Role of multimodality cardiac imaging for evaluation of intramyocardial dissection, from dissecting haematoma to false-pseudoaneurysm: a case series.

Background: Intramyocardial dissection (ID) is an extremely rare myocardial infarction mechanical complication. Although both clinical and imaging assessment of this rare condition remains a challenge, recent multimodality imaging techniques may help to confirm and to assess the progressive nature of the disease. Diagnosis may be reached in different stages, from as early as the intramyocardial dissecting haematoma to the severe false-pseudoaneurysm. Case summary: This series describes five cases of ID and provides insights into imaging findings and clinical course of this extremely uncommon condition. Our patients represented a wide range of clinical stages, from asymptomatic course to cardiogenic shock. The imaging diagnostic approach was very different from case to case and involved techniques such as echocardiography, cardiac CT, and cardiac magnetic resonance. Discussion: Intramyocardial dissection is a challenging condition in terms of diagnosis and clinical management associated with high morbidity and mortality. Furthermore, the different nomenclature found in the literature may be confusing. This case series supports the need of a terminology standardization and a multimodal imaging approach, which might be determinant for an accurate differential diagnosis and a suitable therapeutic management.

Adolescent Reference Values for MR-Derived Biventricular Strain Obtained Using Feature-Tracking and Myocardial Tagging.

BACKGROUND: Myocardial strain is a promising marker for the detection of early left or right ventricular (LV or RV) dysfunction in pediatric populations. The reference standard for MR strain measurement is myocardial tagging (MT); however, MT has limited clinical utility because the additional acquisitions needed are time-consuming. In contrast, MR-feature tracking (FT) allows strain quantification from routinely acquired cine sequences. Studies providing reference values obtained with both FT and MT for adolescents are lacking. PURPOSE: To use MR-FT and MT to define sex-specific LV and RV strain reference values for adolescents. STUDY TYPE: Cross-sectional, prospective. POPULATION: One hundred twenty-three adolescents aged 15-18 years (52% girls) without known cardiovascular disease. FIELD STRENGTH/SEQUENCE: Balanced steady-state free-precession sequence for FT analysis and a spatial modulation of magnetization hybrid TFE-EPI sequence for MT acquisitions at 3.0-T. ASSESSMENT: Segment Medviso software was used to obtain longitudinal (LS) and circumferential (CS) strain for both ventricles, and radial strain (RS) for LV. STATISTICAL TESTS: The Student t-test was used for between-sex comparisons of continuous variables. Sex-specific percentiles were calculated using the weighted average method. Intraobserver and interobserver agreement was assessed in 30 randomly selected studies using intraclass correlation coefficients (ICC). A P-value <0.05 was considered statistically significant. RESULTS: FT-derived LVLS and LVCS were significantly higher in girls than in boys (-19.8% vs. -17.8% and -22.2% vs. -21.0%, respectively), as they were with MT (LVLS: -18.1% vs. -16.8%; LVCS: -20.8% vs. -19.7%). FT-LVRS was higher in girls than in boys (44.8% vs. 35.1%), while MT-LVRS was the opposite (18.6% vs. 22.7%). FT-RVLS was higher in girls (-23.4% vs. -21.3%), but there were no between-sex differences in MT-derived RVLS or RVCS. ICC values for intraobserver agreement were ≥0.89, whereas for interobserver agreement were <0.80 for MT-LVRS and ≥0.80 for all remaining parameters. DATA CONCLUSION: This study provides sex-specific reference biventricular strain values obtained with MR-MT and MR-FT for adolescents aged 15-18 years. MR-FT may be a valid method for obtaining strain values in pediatric populations. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 3.

Absence of Myocardial Involvement After SARS-CoV-2 Vaccination in Asymptomatic Adolescents.

This study aimed to evaluate the presence of subclinical myocardial damage in adolescents who were vaccinated against SARS-CoV-2. One hundred twenty asymptomatic adolescents with a mean age of 16.0 ± 0.4 years (51% girls) underwent cardiac magnetic resonance (CMR) imaging. SARS-CoV-2 IgG/IgM antibody testing was performed, and self-reported dates of confirmed SARS-CoV-2 infection and/or vaccination were collected. Participants were classified according to SARS-CoV-2 status as naïve (non-infected and unvaccinated, n = 74), infected (unvaccinated, n = 23), and vaccinated (independently of past infection status, n = 23). Biventricular volumes and ejection fraction and myocardial T2 relaxation time were similar in the three groups. T1 relaxation time was slightly higher in vaccinated adolescents (1249 ± 35 ms) than in naïve and infected participants (1231 ± 30 ms and 1227 ± 29 ms, respectively; p = 0.035), although this difference was considered clinically irrelevant. This observational study found no evidence of relevant subclinical myocardial involvement after SARS-CoV-2 vaccination in asymptomatic adolescents.

