Browsing by Author "Thomas, B"
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- Angiografia por Ressonância Magnética Tridimensional Optimizada por Contraste nas Doenças da AortaPublication . Thomas, B; Roquette, J; Ferreira, RObjectivos: Avaliar a possibilidade de realizar angiografia de alta resolução com reconstrução tridimensional, com recurso a equipamento de ressonância magnética de 1 Tesla, em doentes com patologia aórtica. Métodos: Efectuaram-se trinta e um exames de ressonâncias magnética em dezassete doentes, após administração, sob a forma de bolus, de gadolinium. Foram adquiridas imagens em spin echo rápido, gradiente echo e angiografia com time-of-flight. Resultados: Todas as aquisições foram bem toleradas e conseguiu-se a opacificação do lumen aórtico, no momento apropriado, em todos os doentes. As sequências angiográficas foram obtidas com respiração suspensa que requereu cerca de 25 segundos por imagem e seis a oito minutos para conseguir uma reconstrução tridimensional. Conclusão: A angiografia aórtica por reconstrução tridimensional é possível com um equipamento de 1 Tesla, com imagens de elevada qualidade e resolução, obtidas em pouco minutos. É possível obter toda a informação facultada pela aquisição em spin echo, convencional ou acelerado, a partir da reconstrução das imagens tridimensionais, afastando assim a necessidade de aquisição, tão incómoda, das imagens spin echo, melhorar a rapidez e diminuir, portanto, o tempo de aquisição, o que se torna relevante em doentes com síndromes aórticos agudos.
- Aortic Arch Geometry after Aortic Coarctation Repair: Systematic Magnetic Resonance Study in a Consecutive Series of PatientsPublication . Martins, JD; Thomas, B; Jalles, N; Pinto, MF
- Associations Between Perfusion Defects, Tissue Changes and Myocardial Deformation in Hypertrophic Cardiomyopathy, Uncovered by a Cardiac Magnetic Resonance Segmental AnalysisPublication . Brás, P; Aguiar Rosa, S; Thomas, B; Fiarresga, A; Cardoso, I; Pereira, R; Branco, G; Cruz, I; Baquero, L; Cruz Ferreira, R; Mota Carmo, M; Rocha Lopes, LBackground: Microvascular dysfunction is an often overlooked feature of hypertrophic cardiomyopathy (HCM). Our aim was to assess the association between microvascular dysfunction, wall thickness, tissue characteristics and myocardial deformation in HCM patients, by analyzing individual myocardial segments. Methods: Prospective assessment including cardiac magnetic resonance to assess wall thickness, T1 and T2 mapping, extracellular volume, late gadolinium enhancement (LGE) and stress perfusion. Results were stratified according to the 16 American Heart Association segments. Results: Seventy-five patients were recruited (1200 segments), 63% male, mean age 54.6±14.8 years, maximal wall thickness of 20.22±4.6 mm. Among the 424 segments (35%) with perfusion defects, 24% had defects only in the endocardial layer and 12% in both endocardial and epicardial layers. Perfusion defects were more often detected in hypertrophied segments (64%). Among the 660 segments with normal wall thickness, 19% presented perfusion defects. Independently of wall thickness, segments with perfusion defects had a higher T1 (β-estimate 30.28, p<0.001), extracelluar volume (β-estimate 1.50, p<0.001) and T2 (β-estimate 0.73, p<0.001) and had late gadolinium enhancement more frequently (odds ratio 4.16, p<0.001). Higher values of circumferential strain (lower deformation) and lower values of radial strain were found in segments with perfusion defects (β-estimate 2.76, p<0.001; and β-estimate -10.39, p<0.001, circumferential and radial strain, respectively). Conclusion: While microvascular dysfunction was more prevalent in more hypertrophied segments, it also had a major presence in segments without hypertrophy. In this segmental analysis, we found an association between the presence of ischemia and tissue abnormalities, replacement fibrosis as well as impaired strain, independently of the segmental wall thickness.
