Case report: Serious unexpected vascular events in two patients with lymphocytic variant hypereosinophilic syndrome

Background

Lymphocytic-variant hypereosinophilic syndrome (L-HES) is a form of reactive hypereosinophilia, most commonly associated with interleukin-5 over-production by clonal, most commonly CD3-CD4+CD2hiCD5hiCD45RO+ T-cells. Patients often present with predominant cutaneous and soft-tissue manifestations, while cardiovascular involvement is uncommon.

Methods

We reviewed the medical files of two L-HES patients followed in our center who developed serious vascular complications and performed a literature review for similar cases.

Results

Patient 1, a 52-year-old female, presented with an ischemic stroke secondary to left middle cerebral artery dissection after 10 years of indolent L-HES. Blood eosinophilia was controlled with oral corticosteroids (OCS), but OCS-tapering attempts with hydroxyurea and pegylated interferon failed, prompting the introduction of mepolizumab with rapid normalization. Patient 2, a 62-year-old female, had been asymptomatic for 10 years without treatment when a NSTEMI occurred, due to coronary artery occlusion secondary to a large cauliflower-aneurysm of the proximal aorta and aneurysmal dilatation of several coronary arteries, requiring semi-urgent surgical management. Aortic wall staining for eosinophil major basic protein showed eosinophils in the adventitia. Blood eosinophilia was controlled with OCS.

Conclusions

Patients with apparently clinically benign L-HES may develop arterial complications, consisting in dissection and/or aneurysm dilatation of medium-to-large vessels with serious consequences. The value of performing regular vascular imaging and monitoring during follow-up has yet to be determined.

Right Heart Adaptation to Exercise in Pulmonary Hypertension: An Invasive Hemodynamic Study

BACKGROUND

Right heart failure (RHF) is associated with a dismal prognosis in patients with pulmonary hypertension (PH). Exercise right heart catheterization may unmask right heart maladaptation as a sign of RHF. We sought to (1) define the normal limits of right atrial pressure (RAP) increase during exercise; (2) describe the right heart adaptation to exercise in PH owing to heart failure with preserved ejection fraction (PH-HFpEF) and in pulmonary arterial hypertension (PAH); and (3) identify the factors associated with right heart maladaptation during exercise.

METHODS AND RESULTS

We analyzed rest and exercise right heart catheterization from patients with PH-HFpEF and PAH. Right heart adaptation was described by absolute or cardiac output (CO)-normalized changes of RAP during exercise. Individuals with noncardiac dyspnea (NCD) served to define abnormal RAP responses (>97.5th percentile). Thirty patients with PH-HFpEF, 30 patients with PAH, and 21 patients with NCD were included. PH-HFpEF were older than PAH, with more cardiovascular comorbidities, and a higher prevalence of severe tricuspid regurgitation (P < .05). The upper limit of normal for peak RAP and RAP/CO slope in NCD were >12 mm Hg and ≥1.30 mm Hg/L/min, respectively. PH-HFpEF had higher peak RAP and RAP/CO slope than PAH (20 mm Hg [16-24 mm Hg] vs 12 mm Hg [9-19 mm Hg] and 3.47 mm Hg/L/min [2.02-6.19 mm Hg/L/min] vs 1.90 mm Hg/L/min [1.01-4.29 mm Hg/L/min], P < .05). A higher proportion of PH-HFpEF had RAP/CO slope and peak RAP above normal (P < .001). Estimated stressed blood volume at peak exercise was higher in PH-HFpEF than PAH (P < .05). In the whole PH cohort, the RAP/CO slope was associated with age, the rate of increase in estimated stressed blood volume during exercise, severe tricuspid regurgitation, and right atrial dilation.

CONCLUSIONS

Patients with PH-HFpEF display a steeper increase of RAP during exercise than those with PAH. Preload-mediated mechanisms may play a role in the development of exercise-induced RHF.

Pulmonary artery wedge pressure and left ventricular end-diastolic pressure during exercise in patients with dyspnoea

Background

Pulmonary artery wedge pressure (PAWP) during exercise, as a surrogate for left ventricular (LV) end-diastolic pressure (EDP), is used to diagnose heart failure with preserved ejection fraction (HFpEF). However, LVEDP is the gold standard to assess LV filling, end-diastolic PAWP (PAWPED) is supposed to coincide with LVEDP and mean PAWP throughout the cardiac cycle (PAWPM) better reflects the haemodynamic load imposed on the pulmonary circulation. The objective of the present study was to determine precision and accuracy of PAWP estimates for LVEDP during exercise, as well as the rate of agreement between these measures.

Methods

46 individuals underwent simultaneous right and left heart catheterisation, at rest and during exercise, to confirm/exclude HFpEF. We evaluated: linear regression between LVEDP and PAWP, Bland-Altman graphs, and the rate of concordance of dichotomised LVEDP and PAWP ≥ or < diagnostic thresholds for HFpEF.

Results

At peak exercise, PAWPM and LVEDP, as well as PAWPED and LVEDP, were fairly correlated (R2>0.69, p<0.01), with minimal bias (+2 and 0 mmHg respectively) but large limits of agreement (±11 mmHg). 89% of individuals had concordant PAWP and LVEDP ≥ or <25 mmHg (Cohen's κ=0.64). Individuals with either LVEDP or PAWPM ≥25 mmHg showed a PAWPM increase relative to cardiac output (CO) changes (PAWPM/CO slope) >2 mmHg·L-1·min-1.

Conclusions

During exercise, PAWP is accurate but not precise for the estimation of LVEDP. Despite a good rate of concordance, these two measures might occasionally disagree.

