High-throughput gadobutrol-enhanced CMR: a time and dose optimization study.

BACKGROUND: Reducing time and contrast agent doses are important goals to provide cost-efficient cardiovascular magnetic resonance (CMR) imaging. Limited information is available regarding the feasibility of evaluating left ventricular (LV) function after gadobutrol injection as well as defining the lowest dose for high quality scar imaging. We sought to evaluate both aspects separately and systematically to provide an optimized protocol for contrast-enhanced CMR (CE-CMR) using gadobutrol. METHODS: This is a prospective, randomized, single-blind cross-over study performed in two different populations. The first population consisted of 30 patients with general indications for a rest CE-CMR who underwent cine-imaging before and immediately after intravenous administration of 0.1 mmol/kg body-weight of gadobutrol. Quantitative assessment of LV volumes and function was performed by the same reader in a randomized and blinded fashion. The second population was composed of 30 patients with indication to late gadolinium enhancement (LGE) imaging, which was performed twice at different gadobutrol doses (0.1 mmol/kg vs. 0.2 mmol/kg) and at different time delays (5 and 10 min vs. 5, 10, 15 and 20 min), within a maximal interval of 21 days. LGE images were analysed qualitatively (contrast-to-noise ratio) and quantitatively (LGE%-of-mass). RESULTS: Excellent correlation between pre- and post-contrast cine-imaging was found, with no difference of LV stroke volume and ejection fraction (p = 0.538 and p = 0.095, respectively). End-diastolic-volume and end-systolic-volume were measured significantly larger after contrast injection (p = 0.008 and p = 0.001, respectively), with a mean difference of 3.7 ml and 2.9 ml, respectively. LGE imaging resulted in optimal contrast-to-noise ratios 10 min post-injection for a gadobutrol dose of 0.1 mmol/kg body-weight and 20 min for a dose of 0.2 mmol/kg body-weight. At these time points LGE quantification did not significantly differ (0.1 mmol/kg: 11% (16.4); 0.2 mmol/kg: 12% (14.5); p = 0.059), showing excellent correlation (ICC = 0.957; p < 0.001). CONCLUSION: A standardized CE-CMR rest protocol giving a dose of 0.1 mmol/kg of gadobutrol before cine-imaging and performing LGE 10 min after injection represents a fast low-dose protocol without significant loss of information in comparison to a longer protocol with cine-imaging before contrast injection and a higher dose of gadobutrol. This approach allows to reduce examination time and costs as well as minimize contrast-agent exposure.

Right ventricular fibrosis in adults with uncorrected secundum atrial septal defect and pulmonary hypertension: a cardiovascular magnetic resonance study with late gadolinium enhancement, native T1 and extracellular volume.

Introduction: Right ventricular (RV) fibrosis represents both adaptive and maladaptive responses to the overloaded RV condition. Its role in pulmonary hypertension (PH) associated with secundum atrial septal defect (ASD), which is the most common adult congenital heart disease (CHD), remains poorly understood. Methods: We enrolled 65 participants aged ≥18 years old with uncorrected secundum ASD who had undergone clinically indicated right heart catheterization (RHC), divided into the non-PH group (n = 7), PH group (n = 42), and Eisenmenger syndrome (ES) group (n = 16). We conducted cardiovascular magnetic resonance (CMR) studies with late gadolinium enhancement (LGE) imaging, native T1 mapping, and extracellular volume (ECV) measurement to evaluate the extent and clinical correlates of RV fibrosis. Results: LGE was present in 94% of the population and 86% of the non-PH group, mostly located at the right ventricular insertion point (RVIP) regions. LGE in the septal and inferior RV region was predominantly observed in the ES group compared to the other groups (p = 0.031 and p < 0.001, respectively). The mean LGE scores in the ES and PH groups were significantly higher than those in the non-PH group (3.38 ± 0.96 vs. 2.74 ± 1.04 vs. 1.57 ± 0.79; p = 0.001). The ES and PH groups had significantly higher degrees of interstitial RV fibrosis compared to those in the non-PH group, indicated by native T1 (1,199.9 ± 68.9 ms vs. 1,131.4 ± 47.8 ms vs. 1,105.4 ± 44.0 ms; p < 0.001) and ECV (43.6 ± 6.6% vs. 39.5 ± 4.9% vs. 39.4 ± 5.8%; p = 0.037). Additionally, native T1 significantly correlated with pulmonary vascular resistance (r = 0.708, p < 0.001), RV ejection fraction (r = -0.468, p < 0.001) and peripheral oxygen saturation (r = -0.410, p = 0.001). Conclusion: In patients with uncorrected secundum ASD, RV fibrosis may occur before the development of PH and progressively intensify alongside the progression of PH severity. A higher degree of RV fibrosis, derived from CMR imaging, correlates with worse hemodynamics, RV dysfunction, and poorer clinical conditions.

