BackgroundCardiovascular magnetic resonance (CMR)-derived extracellular volume (ECV) and tissue tracking strain analyses are proposed as non-invasive methods for quantifying myocardial fibrosis and deformation. This study sought (1) to histologically validate myocardial ECV against the collagen volume fraction (CVF) measured from tissue samples of patients undergoing heart transplantation and (2) to detect the correlations between myocardial systolic strain and the myocardial ECV and histological CVF in patients undergoing heart transplantation.MethodsA total of 12 dilated cardiomyopathy (DCM) and 10 ischaemic cardiomyopathy (ICM) patients underwent T1 mapping with the Modified Look Locker Inversion recovery (MOLLI) sequence, T2 mapping and ECV. Myocardial systolic strain, including left ventricular global longitudinal (GLS), circumferential (GCS) and radial strain (GRS), were quantified using CMR cine images with tissue tracking analysis software. Tissue samples were collected from each of 16 segments of the explanted hearts and were stained with picrosirius red for histological CVF quantification.ResultsA strong relationship was observed between the global myocardial ECV and histological CVF in the DCM and ICM patients based on a per-patient analysis (r = 0.904 and r = 0.901, respectively, p <  0.001). In the linear mixed-effects regression analysis, ECV correlated well with the histological CVF in the DCM and ICM patients on a per-segment basis (β = 0.838 and β = 0.915, respectively, p <  0.001). In the multivariate linear regression analysis, histological CVF was the strongest independent determinant of ECV in the patients awaiting heart transplantation (standardised β = 0.860, p <  0.001). However, the T2 time, GLS, GCS and GRS showed no significant associations with ECV and CVF in the patients awaiting heart transplantation.ConclusionsECV derived from CMR correlated well with histological CVF, indicating its potential as a non-invasive tool for the quantification of myocardial fibrosis. Additionally, impaired myocardial systolic strains were not associated with the ECV and CVF in the patients awaiting heart transplantation.

ObjectiveTo evaluate the efficacy of continuous positive airway pressure (CPAP) on serum testosterone in men with obstructive sleep apnea (OSA).MethodsTwo reviewers independently searched PubMed, Cochrane library, Embase and Web of Science before June 2014. Information on characteristics of subjects, study design, pre- and post-CPAP treatment of serum total testosterone, free testosterone and sexual hormone blinding protein (SHBG) was extracted for analysis.ResultsA total of 7 studies with 9 cohorts that included 232 men were pooled into meta-analysis. There was no change of total testosterone levels before and after CPAP treatment in OSA men (standardized mean difference (SMD) = −0.14, 95%CI: −0.63 to 0.34, z = 0.59, p = 0.558), even subdivided by CPAP therapeutic duration (>3 months). Meanwhile, no significant differences in free testosterone and SHBG were detected after CPAP treatment (SMD =  0.16, 95%CI: −0.09 to 0.40, z = 1.25, p = 0.211 and SMD = −0.58, 95%CI: −1.30 to 0.14, z = 1.59, p = 0.112, respectively).ConclusionCPAP has no influence on testosterone levels in men with OSA, further large-scale, well-design interventional investigation is needed.

Myocardial interstitial expansion seems to be fundamental to the process of adverse left ventricular remodeling. Recent evidence has shown that the extracellular volume fraction (ECV) derived from cardiovascular magnetic resonance (CMR) can be used as a noninvasive method to quantify myocardial interstitial volume in a range of heart diseases. Our aim was to determine whether ECV is increased in asymptomatic orthotopic heart transplant (HTx) patients and its associations with clinical features and T2 values, the elevation of which usually suggests myocardial edema. A group of asymptomatic cardiac transplant recipients and some healthy volunteers were invited to undergo a comprehensive CMR scan, including cine imaging, late gadolinium enhancement, T1 mapping and T2 mapping, from March to June in 2017. All quantitative measurements were averaged from the basal and mid short-axis slices. Fifty-eight recipients (mean age, 42.7 ± 11.5 years; 13 females), at a median of 1.8 years (0.3-6.3 years) after HTx, and 20 healthy volunteers (mean age, 39.5 ± 11.3 years; 5 females) underwent the CMR scan. We found that both the ECV and T2 values were higher in the post-HTx group (ECV: 26.7 ± 3.3 vs. 24.6 ± 2.5%, p = 0.008; T2: 47.7 ± 2.8 vs. 44.5 ± 1.6 ms, p< 0.001) than in the control group. ECV was moderately associated with organ ischemia time at the time of transplantation but not with the hemodynamics parameter or the time since transplantation at CMR. Additionally, a relatively strong correlation was observed between ECV and T2 (r = 0.7, p < 0.001). So, our conclusion is that CMR-derived ECV is increased and associated with peri-transplant ischemia time in asymptomatic HTx patients. And the strong correlation of ECV with elevated T2 indicates that myocardial edema may be an important part of the extracellular volume expansion after heart transplantation.