Endurance training improves oxygen uptake/demand mismatch, metabolic flexibility and recovery in patients with sickle cell disease

Patients with sickle cell disease (SCD) display lower slope coefficients of the oxygen uptake (V_O2) vs. work rate (W) relationship (delineating an O2 uptake/demand mismatch) and a poor metabolic flexibility. Because endurance training (ET) increases the microvascular network and oxidative enzymes activity including one involved in lipid oxidation, ET might improve the slope coefficient of the V_O2 vs. W curve and the metabolic flexibility of SCD patients. ET may also contribute to improve patient post-exercise cardiopulmonary and metabolic recovery. Fifteen patients with SCD performed a submaximal incremental test on a cycle ergometer before (SIT1) and after (SIT2) 8 weeks of ET. Minute ventilation, ventilation rate (VR), heart rate (HR), V_O2, CO2 production, respiratory exchange ratio, carbohydrate/lipid utilization and partitioning (including %Lipidox) and blood lactate concentration ([lactate]b) were measured during and after SIT1 and SIT2. At baseline, the slope coefficient of the V_O2 vs. W curve positively correlated with total hemoglobin, mean corpuscular hemoglobin and percentage of HbF. After training, the slope coefficient of the V_O2 vs. W curve was significantly higher and the [lactate]b increase was delayed. If patients' energy metabolism apparently relied largely on carbohydrate sources during SIT1, %Lipidox tended to increase at low exercise intensities during SIT2, supporting a training-induced improvement of metabolic flexibility in patients with SCD. Post-exercise recovery of VR, V_E/V_CO2, HR and [lactate]b was faster after training. We concluded that ET in patients with SCD i) ameliorated the oxygen uptake/demand mismatch, ii) blunted the metabolic inflexibility, and iii) improved post-exercise cardiopulmonary and metabolic responses.

Patterns of left ventricular remodeling post-myocardial infarction, determinants, and outcome

AIM

Left ventricular remodeling (LVR) after myocardial infarction (MI) can lead to heart failure, arrhythmia, and death. We aim to describe adverse LVR patterns at 6 months post-MI and their relationships with subsequent outcomes and to determine baseline.

METHODS AND RESULTS

A multicenter cohort of 410 patients (median age 57 years, 87% male) with reperfused MI and at least 3 akinetic LV segments on admission was analyzed. All patients had transthoracic echocardiography performed 4 days and 6 months post-MI, and 214 also had cardiac magnetic resonance imaging performed on day 4. To predict LVR, machine learning methods were employed in order to handle many variables, some of which may have complex interactions. Six months post-MI, echocardiographic increases in LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and LV ejection fraction (LVEF) were 14.1% [interquartile range 0.0, 32.0], 5.0% [- 14.0, 25.8], and 8.7% [0.0, 19.4], respectively. At 6 months, ≥ 15% or 20% increases in LVEDV were observed in 49% and 42% of patients, respectively, and 37% had an LVEF < 50%. The rate of death or new-onset HF at the end of 5-year follow-up was 8.8%. Baseline variables associated with adverse LVR were determined best by random forest analysis and included stroke volume, stroke work, necrosis size, LVEDV, LVEF, and LV afterload, the latter assessed by Ea or Ea/Ees. In contrast, baseline clinical and biological characteristics were poorly predictive of LVR. After adjustment for predictive baseline variables, LV dilation > 20% and 6-month LVEF < 50% were significantly associated with the risk of death and/or heart failure: hazard ratio (HR) 2.12 (95% confidence interval (CI) 1.05-4.43; p = 0.04) and HR 2.68 (95% CI 1.20-6.00; p = 0.016) respectively.

CONCLUSION

Despite early reperfusion and cardioprotective therapy, adverse LVR remains frequent after acute MI and is associated with a risk of death and HF. A machine learning approach identified and prioritized early variables that are associated with adverse LVR and which were mainly hemodynamic, combining LV volumes, estimates of systolic function, and afterload.

Novel Cardiokine GDF3 Predicts Adverse Fibrotic Remodeling After Myocardial Infarction

BACKGROUND

Myocardial infarction (MI) induces a repair response that ultimately generates a stable fibrotic scar. Although the scar prevents cardiac rupture, an excessive profibrotic response impairs optimal recovery by promoting the development of noncontractile fibrotic areas. The mechanisms that lead to cardiac fibrosis are diverse and incompletely characterized. We explored whether the expansion of cardiac fibroblasts after MI can be regulated through a paracrine action of cardiac stromal cells.

METHODS

We performed a bioinformatic secretome analysis of cardiac stromal PW1⁺ cells isolated from normal and post-MI mouse hearts to identify novel secreted proteins. Functional assays were used to screen secreted proteins that promote fibroblast proliferation. The expressions of candidates were subsequently analyzed in mouse and human hearts and plasmas. The relationship between levels of circulating protein candidates and adverse post-MI cardiac remodeling was examined in a cohort of 80 patients with a first ST-segment-elevation MI and serial cardiac magnetic resonance imaging evaluations.