Giant lipoma in superior vena cava: A case report and literature review.

INTRODUCTION: Intravascular lipomas are rare occurrences, especially in major vessels. This tumour is composed of adipocytes in a fibrous capsule that has a slow growth rate and usually shows no symptoms. There were only eight reports in the literature regarding intravascular lipoma located in the superior vena cava. CASE PRESENTATION: A 54-year-old man had episodes of supraventricular tachycardia and atrial flutter for over a year. Preoperative radiological findings showed a giant mass that arose from the superior vena cava to the right atrium and a biopsy catheter showed that there were no signs of malignancy. The patient then underwent surgery through median sternotomy and the mass was extirpated on the highest part of the stalk that could be reached. The patient was stable and remained to show no symptoms or evidence of residual mass or stalk in 2 years follow-up. CONCLUSION: The surgical approach in excising lipoma in SVC should be considered wisely with the support of adequate preoperative diagnosis. Since lipoma is a very slow-growing tumour, extensive manipulation that could increase surgical technique difficulty or postoperative morbidity and mortality is not necessary.

Left atrial strain: a multi-modality, multi-vendor comparison study.

AIMS: Left atrial (LA) strain is a prognostic biomarker with utility across a spectrum of acute and chronic cardiovascular pathologies. There are limited data on intervendor differences and no data on intermodality differences for LA strain. We sought to compare the intervendor and intermodality differences between transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) derived LA strain. We hypothesized that various components of atrial strain would show good intervendor and intermodality correlation but that there would be systematic differences between vendors and modalities. METHODS AND RESULTS: We evaluated 54 subjects (43 patients with a clinical indication for CMR and 11 healthy volunteers) in a study comparing TTE- and CMR-derived LA reservoir strain (ƐR), conduit strain (ƐCD), and contractile strain (ƐCT). The LA strain components were evaluated using four dedicated types of post-processing software. We evaluated the correlation and systematic bias between modalities and within each modality. Intervendor and intermodality correlation was: ƐR [intraclass correlation coefficient (ICC 0.64-0.90)], ƐCD (ICC 0.62-0.89), and ƐCT (ICC 0.58-0.77). There was evidence of systematic bias between vendors and modalities with mean differences ranging from (3.1-12.2%) for ƐR, ƐCD (1.6-8.6%), and ƐCT (0.3-3.6%). Reproducibility analysis revealed intraobserver coefficient of variance (COV) of 6.5-14.6% and interobserver COV of 9.9-18.7%. CONCLUSION: Vendor derived ƐR, ƐCD, and ƐCT demonstrates modest to excellent intervendor and intermodality correlation depending on strain component examined. There are systematic differences in measurements depending on modality and vendor. These differences may be addressed by future studies, which, examine calibration of LA geometry/higher frame rate imaging, semi-quantitative approaches, and improvements in reproducibility.

External Counterpulsation Improves Angiogenesis by Preserving Vascular Endothelial Growth Factor-A and Vascular Endothelial Growth Factor Receptor-2 but Not Regulating MicroRNA-92a Expression in Patients With Refractory Angina.

Objective: External counterpulsation (ECP) provides long-term benefits of improved anginal frequency and exercise tolerance in patients with refractory angina (RA). This is postulated as a result of improved angiogenesis and endothelial function through an increase in shear stress. Angiogenesis is mainly represented by vascular endothelial growth factor-A (VEGF-A) and its receptor, vascular endothelial growth factor receptor-2 (VEGFR-2). The microRNA-92a (miR-92a) is a flow-sensitive miRNA that regulates atherosclerosis and angiogenesis in response to shear stress. Thus, ECP beneficial effect might be achieved through interaction between VEGF-A, VEGFR-2, and miR-92a. This study aims to evaluate the ECP effect on VEGF-A, VEGFR-2, and miR-92a in patients with RA in a sham-controlled manner. Methods: This was a randomized sham-controlled trial, enrolling 50 patients with RA who have coronary artery disease (CAD). Participants were randomized (1:1 ratio) to 35 sessions of either ECP (n = 25) or sham (n = 25), each session lasting for 1 h. Plasma levels of VEGF-A and VEGFR-2 were assayed by the ELISA technique. The quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to measure miR-92a circulating levels in plasma. Result: External counterpulsation significantly preserved VEGF-A and VEGFR-2 level compared to sham [ΔVEGF-A: 1 (-139 to 160) vs.-136 (-237 to 67) pg/ml, p = 0.026; ΔVEGFR-2: -171(-844 to +1,166) vs. -517(-1,549 to +1,407) pg/ml, p = 0.021, respectively]. Circulating miR-92a increased significantly in ECP [5.1 (4.2-6.4) to 5.9 (4.8-6.4), p < 0.001] and sham [5.2 (4.1-9.4) to 5.6 (4.8-6.3), p = 0.008] post-intervention. The fold changes tended to be higher in ECP group, although was not statistically different from sham [fold changes ECP = 4.6 (0.3-36.5) vs. sham 2.8 (0-15), p = 0.33)]. Conclusion: External counterpulsation improved angiogenesis by preserving VEGF-A and VEGFR-2 levels. Both ECP and sham increased miR-92a significantly, yet the changes were not different between the two groups. (Study registered on www.clinicaltrials.gov, no: NCT03991871, August 8, 2019, and received a grant from the National Health Research and Development of Ministry of Health of Indonesia, No: HK.02.02/I/27/2020).

