater overall burden on the health care system, reflecting the high unmet need of target therapies for HFpEF.

Impaired myocardial work efficiency in heart failure with preserved ejection fraction

AIMS

Heart failure with preserved ejection fraction (HFpEF) is a growing public health problem. Impairment in left ventricular (LV) diastolic function has been proposed as a key pathophysiologic determinant. However, the role of concomitant systolic dysfunction despite preserved LV ejection fraction (LVEF) has not been well characterized. To analyse LV myocardial deformation, diastolic function, and contractile reserve (CR) in patients with HFpEF at rest and while during exercise, as well as their correlation with functional capacity.

METHODS AND RESULTS

Standard echo, lung ultrasound, LV 2D speckle-tracking strain, and myocardial work efficiency (MWE) were performed at rest and during exercise in 230 patients with HFpEF (female sex 61.2%; 71.3 ± 5.3 years) in 150 age- and sex-comparable healthy controls. LV mass index and LAVI were significantly increased in HFpEF. Conversely, global longitudinal strain (GLS) and MWE were consequently reduced in HFpEF patients. During effort, HFpEF showed reduced exercise time, capacity, and VO2 peak. Increase in LVEF and LV GLS was significantly lower in HFpEF patients, while LV E/e' ratio, pulmonary pressures, and B-lines by lung ultrasound rose. A multivariable analysis outlined that LV MWE at rest was closely related to maximal Watts reached (beta coefficient: 0.43; P < 0.001), peak VO2 (beta: 0.50; P < 0.001), LV E/e' (beta: 0.52, P < 0.001), and number of B-lines during effort (beta: -0.36; P < 0.01).

CONCLUSIONS

The lower resting values of LV GLS and MWE in HFpEF patients suggest an early subclinical myocardial damage, which seems to be closely associated with lower exercise capacity, greater pulmonary congestion, and blunted LV contractile reserve during effort.

Use of Speckle Tracking Echocardiography to Detect Induced Regional Strain Changes in the Murine Myocardium by Acoustic Radiation Force

BACKGROUND

It is difficult to simulate the abnormal myocardial strain patterns caused by ischemic coronary artery disease (CAD) which are a precursor to heart failure (HF) within an animal model. Simulation of these strain changes could contribute to better understanding of the early formative stages of HF. This is especially important in investigating the poorly understood pathogenesis of heart failure with preserved ejection fraction (HFpEF). Here, we discuss delivery of high intensity focused ultrasound (HIFU) in a murine model to alter left ventricular (LV) regional longitudinal strain (RLS), and use of speckle tracking echocardiography to detect these changes.

METHODS

HIFU pulses (pressure amplitude 1.7 MPa) were generated by amplifying a sinusoidal waveform from a function generator into a piezoelectric transducer. These pulses were then directed extracorporeally towards the anterior LV surface of C57BI6 mice during three time periods (early, mid, and late diastole). Speckle tracking echocardiography was then used to quantify changes in RLS within six segments of the LV.

RESULTS

We observed an increase in LV RLS with acoustic augmentation during all three time periods. This augmentation was most prominent near the anterior apical region in early diastole and near the posterior basilar region during late diastole.

CONCLUSIONS

Our findings demonstrate the application of HIFU to non-invasively induce changes in RLS within a murine model. Our results also reflect the capability of speckle tracking echocardiography to analyze and quantify these changes. These findings represent the first demonstration of ultrasound-induced augmentation in LV RLS within a small animal model.

Genetic dysregulation of endothelin-1 is implicated in coronary microvascular dysfunction

AIMS

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide linked to vascular diseases through a common intronic gene enhancer [(rs9349379-G allele), chromosome 6 (PHACTR1/EDN1)]. We performed a multimodality investigation into the role of ET-1 and this gene variant in the pathogenesis of coronary microvascular dysfunction (CMD) in patients with symptoms and/or signs of ischaemia but no obstructive coronary artery disease (CAD).