Pediatric pulmonary arterial hypertension due to a novel homozygous GDF2 missense variant affecting BMP9 processing and activity

Pulmonary arterial hypertension (PAH) is a rare and severe disorder characterized by progressive pulmonary vasculopathy. Growth differentiation factor (GDF)2 encodes the pro-protein bone morphogenetic protein (BMP) 9, activated after cleavage by endoproteases into an active mature form. BMP9, together with BMP10, are high-affinity ligands of activin receptor-like kinase 1 (ALK1) and BMP receptor type II (BMPR2). GDF2 mutations have been reported in idiopathic PAH with most patients being heterozygous carriers although rare homozygous cases have been described. The link between PAH occurrence and BMP9 or 10 expression level is still unclear. In this study, we describe a pediatric case of PAH also presenting with telangiectasias and epistaxis. The patient carries the novel homozygous GDF2 c.946A > G mutation, replacing the first arginine of BMP9's cleavage site (R316) by a glycine. We show that this mutation leads to an absence of circulating mature BMP9 and mature BMP9-10 heterodimers in the patient's plasma although pro-BMP9 is still detected at a similar level as controls. In vitro functional studies further demonstrated that the mutation R316G hampers the correct processing of BMP9, leading to the secretion of inactive pro-BMP9. The heterozygous carriers of the variant were asymptomatic, similarly to previous reports, reinforcing the hypothesis of modifiers preventing/driving PAH development in heterozygous carriers.

Lung diffusion capacity correlates with pre-implant pulmonary hypertension and predicts outcome after LVAD implantation

AIMS

Diffusing capacity of the lung for carbon monoxide (DLCO ) reduction is common in heart failure (HF) and is associated with a worse prognosis. Correlations between DLCO and pulmonary hypertension (PH) are unclear, and published data are conflicting; it has been shown that DLCO impairment may persist or even worsen after normalization of pulmonary pressures following left ventricle assist device (LVAD) implantation, maybe reflecting persistent pulmonary damage. We aimed to investigate the impact of pre-implant DLCO and central haemodynamics on outcome in patients with advanced HF implanted with a LVAD.

METHODS AND RESULTS

We retrospectively analysed pre-implant and post-implant data from 42 patients implanted with a LVAD at our institution. Out of 42 patients, 35 had post-capillary PH before implantation, including 17 with combined post- and pre-capillary PH (Cpc-PH). Median DLCO was 59% (IQR 47-68%), and it inversely correlated with pulmonary vascular resistance (PVR) (P 0.037) and diastolic pulmonary gradient (DPG) (P 0.042). Compared with baseline, LVAD resulted in improvement in LV diameter (LVDd, P < 0.001), mitral regurgitation (P 0.022), and PH (mPAP 24 vs. 36 mmHg, P < 0.001; PAWP 12 vs. 23 mmHg, P 0.001; pulmonary artery compliance, CPA 3.1 vs. 1.9 mL/mmHg, P 0.021). Lower DLCO and Cpc-PH at baseline were associated with a better LV reverse remodelling post-implantation (P 0.027 for LVDd) but also with a smaller gain in CPA (P 0.049).

CONCLUSIONS

Before LVAD implantation, DLCO impairment is associated with higher PVR and DPG, suggesting that it might be an expression of persistent pulmonary damage occurring in Cpc-PH. After LVAD implantation, both LV dimension and haemodynamics improve. Lower pre-implant DLCO is associated with better LV reverse remodelling.

Summary of 2020 ESC guidelines on non-STE ACS, adult congenital heart disease, sports cardiology and atrial fibrillation

During the ESC congress in September 2020, the new ESC guidelines were presented and are available on the ESC website. The new guidelines describe management recommendations on following cardiovascular diseases: non-STE ACS, adult congenital heart disease, sports cardiology and atrial fibrillation. The present document gives a summary of these guidelines and highlights the most important recommendations and changes in the management of these diseases. It will help to increase awareness about the new guidelines and may stimulate to consult the full document for specific items. Ultimately, the authors hope that this document will enhance implementation of new ESC guidelines in daily clinical practice.

An updated meta-analysis of hemodynamics markers of prognosis in patients with pulmonary hypertension due to left heart disease

Background

Pulmonary hypertension (PH) is associated with a poor prognosis in patients with left heart disease (LHD). Several hemodynamic variables have been shown to predict outcome, including pulmonary vascular resistance (PVR), pulmonary artery compliance (PAC), and the diastolic pressure gradient (DPG). We sought to provide an updated analysis on the association of these variables with prognosis in PH-LHD.

Methods

We performed a systematic literature review including studies reporting association measurements between DPG and/or PVR and/or PAC and death in PH-LHD patients. These hemodynamic variables were extracted to estimate the pooled hazard ratio (HR) of adverse outcome for each one, and cumulative meta-analysis was performed to investigate temporal trends in the effects reported in the literature as well as the impact of sample size.

Results

17 articles were identified, including 9716 patients with LHD, heterogeneous in terms of age, sex, and etiology of cardiac disease. In this large population, we found that PVR (HR, 1.09; 95% CI: 1.06–1.12), DPG (HR, 1.02; 95% CI: 1.01–1.02) and PAC (HR, 0.73; 95% CI: 0.76–0.81) were associated with an increased risk of adverse outcome, albeit with a less solid performance of DPG (Figure 1). Similar results were found when hemodynamic variables were analyzed according to the thresholds commonly applied in clinical practice, or subdividing cohorts according to the underlying LHD (either heart failure with preserved or reduced left ventricular ejection fraction, or valvular heart disease). Furthermore, cumulative metanalysis indicated that these results are consistently stable since 2018 (Figure 2).

Conclusions

Despite the heterogeneity of PH-LHD group and the intrinsic limitations of each variable, PVR, DPG, and PAC have an established prognostic value in PH-LHD. The strongest correlation with PVR and PAC supports their use in defining disease severity and identifying a subgroup of patients at higher risk of adverse outcome. We believe that these results are consistent through the years and unlikely to change with the addition of further studies.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship.

A meta-analysis of exercise hemodynamics in heart failure with preserved ejection fraction: the relevance of PAWP/CO slope

Background

Exercise right heart catheterization (RHC) is considered the gold-standard test to diagnose heart failure with preserved ejection fraction (HFpEF). However, exercise RHC is an insufficiently standardized technique, and current hemodynamic thresholds to define HFpEF are not universally accepted. We sought to describe the exercise hemodynamics profile of HFpEF cohorts reported in literature, as compared with control subjects.