- Blunted Coronary Flow Velocity Reserve is Associated With Impairment in Systolic Function and Functional Capacity in Hypertrophic CardiomyopathyPublication . Aguiar Rosa, S; Rocha Lopes, L; Branco, L; Galrinho, A; Fiarresga, A; Thomas, B; Brás, P; Gonçalves, A; Cardoso, I; Papoila, A; Alves, M; Rio, P; Cruz, I; Selas, M; Silva, F; Silva, A; Cruz Ferreira, R; Mota Carmo, MBackground Coronary microvascular dysfunction constitutes an important pathophysiological feature in hypertrophic cardiomyopathy (HCM). We aimed to assess the association between impaired coronary flow velocity reserve (CFVR) and ventricular systolic function and functional capacity. Methods Eighty-three patients with HCM were enrolled in this prospective cohort study. Patients underwent echocardiogram to evaluate ventricular performance and CFVR in the left anterior descending artery (LAD) and posterior descending artery (PD). Diastolic coronary flow velocity was measured in basal conditions and in hyperemia. CFVR was calculated as the ratio of hyperemic and basal peak diastolic flow velocities. Functional capacity was evaluated by cardiopulmonary exercise testing (CPET). The link between CFVR and biventricular systolic function and peak VO2 was studied. Results Age was 55.0(14.4)years, 50 patients (60%) were male; 59 patients (71%) had nonobstructive HCM. Mean CFVR LAD was 1.81(0.49) and CFVR PD was 1.73(0.55). Lower CFVR PD was associated with impaired global longitudinal strain (GLS) 2D (β-estimate:-3.240,95%CI:-4.634;-1.846, p < 0.001), GLS 3D (β-estimate:-2.559,95%CI:-3.932;-1.186, p < 0.001) and area strain (β-estimate:-3.044,95%CI:-5.373;-0.716, p = 0.011). Lower values of CFVR PD related to worse global work index (β-estimate:267.824,95%CI:75.964;459.683, p = 0.007), global constructive work (β-estimate:217.300,95%CI:38.750;395.850, p = 0.018) and global work efficiency (β-estimate:5.656,95%CI:2.229;9.084, p = 0.002). Impaired CFVR LAD (β-estimate:2.826, 95%CI:0.913;4.739, p = 0.004) and CFVR PD (β-estimate:2.801,95%CI:0.657;4.945, p = 0.011) were associated with lower TAPSE. Lower values of CFVR LAD (β-estimate:2.580, 95%CI:0.169;4.991, p = 0.036) and CFVR PD (β-estimate:3.163, 95%CI: 0.721;5.606, p = 0.012) were associated with worse peak VO2. Conclusion Lower CFVR was associated with impairment in biventricular systolic function parameters and functional capacity assessed by pVO2.
- Cardiac Magnetic Resonance in the Assessment of Pericardial Abnormalities: a Case SeriesPublication . Mano, T; Santos, H; Aguiar Rosa, S; Thomas, B; Baquero, LBackground: Cardiac magnetic resonance (CMR) has a unique role in evaluating pericardial disease, permitting non-invasive tissue analysis, and haemodynamic assessment. Case summary: In Case 1 of recurrent pericarditis, CMR confirmed reactivation of inflammation with late gadolinium enhancement and native T1/T2 mapping techniques, prompting therapeutic changes. In constrictive pericarditis, CMR is the only modality capable of differentiating a subacute potentially reversible form (Case 2), from a chronic, burnt out irreversible phase characterized by constrictive physiology (Case 3). Discussion: Cardiac magnetic resonance is an effective tool to tailor individual therapy, particularly in cases of recurrent and constrictive pericarditis. Late gadolinium enhancement provides diagnostic and prognostic information, and multiparametric mapping has emerged as a promising tool with incremental diagnostic value.
- Cardiovascular Magnetic ResonancePublication . Ferreira, V; Thomas, B; Aguiar Rosa, S
- Cirurgia Cardio-TorácicaPublication . Thomas, B; Farto e Abreu, P; Roquette, J; Ferreira, R
- Impact of Treatment Modality on Vascular Function in Coarctation of the Aorta: The LOVE - COARCT StudyPublication . Martins, JD; Zachariah, J; Selamet Tierney, E; Truong, U; Morris, S; Kutty, S; de Ferranti, S; Guarino, M; Thomas, B; Oliveira, D; Marinho, A; António, M; Gauvreau, K; Jalles, N; Geva, T; Mota Carmo, M; Prakash, ABackground Optimally treated patients with coarctation of the aorta remain at risk for late vascular dysfunction. The effect of treatment modality on vascular function is unknown. The LOVE-COARCT (Long-term Outcomes and Vascular Evaluation After Successful Coarctation of the Aorta Treatment) study was done to compare vascular function in patients with coarctation of the aorta treated with surgery, balloon dilation (BD), or stent implantation. Methods and Results In treated coarctation of the aorta patients without residual coarctation, we prospectively compared aortic stiffness by applanation tonometry and cardiac magnetic resonance; endothelial function by endothelial pulse amplitude testing; blood pressure ( BP ) phenotype by office BP , ambulatory BP monitoring, and BP response to exercise; left ventricular mass by cardiac magnetic resonance; and blood biomarkers of endothelial function, inflammation, vascular wall function, and extracellular matrix. Participants included 75 patients treated with surgery (n=28), BD (n=23), or stent (n=24). Groups had similar age at enrollment, coarctation of the aorta severity, residual gradient, and metabolic profile, but differed by age at treatment. Prevalence of systemic hypertension, aortic stiffness, endothelial function, and left ventricular mass were similar among treatment groups. However, BD patients had more-distensible ascending aortas, lower peak systolic BP during exercise, less impairment in diurnal BP variation, and lower inflammatory biomarkers. Results were unchanged after adjustment for potential confounders, including age at treatment. Conclusions In our cohort of patients without residual coarctation, treatment modality was not associated with major vascular outcomes, even though there were some favorable vascular characteristics in the BD patients. Although this suggests that choice of treatment modality should continue to be driven by likelihood of achieving a good anatomical result, more long-term studies are required to assess the clinical significance of the more-optimal results of secondary markers of vascular function in BD patients. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 03262753.
