Reproducibilidad del strain longitudinal global del ventrículo izquierdo por ecocardiografía bidimensional speckle tracking: Estudio Longitudinal de Salud del Adulto (ELSA-Brasil) / Reproducibility of left ventricular global longitudinal strain using two-dimensional ultrasound speckle tracking: Longitudinal Study of Adult Health (ELSA-Brasil)

Resumen Introducción: Se han propuesto técnicas ecocardiográficas avanzadas como el strain longitudinal global por ecocardiografía bidimensional speckle tracking para la detección de alteraciones precoces de la función sistólica del ventrículo izquierdo. La evaluación de la reproducibilidad del strain longitudinal global es fundamental para su aplicación clínica en diferentes escenarios. Objetivo: Estimar la reproducibilidad del strain longitudinal global del ventrículo izquierdo en individuos de un estudio de cohorte del Brasil. Métodos: La reproducibilidad del strain longitudinal global del ventrículo izquierdo fue evaluada mediante lectura y análisis de imágenes de ecocardiografía de una muestra aleatoria de 50 participantes de la línea de base del Estudio Longitudinal de Salud del Adulto (ELSA-Brasil). Resultados: Los participantes tenían una edad promedio de 49,7 ± 7,3 años, 54% eran mujeres y la media del strain longitudinal global fue -19,5% ± 1,9%. La reproducibilidad interobservador de la medida del strain longitudinal global mostró un coeficiente de variación de 7,4% y un coeficiente de correlación intraclase de 0,76 (IC 95%: 0,61, 0,86). El análisis del acuerdo interobservador de las medidas del strain longitudinal global mediante el método de Bland & Altman evidenció un promedio de diferencias de 0,1% ± 1,4% y unos límites de acuerdo superior de 2,9 e inferior de -2,7. Conclusiones: Hubo una reproducibilidad adecuada de las medidas del strain longitudinal global del ventrículo izquierdo en participantes del ELSA-Brasil y los valores fueron similares a los reportados en otros estudios epidemiológicos longitudinales. Los hallazgos refuerzan la utilidad del strain longitudinal global como un índice clínico de deformación miocárdica, capaz de detectar alteraciones subclínicas de la contractilidad miocárdica.

Abstract Introduction: Advanced echocardiography techniques, such as the global longitudinal strain using two-dimensional ultrasound speckle tracking, have been proposed for the detection of early changes in the left ventricular systolic function. The evaluation of the reproducibility of left ventricular global longitudinal strain is essential for its clinical application in different scenarios. Objective: To determine the reproducibility of left ventricular global longitudinal strain in individuals from a Brazil cohort study. Methods: The reproducibility of left ventricular global longitudinal strain was evaluated by the reading and analysis of echocardiograph images of a random sample of 50 participants of the baseline Longitudinal Study of Adult Health (ELSA-Brasil). Results: The mean age of the participants was 49.7 ± 7.3 years, of whom 54% were women, and the mean global longitudinal strain was -19.5% ± 1.9%. The inter-observer reproducibility of the mean global longitudinal strain, had a coefficient of variation of 7.4%, and an intra-class correlation of 0.76 (95% CI: 0.61 - 0.86). The analysis of the inter-observer agreement of the global longitudinal strain measurements using the Bland and Altman method showed a mean differences of 0.1% ± 1.4%, and upper and lower limits of agreement of 2.9 and -2.7, respectively. Conclusions: There was adequate reproducibility of the left ventricular global longitudinal strain measurements in participants of the ELSA-Brasil study, and the values were similar to those reported in other longitudinal epidemiological studies. The findings reinforce the use of the global longitudinal strain as a clinical marker of myocardial deformation, capable of detecting subclinical changes in myocardial contractility.

Alteração precoce da matriz extracelular e parâmetros diastólicos na síndrome metabólica / Early change of extracellular matrix and diastolic parameters in metabolic syndrome

FUNDAMENTOS: Síndrome Metabólica (SM) está associada com maior risco cardiovascular, porém não está claro se as alterações miocárdicas presentes nessa condição, como a disfunção diastólica, são consequência de mecanismos sistêmicos ou de efeitos diretos no miocárdio. OBJETIVOS: Comparar função diastólica, biomarcadores de atividade da Matriz Extracelular (MEC), inflamação e estresse hemodinâmico, em pacientes com SM e controles saudáveis. MÉTODOS: Pacientes com SM (n = 76) e controles saudáveis (n = 30) foram avaliados clinicamente e submetidos a exame ecocardiográfico e mensuração dos níveis plasmáticos de metaloproteinase-9 (MMP9), inibidor tecidual da metaloproteinase-1 (TIMP1), proteína C reativa ultrassensível (PCR-us), resistência insulínica (HOMA-RI) e NT-proBNP. RESULTADOS: O grupo SM apresentou menor onda E' (10,1 ± 3,0 cm/s vs. 11,9 ± 2,6 cm/s, p = 0,005), maiores valores para onda A (63,4 ± 14,1 vs. 53,1 ± 8,9 cm/s, p < 0,001), razão E/E'(8,0 ± 2,2 vs. 6,3 ± 1,2; p < 0,001), MMP9 (502,9 ± 237,1 vs. 330,4 ± 162,7 ng/mL, p < 0,001), PCR-us (p = 0,001) e HOMA-RI (p < 0,001), sem diferença nos níveis de TIMP1 e NT-proBNP. Na análise multivariada, apenas MMP9 foi independentemente associada a SM. CONCLUSÃO: Pacientes com SM apresentaram diferenças em medidas ecocardiográficas de função diastólica, na atividade da MEC, PCR-us e HOMA-RI em relação aos controles. Porém, somente MMP9 foi independentemente associada com SM. Esses achados sugerem que os efeitos precoces da SM sobre a atividade da MEC podem não ser detectados nas medidas ecocardiográficas de função diastólica usuais.

BACKGROUND: Metabolic syndrome (MS) is associated with increased cardiovascular risk. It is not clear whether myocardial changes showed in this syndrome, such as diastolic dysfunction, are due to the systemic effects of the syndrome, or to specific myocardial effects. OBJECTIVES: Compare diastolic function, biomarkers representing extracellular matrix activity (ECM), inflammation and cardiac hemodynamic stress in patients with the MS and healthy controls. METHODS: MS patients (n=76) and healthy controls (n=30) were submitted to a clinical assessment, echocardiographic study, and measurement of plasma levels of metalloproteinase-9 (MMP9), tissue inhibitor of metalloproteinase-1 (TIMP1), ultrasensitive-reactive-C-Protein (us-CRP), insulin resistance (HOMA-IR) and natriuretic peptide (NT-proBNP). RESULTS: MS group showed lower E' wave (10.1 ± 3.0 cm/s vs 11.9 ± 2.6 cm/s, p = 0.005), increased A wave (63.4 ± 14.1 cm/s vs. 53.1 ± 8.9 cm/s; p < 0.001), E/E' ratio (8.0 ± 2.2 vs. 6.3 ± 1.2; p < 0.001), MMP9 (502.9 ± 237.1 ng/mL vs. 330.4±162.7 ng/mL; p < 0.001), us-CRP (p = 0.001) and HOMA-IR (p < 0.001), but no difference for TIMP1 or NT-proBNP levels. In a multivariable analysis, only MMP9 was independently associated with MS. CONCLUSION: MS patients showed differences for echocardiographic measures of diastolic function, ECM activity, us-CRP and HOMA-IR when compared to controls. However, only MMP9 was independently associated with the MS. These findings suggest that there are early effects on ECM activity, which cannot be tracked by routine echocardiographic measures of diastolic function.