Methods

We performed a systematic literature review following the PRISMA statement until December 2020. Studies reporting pulmonary artery wedge pressure (PAWP) at rest and peak exercise were extracted. Summary estimates of all hemodynamic variables were evaluated, stratified according to body position (supine/upright exercise). The PAWP / cardiac output (CO) slope during exercise was extrapolated.

Results

Twenty-seven studies were identified, providing data for 2180 HFpEF patients and 682 controls. At peak exercise, HfpEF cohorts showed a summary estimate of PAWP at peak which was twice as high as compared with control cohorts (30; 95% CI: 29–31 mmHg and 16; 95% CI: 15–17 mmHg, respectively), as well as of delta PAWP (15; 95% CI: 14–16 mmHg and 7; 95% CI: 6–8 mmHg, respectively), and of right atrial pressure (18; 95% CI: 16–19 mmHg and 8; 95% CI: 8–9 mmHg, respectively). These differences persisted after adjustment for age, sex, body mass index, body position. Additionally, summary estimates of PAWP at peak performed during supine exercise was slightly higher than that obtained in upright position only for HFpEF cohorts (supine position: 31; 95% CI: 30–32 mmHg vs upright position; 26; 95% CI: 25–27 mmHg, respectively, p-value&lt;0.01). However, peak PAWP values were highly heterogeneous among the cohorts (I2=93%), with a relative overlap with controls (Figure 1). HFpEF had a significantly larger impairment in the hemodynamic response to exercise, witnessed by a steeper summary PAWP/CO slope than controls (3.75; 95% CI: 3.20–4.28 mmHg/L/min and 0.95; 95% CI: 0.30–1.59 mmHg/L/min, p-value &lt;0.0001), even after adjustment for covariates (p=0.007) (Figure 2). Finally, summary estimates of PAWP/CO slope were higher in HFpEF cohorts performing exercise in the supine position compared with those in upright position (p&lt;0.0001 and p=0.0002 at non-adjusted and adjusted analysis, respectively), but not in control cohorts (p=0.135 and p=0.966 at non-adjusted and adjusted analysis, respectively).

Conclusions

Despite methodological heterogeneity across centers, the hemodynamic profile of HFpEF patients is consistent across studies and characterized by a higher left and right filling pressure at rest compared with controls, enhanced by physical exercise. A PAWP/CO slope cut-off &gt;2 mmHg/L/min seems to retain validity also for studies conducted in the supine position, potentially overcoming the need of different supine and upright PAWP cut-offs.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship.

An updated meta-analysis of hemodynamics markers of prognosis in patients with pulmonary hypertension due to left heart disease

Pulmonary hypertension (PH) is associated with a poor prognosis in left heart disease (LHD). We sought to provide an updated analysis on the association of hemodynamic variables, such as pulmonary vascular resistance (PVR), pulmonary artery compliance (PAC), and diastolic pressure gradient (DPG), with prognosis in PH-LHD, through a systematic literature review. Sixteen articles were identified, including 9600 patients with LHD, heterogeneous in terms of age, sex, and etiology of cardiac disease. In this large population, PVR (hazard ratio [HR], 1.07; 95% confidence interval [CI]: 1.05-1.0), DPG (HR, 1.02; 95% CI: 1.01-1.02) and PAC (HR, 0.76; 95% CI: 0.69-0.84) were associated with an increased risk of adverse outcome, albeit with a less solid performance of DPG. Similar results were found when hemodynamic variables were analyzed according to the thresholds commonly applied in clinical practice, or subdividing cohorts according to the underlying LHD. Furthermore, cumulative metanalysis indicated that these results are consistently stable since 2018. Thus, PVR, DPG and PAC have an established prognostic value in PH-LHD. These results are consistent through the years and unlikely to change with further studies.

Exercise haemodynamics in heart failure with preserved ejection fraction: a systematic review and meta-analysis

AIMS

Exercise right heart catheterization (RHC) is considered the gold-standard test to diagnose heart failure with preserved ejection fraction (HFpEF). However, exercise RHC is an insufficiently standardized technique, and current haemodynamic thresholds to define HFpEF are not universally accepted. We sought to describe the exercise haemodynamics profile of HFpEF cohorts reported in literature, as compared with control subjects.

METHODS AND RESULTS

We performed a systematic literature review until December 2020. Studies reporting pulmonary artery wedge pressure (PAWP) at rest and peak exercise were extracted. Summary estimates of all haemodynamic variables were evaluated, stratified according to body position (supine/upright exercise). The PAWP/cardiac output (CO) slope during exercise was extrapolated. Twenty-seven studies were identified, providing data for 2180 HFpEF patients and 682 controls. At peak exercise, patients with HFpEF achieved higher PAWP (30 [29-31] vs. 16 [15-17] mmHg, P < 0.001) and mean right atrial pressure (P < 0.001) than controls. These differences persisted after adjustment for age, sex, body mass index, and body position. However, peak PAWP values were highly heterogeneous among the cohorts (I²  = 93%), with a relative overlap with controls. PAWP/CO slope was steeper in HFpEF than in controls (3.75 [3.20-4.28] vs. 0.95 [0.30-1.59] mmHg/L/min, P value < 0.0001), even after adjustment for covariates (P = 0.007).

CONCLUSIONS

Despite methodological heterogeneity, as well as heterogeneity of pooled haemodynamic estimates, the exercise haemodynamic profile of HFpEF patients is consistent across studies and characterized by a steep PAWP rise during exercise. More standardization of exercise haemodynamics may be advisable for a wider application in clinical practice.

Early‐onset and severe Pulmonary Arterial Hypertension due to a novel compound heterozygous association of rare VHL mutations: a case report and review of existing data

Very rare cases of pulmonary arterial hypertension (PAH) have been linked to homozygous or compound heterozygous von Hippel–Lindau (VHL) tumor suppressor gene mutations, while heterozygous VHL mutations lead to VHL tumor syndrome. Although those entities are defined, the genotype–phenotype correlation is incompletely understood, and patient management recommendations are lacking. Here, we describe a case of severe early‐onset PAH due to a so‐far unreported compound heterozygous association of VHL mutations and review the existing data.