RESULTS

Cardiac stromal PW1⁺ cells undergo a change in paracrine behavior after MI, and the conditioned media from these cells induced a significant increase in the proliferation of fibroblasts. We identified a total of 12 candidates as secreted proteins overexpressed by cardiac PW1⁺ cells after MI. Among these factors, GDF3 (growth differentiation factor 3), a member of the TGF-β (transforming growth factor-β) family, was markedly upregulated in the ischemic hearts. Conditioned media specifically enriched with GDF3 induced fibroblast proliferation at a high level by stimulation of activin-receptor-like kinases. In line with the secretory nature of this protein, we next found that GDF3 can be detected in mice and human plasma samples, with a significant increase in the days after MI. In humans, higher GDF3 circulating levels (measured in the plasma at day 4 after MI) were significantly associated with an increased risk of adverse remodeling 6 months after MI (adjusted odds ratio, 1.76 [1.03-3.00]; P=0.037), including lower left ventricular ejection fraction and a higher proportion of akinetic segments.

CONCLUSIONS

Our findings define a mechanism for the profibrotic action of cardiac stromal cells through secreted cardiokines, such as GDF3, a candidate marker of adverse fibrotic remodeling after MI.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01113268.

Pro-inflammatory cytokine secretion induced by amyloid transthyretin in human cardiac fibroblasts

Extracellular aggregates of wild-type human transthyretin are associated with heart diseases such as wild-type transthyretin (TTR)-derived amyloidosis (ATTR-wt). Due to their strategic location, cardiac fibroblasts act as sentinel cells that sense injury and activate the inflammasome. No studies of the effects of TTR amyloid aggregation on the secretion of inflammatory factors by primary human cardiac fibroblasts (hCFs) have been reported yet. The intracellular internalization of TTR aggregates, which correspond to the early stage of ATTR-wt, were determined using immunofluorescence and Western blotting of cell lysates. A further objective of this study was to analyze the secretion of inflammatory factors by hCFs after analysis of TTR amyloid aggregation using X-MAP® Luminex Assay techniques. We show that TTR aggregates are internalized in hCFs and induce the secretion of both Brain Natriuretic Peptide (BNP) and N-terminal pro B-type Natriuretic Peptide(NT-proBNP). Also, pro-inflammatory mediators such as interleukin-6 (IL-6) and IL-8 are secreted without significant changes in the levels of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). In conclusion, these findings suggest that IL-6 and IL-8 play important roles in the development of ATTR-wt, and indicate that IL-6 in particular could be a potentially important therapeutic target in patients with ATTR-wt.

Increased serum S100A12 levels are associated with higher risk of acute heart failure in patients with type 2 diabetes

AIMS

The hyperglycaemic stress induces the release of inflammatory proteins such as S100A12, one of the endogenous ligands of the receptors for advanced glycation end products (RAGE). Chronic activation of RAGE has multiple deleterious effects in target tissues such as the heart and the vessels by promoting oxidative stress, inflammation by the release of cytokines, macrophages infiltration, and vascular cell migration and proliferation, causing ultimately endothelial cell and cardiomyocyte dysfunction. The aim of our study was to investigate the prognostic value of circulating S100A12 beyond established cardiovascular risk factors (CVRF) for heart failure (HF) and major adverse cardiovascular events (MACE) in a cohort of patients with type 2 diabetes.

METHODS AND RESULTS

Serum S100A12 concentrations were measured at baseline in 1345 type 2 diabetes patients (58% men, 64 ± 11 years) recruited in the SURDIAGENE prospective cohort. Endpoints were the occurrence of acute HF requiring hospitalization (HHF) and MACE. We used a proportional hazard model adjusted for established CVRF (age, sex, duration of diabetes, estimated glomerular filtration rate, albumin/creatinine ratio, history of coronary artery disease) and serum S100A12. During the median follow-up of 84 months, 210 (16%) and 505 (38%) patients developed HHF and MACE, respectively. Baseline serum S100A12 concentrations were associated with an increased risk of HHF [hazard ratio (HR) (95% confidence interval) 1.28 (1.01-1.62)], but not MACE [1.04 (0.90-1.20)]. After adjustment for CVRF, S100A12 concentrations remained significantly associated with an increased risk of HHF [1.29 (1.01-1.65)]. In a sub-analysis, patients with high probability of pre-existing HF [N terminal pro brain natriuretic peptide (NT-proBNP) >1000 pg/mL, n = 87] were excluded. In the remaining 1258 patients, the association of serum S100A12 with the risk of HHF tended to be more pronounced [1.39 (1.06-1.83)]. When including the gold standard HF marker NT-proBNP in the model, the prognostic value of S100A12 for HHF did not reach significance. Youden method performed at 7 years for HHF prediction yielded an optimal cut-off for S100A12 concentration of 49 ng/mL (sensitivity 53.3, specificity 52.2). Compared with those with S100A12 ≤ 49 ng/mL, patients with S100A12 > 49 ng/mL had a significantly increased risk of HHF in the univariate model [HR = 1.58 (1.19-2.09), P = 0.0015] but also in the multivariate model [HR = 1.63 (1.23-2.16), P = 0.0008]. After addition of NT-proBNP to the multivariate model, S100A12 > 49 ng/mL remained associated with an increased risk of HHF [HR = 1.42 (1.07-1.90), P = 0.0160]. However, the addition of S100A12 categories on top of multivariate model enriched by NT-pro BNP did not improve the ability of the model to predict HHF (relative integrated discrimination improvement = 1.9%, P = 0.1500).