Left Ventricular Dimension after Mitral Valve Surgery in Rheumatic Mitral Stenosis: The Impact of Myocardial Fibrosis.

Background: Patients with rheumatic mitral stenosis (MS) experience changes in left ventricular (LV) dimensions after mitral valve surgery. We sought to investigate changes in LV dimensional parameters after mitral valve surgery and find out whether the same changes occurred in different extents of myocardial fibrosis. Methods: This prospective observational study comprised 43 patients with rheumatic MS planned for mitral valve surgery between October 2017 and April 2018 in National Cardiovascular Center Harapan Kita (NCCHK) Jakarta. All the patients underwent cardiac magnetic resonance imaging based on the late gadolinium enhancement (LGE) protocol for myocardial fibrosis assessment prior to surgery. The patients were classified according to the estimated fibrosis volume considered to influence hemodynamic performance (myocardial fibrosis <5% and myocardial fibrosis ≥5%). Serial transthoracic echocardiographic examinations before and after surgery were performed to detect changes in LV dimensional parameters. Results: This study consisted of 31 (72.1%) women and 12 (27.9%) men at a mean age of 46±9 years. The LGE protocol revealed myocardial fibrosis of less than 5% in 32 (74.4%) patients. A significant increase was detected in the LV end-diastolic diameter postoperatively, specifically in the patients with myocardial fibrosis of less than 5% (44.0±4.8 mm vs 46.6±5.6 mm; P value=0.027). A similar significant increase was not found in the other group (45.0±6.6 mm vs 46.7±6.9 mm; P value=0.256). Other changes in echocardiographic parameters showed similar patterns in both groups. Conclusion: Our patients with rheumatic MS who had myocardial fibrosis of less than 5% demonstrated better improvements in terms of increased preload. Myocardial fibrosis of less than 5% is associated with more favorable improvements in LV geometry.

Prognostic Value of Late Gadolinium Enhancement in Postoperative Morbidity following Mitral Valve Surgery in Rheumatic Mitral Stenosis.

Myocardial fibrosis in rheumatic mitral stenosis (MS) is caused by chronic inflammatory process. Its occurrence may lead to hemodynamic problems, especially after cardiac surgery. Myocardial fibrosis predicts worse morbidity after cardiac surgery, notably in coronary heart disease and aortic valve abnormalities. However, this issue has not been explored yet among patients with rheumatic MS. The aim of the study was to investigate prognostic impact of myocardial fibrosis to postoperative morbidity after mitral valve surgery in patients with rheumatic MS. This is a prospectively enrolled observational study of 47 consecutive rheumatic MS patients. All patients had preoperative evaluation with cardiac magnetic resonance imaging (CMR) including late gadolinium enhancement (LGE) protocol for left ventricular myocardial fibrosis assessment prior to mitral valve surgery. All patients were followed during hospitalization period. Postoperative morbidities were defined as stroke, renal failure, and prolonged mechanical ventilation. This study involved 33 women (70.2%) and 14 men (29.8%) with a mean age of 46 ± 10 years. Preoperative myocardial fibrosis was identified in 43 patients (91.5%). Estimated fibrosis volume ranged from 0% to 12.8% (median 2.8%). Postoperative morbidities occurred in 11 patients (23.4%). Significant mean difference of myocardial fibrosis volume was observed between patients with and without morbidity after mitral valve surgery (5.97 ± 4.16% and 3.12 ± 2.62%, p = 0.04). This significant association was allegedly influenced by different postoperative hemodynamic changes between the two groups. More extensive myocardial fibrosis is associated with postoperative morbiditiy after mitral valve surgery in patients with rheumatic MS.