METHODS AND RESULTS

Three hundred and ninety-one patients with angina were enrolled. Of these, 206 (53%) with obstructive CAD were excluded leaving 185 (47%) eligible. One hundred and nine (72%) of 151 subjects who underwent invasive testing had objective evidence of CMD (COVADIS criteria). rs9349379-G allele frequency was greater than in contemporary reference genome bank control subjects [allele frequency 46% (129/280 alleles) vs. 39% (5551/14380); P = 0.013]. The G allele was associated with higher plasma serum ET-1 [least squares mean 1.59 pg/mL vs. 1.28 pg/mL; 95% confidence interval (CI) 0.10-0.53; P = 0.005]. Patients with rs9349379-G allele had over double the odds of CMD [odds ratio (OR) 2.33, 95% CI 1.10-4.96; P = 0.027]. Multimodality non-invasive testing confirmed the G allele was associated with linked impairments in myocardial perfusion on stress cardiac magnetic resonance imaging at 1.5 T (N = 107; GG 56%, AG 43%, AA 31%, P = 0.042) and exercise testing (N = 87; -3.0 units in Duke Exercise Treadmill Score; -5.8 to -0.1; P = 0.045). Endothelin-1 related vascular mechanisms were assessed ex vivo using wire myography with endothelin A receptor (ETA) antagonists including zibotentan. Subjects with rs9349379-G allele had preserved peripheral small vessel reactivity to ET-1 with high affinity of ETA antagonists. Zibotentan reversed ET-1-induced vasoconstriction independently of G allele status.

CONCLUSION

We identify a novel genetic risk locus for CMD. These findings implicate ET-1 dysregulation and support the possibility of precision medicine using genetics to target oral ETA antagonist therapy in patients with microvascular angina.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03193294.

Therapy for heart failure with preserved ejection fraction: current status, unique challenges, and future directions

Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common form of HF. Among elderly women, HFpEF comprises more than 80% of incident HF cases. Adverse outcomes-exercise intolerance, poor quality of life, frequent hospitalizations, and reduced survival-approach those of classic HF with reduced EF (HFrEF). However, despite its importance, our understanding of the pathophysiology of HFpEF is incomplete, and despite intensive efforts, optimal therapy remains uncertain, as most trials to date have been negative. This is in stark contrast to management of HFrEF, where dozens of positive trials have established a broad array of effective, guidelines-based therapies that definitively improve a range of clinically meaningful outcomes. In addition to providing an overview of current management status, we examine evolving data that may help explain this paradox, overcome past challenges, provide a roadmap for future success, and that underpin a wave of new trials that will test novel approaches based on these insights.

Epidemiologists of the Future: Data Collectors or Scientists?

Epidemiology is the study of epidemics. It is a biological science that includes expertise in many disciplines in social and behavioral sciences. Epidemiology is also a key component of preventive medicine and public health. Unfortunately, over recent years, academic epidemiology has lost its relationship with preventive medicine, as well as much of its focus on epidemics. The new "-omics" technologies to measure risk factors and phenotypes, and advances in genomics (e.g., host susceptibility) consistent with good epidemiology methods will likely enhance epidemiology research. There is a need based on these new technologies to modify training, especially for the first-level doctorate epidemiologist.

Mediterranean diet and prognosis of first-diagnosed Acute Coronary Syndrome patients according to heart failure phenotype: Hellenic Heart Failure Study

BACKGROUND/OBJECTIVES

Nutrition in secondary prevention of Acute Coronary Syndrome (ACS) is inadequately investigated. We sought to evaluate the role of Mediterranean diet in prognosis of first-diagnosed ACS patients, according to heart failure type.

SUBJECTS/METHODS

in 2006-2009, 1000 consecutive patients hospitalized at First Cardiology Clinic of Athens with ACS diagnosis were enrolled in the study. In 2016, 10-year follow-up was performed (75% participation rate). Only n=690 (69%) first-diagnosed ACS patients were included. Adherence to Mediterranean diet was assessed through MedDietScore (range 0-55). Heart failure phenotypes were reduced, mid-range and preserved ejection fraction (that is, HFrEF, HFmrEF and HFpEF, respectively).

RESULTS

Ranking from first to third MedDietScore tertile, fewer 1, 2 and 10-year fatal/non-fatal ACS events were observed. Multivariate logistic regression analysis highlighted a significantly inverse association between MedDietScore and long-term ACS prognosis in 1 year (odds ratio (OR)=0.84, 95% confidence interval (CI) (0.71, 1.00), P=0.05), 2 year (OR=0.91, 95% CI (0.82, 1.00), P=0.04) and 10 year (OR=0.93, 95% CI (0.85, 1.00), P=0.05) follow-up. Further analysis revealed that MedDietScore differentially affected patients' prognosis according to heart failure phenotype, with short-term impact in HFrEF and HFmrEF patients yet longer positive outcomes in HFpEF and C-reactive protein potentially mediated these relations.