CONCLUSIONS

In patients with type 2 diabetes, increased serum S100A12 concentration is independently associated with risk of HHF, but not with risk of MACE. Compared with NT-proBNP, the potential clinical interest of S100A12 for the prediction of HF events remains limited. However, S100A12 could be a candidate for a multimarker approach for HF risk assessment in diabetic patients.

Skeletal Muscle Satellite Cells in Sickle Cell Disease Patients and Their Responses to a Moderate-intensity Endurance Exercise Training Program

We previously demonstrated that 8 weeks of moderate-intensity endurance training is safe and improves muscle function and characteristics of sickle cell disease (SCD) patients. Here, we investigated skeletal muscle satellite cells (SCs) in SCD patients and their responses to a training program. Fifteen patients followed the training program while 18 control patients maintained a normal lifestyle. Biopsies of the vastus lateralis muscle were performed before and after training. After training, the cross-sectional area and myonuclear content in type I fibers were slightly increased in the training patients compared to non-training patients. The SC pool was unchanged in type I fibers while it was slightly decreased in type II fibers in the training patients compared to non-training patients. No necrotic fibers were detected in patients before or after training. Therefore, the slight myonuclear accretion in type I fibers in trained SCD patients may highlight the contribution of SCs to training-induced slight type I fiber hypertrophy without expansion of the SC pool. The low training intensity and the short duration of training sessions could explain the low SC response to the training program. However, the lack of necrotic fibers suggests that the training program seemed to be safe for patients' muscle tissue.

First symptoms and health care pathways in hospitalized patients with acute heart failure: ICPS2 survey. A report from the Heart Failure Working Group (GICC) of the French Society of Cardiology

BACKGROUND

Acute heart failure (AHF) is a common serious condition that contributes to about 5% of all emergency hospital admissions in Europe.

HYPOTHESIS

To assess the type and chronology of the first AHF symptoms before hospitalization and to examine the French healthcare system pathways before, during and after hospitalization.

MATERIAL AND METHODS

A retrospective observational study including patients hospitalized for AHF RESULTS: 793 patients were included, 59.0% were men, 45.6% identified heart failure (HF) as the main cause of hospitalization; 36.0% were unaware of their HF. Mean age was 72.9 ± 14.5 years. The symptoms occurring the most before hospitalization were dyspnea (64.7%) and lower limb edema (27.7%). Prior to hospitalization, 47% had already experienced symptoms for 15 days; 32% of them for 2 months. Referral to hospital was made by the emergency medical assistance service (SAMU, 41.6%), a general practitioner (GP, 22.3%), a cardiologist (19.5%), or the patient (16.6%). The modality of referral depended more on symptom acuteness than on type of symptoms. A sudden onset of AHF symptoms led to making an emergency call or to spontaneously attending an emergency room (ER), whereas cardiologists were consulted when symptoms had already been present for over 15 days. Cardiologists referred more patients to cardiology departments and fewer patients to the ER than general practitioners or the SAMU.

CONCLUSION

This study described the French healthcare system pathways before, during and after hospitalization AHF. AHF clinic network should be developed to provide adequate care for all HF patients and create awareness regarding AHF symptoms.

Measuring physical activity with activity monitors in patients with heart failure: from literature to practice. A position paper from the Committee on Exercise Physiology and Training of the Heart Failure Association of the European Society of Cardiology

The aims of this paper were to provide an overview of available activity monitors used in research in patients with heart failure and to identify the key criteria in the selection of the most appropriate activity monitor for collecting, reporting, and analysing physical activity in heart failure research. This study was conducted in three parts. First, the literature was systematically reviewed to identify physical activity concepts and activity monitors used in heart failure research. Second, an additional scoping literature search for validation of these activity monitors was conducted. Third, the most appropriate criteria in the selection of activity monitors were identified. Nine activity monitors were evaluated in terms of size, weight, placement, costs, data storage, water resistance, outcomes and validation, and cut‐off points for physical activity intensity levels were discussed. The choice of a monitor should depend on the research aims, study population and design regarding physical activity. If the aim is to motivate patients to be active or set goals, a less rigorously tested tool can be considered. On the other hand, if the aim is to measure physical activity and its changes over time or following treatment adjustment, it is important to choose a valid activity monitor with a storage and battery longevity of at least one week. The device should provide raw data and valid cut‐off points should be chosen for analysing physical activity intensity levels. Other considerations in choosing an activity monitor should include data storage location and ownership and the upfront costs of the device.

Muscle structural, energetic and functional benefits of endurance exercise training in sickle cell disease

Sickle cell disease (SCD) patients display skeletal muscle hypotrophy, altered oxidative capacity, exercise intolerance and poor quality of life. We previously demonstrated that moderate-intensity endurance training is beneficial for improving muscle function and quality of life of patients. The present study evaluated the effects of this moderate-intensity endurance training program on skeletal muscle structural and metabolic properties. Of the 40 randomized SCD patients, complete data sets were obtained from 33. The training group (n = 15) followed a personalized moderate-intensity endurance training program, while the non-training (n = 18) group maintained a normal lifestyle. Biopsies of the vastus lateralis muscle and submaximal incremental cycling tests were performed before and after the training program. Endurance training increased type I muscle fiber surface area (P = .038), oxidative enzyme activity [citrate synthase, P < .001; β-hydroxyacyl-CoA dehydrogenase, P = .009; type-I fiber cytochrome c oxidase, P = .042; respiratory chain complex IV, P = .017] and contents of respiratory chain complexes I (P = .049), III (P = .005), IV (P = .003) and V (P = .002). Respiratory frequency, respiratory exchange ratio, blood lactate concentration and rating of perceived exertion were all lower at a given submaximal power output after training vs non-training group (all P < .05). The muscle content of proteins involved in glucose transport and pH regulation were unchanged in the training group relative to the non-training group. The moderate-intensity endurance exercise program improved exercise capacity and muscle structural and oxidative properties. This trial was registered at www.clinicaltrials.gov as #NCT02571088.

