Magalie Mercy

Prognostic value of exercise pulmonary haemodynamics in pulmonary arterial hypertension

The aim of the study was to investigate the prognostic value of right heart catheterisation variables measured during exercise. 55 incident patients with idiopathic, familial or anorexigen-associated pulmonary arterial hypertension (PAH) underwent right heart catheterisation at rest and during exercise and 6-min walk testing before PAH treatment initiation. Patients were treated according to recommendations within the next 2 weeks. Right heart catheterisation was repeated 3–5 months into the PAH treatment in 20 patients. Exercise cardiac index decreased gradually as New York Heart Association (NYHA) functional class increased whereas cardiac index at rest was not significantly different across NYHA groups. Baseline 6-min walk distance correlated significantly with exercise and change in cardiac index from rest to exercise (r=0.414 and r=0.481, respectively; p<0.01). Change in 6-min walk distance from baseline to 3–5 months under PAH treatment was highly correlated with change in exercise cardiac index (r=0.746, p<0.001). The most significant baseline covariates associated with survival were change in systolic pulmonary artery pressure from rest to exercise and exercise cardiac index (hazard ratio 0.56 (95% CI 0.37–0.86) and 0.14 (95% CI 0.05–0.43), respectively). Change in pulmonary haemodynamics during exercise is an important tool for assessing disease severity and may help devise optimal treat-to-target strategies. Exercise cardiac index correlated with exercise capacity and was associated with long-term survival in PAH http://ow.ly/vG2bb

Lack of correlation between the ventilatory response to CO2 and lung function impairment in myotonic dystrophy patients: Evidence for a dysregulation at central level

Myotonic dystrophy Type 1 (DM1) is the most common muscular dystrophy in adults. Respiratory failure is common but clinical findings support a dysregulation of the control of breathing at central level, furthermore contributing to alveolar hypoventilation independently of the severity of respiratory weakness. We therefore intended to study the relationship between the ventilatory response to CO2 and the impairment of lung function in DM1 patients. Sixty-nine DM1 patients were prospectively investigated (43.5 ± 12.7 years). Systematic pulmonary lung function evaluation including spirometry, plethysmography, measurements of respiratory muscle strength, arterial blood gas analysis and ventilatory response to CO2 were performed. Thirty-one DM1 patients (45%) presented a ventilatory restriction, 38 (55%) were hypoxaemic and 15 (22%) were hypercapnic. Total lung capacity decline was correlated to hypoxaemia (p = 0.0008) and hypercapnia (p = 0.0013), but not to a decrease in ventilatory response to CO2 (p = 0.194). Ventilatory response to CO2 was reduced to 0.85 ± 0.67 L/min/mmHg and not correlated to respiratory muscle weakness. Ventilatory response to CO2 was neither different among restricted/non-restricted patients (p = 0.2395) nor among normoxaemic/hypoxaemic subjects (p = 0.6380). The reduced ventilatory response to CO2 in DM1 patients appeared independent of lung function impairment and respiratory muscle weakness, suggesting a central cause of CO2 insensitivity.

Évaluation de l’IRM cardiaque dans le suivi des patients ayant une hypertension artérielle pulmonaire (EVITA). IRM cardiaque dans le suivi de l’hypertension artérielle pulmonaire

Haemodynamic follow up in pulmonary arterial hypertension (PAH) is currently based on right heart catheterisation (RHC). The primary objective of the EVITA study is to compare the use of cardiac magnetic resonance imaging (cMRI) with RHC in the identification of an unfavourable hemodynamic status. The secondary objectives are to determine the role of cMRI in the follow up process. Patients will undergo at diagnosis and at follow up visits both RHC and cMRI. Patients will be followed and treated according to the current guidelines. The primary endpoint will be an unfavourable haemodynamic status defined by cardiac index<2.5L/min/m2 or a right atrial pressure≥8mm Hg measured with RHC compared with a cardiac index<2.5L/min/m2 or right ventricle ejection fraction<35% or an absolute decrease of 10% from the previous measurement with cMRI. Exact values of sensitivity, specificity and 95% confidence intervals will be computed. A population of 180 subjects will have a power of 90% with an α risk of 5%. Univariate and multivariate Cox analysis will allow answering to the secondary objectives. We expect to demonstrate that cMRI could be partly used instead of RHC in the follow up of patients with PAH.

Comparison of exercise capacity and exercise haemodynamic relationships between severe group 3 pulmonary hypertension and pulmonary arterial hypertension

In severe pulmonary hypertension (PH) due to lung disease and/or hypoxia, group 3 of PH, it is important to determine the impact of PH on exercise tolerance. We compared 3 groups of incident patients: 24 with non severe group 3 PH, 57 patients with severe group 3 PH and 59 patients with pulmonary arterial hypertension (PAH).Patients from group 3 PH were 10 years older in comparison with PAH patients. The percentages of patients in NYHA class III and IV were higher in patients with group 3 PH compared to PAH patients.The means of 6-minute walk distance (6-MWD) (SD) were 308±24m (non severe group 3 PH), 266±14m (severe group 3 PH) and 377±14m (PAH) (p These correlations show that the pulmonary haemodynamic abnormalities at rest and during exercise have an impact on exercise capacity in severe PH due to lung disease and/or hypoxia but causes appear to be different compared with PAH.

Impact de la BPCO : du handicap aux exacerbations

COPD is a common disease characterized by health status impairment and disability that is usually progressive. Exacerbations of COPD, an acute event in the course of the disease, have effects on symptoms and patients quality of life. Assessment of symptoms and risk of exacerbations is useful to guide strategy management of the disease. COPD disability includes different aspects. Its assessment needs to consider the classification of severity of airflow limitation, symptoms, comorbidities and impairment of patients health-related quality of life. The rate at which exacerbations occur varies between patients. History of previous exacerbations and severity of airflow limitation are the best predictors of the frequency and severity of exacerbations. Severity of the symptoms is associated with an increased risk of exacerbations. Exacerbations increase deterioration in health status and leads to severe disability, inducing a vicious circle from disability to exacerbations. At an individual patient level, an understanding of the impact of COPD requires to assess the patients disability, the risk of future exacerbations, and the identification of comorbidities.