CONCLUSIONS

Mediterranean diet seemed to protect against recurrent cardiac episodes in coronary patients with major ACS complications. Results were more encouraging with regard to patients with preserved left ventricle function. Such findings may possess a cost-effective, supplementary-to-medical, treatment approach in this patient category where evidence concerning their management are inconclusive.European Journal of Clinical Nutrition advance online publication, 23 August 2017; doi:10.1038/ejcn.2017.122.

Management of Heart Failure with Preserved Ejection Fraction: Current Challenges and Future Directions

Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common form of HF in patients older than 65 years. Among elderly women living in the community, HFpEF comprises nearly 90% of incident HF cases. The health and economic impact of HFpEF is at least as great as that of HF with reduced ejection fraction (HFrEF), with similar severity of acute hospitalization rates and substantial mortality. Despite the importance of HFpEF, our understanding of its pathophysiology is incomplete, and optimal treatment remains largely undefined. Unlike the management of HFrEF, there is a paucity of large evidence-based trials demonstrating morbidity and mortality benefit for the treatment of HFpEF. The agents tested in trials to date, which were based upon an incomplete understanding of the pathophysiology of HFpEF, have not been positive. There is an urgent need to understand HFpEF pathophysiology and to focus on developing novel therapeutic targets.

Heart Failure with Preserved Ejection Fraction in Older Adults

Most elderly patients, particularly women, who have heart failure, have a preserved ejection fraction. Patients with this syndrome have severe symptoms of exercise intolerance, frequent hospitalizations, and increased mortality. Despite the importance of heart failure with preserved ejection fraction (HFpEF), the understanding of its pathophysiology is incomplete, and optimal treatment remains largely undefined. Unlike the management of HFrEF, there is a paucity of large evidence-based trials demonstrating morbidity and mortality benefit for the treatment of HFpEF. An update is presented on information regarding pathophysiology, diagnosis, management, and future directions in this important and growing disorder.

Five-year changes in cardiac structure and function in patients with rheumatoid arthritis compared with the general population

BACKGROUND

Patients with rheumatoid arthritis (RA) have increased risk of heart failure with preserved ejection fraction. The development and progression of left ventricular dysfunction before onset of clinical heart failure are unknown. The objective of this study was to evaluate longitudinal changes in cardiac structure and function of patients with RA compared with persons in the general population.

METHODS

A prospective longitudinal study of a population-based cohort of 160 patients with RA and a population-based cohort of 1391 persons without RA (non-RA cohort) was performed. Each participant underwent 2-dimensional, pulsed-wave tissue Doppler echocardiography at baseline and after 4 to 5years of follow-up. Age- and sex-adjusted linear regression models were used to test for differences between the RA and non-RA cohorts in annualized rates of change for echocardiographic parameters.

RESULTS

Mitral A velocity increased more rapidly among the patients with RA than the non-RA cohort (age- and sex-adjusted parameter estimate, 0.030; P<0.001). Correspondingly, the mean mitral inflow E/A ratio decreased faster in the RA cohort than the non-RA cohort (adjusted parameter estimate, -0.096; P<0.001). The left atrial volume index increased at a higher rate in the RA cohort than the non-RA cohort (adjusted parameter estimate, 0.150; P<0.001).

CONCLUSIONS

This pattern of echocardiographic findings confirms previous cross-sectional studies and indicates that subclinical changes in diastolic function occur more rapidly over 5years in RA patients than in the general population. Further research into the mechanisms of myocardial disease in these patients and the relationship with disease activity and treatment is warranted.

Diastolic heart failure: diagnosis and therapy

PURPOSE OF REVIEW

This article focuses on the recent findings in the diagnosis and treatment of diastolic heart failure (DHF) or heart failure with preserved ejection fraction.

RECENT FINDINGS

DHF has become the most common form of heart failure in the population. Although diastolic dysfunction still plays a central role, it is now understood that DHF is a very complex clinical entity with heterogeneous pathophysiology and significant contribution from extracardiac comorbidities. Alterations in ventricular-arterial coupling play a significant role in the impaired hemodynamic response to exercise seen in these patients. The absence of diastolic dysfunction at rest does not exclude the diagnosis of DHF. There has been little to no progress made in identifying evidence-based, effective, and specific treatments for patients with DHF. This may be because of the pathophysiological heterogeneity, incomplete understanding of DHF, and heterogeneity of patients included in clinical trials with variable inclusion criteria.

