Reduced global longitudinal strain in association to increased left ventricular mass in patients with aortic valve stenosis and normal ejection fraction: a hybrid study combining echocardiography and magnetic resonance imaging.

BACKGROUND: Increased muscle mass index of the left ventricle (LVMi) is an independent predictor for the development of symptoms in patients with asymptomatic aortic stenosis (AS). While the onset of clinical symptoms and left ventricular systolic dysfunction determines a poor prognosis, the standard echocardiographic evaluation of LV dysfunction, only based on measurements of the LV ejection fraction (EF), may be insufficient for an early assessment of imminent heart failure. Contrary, 2-dimensional speckle tracking (2DS) seems to be superior in detecting subtle changes in myocardial function. The aim of the study was to assess these LV function deteriorations with global longitudinal strain (GLS) analysis and the relations to LVMi in patients with AS and normal EF. METHODS: 50 patients with moderate to severe AS and 31 controls were enrolled. All patients underwent echocardiography, including 2DS imaging. LVMi measures were performed with magnetic resonance imaging in 38 patients with AS and indexed for body surface area. RESULTS: The total group of patients with AST showed a GLS of -15,2 +/- 3,6% while the control group reached -19,5 +/- 2,7% (p < 0,001). By splitting the group with AS in normal, moderate and severe increased LVMi, the GLS was -17,0 +/- 2,6%, -13,2 +/- 3,8% and -12,4 +/- 2,9%, respectively (p = 0,001), where LVMi and GLS showed a significant correlation (r = 0,6, p < 0,001). CONCLUSIONS: In conclusion, increased LVMi is reflected in abnormalities of GLS and the proportion of GLS impairment depends on the extent of LV hypertrophy. Therefore, simultaneous measurement of LVMi and GLS might be useful to identify patients at high risk for transition into heart failure who would benefit from aortic valve replacement irrespectively of LV EF.

Qualitative and Quantitative Analysis of Cardiac Progenitor Cells in Cases of Myocarditis and Cardiomyopathy.

We aimed to identify and quantify CD117+ and CD90+ endogenous cardiac progenitor cells (CPC) in human healthy and diseased hearts. We hypothesize that these cells perform a locally acting, contributing function in overcoming medical conditions of the heart by endogenous means. Human myocardium biopsies were obtained from 23 patients with the following diagnoses: Dilatative cardiomyopathy (DCM), ischemic cardiomyopathy (ICM), myocarditis, and controls from healthy cardiac patients. High-resolution scanning microscopy of the whole slide enabled a computer-based immunohistochemical quantification of CD117 and CD90. Those signals were evaluated by Definiens Tissue Phenomics® Technology. Co-localization of CD117 and CD90 was determined by analyzing comparable serial sections. CD117+/CD90+ cardiac cells were detected in all biopsies. The highest expression of CD90 was revealed in the myocarditis group. CD117 was significantly higher in all patient groups, compared to healthy specimens (*p < 0.05). The highest co-expression was found in the myocarditis group (6.75 ± 3.25 CD90+CD117+ cells/mm2) followed by ICM (4 ± 1.89 cells/mm2), DCM (1.67 ± 0.58 cells/mm2), and healthy specimens (1 ± 0.43 cells/mm2). We conclude that the human heart comprises a fraction of local CD117+ and CD90+ cells. We hypothesize that these cells are part of local endogenous progenitor cells due to the co-expression of CD90 and CD117. With novel digital image analysis technologies, a quantification of the CD117 and CD90 signals is available. Our experiments reveal an increase of CD117 and CD90 in patients with myocarditis.

Assessment of aortic valve area combining echocardiography and magnetic resonance imaging.

BACKGROUND: Transthoracic echocardiography (TTE) is routinely used to calculate aortic valve area (AVA) by continuity equation (CE). However, accurate measurement of the left ventricular outflow tract (LVOT) can be difficult and flow acceleration in the LVOT may lead to miscalculation of the AVA. OBJECTIVE: The aim of our study was to compare AVA measurements by standard TTE, cardiac magnetic resonance imaging (MRI) and a hybrid approach combining both techniques. METHODS: AVA was calculated in 38 patients (age 73±9 years) with standard TTE, cine-MRI planimetry and a hybrid approach: Hybrid Method 1: TTE-derived LVOT measurement in the CE numerator was replaced by the MRI assessment of the LVOT and AVA was calculated: (LVOT(MRI)/*LVOT-VTI(TTE))/transaortic-VTI(TTE). Method 2: We replaced the SV in the numerator by the MRI-derived SV and calculated AVA = SV(MRI)/ transaortic-VTI(TTE). RESULTS: Mean AVA derived by TTE was 0.86 cm(2)±0.23 cm(2) and 0.83 cm(2)±0.3 cm(2) by MRI- planimetry, respectively. The mean absolute difference in AVA was 0.03 cm(2) for TTE vs. MRI planimetry. AVA calculated with method 1 and method 2 was 1.23 cm(2)±0.4 cm(2) and 0.92 cm(2)±0.32 cm(2), respectively. The mean absolute difference between TTE and method 1 and method 2 was 0.37 cm(2) and 0.06 cm(2), respectively (p<0.001). CONCLUSION: MRI-planimetry of AVA and hybrid method 2 are accurate and showed a good agreement with standard TTE measurements. Therefore, hybrid method 1 is a reasonable alternative if poor acoustic windows or LVOT flow accelerations limit the accuracy of TTE, particularly in patients at high risk for an invasive hemodynamic study.