Serum tenascin-C is independently associated with increased major adverse cardiovascular events and death in individuals with type 2 diabetes: a French prospective cohort

AIMS/HYPOTHESIS

Tenascin-C (TN-C) is an extracellular matrix glycoprotein highly expressed in inflammatory and cardiovascular (CV) diseases. Serum TN-C has not yet been specifically studied in individuals with type 2 diabetes, a condition associated with chronic low-grade inflammation and increased CV disease risk. In this study, we hypothesised that elevated serum TN-C at enrolment in participants with type 2 diabetes would be associated with increased risk of death and major adverse CV events (MACE) during follow-up.

METHODS

We used a prospective, monocentric cohort of consecutive type 2 diabetes participants (the SURDIAGENE [SUivi Rénal, DIAbète de type 2 et GENEtique] cohort) with all-cause death as a primary endpoint and MACE (CV death, non-fatal myocardial infarction or stroke) as a secondary endpoint. We used a proportional hazard model after adjustment for traditional risk factors and the relative integrated discrimination improvement (rIDI) to assess the incremental predictive value of TN-C for these risk factors.

RESULTS

We monitored 1321 individuals (58% men, mean age 64 ± 11 years) for a median of 89 months. During follow-up, 442 individuals died and 497 had MACE. Multivariate Cox analysis showed that serum TN-C concentrations were associated with an increased risk of death (HR per 1 SD: 1.27 [95% CI 1.17, 1.38]; p < 0.0001) and MACE (HR per 1 SD: 1.23 [95% CI 1.13, 1.34]; p < 0.0001). Using TN-C concentrations on top of traditional risk factors, prediction of the risk of all-cause death (rIDI: 8.2%; p = 0.0006) and MACE (rIDI: 6.7%; p = 0.0014) improved significantly, but modestly.

CONCLUSIONS/INTERPRETATION

In individuals with type 2 diabetes, increased serum TN-C concentrations were independently associated with death and MACE. Therefore, including TN-C as a prognostic biomarker could improve risk stratification in these individuals.

Physiological Evaluation for Endurance Exercise Prescription in Sickle Cell Disease

PURPOSE

Although strenuous exercise may expose sickle cell disease (SCD) patients to risks of vaso-occlusive crisis, evidence suggests that regular endurance exercise may be beneficial. This study aimed to test (i) the safety and usefulness of a submaximal incremental exercise in evaluating physical ability of SCD patients and identify a marker for the management of endurance exercise and (ii) the feasibility of endurance exercise sessions in SCD patients.

METHODS

Twenty adults with SCD (12 men and 8 women) performed a submaximal incremental exercise used to determine the first lactate threshold (LT1) and stopped as soon as blood lactate concentration ([lactate]b) reached ≥4 mmol·L. Fifteen of those patients (8 men and 7 women) also performed three 30-min endurance exercise sessions at ~2.5 mmol·L of [lactate]b on separate occasions.

RESULTS

LT1 occurred at 47 ± 3 and 33 ± 3 W for men and women, respectively, demonstrating the extreme deconditioning and, thus, low physical ability of adult SCD patients. During endurance exercise, peripheral oxygen saturation and [lactate]b most often remained stable and within acceptable ranges.

CONCLUSIONS

The proposed strategy of submaximal incremental exercise allowed safe determination of LT1, an important parameter of patients' physical ability. The study also demonstrated the feasibility and safety of individually tailored endurance exercises at ~2.5 mmol·L of [lactate]b. These latter results suggest that endurance training programs may be considered for adult SCD patients and that the method proposed here may be helpful in that regard.

P1272 Echocardiographic evaluation of left ventricular filling pressure in patients with heart failure with preserved ejection fraction : usefulness of inferior vena cava measurement

Methods

Invasive hemodynamics and echocardiographic measurements were documented in 132 consecutive patients referred to our centre with dyspnea, left ventricular ejection fraction (LVEF) ≥50%, and suspected pulmonary hypertension on a previous echocardiogram. Echocardiographic measurements of mitral flow (E and A wave velocities), the E/e’ratio, indexed left atrial volume (LAV), tricuspid regurgitation velocity (TRV) and the IVC size and collapsibility were obtained. Increased LVFP was defined by an invasive pulmonary artery wedge pressure (PAWP) &gt; 15 mmHg.

Results

In sinus rhythm patients, the sum of the criteria (E/e’ ratio &gt; 14, TRV &gt; 2.8 m/s and indexed LAV &gt; 34 ml/m²) ≥ 2 had a positive predictive value (PPV) of 63% for PAWP &gt; 15 mmHg, whereas a dilated (&gt; 2.1 cm) and/or non collapsible (≤ 50%) IVC had a PPV of 83%. In atrial fibrillation (AF), a dilated and/or non collapsible IVC had an 86% PPV for increased LVFP. We found that 16% of patients with elevated LVFP were more accurately classified using IVC evaluation than using the current guidelines criteria (net reclassification improvement = 0.25, p &lt;0.05).

