Distinct Hemodynamic Responses That Culminate With Postural Orthostatic Tachycardia Syndrome.

It is of paramount importance to characterize the individual hemodynamic response of patients with postural orthostatic tachycardia syndrome (POTS) to select the best therapeutic intervention. Our aim in this study was to describe the hemodynamic changes in 40 patients with POTS during the head-up tilt test and compare them with 48 healthy patients. Hemodynamic parameters were obtained by cardiac bioimpedance. Patients were compared in supine position and after 5, 10, 15, and 20 minutes of orthostatic position. Patients with POTS demonstrated higher heart rate (74 beats per minute [64 to 80] vs 67 [62 to 72], p <0.001) and lower stroke volume (SV) (83.0 ml [72 to 94] vs 90 [79 to 112], p <0.001) at supine position. The response to orthostatic challenge was characterized by a decrease in SV index (SVI) in both groups (ΔSVI in ml/m2: -16 [-25 to -7.] vs -11 [-17 to -6.1], p = NS). Peripheral vascular resistance (PVR) was reduced only in POTS (ΔPVR in dyne.seg/cm5:-52 [-279 to 163] vs 326 [58 to 535], p <0.001). According to the best cut-off points obtained using the receiver operating characteristic analysis for the variation of SVI (-15.5%) and PVR index (PVRI) (-5.5%), we observed 4 distinct groups of POTS: 10% presented an increase in both SVI and PVRI after the orthostatic challenge, 35% presented a PVRI decrease with SVI maintenance or increase, 37.5% presented an SVI decrease with PVRI maintenance or elevation, and 17.5% presented a reduction in both variables. Body mass index, ΔSVI, and ΔPVRI were strongly correlated with POTS (area under the curve = 0.86 [95% confidence interval 0.77 to 0.92], p <0.0001). In conclusion, the use of appropriate cut-off points for hemodynamic parameters using bioimpedance cardiography during the head-up tilt test could be a useful strategy to identify the main mechanism involved and to select the best individual therapeutic strategy in POTS.

Strain longitudinal global como preditor de cardiotoxicidade induzida por quimioterapia / Global longitudinal strain as predictor of chemotherapy-induced cardiotoxicity

Fundamento: A cardiotoxicidade induzida por quimioterapia (CiC) é uma complicação importante entre os pacientes que recebem antraciclinas. Biomarcadores e parâmetros de imagem têm sido estudados por sua capacidade de identificar pacientes com risco de desenvolver essa complicação. O strain longitudinal global do ventrículo esquerdo (SLG-VE) tem sido descrito como um parâmetro sensível para detectar disfunção sistólica, mesmo na presença de fração de ejeção do ventrículo esquerdo (FEVE) preservada. Objetivo: avaliar o papel do SLG-VE como preditor de CiC. Métodos: O presente estudo consiste em uma análise post-hoc do estudo CECCY (Carvedilol for Prevention of ChemotherapyRelated Cardiotoxicity [Carvedilol para Prevenção da Cardiotoxicidade Relacionada à Quimioterapia]), que avaliou a prevenção primária de cardiotoxicidade com carvedilol durante quimioterapia com doxorrubicina em uma população com câncer de mama. Definiu-se cardiotoxicidade como uma redução >10% na FEVE. O SLG-VE foi obtido antes da quimioterapia em pacientes sem doença cardiovascular prévia ou anormalidades no ecocardiograma. Resultados: Trinta e um pacientes submetidos a estudo ecocardiográfico completo incluindo avaliação de SLG-VE antes da quimioterapia foram incluídos nesta análise. Um SLG-VE absoluto <16,9% antes da quimioterapia mostrou 100% de sensibilidade e 73% de especificidade para predizer cardiotoxicidade (AUC=0,85; IC 95% 0,680­0,959, p<0,001). Nesta população, os valores de FEVE antes da quimioterapia não foram preditores de CiC (IC 95% 0,478 a -0,842, p=0,17). A associação de baixos níveis séricos de SLG-VE (<17%) e BNP (>17 pg/mL) dois meses após a quimioterapia aumentou a precisão para detectar CiC de início precoce (100% de sensibilidade, 88% de especificidade, AUC=0,94; IC 95% 0,7810,995, p<0,0001). Conclusões: Nossos dados sugerem que o SLG-VE é um possível preditor de cardiotoxicidade induzida por quimioterapia. São necessários estudos maiores para confirmar a relevância clínica desse parâmetro ecocardiográfico nesse cenário clínico. (AU)