Hypereosinophilic syndrome: considerations for the cardiologist

Eosinophil-mediated endomyocardial damage is a well-known complication in patients with hypereosinophilic syndromes (HES). Although management and survival have improved significantly, some patients continue to develop severe cardiomyopathy as a direct consequence of uncontrolled hypereosinophilia. Cardiologists play a key role in early detection and treatment. At the early generally asymptomatic stage, related to subendocardial eosinophilic infiltrates, elevation of the biomarker of cardiac damage (serum troponin) and cardiac MRI are the best tools for diagnosis. As disease progresses, patients typically develop intracardiac mural thrombi and may experience variable degrees of heart failure due to valve damage and/or subendocardial fibrosis, all of which are more readily detectable with traditional echocardiographic investigation. New imaging modalities such as strain imaging and specific sequences in MRI offer the perspective of detecting subtle perturbations and distinguishing inflammatory versus fibrotic stages. Endomyocardial biopsy may help in difficult settings, namely, when blood eosinophilia is not prominent, but may be non-contributive due to sampling issues or eosinophil degranulation or replacement by fibrosis, and must always be performed after careful consideration of the risk:benefit ratio. Although treatment of the HES itself should be managed by clinicians with expertise in this rare disorder with the aim of lowering eosinophil counts to prevent and treat eosinophil-mediated organ damage and dysfunction, cardiologists play a key role in managing the associated cardiopathy. There are no consensual disease-specific guidelines for treating eosinophil-mediated thrombotic complications and cardiopathy, which should be managed according to classical international recommendations.

Current Limitations of Invasive Exercise Hemodynamics for the Diagnosis of Heart Failure With Preserved Ejection Fraction

BACKGROUND

Exercise hemodynamics can differentiate heart failure with preserved ejection fraction (HFpEF) from noncardiac dyspnea. However, respiratory pressure swings may impact hemodynamic measurements, potentially leading to misdiagnosis of HFpEF. Moreover, threshold values for abnormal hemodynamic response indicative of HFpEF are not universally accepted. Thus, we sought to evaluate the impact of respiratory pressure swings on hemodynamic data interpretation as well as the concordance among 3 proposed exercise hemodynamic criteria for HFpEF: (1) end-expiratory pulmonary artery wedge pressure (PAWP_exp) ≥25 mm Hg; (2) PAWP_exp/cardiac output slope >2 mm Hg/L per minute; and (3) respiratory-averaged (avg) mean pulmonary artery pressure >30 mm Hg, total pulmonary resistance_avg >3 WU, PAWP_avg ≥20 mm Hg.

METHODS

Fifty-seven patients with unexplained dyspnea (70% women, 70±9 years) underwent exercise cardiac catheterization. The difference between end-expiratory and averaged hemodynamic values, as well as the concordance among the 3 hemodynamic definitions of HFpEF, were assessed.

RESULTS

End-expiratory hemodynamics measurements were higher than values averaged across the respiratory cycle. During exercise, a larger proportion of patients exceeded the threshold of 25 mm Hg for PAWP_exp rather than for PAWP_avg (70% versus 53%, P<0.01). The concordance of 3/3 HFpEF exercise hemodynamic criteria was recorded in 70% of patients. PAWP_exp/cardiac output slope identified HFpEF more frequently than the other 2 criteria (81% versus 64% to 69%), incorporating over 97% of abnormal responses to the latter. Patients with 3/3 positive criteria had worse clinical, gas-exchange, and hemodynamic profiles.

CONCLUSIONS

Respiratory pressure swings impact on the exercise hemodynamic definitions of HFpEF that provide discordant results in 30% of patients. Equivocal diagnoses of HFpEF might be limited by adopting the most sensitive and inclusive criterion alone (ie, PAWP_exp/cardiac output slope).

Feasibility and cost of FH cascade screening in Belgium (BEL-CASCADE) including a novel rapid rule-out strategy

BACKGROUND

Familial hypercholesterolaemia (FH) is underdiagnosed in most countries. We report our first experience from a national pilot project of cascade screening in relatives of FH patients.

METHODOLOGY

Participating specialists recruited consecutive index patients (IP) with Dutch Lipid Clinic Network (DLCN) score ≥6. After informed consent, the relatives were visited by the nurses to collect relevant clinical data and perform blood sampling for lipid profile measurement. FH diagnosis in the relatives was based on the DLCN and/or MEDPED FH (Make-Early-Diagnosis-to-Prevent-Early-Deaths-in-FH) criteria.

RESULTS

In a period of 18 months, a total of 127 IP (90 with definite FH and 37 with probable FH) were enrolled in 15 centres. Out of the 270 relatives visited by the nurses, 105 were suspected of having FH: 31 with DCLN score >8, 33 with DLCN score 5-8 and 41 with MEDPED FH criteria. In a post-hoc analysis, another set of MEDPED FH criteria established in the Netherlands and adapted to Belgium allowed to detect FH in 51 additional relatives.

CONCLUSION

In a country with no national FH screening program, our pilot project demonstrated that implementing a simple phenotypical FH cascade screening strategy using the collaboration of motivated specialists and two nurses, allowed to diagnose FH in 127 index patients and an additional 105 of their relatives over the two-year period. Newly developed MEDPED FH cut-offs, easily applicable by a nurse with a single blood sample, might further improve the sensitivity of detecting FH within families.

P4685Validation of noninvasive pulmonary artery pressure/flow relationship: echocardiography vs right heart catheterization

Background

Invasive pressure-flow (P/Q) relationship of the pulmonary circulation can detect the presence of pulmonary hypertension (PH) during exercise and provide information on patients' symptoms and assess disease severity. Doppler-echocardiography was reported to provide accurate but imprecise noninvasive estimates of both resting and exercise pulmonary haemodynamics. However, data on the direct comparison of invasive vs noninvasive approaches to build pressure-flow relationship are scarce.

Purpose

To compare echocardiographic estimates with invasive measurements of P/Q relationship of the pulmonary circulation during exercise.

Methods

Patients undergoing a clinically indicated right heart catheterization and echocardiography were studied at rest and during exercise. The ratio between mean pulmonary artery pressure and cardiac output at peak exercise (TPR), as well as P/Q slope throughout exercise were calculated. Both TPR and P/Q slope are abnormal when ≥3 mmHg/L/min. Echocardiographic estimates were compared with invasive measurements.