Conclusion

Echographic measurements of the IVC size and collapsibility outperformed the classic 2016 recommendations algorithm to evaluate LVFP in sinus rhythm patients with suspected HFpEF. The IVC study was also valuable in patients with atrial fibrillation.

Physical activity for patients with heart failure: Position paper from the heart failure (GICC) and cardiac rehabilitation (GERS-P) Working Groups of the French Society of Cardiology

Physical activity is important in heart failure to improve functional capacity, quality of life and prognosis, and is a class IA recommendation in the European Society of Cardiology guidelines (Ponikowski et al., 2016). The benefits of exercise training are widely recognized. Cardiac rehabilitation centres offer tailored exercise training to patients with heart failure, as part of specialized multidisciplinary care, alongside pharmacological treatment optimization and patient education. After cardiac rehabilitation, maintenance of regular physical activity long term is essential, as the benefits of exercise training vanish within a few weeks. Unfortunately, only 10% of patients benefit from a cardiac rehabilitation programme after hospitalization for acute heart failure, and the majority of patients do not pursue long-term physical activity. In this paper, two Working Groups of the French Society of Cardiology (the heart failure group [Groupe Insuffisance Cardiaque et Cardiomyopathies; GICC] and the cardiac rehabilitation group [Groupe Exercice Réadaptation Sport et Prévention; GERS-P]) discuss the obstacles to broader access to cardiac rehabilitation centres, and propose ways to improve the diffusion of cardiac rehabilitation programmes and encourage long-term adherence to physical activity.

Prognostic value of plasma MR-proADM vs NT-proBNP for heart failure in people with type 2 diabetes: the SURDIAGENE prospective study

AIMS/HYPOTHESIS

N-terminal pro-B-type natriuretic peptide (NT-proBNP) is the gold standard prognostic biomarker for diagnosis and occurrence of heart failure. Here, we compared its prognostic value for the occurrence of congestive heart failure with that of plasma mid-region pro-adrenomedullin (MR-proADM), a surrogate for adrenomedullin, a vasoactive peptide with vasodilator and natriuretic properties, in people with type 2 diabetes.

METHODS

Plasma MR-proADM concentration was measured in baseline samples of a hospital-based cohort of consecutively recruited participants with type 2 diabetes. Our primary endpoint was heart failure requiring hospitalisation.

RESULTS

We included 1438 participants (age 65 ± 11 years; 604 women and 834 men). Hospitalisation for heart failure occurred during follow-up (median 64 months) in 206 participants; the incidence rate of heart failure was 2.5 (95% CI 2.2, 2.9) per 100 person-years. Plasma concentrations of MR-proADM and NT-proBNP were significantly associated with heart failure in a Cox multivariable analysis model when adjusted for age, diabetes duration, history of coronary heart disease, proteinuria and baseline eGFR (_adjHR [95%CI] 1.83 [1.51, 2.21] and 2.20 [1.86, 2.61], respectively, per 1 SD log₁₀ increment, both p < 0.001). MR-proADM contributed significant supplementary information to the prognosis of heart failure when we considered the clinical risk factors (integrated discrimination improvement [IDI, mean ± SEM] 0.021 ± 0.007, p = 0.001) (Table 3). Inclusion of NT-proBNP in the multivariable model including MR-proADM contributed significant complementary information on prediction of heart failure (IDI [mean ± SEM] 0.028 ± 0.008, p < 0.001). By contrast, MR-proADM did not contribute supplementary information on prediction of heart failure in a model including NT-proBNP (IDI [mean ± SEM] 0.003 ± 0.003, p = 0.27), with similar results for heart failure with reduced ejection fraction and preserved ejection fraction.

CONCLUSIONS/INTERPRETATION

MR-proADM is a prognostic biomarker for heart failure in people with type 2 diabetes but gives no significant complementary information on prediction of heart failure compared with NT-proBNP.

Pulmonary hypertension in chronic heart failure: definitions, advances, and unanswered issues

Pulmonary hypertension (PH) is a common and severe complication of heart failure (HF). Consequently, HF is the leading cause of PH. For many years, specialists have attempted to better understand the pathophysiology of PH in HF, to define its prevalence and its impact on prognosis in order to improve the therapeutic management of these patients. Nowadays, despite the recent guidelines published on the subject, several points remain unclear or debated, and until now, no study has demonstrated the efficacy of any treatment. The aim of this review is to report the evolution of the concepts on post‐capillary PH (diagnosis, prevalence, prognosis, and therapeutics). The main issues are raised, focusing especially on the link between structural alterations and haemodynamic abnormalities, to discuss the possible reasons for treatment failures and future potential targets.