Relation of global longitudinal strain to left ventricular geometry in aortic valve stenosis.

BACKGROUND: In patients with aortic stenosis (AS), increased afterload induces changes in left ventricular (LV) geometry to preserve a normal ejection fraction (EF). Nevertheless, myocardial dysfunction may occur in spite of a normal EF. Global longitudinal strain (GLS) analysis can detect subtle contractile dysfunction at a pre-clinical stage. The aim of our study was to assess LV function deteriorations with GLS analysis and the association with geometric changes in patients with AS and normal EF. METHODS: Forty four patients with moderate to severe AS and 40 controls were enrolled. All patients underwent echocardiography, including two-dimensional strain imaging. The relative wall thickness and LV muscle mass measurements were performed with magnetic resonance imaging and patients were subdivided into four groups: Group 1 with normal LV, Group 2 with concentric remodeling, Group 3 with eccentric hypertrophy, and Group 4 with concentric hypertrophy. RESULTS: The total group of patients with AS showed a GLS of -15.3 ± 3.6% while the control group reached -18.9 ± 3.2% (p < 0.001). GLS was lower in the hypertrophy Groups 3 and 4 compared to Groups 1 and 2 (12.9 ± 3.4% vs 17.2 ± 2.5%, p < 0.05, respectively). Splitting the patients into Groups 1 to 4, the GLS was -17.2 ± 2.4%, -17.2 ± 2.7%, -12.4 ± 3.8% and -13.1 ± 3.3, respectively (p = 0.002). CONCLUSIONS: In subjects with AS, lower GLS is related to LV hypertrophy, but not to the presence of concentric remodeling. Assessment of GLS can identify subtle contractile dysfunction independent of a preserved EF, and might be useful in identifying patients at high risk for the transition from compensatory to pathological remodeling. (Cardiol J 2011; 18, 2: 151-156).

Avaliação da área valvar aórtica combinando ecocardiografia e ressonância magnética / Assessment of aortic valve area combining echocardiography and magnetic resonance imaging / Evaluación del área valvular aórtica combinando ecocardiografía y resonancia magnética

FUNDAMENTO: A ecocardiografia transtorácica (ETT) é rotineiramente utilizada para calcular a área da valva aórtica (AVA) pela equação de continuidade (EC). No entanto, a medida exata das vias de saída do ventrículo esquerdo (VSVE) pode ser difícil e a aceleração do fluxo no VSVE pode levar a erro de cálculo da AVA. OBJETIVO: O objetivo do nosso estudo foi comparar as medições da AVA por ETT padrão, ressonância magnética cardíaca (RM) e uma abordagem híbrida que combina as duas técnicas. MÉTODOS: A AVA foi calculada em 38 pacientes (idade 73 ± 9 anos) com a ETT padrão, planimetria cine-RM e uma abordagem híbrida: Método híbrido 1: a medição da VSVE derivada pelo ETT no numerador CE foi substituída pela avaliação de ressonância magnética da VSVE e a AVA foi calculada: (VSVE RM/*VSVE-VTI ETT)/transaórtico-VTI ETT; Método 2: Substituímos o VS no numerador pelo VS derivado pela RM e calculamos a AVA = VS RM/transaórtico-VTI ETT. RESULTADOS: Amédia de AVAobtida pela ETTfoi 0,86 cm² ± 0,23 cm² e 0,83 cm² ± 0,3 cm² pela RM-planimetria, respectivamente. A diferença média absoluta da AVA foi de 0,03 cm² para a RM versus planimetria-ressonância magnética. A AVA calculada com o método 1 e o método 2 foi de 1,23 cm² ± 0,4 cm² e 0,92cm² ± 0,32 cm², respectivamente. A diferença média absoluta entre a ETT e os métodos 1 e 2 foi de 0,37 cm² e 0,06 cm², respectivamente (p < 0,001). CONCLUSÃO: A RM-planimetria da AVA e o método híbrido 2 são precisos e demonstraram boa consistência com as medições padrão obtidas pela ETT. Portanto, o método híbrido 2 é uma alternativa razoável na eventualidade de janelas acústicas ruins ou em caso de acelerações de fluxo VSVE que limitem a precisão da ETT, particularmente em pacientes com alto risco de um estudo hemodinâmico invasivo.