Results

Sixty patients were included (mean age 65±14 years, 73% female). PH was present at rest in 38 cases (63%), of precapillary origin in 23 (61%). Heart failure with preserved ejection fraction was diagnosed in 23 patients, of which 17 had no PH at rest. TPR at peak exercise and P/Q slope were abnormal (≥3 mmHg/L/min) in the majority of patients (56 and 45 subjects, respectively).

Echocardiographic estimates of P/Q slope and TPR correlated significantly although weakly with invasive measurements (R2=0.38 and 0.56, respectively, p<0.001). Bias of echocardiography for P/Q slope and TPR was 1.1±4.2 and 0.4±2.9 mmHg/L/min, respectively (figure). Sensitivity of echocardiography to detect an abnormal TPR or P/Q slope (i.e. ≥3 mmHg/L/min) was 100 and 98%, respectively, faced by low specificity (0 and 33%, respectively).

Figure 1

Conclusions

Doppler-echocardiography can provide rather accurate and sensitive but imprecise estimates of pressure-flow relationships of the pulmonary circulation during exercise. This intrinsic imprecision may limit its use in clinical practice.

P4437Exercise limitation in systemic sclerosis: a case-controlled study

Introduction

Interstitial lung disease and pulmonary hypertension are the leading causes of morbidity and mortality in patients with systemic sclerosis (SSc). Exercise-induced dyspnea is the first manifestation of both complications, which explains why the value of resting tests to predict preclinical heart or lung involvement is limited. Cardiopulmonary exercise testing (CPET) offers a comprehensive approach to identify the cause of exercise limitation. However, the role of CPET in SSc patients without demonstrated cardiac and/or respiratory disease has not been extensively investigated.

Aim

We sought to compare the cardiopulmonary adaptation to exercise of SSc patients without cardiac or pulmonary disease vs healthy volunteers.

Methods

SSc patients (normal resting echocardiography and pulmonary functional test) and healthy volunteers were prospectively enrolled. They underwent maximal symptom-limited CPET, exercise echocardiography (EXEcho), and 6 minutes walk test. Results were compared after adjustment for age and gender.

Results

Thirty-nine patients (54±12 years) and 43 healthy subjects (46±11 years) were included.

Workload was lower in patients than controls (84±42 vs 178±58 W, p<0.001), with similar respiratory exchange ratio (1.27±0.11 vs 1.28±0.10, p=0.570) at peak exercise. Patients had lower oxygen uptake (VO2) at peak exercise (17±6 vs 30±8 ml min kg–1, p<0.001), and higher minute ventilation/carbon dioxide production (VE/VCO2) slope (41±8 vs 33±5, p<0.001) than controls (Figure 1). They had higher VE/VCO2 ratio (40±7 vs 30±3, p<0.001) and lower end-tidal pCO2 (PetCO2) (35±5 vs 41±3 mmHg, p<0.001) at the ventilatory threshold (VT). Respiratory reserve was preserved, and peripheral oxygen saturation was normal at peak exercise in both groups.

Resting echocardiography revealed larger left atrium in SSc-patients (24±8 vs 20±7 ml/m2, p=0.013) and higher estimated left atrial pressure (LAP) (10±2 vs 8±2 mmHg, p=0.001) vs controls. At ExEcho, total pulmonary resistance (TPR) was higher (3.2±0.6 vs 2.6±0.5 WU, p=0.003) and right ventricular function markers were lower at peak exercise in patients vs controls, despite similar values at rest. Plasma NT-proBNP was within normal range in all patients.

Walk distance was shorter in SSc-patients vs controls (505±80 vs 624±50 m, p<0.001), and correlated with peak VO2, VE/VCO2 slope, and VE/VCO2 at VT.

In Ssc patients, peak VO2 also correlated with DLCO (r=0.640, p<0.001), with left atrial volume (r=−0.344, p=0.002), and with estimated LAP (r=−0.490, p<0.001) but not with NT-proBNP or lung volumes.

Conclusion

The combination of low peak VO2, high VE/VCO2 slope, low PetCO2, and high respiratory reserve suggests that patients with SSc, without overt cardiac or respiratory disease, present with cardiovascular limitation to exercise. This may be related to latent cardiac dysfunction or pulmonary vascular disease.

Acknowledgement/Funding

This work was partially funded by research grants from GSK, Actelion, and from the Belgian Foundation for Cardiac Surgery.

Genetic counselling and testing in adults with congenital heart disease: A consensus document of the ESC Working Group of Grown-Up Congenital Heart Disease, the ESC Working Group on Aorta and Peripheral Vascular Disease and the European Society of Human Genetics

Thanks to a better knowledge of the genetic causes of many diseases and an improvement in genetic testing techniques, genetics has gained an important role in the multidisciplinary approach to diagnosis and management of congenital heart disease and aortic pathology. With the introduction of strategies for precision medicine, it is expected that this will only increase further in the future. Because basic knowledge of the indications, the opportunities as well as the limitations of genetic testing is essential for correct application in clinical practice, this consensus document aims to give guidance to care-providers involved in the follow-up of adults with congenital heart defects and/or with hereditary aortic disease. This paper is the result of a collaboration between the ESC Working Group of Grown-Up Congenital Heart Disease, the ESC Working Group on Aorta and Peripheral Vascular Disease and the European Society of Human Genetics. Throughout the document, the importance of correct counseling in the process of genetic testing is emphasized, indications and timing for genetic studies are discussed as well as the technical modalities of genetic testing. Finally, the most important genetic diseases in adult congenital heart disease and aortic pathology are also discussed.