Extracellular Calpain/Calpastatin Balance Is Involved in the Progression of Pulmonary Hypertension

Excessive growth of pulmonary arterial (PA) smooth muscle cells (SMCs) is a major component of PA hypertension (PAH). The calcium-activated neutral cysteine proteases calpains 1 and 2, expressed by PASMCs, contribute to PH but are tightly controlled by a single specific inhibitor, calpastatin. Our objective was to investigate calpastatin during pulmonary hypertension (PH) progression and its potential role as an intracellular and/or extracellular effector. We assessed calpains and calpastatin in patients with idiopathic PAH and mice with hypoxic or spontaneous (SM22-5HTT(+) strain) PH. To assess intracellular and extracellular roles for calpastatin, we studied effects of the calpain inhibitor PD150606 on hypoxic PH in mice with calpastatin overexpression driven by the cytomegalovirus promoter (CMV-Cast) or C-reactive protein (CRP) promoter (CRP-Cast), inducing increased calpastatin production ubiquitously and in the liver, respectively. Chronically hypoxic and SM22-5HTT(+) mice exhibited increased lung calpastatin and calpain 1 and 2 protein levels and activity, both intracellularly and extracellularly. Prominent calpastatin and calpain immunostaining was found in PASMCs of remodeled vessels in mice and patients with PAH, who also exhibited increased plasma calpastatin levels. CMV-Cast and CRP-Cast mice showed similarly decreased PH severity compared with wild-type mice, with no additional effect of PD150606 treatment. In cultured PASMCs from wild-type and CMV-Cast mice, exogenous calpastatin decreased cell proliferation and migration with similar potency as PD150606 and suppressed fibronectin-induced potentiation. These results indicate that calpastatin limits PH severity via extracellular mechanisms. They suggest a new approach to the development of treatments for PH.

Apical left ventricular myocardial dysfunction is an early feature of cardiac involvement in myotonic dystrophy type 1

INTRODUCTION

Left ventricular (LV) dysfunction is a major prognostic determinant in myotonic dystrophy type 1 (DM1). Therefore, markers of early-stage LV impairment may be useful. The aim of this study was to evaluate 2D echocardiographic LV strain in a cohort of DM1 patients with preserved left ventricular ejection fraction (LVEF) and to compare the results with matched controls.

METHODS

This prospective single-center study included 33 consecutive DM1 patients between February 2014 and February 2015. Mean age was 38.2±12.9 years, and 17 (52%) were males. Exclusion criteria were LVEF <55%, QRS >120 milliseconds, history of atrial fibrillation, and presence of a pacemaker with ventricular pacing. DM1 patients were matched to healthy controls according to sex and age.

RESULTS

DM1 patients showed significant impairment of global longitudinal strain (GLS) as compared to controls (-18.0±1.9 vs -19.1±2.4; P=.03), characterized by a marked alteration at the apex (-20.0±3.3 vs -22.7±3.1; P<.001). DM1 patients had also global radial strain impairment (20.0±9.8 vs 27.5±14.9; P=.024) compared to controls while global circumferential strain was not statistically different between groups (P=.94). Intra- and inter-observer analysis showed good reproducibility of GLS.

CONCLUSION

Despite preserved LVEF, DM1 patients exhibited significantly altered LV GLS, particularly at the apex, as compared with controls. The detection of impaired myocardial deformation at early stages of the disease might help to screen high-risk patients who need closer follow-up.

Arterio-venous fistula for automated red blood cells exchange in patients with sickle cell disease: Complications and outcomes

Erythrocytapheresis (ER) can improve outcome in patients with sickle cell disease (SCD). A good vascular access is required but frequently it can be difficult to obtain for sickle cell patients. Arterio-venous fistulas (AVFs) have been suggested for ER in SCD supported by limited evidence. We report the largest cohort of ER performed with AVFs from three French SCD reference centers. Data of SCD patients undergoing ER with AVFs in the French SCD reference center were retrospectively collected. The inclusion criteria were: SS or Sβ-Thalassemia and AVF surgery for ER. SCD-related complications, transfusion history, details about AVF surgical procedure, echocardiographic data before and after AVF, AVF-related surgical and hemodynamical complications were collected. Twenty-six patients (mean age 20.5 years, mean follow-up 68 months [11-279]) were included. Twenty-three patients (88.5%) required central vascular access before AVF. Fifteen AVFs (58%) were created on the forearm and 11 (42%) on the arm. Nineteen patients (73%) had stenotic, thrombotic or infectious AVF complications. A total of 0.36 stenosis per 1,000 AVF days, 0.37 thrombosis per 1,000 AVF days and 0.078 infections per 1.000 AVF days were observed. The mean AVF lifespan was 51 months [13-218]. One patient with severe pulmonary hypertension worsened after AVF creation and died. We report the first series of SCD patients with AVF for ER, demonstrating that AVFs could be considered as a potential vascular access for ER. Patients with increased risk for hemodynamic intolerance of AVFs must be carefully identified, so that alternative vascular accesses can be considered. Am. J. Hematol. 92:136-140, 2017. © 2016 Wiley Periodicals, Inc.

ANGPTL2 is associated with an increased risk of cardiovascular events and death in diabetic patients

AIMS/HYPOTHESIS

A high serum angiopoietin-like 2 (ANGPTL2) concentration is an independent risk factor for developing diabetes and is associated with insulin resistance and atherosclerosis. In this work, we have examined the impact of serum ANGPTL2 on improving cardiovascular (CV) risk stratification in patients with type 2 diabetes.

METHODS

A prospective, monocentric cohort of consecutive type 2 diabetes patients (the SURDIAGENE cohort; total of 1353 type 2 diabetes patients; 58% men, mean ± SD age 64 ± 11 years) was followed for a median of 6.0 years for death as primary endpoint and major adverse CV events (MACE; i.e. CV death, myocardial infarction or stroke) as a secondary endpoint. Patients with end-stage renal disease, defined as a requirement for dialysis or a history of kidney transplantation, were excluded. Patients were grouped into quartiles according to ANGPTL2 concentrations at inclusion: <11.2 (Q1), 11.2-14.7 (Q2), 14.8-19.5 (Q3) or >19.5 (Q4) ng/ml.