Background: Chemotherapy-induced cardiotoxicity (ChC) is an important complication among patients receiving anthracyclines. Biomarkers and imaging parameters have been studied for their ability to identify patients at risk of developing ChC. Left ventricular global longitudinal strain (LV-GLS) is a sensitive parameter for detecting systolic dysfunction despite the presence of preserved left ventricular ejection fraction (LVEF). Objective: To evaluate the role of the LV-GLS as a predictor of ChC. Methods: This was a post-hoc analysis of the Carvedilol for Prevention of Chemotherapy-Related Cardiotoxicity trial, which evaluated the primary prevention of cardiotoxicity with carvedilol during doxorubicin chemotherapy in a population of patients with breast cancer. Cardiotoxicity was defined as a reduction ≥10% in LVEF. LV-GLS was determined before chemotherapy in patients with no prior cardiovascular disease or echocardiogram abnormalities. Results: Thirty-one patients for whom a complete echocardiography study including measurement of LV-GLS was performed before chemotherapy were included in this analysis. An absolute LV-GLS<16.9% before chemotherapy showed 100% sensitivity and 73% specificity for predicting cardiotoxicity (area under the curve [AUC], 0.85; 95% confidence interval [CI], 0.680­0.959; p<0.001). In this population, LVEF values before chemotherapy did not predict ChC (95% CI, 0.478 to -0.842; p=0.17). The association of low LV-GLS (<17%) and brain-type natriuretic peptide serum levels (>17 pg/mL) at 2 months after chemotherapy increased the accuracy for detecting early-onset ChC (100% sensitivity, 88% specificity; AUC, 0.94; 95% CI, 0.781­0.995; p<0.0001). Conclusions: Our data suggest that LV-GLS is a potential predictor of ChC. Larger studies are needed to confirm its clinical relevance in this clinical setting. (AU)

Echocardiographic evaluation in type 1 diabetes mellitus.

INTRODUCTION: Type 1 diabetes (T1D) is a chronic disease with peak incidence in adolescence; it has a major impact on morbidity and mortality, especially cardiovascular. Diabetic cardiomyopathy is characterized by structural and functional lesions in the absence of other diseases and is involved in the progression to heart failure. Echocardiography has led to the identification of early cardiac lesions, despite controversial results in the literature in patients with T1D. OBJECTIVE: The objective of this study is to assess cardiac changes in individuals with TD1 compared to the control group using conventional two-dimensional Doppler and advanced speckle tracking echocardiography. METHODS: This is a case-control study with 40 asymptomatic, normotensive T1D patients aged 20 to 50 years and 40 healthy subjects. Two-dimensional echocardiography was performed to measure myocardial thickness and cardiac chambers. Tissue Doppler echocardiography was used for diastolic analysis and speckle tracking echocardiography to quantify ventricular systolic function. RESULTS: The mean age was 33 years in both groups, with an average T1D duration of 18 years; 20% of patients with T1D had diabetic retinopathy; 12.5% kidney injury; and 10% peripheral neuropathy. There were differences in the left ventricular diastolic function parameters (lateral E', middle E' and S/D ratio) and right ventricle (tricuspid E and tricuspid E'/A' ratio). The mean value of the global longitudinal strain was -21.7% (+- 2.3) in the T1D group and -21.0% (+-2.0) in the control group (p=0.21). CONCLUSION: Echocardiography revealed a reduction in indices of diastolic function in T1D compared to the control group, which may be the initial cardiac lesion in diabetes.

Carvedilol for Prevention of Chemotherapy-Related Cardiotoxicity: The CECCY Trial.

BACKGROUND: Anthracycline (ANT) chemotherapy is associated with cardiotoxicity. Prevention with ß-blockers remains controversial. OBJECTIVES: This prospective, randomized, double-blind, placebo-controlled study sought to evaluate the role of carvedilol in preventing ANT cardiotoxicity. METHODS: The authors randomized 200 patients with HER2-negative breast cancer tumor status and normal left ventricular ejection fraction (LVEF) referred for ANT (240 mg/m2) to receive carvedilol or placebo until chemotherapy completion. The primary endpoint was prevention of a ≥10% reduction in LVEF at 6 months. Secondary outcomes were effects of carvedilol on troponin I, B-type natriuretic peptide, and diastolic dysfunction. RESULTS: Primary endpoint occurred in 14 patients (14.5%) in the carvedilol group and 13 patients (13.5%) in the placebo group (p = 1.0). No differences in changes of LVEF or B-type natriuretic peptide were noted between groups. A significant difference existed between groups in troponin I levels over time, with lower levels in the carvedilol group (p = 0.003). Additionally, a lower incidence of diastolic dysfunction was noted in the carvedilol group (p = 0.039). A nonsignificant trend toward a less-pronounced increase in LV end-diastolic diameter during the follow-up was noted in the carvedilol group (44.1 ± 3.64 mm to 45.2 ± 3.2 mm vs. 44.9 ± 3.6 mm to 46.4 ± 4.0 mm; p = 0.057). CONCLUSIONS: In this largest clinical trial of ß-blockers for prevention of cardiotoxicity under contemporary ANT dosage, the authors noted a 13.5% to 14.5% incidence of cardiotoxicity. In this scenario, carvedilol had no impact on the incidence of early onset of LVEF reduction. However, the use of carvedilol resulted in a significant reduction in troponin levels and diastolic dysfunction. (Carvedilol Effect in Preventing Chemotherapy-Induced Cardiotoxicity [CECCY]; NCT01724450).