Complex roads from genotype to phenotype in dilated cardiomyopathy: scientific update from the Working Group of Myocardial Function of the European Society of Cardiology

Dilated cardiomyopathy (DCM) frequently affects relatively young, economically, and socially active adults, and is an important cause of heart failure and transplantation. DCM is a complex disease and its pathological architecture encounters many genetic determinants interacting with environmental factors. The old perspective that every pathogenic gene mutation would lead to a diseased heart, is now being replaced by the novel observation that the phenotype depends not only on the penetrance-malignancy of the mutated gene-but also on epigenetics, age, toxic factors, pregnancy, and a diversity of acquired diseases. This review discusses how gene mutations will result in mutation-specific molecular alterations in the heart including increased mitochondrial oxidation (sarcomeric gene e.g. TTN), decreased calcium sensitivity (sarcomeric genes), fibrosis (e.g. LMNA and TTN), or inflammation. Therefore, getting a complete picture of the DCM patient will include genomic data, molecular assessment by preference from cardiac samples, stratification according to co-morbidities, and phenotypic description. Those data will help to better guide the heart failure and anti-arrhythmic treatment, predict response to therapy, develop novel siRNA-based gene silencing for malignant gene mutations, or intervene with mutation-specific altered gene pathways in the heart.This article is part of the Mini Review Series from the Varenna 2017 meeting of the Working Group of Myocardial Function of the European Society of Cardiology.

Clinical phenotypes and outcomes of pulmonary hypertension due to left heart disease: Role of the pre-capillary component

Background

In pulmonary hypertension (PH), both wedge pressure elevation (PAWP) and a precapillary component may affect right ventricular (RV) afterload. These changes may contribute to RV failure and prognosis. We aimed at describing the different haemodynamic phenotypes of patients with PH due to left heart disease (LHD) and at characterizing the impact of pulmonary haemodynamics on RV function and outcome PH-LHD.

Methods

Patients with PH-LHD were compared with treatment-naïve idiopathic/heritable pulmonary arterial hypertension (PAH, n = 35). PH-LHD patients were subdivided in Isolated post-capillary PH (IpcPH: diastolic pressure gradient, DPG<7 mmHg and pulmonary vascular resistance, PVR≤3 WU, n = 37), Combined post- and pre-capillary PH (CpcPH: DPG≥7 mmHg and PVR>3 WU, n = 27), and “intermediate” PH-LHD (either DPG <7 mmHg or PVR ≤3 WU, n = 29).

Results

Despite similar PAWP and cardiac index, haemodynamic severity and prevalence of RV dysfunction increased from IpcPH, to “intermediate” and CpcPH. PVR and DPG (but not compliance, Ca) were linearly correlated with RV dysfunction. CpcPH had worse prognosis (p<0.05) than IpcPH and PAH, but similar to “intermediate” patients. Only NTproBNP and Ca independently predicted survival in PH-LHD.

Conclusions

In PH-LHD, haemodynamic characterization according to DPG and PVR provides important information on disease severity, predisposition to RV failure and prognosis. Patients presenting the CpcPH phenotype appear to have haemodynamic profile closer to PAH but with worse prognosis. In PH-LHD, Ca and NTproBNP were independent predictors of survival.

[Left ventricular hypertrophy : how to identity the cause ?]

Left ventricular hypertrophy (LVH) is defined by an increase in left ventricular mass. LVH can be adaptive and related to an increase in left ventricular pressure or volume load, or can be related to a primary myocardial disease including sarcomeric, inflammatory or infiltrative disorders. The prevalence of left ventricular hypertrophy increases with age, and its presence is a risk factor for cardiovascular events and death. Recognizing the exact condition underlying LVH is a key step to provide an optimal medical management of those patients, including risk stratification, prognosis and treatment. By the use of multimodal imaging, by the appropriate use of genetics, and by considering clinical, electrical and biological red flags, the identification of the underlying disease becomes more and more achievable in the clinics, without the need for a myocardial biopsy. This review describes the recent diagnostic advances for the medical management of left ventricular hypertrophy.

Pulmonary hypertension and ventilation during exercise: Role of the pre-capillary component

BACKGROUND

Excessive exercise-induced hyperventilation and high prevalence of exercise oscillatory breathing (EOB) are present in patients with post-capillary pulmonary hypertension (PH) complicating left heart disease (LHD). Patients with pre-capillary PH have even higher hyperventilation but no EOB. We sought to determine the impact of a pre-capillary component of PH on ventilatory response to exercise in patients with PH and left heart disease.

METHODS

We retrospectively compared patients with idiopathic or heritable pulmonary arterial hypertension (PAH, n = 29), isolated post-capillary PH (IpcPH, n = 29), and combined post- and pre-capillary PH (CpcPH, n = 12). Diastolic pressure gradient (DPG = diastolic pulmonary artery pressure - pulmonary wedge pressure) was used to distinguish IpcPH (DPG <7 mm Hg) from CpcPH (DPG ≥7 mm Hg).

RESULTS

Pulmonary vascular resistance (PVR) was higher in PAH, intermediate in CpcPH, and low in IpcPH. All patients with CpcPH but 1 had PVR >3 Wood unit. Exercise-induced hyperventilation (high minute ventilation over carbon dioxide production, low end-tidal carbon dioxide) was marked in PAH, intermediate in CpcPH, and low in IpcPH (p < 0.001) and correlated with DPG and PVR. Prevalence of EOB decreased from IpcPH to CpcPH to PAH (p < 0.001).

CONCLUSIONS

Patients with CpcPH may have worse hemodynamics than patients with IpcPH and distinct alterations of ventilatory control, consistent with more exercise-induced hyperventilation and less EOB. This might be explained at least in part by the presence and extent of pulmonary vascular disease.

Mesp1 controls the speed, polarity, and directionality of cardiovascular progenitor migration

During embryonic development, Mesp1 marks the earliest cardiovascular progenitors (CPs) and promotes their specification, epithelial-mesenchymal transition (EMT), and cardiovascular differentiation. However, Mesp1 deletion in mice does not impair initial CP specification and early cardiac differentiation but induces cardiac malformations thought to arise from a defect of CP migration. Using inducible gain-of-function experiments during embryonic stem cell differentiation, we found that Mesp2, its closest homolog, was as efficient as Mesp1 at promoting CP specification, EMT, and cardiovascular differentiation. However, only Mesp1 stimulated polarity and directional cell migration through a cell-autonomous mechanism. Transcriptional analysis and chromatin immunoprecipitation experiments revealed that Mesp1 and Mesp2 activate common target genes that promote CP specification and differentiation. We identified two direct Mesp1 target genes, Prickle1 and RasGRP3, that are strongly induced by Mesp1 and not by Mesp2 and that control the polarity and the speed of cell migration. Altogether, our results identify the molecular interface controlled by Mesp1 that links CP specification and cell migration.