Redefining cardiac damage staging in aortic stenosis: the value of GLS and RVAc.

AIMS: Cardiac damage staging has been postulated as a prognostic tool in patients undergoing transcatheter aortic valve replacement (TAVR). The aims of our study are (i) to validate cardiac damage staging systems previously described to stratify patients with aortic stenosis (AS), (ii) to identify independent risk factors for 1-year mortality in patients with severe AS undergoing TAVR, and (iii) to develop a novel staging model and compare its predictive performance to that of the above mentioned. METHODS AND RESULTS: Patients undergoing TAVR from 2017 to 2021 were included in a single-centre prospective registry. Transthoracic echocardiography was performed in all patients before TAVR. Logistic and Cox's regression analysis were used to identify predictors of 1-year all-cause mortality. In addition, patients were classified based on previously published cardiac damage staging systems, and the predictive performance of the different scores was measured.Four hundred and ninety-six patients (mean age 82.1 ± 5.9 years, 53% female) were included. Mitral regurgitation (MR), left ventricle global longitudinal strain (LV-GLS) and right ventricular-arterial coupling (RVAc) were independent predictors of all-cause 1-year mortality. A new classification system with four different stages was developed using LV-GLS, MR, and RVAc. The area under the receiver operating characteristic curve was 0.66 (95% confidence interval 0.63-0.76), and its predictive performance was superior compared with the previously published systems (P < 0.001). CONCLUSION: Cardiac damage staging might have an important role in patients' selection and better timing for TAVR. A model that includes LV-GLS, MR, and RVAc may help to improve prognostic stratification and contribute to better selection of patients undergoing TAVR.

Magnetic resonance imaging reference values for cardiac morphology, function and tissue composition in adolescents.

Background: Cardiovascular magnetic resonance (CMR) is a precise tool for the assessment of cardiac anatomy, function, and tissue composition. However, studies providing CMR reference values in adolescence are scarce. We aim to provide sex-specific CMR reference values for biventricular and atrial dimensions and function and myocardial relaxation times in this population. Methods: Adolescents aged 15-18 years with no known cardiovascular disease underwent a non-contrast 3-T CMR scan between March 2021 and October 2021. The imaging protocol included a cine steady-state free-precession sequence for the analysis of chamber size and function, as well as T2-GraSE and native MOLLI T1-mapping for the characterization of myocardial tissue. Findings: CMR scans were performed in 123 adolescents (mean age 16 ± 0.5 years, 52% girls). Mean left and right ventricular end-diastolic indexed volumes were higher in boys than in girls (91.7 ± 11.6 vs 78.1 ± 8.3 ml/m2, p < 0.001; and 101.3 ± 14.1 vs 84.1 ± 10.5 ml/m2, p < 0.001), as was the indexed left ventricular mass (48.5 ± 9.6 vs 36.6 ± 6.0 g/m2, p < 0.001). Left ventricular ejection fraction showed no significant difference by sex (62.2 ± 4.1 vs 62.8 ± 4.2%, p = 0.412), whereas right ventricular ejection fraction trended slightly lower in boys (55.4 ± 4.7 vs. 56.8 ± 4.4%, p = 0.085). Indexed atrial size and function parameters did not differ significantly between sexes. Global myocardial native T1 relaxation time was lower in boys than in girls (1215 ± 23 vs 1252 ± 28 ms, p < 0.001), whereas global myocardial T2 relaxation time did not differ by sex (44.4 ± 2.0 vs 44.1 ± 2.4 ms, p = 0.384). Sex-stratified comprehensive percentile tables are provided for most relevant cardiac parameters. Interpretation: This cross-sectional study provides overall and sex-stratified CMR reference values for cardiac dimensions and function, and myocardial tissue properties, in adolescents. This information is useful for clinical practice and may help in the differential diagnosis of cardiac diseases, such as cardiomyopathies and myocarditis, in this population. Funding: Instituto de Salud Carlos III (PI19/01704).