RESULTS

During follow up, 367 patients (representing 4.5% of the total person-years) died and 290 patients (representing 3.7% of the total person-years) presented with MACE. Both the survival and MACE-free survival rates were significantly different between ANGPTL2 quartiles (logrank 82.12, p < 0.0001 for death; and logrank 65.14, p < 0.0001 for MACE). Patients with ANGPTL2 concentrations higher than 19.5 ng/ml (Q4) had a significantly higher risk of death and MACE than those with ANGPTL2 levels of 19.5 ng/ml or less (Q1-3) (HR for death 2.44 [95% CI 1.98, 3.00], p < 0.0001; HR for MACE 2.43 [95% CI 1.92, 3.06], p < 0.0001) after adjustment for sex, age and established CV risk factors. Using ANGPTL2 concentrations, prediction of the risk of mortality, as assessed by integrated discrimination improvement (IDI), was significantly improved (IDI 0.006 ± 0.002, p = 0.0002).

CONCLUSIONS/INTERPRETATION

In patients with type 2 diabetes, serum ANGPTL2 concentrations were independently associated with death and MACE. Therefore, ANGPTL2 is a promising candidate biomarker for improving risk stratification in type 2 diabetes patients, and may prove to be a valuable therapeutic target.

Apnea-hypopnea and desaturations in heart failure with reduced ejection fraction: Are we aiming at the right target?

BACKGROUND

Sleep disordered breathing (SDB) is common in patients with heart failure with reduced ejection fraction (HFrEF). An increased apnea-hypopnea index (AHI) is associated with poor outcomes. We examined whether an analysis of nocturnal desaturations (NDs) can improve the risk stratification.

METHODS

Three-hundred seventy-six consecutive patients with stable chronic HFrEF and LVEF ≤ 45% were prospectively screened using polygraphy. Sleep apnea (SA) was defined as an AHI ≥ 15. The mean age was 59 ± 13 years, the mean LVEF was 30 ± 6%, and the median AHI was 18 [IQR: 9.33). The composite end-point of death, heart transplantation or LV assistance occurred in 98 patients (26%) within 3 years. Minimal oxygen saturation (MOS) during sleep, the number of desaturations <90%/h and the time spent with oxygen saturation <90% were significantly associated with adverse events (adjusted HR 1.25 [1.03-1.52], 1.25 [1.03-1.53], and 1.28 [1.04-1.59]), whereas the AHI was not (1.10 [0.86-1.39]). The best MOS cut-off value for poor outcomes was ≤ 88%. The patients with an MOS ≤ 88% had a significantly higher event rate (31.9%) than those with an MOS >88% (15.6%; p<0.01). The risk assessment using an MOS of ≤ 88% in addition to established prognostic markers yielded a net reclassification index (NRI) of nearly 6% and was particularly useful in the subgroup of patients with events (NRI: 8.4%).

CONCLUSIONS

In HFrEF patients, ND ≤ 88% appears to be predictive of adverse events, independent of the presence of SA. This suggests that the risk assessment in HFrEF should also include ND in top of AHI.

Calpastatin overexpression impairs postinfarct scar healing in mice by compromising reparative immune cell recruitment and activation

The activation of the calpain system is involved in the repair process following myocardial infarction (MI). However, the impact of the inhibition of calpain by calpastatin, its natural inhibitor, on scar healing and left ventricular (LV) remodeling is elusive. Male mice ubiquitously overexpressing calpastatin (TG) and wild-type (WT) controls were subjected to an anterior coronary artery ligation. Mortality at 6 wk was higher in TG mice (24% in WT vs. 44% in TG, P < 0.05) driven by a significantly higher incidence of cardiac rupture during the first week post-MI, despite comparable infarct size and LV dysfunction and dilatation. Calpain activation post-MI was blunted in TG myocardium. In TG mice, inflammatory cell infiltration and activation were reduced in the infarct zone (IZ), particularly affecting M2 macrophages and CD4(+) T cells, which are crucial for scar healing. To elucidate the role of calpastatin overexpression in macrophages, we stimulated peritoneal macrophages obtained from TG and WT mice in vitro with IL-4, yielding an abrogated M2 polarization in TG but not in WT cells. Lymphopenic Rag1(-/-) mice receiving TG splenocytes before MI demonstrated decreased T-cell recruitment and M2 macrophage activation in the IZ day 5 after MI compared with those receiving WT splenocytes. Calpastatin overexpression prevented the activation of the calpain system after MI. It also impaired scar healing, promoted LV rupture, and increased mortality. Defective scar formation was associated with blunted CD4(+) T-cell and M2-macrophage recruitment.