NKX2-5 mutations causative for congenital heart disease retain functionality and are directed to hundreds of targets

We take a functional genomics approach to congenital heart disease mechanism. We used DamID to establish a robust set of target genes for NKX2-5 wild type and disease associated NKX2-5 mutations to model loss-of-function in gene regulatory networks. NKX2-5 mutants, including those with a crippled homeodomain, bound hundreds of targets including NKX2-5 wild type targets and a unique set of "off-targets", and retained partial functionality. NKXΔHD, which lacks the homeodomain completely, could heterodimerize with NKX2-5 wild type and its cofactors, including E26 transformation-specific (ETS) family members, through a tyrosine-rich homophilic interaction domain (YRD). Off-targets of NKX2-5 mutants, but not those of an NKX2-5 YRD mutant, showed overrepresentation of ETS binding sites and were occupied by ETS proteins, as determined by DamID. Analysis of kernel transcription factor and ETS targets show that ETS proteins are highly embedded within the cardiac gene regulatory network. Our study reveals binding and activities of NKX2-5 mutations on WT target and off-targets, guided by interactions with their normal cardiac and general cofactors, and suggest a novel type of gain-of-function in congenital heart disease.

The expression of Sox17 identifies and regulates haemogenic endothelium

Although it is well recognized that haematopoietic stem cells (HSCs) develop from a specialized population of endothelial cells known as haemogenic endothelium, the regulatory pathways that control this transition are not well defined. Here we identify Sox17 as a key regulator of haemogenic endothelial development. Analysis of Sox17-GFP reporter mice revealed that Sox17 is expressed in haemogenic endothelium and emerging HSCs and that it is required for HSC development. Using the mouse embryonic stem cell differentiation model, we show that Sox17 is also expressed in haemogenic endothelium generated in vitro and that it plays a pivotal role in the development and/or expansion of haemogenic endothelium through the Notch signalling pathway. Taken together, these findings position Sox17 as a key regulator of haemogenic endothelial and haematopoietic development.

Defining the earliest step of cardiovascular progenitor specification during embryonic stem cell differentiation

Mesp1, the earliest marker of cardiovascular development in vivo, is used to isolate and characterize multipotent cardiovascular progenitors during ESC differentiation.

During embryonic development and embryonic stem cell (ESC) differentiation, the different cell lineages of the mature heart arise from two types of multipotent cardiovascular progenitors (MCPs), the first and second heart fields. A key question is whether these two MCP populations arise from differentiation of a common progenitor. In this paper, we engineered Mesp1–green fluorescent protein (GFP) ESCs to isolate early MCPs during ESC differentiation. Mesp1-GFP cells are strongly enriched for MCPs, presenting the ability to differentiate into multiple cardiovascular lineages from both heart fields in vitro and in vivo. Transcriptional profiling of Mesp1-GFP cells uncovered cell surface markers expressed by MCPs allowing their prospective isolation. Mesp1 is required for MCP specification and the expression of key cardiovascular transcription factors. Isl1 is expressed in a subset of early Mesp1-expressing cells independently of Mesp1 and acts together with Mesp1 to promote cardiovascular differentiation. Our study identifies the early MCPs residing at the top of the cellular hierarchy of cardiovascular lineages during ESC differentiation.

Mesp1: a key regulator of cardiovascular lineage commitment

In mammals, the heart arises from the differentiation of 2 sources of multipotent cardiovascular progenitors (MCPs). Different studies indicated that an evolutionary conserved transcriptional regulatory network controls cardiovascular development from flies to humans. Whereas in Drosophila, Tinman acts as a master regulator of cardiac development, the identification of such a master regulator in mammals remained elusive for a long time. In this review, we discuss the recent findings suggesting that Mesp1 acts as a key regulator of cardiovascular progenitors in vertebrates. Lineage tracing in mice demonstrated that Mesp1 represents the earliest marker of cardiovascular progenitors, tracing almost all the cells of the heart including derivatives of the primary and second heart fields. The inactivation of Mesp1/2 indicated that Mesp genes are essential for early cardiac mesoderm formation and MCP migration. Several recent studies have demonstrated that Mesp1 massively promotes cardiovascular differentiation during embryonic development and pluripotent stem cell differentiation and indicated that Mesp1 resides at the top of the cellular and transcriptional hierarchy that orchestrates MCP specification. In primitive chordates, Mesp also controls early cardiac progenitor specification and migration, suggesting that Mesp arises during chordate evolution to regulate the earliest step of cardiovascular development. Defining how Mesp1 regulates the earliest step of MCP specification and controls their migration is essential to understand the root of cardiovascular development and how the deregulation of these processes can lead to congenital heart diseases. In addition, these findings will be very useful to boost the production of cardiovascular cells for cellular therapy, drug and toxicity screening.

Mesp1 acts as a master regulator of multipotent cardiovascular progenitor specification

During embryonic development, multipotent cardiovascular progenitor cells are specified from early mesoderm. Using mouse ESCs in which gene expression can be temporally regulated, we have found that transient expression of Mesp1 dramatically accelerates and enhances multipotent cardiovascular progenitor specification through an intrinsic and cell autonomous mechanism. Genome-wide transcriptional analysis indicates that Mesp1 rapidly activates and represses a discrete set of genes, and chromatin immunoprecipitation shows that Mesp1 directly binds to regulatory DNA sequences located in the promoter of many key genes in the core cardiac transcriptional machinery, resulting in their rapid upregulation. Mesp1 also directly represses the expression of key genes regulating other early mesoderm and endoderm cell fates. Our results demonstrate that Mesp1 acts as a key regulatory switch during cardiovascular specification, residing at the top of the hierarchy of the gene network responsible for cardiovascular cell-fate determination.

