No abstract

Background: Little is known about right ventricular dysfunction in non-advanced idiopathic pulmonary fibrosis (IPF) patients without hypoxemia at rest. We evaluated it at rest and during exercise. Research design and methods: 123 IPF patients were evaluated, and 27 met all the following criteria: Gender-Age-Physiology Index score ≤5, modified Medical Research Council dyspnea score ≤3, peripheral oxygen saturation ≥92% at rest, and no history of oxygen therapy. They were submitted to twodimensional speckle-tracking echocardiography at rest and during cardiopulmonary exercise to analyze right ventricular global longitudinal strain. Results: Abnormal speckle-tracking echocardiography findings were identified in 10/27 patients (37%), indicating right ventricular (RV) dysfunction. No patients had abnormalities observed in conventional echocardiographic parameters. Significant differences in mPAP were observed between patients with RV dysfunction and those without dysfunction (at rest: 26.0 ± 4.8 vs. 19.1 ± 4.2 mmHg, p = 0.001; during exercise: 51.3 ± 6.4 vs. 36.9 ± 14.7 mmHg, p = 0.002). Conclusions: RV dysfunction was detected in 37% of non-advanced IPF patients and early recognition was only possible using speckle-tracking echocardiography. Special attention should be given to these patients as RV dysfunction is suggestive of worse prognosis. These patients could benefit from new specific drugs or even oxygen therapy for transitory hypoxia.

Background: To investigate differences in magnetic resonance imaging (MRI) features of rectus femoris muscle between idiopathic pulmonary fibrosis (IPF) patients and healthy volunteers.Methods: Thirteen IPF patients with GAP Index stage II disease were subjected to pulmonary function tests, 6-minute walk test (6MWT), quadriceps femoris muscle strength measurement and MRI of the thigh at rest. At MRI, muscle cross-sectional areas, T2 and T2* relaxometry, and 3-point Dixon fat fraction were measured. The results were compared to those of eight healthy sedentary volunteers.Results: IPF patients had significantly lower %predicted FVC, FEV1 and DLCO (p<0.001 for the three variables) and walked significantly less in the 6MWT (p=0.008). Mean quadriceps femoris muscle strength also was significantly lower in IPF patients (p=0.041). Rectus femoris muscle T2* measurements were significantly shorter in IPF patients (p=0.027). No significant intergroup difference was found regarding average muscle cross-sectional areas (p=0.790 for quadriceps and p=0.816 for rectus femoris) or rectus femoris fat fraction (p=0.901). Rectus femoris T2 values showed a non-significant trend to be shorter in IPF patients (p=0.055).Conclusions: Our preliminary findings suggest that, besides disuse atrophy, other factors such as hypoxia (but not inflammation) may play a role in the peripheral skeletal muscle dysfunction observed in IPF patients. This might impact the rehabilitation strategies for IPF patients and warrants further investigation.