Multiparametric assessment of right ventricular function in heart transplant recipients by echocardiography and relations with pulmonary hemodynamics.

OBJECTIVE: Right ventricular (RV) dilatation and dysfunction are usually present in heart transplant (HTx) patients and worsened with residual pulmonary hypertension (PH). We aimed to determine the ability of different echocardiographic modalities to evaluate RV function in comparison with cardiac magnetic resonance (CMR) and their relations with pulmonary hemodynamics in HTx patients. METHODS: A total of 62 data sets [echocardiographic, hemodynamic, and CMR] were acquired from 35 HTx patients. Comprehensive echocardiography, including two-dimensional (2D) transthoracic echocardiography, speckle tracking echocardiography, and three-dimensional (3D) echocardiography, was performed. Mean pulmonary artery pressure (mPAP) was obtained invasively from right heart catheterization. The correlations between all echocardiographic parameters and CMR imaging data and the differences between patients with and without residual PH were evaluated. RESULTS: Diastolic and systolic RV volumes and RV ejection fraction (RVEF) by 3D echocardiography correlated strongly with CMR-derived volumes and RVEF (r = .91, r = .79, r = .64; p < .0001 for each, respectively). Among other parameters, RV fractional area change (r = .439; p < .001) and RV free wall longitudinal strain (RVFW-LS) (r = -.34; p < .05) correlated moderately with CMR-RVEF, whereas tricuspid annulus S' velocity (r = .29; p < .05) and tricuspid annular systolic plane excursion (r = .27; p < .05) correlated weakly with CMR-RVEF. Additionally, 3D-RVEF and RVFW-LS were significantly decreased in studies with mPAP ≥ 20 mm Hg in comparison to those with mPAP < 20 mm Hg (47.7 ± 3.7 vs. 50.9 ± 5.3, p = .04 and -15.5 ± 3.1 vs. -17.5 ± 3, p = .03, respectively). CONCLUSION: The best method for the evaluation of RV function in HTx recipients is 3D echocardiography. Besides, the subclinical impact of residual PH on RV function can be best determined by RVFW-LS and 3D-RVEF in these patients.

Approach to optimal assessment of right ventricular remodelling in heart transplant recipients: insights from myocardial work index, T1 mapping, and endomyocardial biopsy.

AIMS: Right ventricular (RV) dysfunction is an important cause of graft failure after heart transplantation (HTx). We sought to investigate relative merits of echocardiographic tools and cardiac magnetic resonance (CMR) with T1 mapping for the assessment of functional adaptation and remodelling of the RV in HTx recipients. METHODS AND RESULTS: Sixty-one complete data set of echocardiography, CMR, right heart catheterization, and biopsy were obtained. Myocardial work index (MWI) was quantified by integrating longitudinal strain (LS) with invasively measured pulmonary artery pressure. CMR derived RV volumes, T1 time, and extracellular volume (ECV) were quantified. Endomyocardial biopsy findings were used as the reference standard for myocardial microstructural changes. In HTx recipients who never had a previous allograft rejection, longitudinal function parameters were lower than healthy organ donors, while ejection fraction (EF) (52.0 ± 8.7%) and MWI (403.2 ± 77.2 mmHg%) were preserved. Rejection was characterized by significantly reduced LS, MWI, longer T1 time, and increased ECV that improved after recovery, whereas RV volumes and EF did not change MWI was the strongest determinant of rejection related myocardial damage (area under curve: 0.812, P < 0.0001, 95% CI: 0.69-0.94) with good specificity (77%), albeit modest sensitivity. In contrast, T1 time and ECV were sensitive (84%, both) but not specific to detect subclinical RV damage. CONCLUSION: Subclinical adaptive RV remodelling is characterized by preserved RV EF despite longitudinal function abnormalities, except for MWI. While ultrastructural damage is reflected by MWI, ECV, and T1 time, only MWI has the capability to discriminate functional adaptation from transition to subclinical structural damage.

Assessment of epicardial adipose tissue and carotid/femoral intima media thickness in insulin resistance.

BACKGROUND: Metabolic syndrome is a combination of multiple cardiovascular (CV) risk factors including insulin resistance (IR). Carotid, femoral intima media thickness (IMT), and epicardial fat thickness (EFT) are considered as novel cardiometabolic risk factors. We aimed to test the hypothesis that carotid, femoral IMT, and EFT are increased in patients with IR. METHODS: We enrolled consecutively and prospectively 113 patients with IR. Then we collected data from an age- and sex-matched control group of 112 individuals without IR. Homeostasis model assessment (HOMA) index value >2.5 was accepted as IR. Patients with diabetes mellitus, CV diseases, systolic heart failure, chronic liver or renal diseases were excluded. On B-mode duplex ultrasound the mean IMT at the far wall of both left and right common carotid/femoral arteries were measured manually. EFT was measured on the free wall of the right ventricle at end-diastole from the parasternal long-axis views by standard transthoracic 2D echocardiography. RESULTS: Both carotid IMT and EFT were significantly higher in patients with IR compared to controls (0.80±0.21mm vs 0.60±0.21mm; p<0.001 and 7.34±1.96mm vs 5.22±1.75mm; p<0.001, respectively). However, there were no significant differences in femoral IMT between the groups (0.74±0.20 vs 0.69±0.17; p=0.062). In multivariate linear regression analysis age (ß=0.223, p=0.010), 2-h blood glucose (ß=0.198, p=0.021), and IR (ß=0.369, p<0.001) were independent predictors of EFT. On the other hand age (ß=0.363, p<0.001) and IR (ß=0.321, p<0.001) were independent predictors of carotid IMT. CONCLUSIONS: Patients with IR have increased carotid IMT and EFT, but not femoral IMT. This apparent incoherence may be due to the involvement of carotid arteries prior to femoral arteries in patients with IR.

Assessment of Subclinical Atherosclerosis by Carotid Intima-Media Thickness and Epicardial Adipose Tissue Thickness in Prediabetes.

Impaired fasting glucose (IFG) and impaired glucose intolerance (IGT) are predictors of cardiovascular disease (CVD). We tested the hypothesis that epicardial fat thickness (EFT) and carotid intima-media thickness (cIMT), as markers of early atherosclerosis, are increased in patients with prediabetes. We prospectively enrolled 246 patients (162 with prediabetes and 84 controls). Prediabetes was defined according to American Diabetes Association criteria, and patients were divided into 3 groups: group 1-IFG, group 2-IGT, and group 3-IFG + IGT. Both cIMT and EFT were significantly greater in patients with prediabetes compared with controls (0.81 ± 0.20 mm vs 0.68 ± 0.16 mm, P < .001 and 7.0 ± 2.0 mm vs 5.6 ± 1.6 mm, P < .001, respectively). This difference was mainly attributed to patients with IGT. Age, waist circumference, and 2-hour glucose independently predicted cIMT, while 2-hour glucose was the only independent predictor of EFT in multivariate analysis among other relevant parameters for cIMT and EFT. The cIMT and EFT (measured noninvasively) could be useful indicators of CVD risk in these patients. In order to prove this hypothesis, long-term prospective studies with greater patient numbers are required.