Right-to-left shunting with normal pulmonary pressure complicating atrial septal defect surgery

We report on a patient in whom a right-to-left shunt with normal pulmonary arterial pressures occurred after surgery of an inferior vena caval sinus venosus-type atrial septal defect. In addition to the inferior vena cava to left atrium anatomic defect, the exceptional occurrence of a post-operative right atrial inflow stenosis contributed to the right-to-left shunting.

The core domain of chemokines binds CCR5 extracellular domains while their amino terminus interacts with the transmembrane helix bundle

CCR5 is a functional receptor for various inflammatory CC-chemokines, including macrophage inflammatory protein (MIP)-1alpha and RANTES (regulated on activation normal T cell expressed and secreted), and is the main coreceptor of human immunodeficiency viruses. The second extracellular loop and amino-terminal domain of CCR5 are critical for chemokine binding, whereas the transmembrane helix bundle is involved in receptor activation. Chemokine domains and residues important for CCR5 binding and/or activation have also been identified. However, the precise way by which chemokines interact with and activate CCR5 is presently unknown. In this study, we have compared the binding and functional properties of chemokine variants onto wild-type CCR5 and CCR5 point mutants. Several mutations in CCR5 extracellular domains (E172A, R168A, K191A, and D276A) strongly affected MIP-1alpha binding but had little effect on RANTES binding. However, a MIP/RANTES chimera, containing the MIP-1alpha N terminus and the RANTES core, bound to these mutants with an affinity similar to that of RANTES. Several CCR5 mutants affecting transmembrane helices 2 and 3 (L104F, L104F/F109H/F112Y, F85L/L104F) reduced the potency of MIP-1alpha by 10-100 fold with little effect on activation by RANTES. However, the MIP/RANTES chimera activated these mutants with a potency similar to that of MIP-1alpha. In contrast, LD78beta, a natural MIP-1alpha variant, which, like RANTES, contains a proline at position 2, activated these mutants as well as RANTES. Altogether, these results suggest that the core domains of MIP-1alpha and RANTES bind distinct residues in CCR5 extracellular domains, whereas the N terminus of chemokines mediates receptor activation by interacting with the transmembrane helix bundle.

Activation of CCR5 by chemokines involves an aromatic cluster between transmembrane helices 2 and 3

CCR5 is a G protein-coupled receptor responding to four natural agonists, the chemokines RANTES (regulated on activation normal T cell expressed and secreted), macrophage inflammatory protein (MIP)-1 alpha, MIP-1 beta, and monocyte chemotactic protein (MCP)-2, and is the main co-receptor for the macrophage-tropic human immunodeficiency virus strains. We have previously identified a structural motif in the second transmembrane helix of CCR5, which plays a crucial role in the mechanism of receptor activation. We now report the specific role of aromatic residues in helices 2 and 3 of CCR5 in this mechanism. Using site-directed mutagenesis and molecular modeling in a combined approach, we demonstrate that a cluster of aromatic residues at the extracellular border of these two helices are involved in chemokine-induced activation. These aromatic residues are involved in interhelical interactions that are key for the conformation of the helices and govern the functional response to chemokines in a ligand-specific manner. We therefore suggest that transmembrane helices 2 and 3 contain important structural elements for the activation mechanism of chemokine receptors, and possibly other related receptors as well.

Characterization of the role of the N-loop of MIP-1 beta in CCR5 binding

MIP-1beta is a CC-chemokine that plays a role in inflammation and host defense mechanisms by interacting with its specific receptor CCR5. CCR5 is a major coreceptor for macrophage-tropic human immunodeficiency virus (HIV), and as a consequence, MIP-1beta can inhibit HIV entry. It is therefore of interest to understand how MIP-1beta and other CCR5 ligands bind to their receptor, as such understanding could lead to the rational design of more efficient HIV entry blockers. We have previously demonstrated the importance of Phe13, and of basic residues of the 40's loop, in mediating high-affinity binding of MIP-1beta to CCR5. We have now investigated further the relative contribution of other MIP-1beta residues in the interaction of the chemokine with CCR5, by studying the functional consequences of point mutations within the N-loop and the 3(10) turn of MIP-1beta, affecting the charge, size, and H-bonding properties of the side chains. Our data suggest that, in addition to Phe13, three amino acids of the N-loop and 3(10) turn (Arg18, Lys19, and Arg22) interact with CCR5 through their positive charge. We also found that Pro21 contributes to the CCR5 binding properties of MIP-1beta. Moreover, NMR spectroscopy has revealed that the presence of Tyr at position 15 is necessary for the proper folding of the chemokine. Our results therefore demonstrate that the binding determinants of MIP-1beta consist of residues arranged on one surface of the protein, including most of the basic residues in MIP-1beta, as well as two key hydrophobic groups. The good correlation observed between the potency of the mutants in a functional assay and their binding affinity strongly argues that basic residues Arg18, Lys19, and Arg22 of MIP-1beta are essential for its CCR5 binding properties, without a primary effect on CCR5 activation.

Characterization of a novel VPAC(1) selective agonist and identification of the receptor domains implicated in the carboxyl-terminal peptide recognition

Vasoactive Intestinal Polypeptide (VIP) interacts with a high affinity to two subclasses of G protein coupled receptors named VPAC(1) and VPAC(2), and has a 3 - 10 fold preference for VPAC(1) over VPAC(2) receptors. Selective ligands for each receptor subclass were recently described. [R(16)]-PACAP (1 - 23) and [L(22)]-VIP are two selective VPAC(1) agonists. Chimaeric human VPAC(2)-VPAC(1) recombinant receptors expressed in CHO cells were used to identify the receptor domains implicated in these two selective ligands recognition. The VPAC(2) preference for [R(16)]-PACAP (1 - 27) over [R(16)]-PACAP (1 - 23) did not require the receptor's NH(2)-terminus domain but involved the whole transmembrane domain. In contrast, the selectivity of [L(22)]-VIP depended only on the presence of the NH(2) terminus and EC(2) domains of the VPAC(1) receptor. The present data support the idea that in the GPCR-B family of receptors the different selective ligands require different domains for their selectivity, and that the peptides carboxyl terminal sequence (amino acids 24 - 27) folds back on the transmembrane receptor domain, close to the peptides, aminoterminus.