SUMMARY

The understanding of the phenotypic heterogeneity and multifactorial pathophysiology of DHF may lead to novel therapeutic targets in the future. Currently, the key to the treatment of DHF is aggressive management of contributing factors.

Left atrial changes in early stages of heart failure with preserved ejection fraction

BACKGROUND AND AIM

Increased left atrial (LA) mass was introduced as a compensatory mechanism in heart failure (HF) patients. Furthermore, atrial conduction time and LA emptying fraction is are deteriorated in HF with preserved ejection fraction (HFpEF). The aim of this study was to assess the early LA changes in HFpEF patients.

METHODS

In 79 consecutive patients with HFpEF (age 61±8 years, NYHA class I-III, LV EF ≥45%), a complete 2-dimensional, M-mode, and Doppler echocardiographic study was performed. According to the diastolic dysfunction (DD), patients were divided into three groups: Group I-29 healthy subjects (control group); Group II-HFpEF patients with mild DD; and Group III-HFpEF patients with moderate DD.

RESULTS

The LV mass was increased (P<.05), septal s', lateral s', septal and lateral MAPSE were decreased (P<.05, for all), E/e' ratio was increased (P<.001), LA mass and minimal volume were increased (P<.001, P<.05), LA emptying fraction was decreased (P<.05), and LA dyssynchrony was deteriorated (P<.05) in patients with mild DD compared to controls. These changes were of the same nature in patients with moderate LV DD.

CONCLUSIONS

In early stage of DD, in patients with HFpEF, in addition to LV hypertrophy and compromised LV longitudinal systolic function, the LA emptying fraction is reduced, LA mass and LAV min are increased and LA dyssynchrony is significant, despite normal LA dimensions. These findings suggest early LA function deterioration irrespective of normal cavity measurements, hence a need for optimum therapy.

Association Between 6-Minute Walk Test Distance and Objective Variables of Functional Capacity After Exercise Training in Elderly Heart Failure Patients With Preserved Ejection Fraction: A Randomized Exercise Trial

OBJECTIVE

To evaluate the change in the 6-minute walk test (6-MWT) distance relative to changes in key functional capacity measures after 16 weeks of exercise training in older patients (≥65y) who have heart failure with preserved ejection fraction (HFpEF).

DESIGN

Prospective, randomized, single-blinded (by researchers to patient group) comparison of 2 groups of HFpEF patients.

SETTING

Hospital and clinic records; ambulatory outpatients.

PARTICIPANTS

Participants (N=47) randomly assigned to an attention control (AC) (n=24) or exercise training (ET) (n=23) group.

INTERVENTION

The ET group performed cycling and walking at 50% to 70% of peak oxygen uptake (V˙o₂peak) intensity (3d/wk, 60min each session).

MAIN OUTCOME MEASURES

V˙o₂peak, ventilatory threshold (VT), and 6-MWT distance were measured at baseline and after the 16-week study period.

RESULTS

At follow-up, the 6-MWT distance was higher than at the baseline in both the ET (11%, P=.005) and AC (9%, P=.004) groups. In contrast, V˙o₂peak and VT values increased in the ET group (19% and 11%, respectively; P=.001), but decreased in the AC group at follow-up (2% and 0%, respectively). The change in V˙o₂peak versus 6-MWT distance after training was also not significantly correlated in the AC group (r=.01, P=.95) or in the ET group (r=.13, P=.57). The change in 6-MWT distance and VT (an objective submaximal exercise measure) was also not significantly correlated in the AC group (r=.08, P=.74) or in the ET group (r=.16, P=.50).

CONCLUSIONS

The results of this study challenge the validity of using the 6-MWT as a serial measure of exercise tolerance in elderly HFpEF patients and suggest that submaximal and peak exercise should be determined objectively by VT and V˙o₂peak in this patient population.

One Week of Daily Dosing With Beetroot Juice Improves Submaximal Endurance and Blood Pressure in Older Patients With Heart Failure and Preserved Ejection Fraction

OBJECTIVES

This study sought to determine whether a relatively low single dose or a week-long dosage of dietary inorganic nitrate could improve exercise tolerance in patients with heart failure with preserved ejection fraction (HFpEF).

BACKGROUND

Exercise intolerance is the primary manifestation of HFpEF and is largely due to noncardiac factors that reduce oxygen delivery to active skeletal muscles. A recent study showed improved exercise capacity in patients with HFpEF after a single, acute dose of beetroot juice (BRJ) (12.9 mmol inorganic nitrate) while another recent study showed neutral and negative effects of an organic nitrate.