- Index of Microcirculatory Resistance in the Assessment of Coronary Microvascular Dysfunction in Hypertrophic CardiomyopathyPublication . Aguiar Rosa, S; Mota Carmo, M; Rocha Lopes, L; Oliveira, E; Thomas, B; Baquero, L; Cruz Ferreira, R; Fiarresga, AIntroduction and objectives: Coronary microvascular dysfunction (CMD) is one of the most important pathophysiological features in hypertrophic cardiomyopathy (HCM). The index of microcirculatory resistance (IMR) is an invasive method to assess the coronary microcirculation. The aim was to assess CMD in patients with HCM by IMR. Methods: Adult patients with HCM without epicardial coronary artery disease underwent cardiac catheterization for the assessment of CMD by IMR (normal cut-off value ≤22.0) and coronary flow reserve (CFR) (normal cut-off value ≥2). Cardiovascular magnetic resonance (CMR) was performed to assess the ischemic burden by perfusion imaging during regadenoson-induced hyperemia, and the extent of myocardial fibrosis was assessed by late gadolinium enhancement (LGE), native T1 mapping and extracellular volume (ECV). Results: Fourteen patients were enrolled with a mean age of 62.8±6.2years, 8 (57.1%) males, of whom 9 (64.3%) had obstructive HCM. Using IMR, CMD was detected in 4 (29%) patients. Among four patients with an IMR>22.0, all had non-obstructive HCM and two had angina. CFR<2 was reported in eight patients (57%). Concordance between IMR and CFR (both normal or both abnormal) was verified in 6 patients (43%). Among four patients with IMR>22.0, perfusion defects were found in two of the three patients who underwent stress CMR. Increased ECV (>28%) was documented in two of the patients with IMR>22 and in three of the patients with IMR≤22.0. LGE was >15% in 2 of the patients with IMR>22 and in 4 with IMR≤22.0. Conclusions: IMR assessment in HCM is feasible and safe. Patients with abnormal IMR seemed to have more significant tissue abnormalities on CMR.
- Microvascular Dysfunction Is Associated With Impaired Myocardial Work in Obstructive and Nonobstructive Hypertrophic Cardiomyopathy: A Multimodality StudyPublication . Garcia Brás, P; Aguiar Rosa, S; Cardoso, I; Branco, L; Galrinho, A; Valentim Gonçalves, A; Thomas, B; Viegas, JM; Fiarresga, A; Branco, G; Pereira, R; Selas, M; Silva, F; Cruz, I; Baquero, L; Cruz Ferreira, R; Rocha Lopes, LBackground Two-dimensional speckle tracking echocardiography has been shown to correlate with microvascular dysfunction, a hallmark of hypertrophic cardiomyopathy (HCM). We hypothesized that there is an association between myocardial work and left ventricular ischemia, with incremental value to global longitudinal strain, in patients with HCM. Methods and Results We performed a prospective assessment of patients with HCM, undergoing 2-dimensional speckle tracking echocardiography and stress perfusion cardiac magnetic resonance. Results were stratified according to obstructive or nonobstructive HCM and the presence of significant replacement fibrosis (late gadolinium enhancement ≥15% of left ventricular mass). Seventy-five patients with HCM (63% men, age 55±15 years) were evaluated, 28% with obstructive HCM (mean gradient 89±60 mm Hg). Perfusion defects were found in 90.7%, involving 22.5±16.9% of left ventricular mass, and 38.7% had late gadolinium enhancement ≥15%. In a multivariable analysis, a lower global work index (r=-0.519, β-estimate -10.822; P=0.001), lower global work efficiency (r=-0.379, β-estimate -0.123; P=0.041), and impaired global constructive work (r=-0.532, β-estimate -13.788; P<0.001) significantly correlated with ischemia. A segmental analysis supported these findings, albeit with lower correlation coefficients. A global work index cutoff ≤1755 mm Hg% was associated with hypoperfusion with a sensitivity of 88% and a specificity of 71%, while the best cutoff for global longitudinal strain (>-15.5%) had a sensitivity of 64% and a specificity of 57%. The association between myocardial work and perfusion defects was significant independently of late gadolinium enhancement ≥15% and obstructive HCM. Conclusions Impaired myocardial work was significantly correlated with the extent of ischemia in cardiac magnetic resonance, independently of the degree of left ventricular hypertrophy or fibrosis, with a higher predictive power than global longitudinal strain.