Reconciling depressed Ca2+ sparks occurrence with enhanced RyR2 activity in failing mice cardiomyocytes

Abnormalities in cardiomyocyte Ca2+ handling contribute to impaired contractile function in heart failure (HF). Experiments on single ryanodine receptors (RyRs) incorporated into lipid bilayers have indicated that RyRs from failing hearts are more active than those from healthy hearts. Here, we analyzed spontaneous Ca2+ sparks (brief, localized increased in [Ca2+]i) to evaluate RyR cluster activity in situ in a mouse post-myocardial infarction (PMI) model of HF. The cardiac ejection fraction of PMI mice was reduced to ∼30% of that of sham-operated (sham) mice, and their cardiomyocytes were hypertrophied. The [Ca2+]i transient amplitude and sarcoplasmic reticulum (SR) Ca2+ load were decreased in intact PMI cardiomyocytes compared with those from sham mice, and spontaneous Ca2+ sparks were less frequent, whereas the fractional release and the frequency of Ca2+ waves were both increased, suggesting higher RyR activity. In permeabilized cardiomyocytes, in which the internal solution can be controlled, Ca2+ sparks were more frequent in PMI cells (under conditions of similar SR Ca2+ load), confirming the enhanced RyR activity. However, in intact cells from PMI mice, the Ca2+ sparks frequency normalized by the SR Ca2+ load in that cell were reduced compared with those in sham mice, indicating that the cytosolic environment in intact cells contributes to the decrease in Ca2+ spark frequency. Indeed, using an internal "failing solution" with less ATP (as found in HF), we observed a dramatic decrease in Ca2+ spark frequency in permeabilized PMI and sham myocytes. In conclusion, our data show that, even if isolated RyR channels show more activity in HF, concomitant alterations in intracellular media composition and SR Ca2+ load may mask these effects at the Ca2+ spark level in intact cells. Nonetheless, in this scenario, the probability of arrhythmogenic Ca2+ waves is enhanced, and they play a potential role in the increase in arrhythmia events in HF patients.

Usefulness of tissue Doppler imaging for assessing left ventricular filling pressure in patients with stable severe systolic heart failure

The ratio of early transmitral blood flow velocity over tissue Doppler early diastolic mitral annulus velocity (E/e') was found unreliable for estimating pulmonary capillary wedge pressure (PCWP) in patients with decompensated systolic heart failure (HF). The objective of this study was to test its reliability in stable HF. Therefore, 130 consecutive patients with a left ventricular (LV) ejection fraction of <35% and stable HF underwent right-sided cardiac catheterization and transthoracic echocardiography with measurement of transmitral flow velocities (E, A) and mitral annulus velocities during systole (s') and diastole (e'). Mean age was 56 ± 11 years and mean LV ejection fraction was 28 ± 8%; 48% had PCWP of >15 mm Hg. E/e'septal correlated more strongly with PCWP (r = 0.53) compared with E/e'lateral (r = 0.41) and E/e'mean (r = 0.50; all p values <0.001). The area under the receiver operating characteristic curve (AUC) of E/e' ratios for PCWP estimation was 0.79 (95% confidence interval [CI] 0.70 to 0.87) for E/e'septal, 0.72 (95% CI 0.63 to 0.82) for E/elateral, and 0.79 (95% CI 0.70 to 0.87) for E/emean (all p values <0.0001). AUCs of E/eseptal and E/emean did not vary with s'septal, QRS width, or resynchronization. Using a cutoff of 8, negative predictive value of E/e'septal was 89% and negative likelihood ratio of 0.15. E/e'lateral showed good diagnostic performance only in patients with s'lateral of >4.5 cm/s (n = 77, 59%; AUC = 0.82; 95% CI 0.71 to 0.92; s'lateral of ≤4.5 cm/s: AUC = 0.54; 95% CI 0.38 to 0.70; p = 0.005). In conclusion, e' is useful for estimating LV filling pressure in stable severe systolic HF. E/e'septal showed good diagnostic performance for detecting normal filling pressures.

FKBP12.6 overexpression does not protect against remodelling after myocardial infarction

Reducing the open probability of the ryanodine receptor (RyR) has been proposed to have beneficial effects in heart failure. We investigated whether conditional FKBP12.6 overexpression at the time of myocardial infarction (MI) could improve cardiac remodelling and cell Ca(2+) handling. Wild-type (WT) mice and mice overexpressing FKBP12.6 (Tg) were studied on average 7.5 ± 0.2 weeks after MI and compared with sham-operated mice for in vivo, myocyte function and remodelling. At baseline, unloaded cell shortening in Tg was not different from WT. The [Ca(2+)](i) transient amplitude was similar, but sarcoplasmic reticulum (SR) Ca(2+) content was larger in Tg, suggesting reduced fractional release. Spontaneous spark frequency was similar despite the increased SR Ca(2+) content, consistent with a reduced RyR channel open probability in Tg. After MI, left ventricular dilatation and myocyte hypertrophy were present in both groups, but more pronounced in Tg. Cell shortening amplitude was unchanged with MI in WT, but increased with MI in Tg. The amplitude of the [Ca(2+)](i) transient was not affected by MI in either genotype, but time to peak was increased; this was most pronounced in Tg. The SR Ca(2+) content and Na(+)- Ca(2+) exchanger function were not affected by MI. Spontaneous spark frequency was increased significantly after MI in Tg, and larger than in WT (at 4 Hz, 2.6 ± 0.4 sparks (100 μm)(-1) s(-1) in Tg MI versus 1.6 ± 0.2 sparks (100 μm)(-1) s(-1) in WT MI; P < 0.05). We conclude that FKPB12.6 overexpression can effectively reduce RyR open probability with maintained cardiomyocyte contraction. However, this approach appears insufficient to prevent and reduce post-MI remodelling, indicating that additional pathways may need to be targeted.