METHODS

Twenty HFpEF patients (69 ± 7 years of age ) were enrolled in an initial cross-over design comparing a single, acute dose of BRJ (6.1 mmol nitrate) to a nitrate-depleted placebo BRJ. A second phase, 1 week of daily doses, used an all-treated design in which patients consumed BRJ for an average of 7 days. The primary outcome of the study was submaximal aerobic endurance, measured as cycling time to exhaustion at 75% of measured maximal power output.

RESULTS

No adverse events were associated with the intervention. Submaximal aerobic endurance improved 24% after 1 week of daily BRJ dosing (p = 0.02) but was not affected by the single, acute dose of the BRJ compared to placebo. Consumption of BRJ significantly reduced resting systolic blood pressure and increased plasma nitrate and nitrite in both of the dosing schemes.

CONCLUSIONS

One week of daily dosing with BRJ (6.1 mmol inorganic nitrate) significantly improves submaximal aerobic endurance and blood pressure in elderly HFpEF patients.

Advances in the pathophysiology and treatment of heart failure with preserved ejection fraction

PURPOSE OF REVIEW

With the failure of multiple trials to identify a successful therapy for heart failure with preserved ejection fraction (HFpEF), attention has shifted to defining specific phenotypes within the HFpEF spectrum in an effort to develop a targeted approach to treatment. Here we summarize the most recent studies investigating the pathophysiology and clinical features of HFpEF, and discuss recent clinical trials in the context of developing treatments that look toward the underlying cause of this disorder.

RECENT FINDINGS

Advances in basic science and clinical research have further characterized HFpEF, identifying multiple pathophysiological mechanisms that ultimately lead to exercise intolerance and volume overload. The success of small studies focused on specific subsets of the HFpEF population has promoted the concept that there may not be one treatment strategy that can universally be applied to HFpEF.

SUMMARY

HFpEF is associated with significant morbidity and mortality and accounts for approximately half of patients with chronic heart failure. HFpEF is a complex disease, encompassing a diverse cohort of patients and marked by the presence of multiple etiological mechanisms. The failure to develop successful therapies for the management of HFpEF may be because of inadequate standardization of the HFpEF diagnosis, overly broad inclusion criteria and inadequate differentiation of disease subtypes. Given the heterogeneity among patients with HFpEF, much of the current research is focused on understanding of pathophysiology and identifying disease phenotypes that may respond to a targeted treatment approach. Several newer approaches, including neprilysin inhibition and device therapy, offer promise for a new era of HFpEF treatment.

Comparison of Risk of Re-hospitalization, All-Cause Mortality, and Medical Care Resource Utilization in Patients With Heart Failure and Preserved Versus Reduced Ejection Fraction

Because heart failure (HF) with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF) are different clinical entities with differing demographic characteristics, common HF outcomes may occur at different rates. Comparative outcome studies have been equivocal, and studies comparing resource utilization are scant. We used an observational cohort design to study 6,513 patients hospitalized for HF who had an EF measured during the hospitalization and were discharged alive within 30 days. We excluded 677 patients with borderline EF values (41% to 49%) and categorized the remaining as HFrEF (EF ≤40%, n = 2,205) and HFpEF (EF >50%, n = 3,631). Patients were followed for up to 1 year for all-cause re-hospitalization and mortality and annualized medical resource utilization. Patients with HFrEF and HFpEF experienced similar adjusted incidence rates of re-hospitalization, but those with HFrEF had a 39% increased risk of mortality at 30 days (rate ratio 1.39, 95% confidence interval 1.10 to 1.76) and 25% greater risk at 1 year (rate ratio1.25, 95% confidence interval 1.12 to 1.41). After adjustment for covariates, patients with HFpEF incurred significantly more annualized outpatient visits (21.5 vs 20.1, p = 0.002) and emergency room visits (3.24 vs 2.94, p = 0.002) than those with HFrEF, but absolute differences were small. High inpatient and pharmacy utilization did not differ. Our study suggests that whether a patient has HFrEF or HFpEF has little bearing on risk of re-hospitalization or inpatient resource utilization in the year after an HF hospitalization. Both groups experienced high mortality, but those with HFrEF had greater risk. In conclusion, from the standpoint of resource use, HF can be considered a single entity.

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.