BACKGROUND: Transthoracic echocardiography (TTE) is routinely used to calculate aortic valve area (AVA) by continuity equation (CE). However, accurate measurement of the left ventricular outflow tract (LVOT) can be difficult and flow acceleration in the LVOT may lead to miscalculation of the AVA. OBJECTIVE: The aim of our study was to compare AVA measurements by standard TTE, cardiac magnetic resonance imaging (MRI) and a hybrid approach combining both techniques. METHODS: AVA was calculated in 38 patients (age 73±9 years) with standard TTE, cine-MRI planimetry and a hybrid approach: Hybrid Method 1: TTE-derived LVOT measurement in the CE numerator was replaced by the MRI assessment of the LVOT and AVA was calculated: (LVOT MRI/*LVOT-VTI TTE)/transaortic-VTI TTE. Method 2: We replaced the SV in the numerator by the MRI-derived SV and calculated AVA = SV MRI/ transaortic-VTI TTE. RESULTS: Mean AVA derived by TTE was 0.86 cm²±0.23 cm² and 0.83 cm²±0.3 cm² by MRI- planimetry, respectively. The mean absolute difference in AVA was 0.03cm² for TTE vs. MRI planimetry. AVA calculated with method 1 and method 2 was 1.23 cm²±0.4cm² and 0.92cm²±0.32cm², respectively. The mean absolute difference between TTE and method 1 and method 2 was 0.37cm² and 0.06cm², respectively (p<0.001). CONCLUSION: MRI-planimetry of AVA and hybrid method 2 are accurate and showed a good agreement with standard TTE measurements. Therefore, hybrid method 1 is a reasonable alternative if poor acoustic windows or LVOT flow accelerations limit the accuracy of TTE, particularly in patients at high risk for an invasive hemodynamic study.

FUNDAMENTO: La ecocardiografía transtorácica (ETT) es habitualmente utilizada para calcular el área de la válvula aórtica (AVA) por la ecuación de continuidad (EC). Mientras tanto, la medida exacta de las vías de salida del ventrículo izquierdo (VSVI) puede ser difícil y la aceleración del flujo en el VSVI puede llevar a error de cálculo del AVA. OBJETIVO: El objetivo del nuestro estudio fue comparar las mediciones del AVA por ETT estándar, resonancia magnética cardíaca (RM) y un abordaje híbrido que combina las dos técnicas. MÉTODOS: AEI AVA fue calculada en 38 pacientes (edad 73 ± 9 años) con la ETT estándar, planimetría cine-RM y un abordaje híbrido: Método híbrido 1: la medición de la VSVI derivada por el ETT en el numerador CE fue substituida por la evaluación de resonancia magnética de la VSVI y el AVA fue calculada: (VSVI RM/*VSVI-VTI ETT)/transaórtico-VTI ETT; Método 2: Substituimos el VS en el numerador por el VS derivado por la RM y calculamos el AVA = VS RM/transaórtico-VTI ETT. RESULTADOS: La media de AVA obtenida por la ETT fue 0,86 cm² ± 0,23 cm2 y 0,83 cm² ± 0,3 cm² por la RM-planimetría, respectivamente. La diferencia media absoluta del AVA fue de 0,03 cm² para la RM versus planimetría-resonancia magnética. El AVA calculada con el método 1 y el método 2 fue de 1,23 cm² ± 0,4 cm² y 0,92cm² ± 0,32 cm², respectivamente. La diferencia media absoluta entre la ETT y los métodos 1 y 2 fue de 0,37 cm² y 0,06 cm², respectivamente (p < 0,001). CONCLUSION: La RM-planimetría del AVA y el método híbrido 2 son precisos y demostraron buena consistencia con las mediciones estándar obtenidas por la ETT. Por lo tanto, el método híbrido 2 es una alternativa razonable en la eventualidad de ventanas acústicas malas o en caso de aceleraciones de flujo VSVI que limiten la precisión de la ETT, particularmente en pacientes con alto riesgo de un estudio hemodinámico invasivo.