Guillermo Torre-Amione

Bio: Guillermo Torre-Amione is an academic researcher from Baylor College of Medicine. The author has contributed to research in topics: Heart failure & Transplantation. The author has an hindex of 41, co-authored 110 publications receiving 7843 citations. Previous affiliations of Guillermo Torre-Amione include Houston Methodist Hospital.

Altered Titin Expression, Myocardial Stiffness, and Left Ventricular Function in Patients With Dilated Cardiomyopathy

Abstract: Background—The role of the giant protein titin in patients with heart failure is not well established. We investigated titin expression in patients with end-stage heart failure resulting from nonischemic dilated cardiomyopathy, in particular as it relates to left ventricular (LV) myocardial stiffness and LV function. Methods and Results—SDS-agarose gels revealed small N2B (stiff) and large N2BA (compliant) cardiac titin isoforms with a mean N2BA:N2B expression ratio that was significantly (P0.003) increased in 20 heart failure patients versus 6 controls. However, total titin was unchanged. The coexpression ratio was highest in a subsample of patients with an impaired LV relaxation pattern (n7), intermediate in those with pseudonormal filling (n6), and lowest in the group with restrictive filling (n7). Mechanical measurements on LV muscle strips dissected from these hearts (n8) revealed that passive muscle stiffness was significantly reduced in patients with a high N2BA:N2B expression ratio. Clinical correlations support the relevance of these changes for LV function (assessed by invasive hemodynamics and Doppler echocardiography). A positive correlation between the N2BA:N2B titin isoform ratio and deceleration time of mitral E velocity, A wave transit time, and end diastolic volume/pressure ratio was found. These changes affect exercise tolerance, as indicated by the positive correlation between the N2BA:N2B isoform ratio and peak O2 consumption (n10). Upregulated N2BA expression was accompanied by increased expression levels of titin-binding proteins (cardiac ankyrin repeat protein, ankrd2, and diabetes ankyrin repeat protein) that bind to the N2A element of N2BA titin (studied in 13 patients). Conclusions—Total titin content was unchanged in end-stage failing hearts and the more compliant N2BA isoform comprised a greater percentage of titin in these hearts. Changes in titin isoform expression in heart failure patients with dilated cardiomyopathy significantly impact diastolic filling by lowering myocardial stiffness. Upregulation of titin-binding proteins indicates that the importance of altered titin expression might extend to cell signaling and regulation of gene expression. (Circulation. 2004;110:155-162.)

Tumor necrosis factor-alpha gene and protein expression in adult feline myocardium after endotoxin administration.

Abstract: TNF alpha mRNA and protein biosynthesis were examined in the adult feline heart after stimulation with endotoxin. When freshly isolated hearts were stimulated with endotoxin in vitro, de novo TNF alpha mRNA expression occurred within 30 min, and TNF alpha protein production was detected within 60-75 min; however, TNF alpha mRNA and protein production were not detected in diluent-treated hearts. Immunohistochemical studies localized TNF alpha to endothelial cells, smooth muscle cells, and cardiac myocytes in the endotoxin-treated hearts, whereas TNF alpha immunostaining was absent in the diluent-treated hearts. To determine whether the cardiac myocyte was a source for TNF alpha production, two studies were performed. First, in situ hybridization studies, using highly specific biotinylated probes, demonstrated TNF alpha mRNA in cardiac myocytes from endotoxin-stimulated hearts; in contrast, TNF alpha mRNA was not expressed in myocytes from diluent-treated hearts. Second, TNF alpha protein production was observed when cultured cardiac myocytes were stimulated with endotoxin, whereas TNF alpha protein production was not detected in the diluent-treated cells. The functional significance of the intramyocardial production of TNF alpha was determined by examining cell motion in isolated cardiac myocytes treated with superfusates from endotoxin- and diluent-stimulated hearts. These studies showed that cell motion was depressed in myocytes treated with superfusates from the endotoxin-treated hearts, but was normal with the superfusates from the diluent-treated hearts; moreover, the negative inotropic effects of the superfusates from the endotoxin-treated hearts could be abrogated completely by pretreatment with an anti-TNF alpha antibody. Finally, endotoxin stimulation was also shown to result in the intramyocardial production of TNF alpha mRNA and protein in vivo. Thus, this study shows for the first time that the adult mammalian myocardium synthesizes biologically active TNF alpha.

Cardiac Improvement During Mechanical Circulatory Support A Prospective Multicenter Study of the LVAD Working Group

Abstract: Background— Myocardial recovery after left ventricular assist device (LVAD) support has been reported. The LVAD Working Group Recovery Study was a prospective multicenter trial to assess the incidence of myocardial recovery in patients bridged to cardiac transplantation. Methods and Results— After LVAD implantation, patients were evaluated with the use of rest echocardiograms with partial LVAD support and cardiopulmonary exercise testing. Dobutamine echocardiography with hemodynamic measurements was performed in those patients with left ventricular ejection fraction >40% during resting studies. Histological analysis was performed on myocardial samples taken at LVAD implantation and explantation. Sixty-seven LVAD patients with heart failure participated in the study. After 30 days, significant improvement occurred in left ventricular ejection fraction (17±7% versus 34±12%; P<0.001) and reductions in left ventricular end-diastolic diameter (7.1±1.2 versus 5.1±1.1 cm; P<0.001) and left ventricular mass (320±...

Effects of Tezosentan on Symptoms and Clinical Outcomes in Patients With Acute Heart Failure: The VERITAS Randomized Controlled Trials

Abstract: ContextPlasma concentrations of the vasoconstrictor peptide endothelin-1 are increased in patients with heart failure, and higher concentrations are associated with worse outcomes. Tezosentan is an intravenous short-acting endothelin receptor antagonist that has favorable hemodynamic actions in heart failure.ObjectiveTo determine if tezosentan improves outcomes in patients with acute heart failure.Design, Setting, and ParticipantsThe Value of Endothelin Receptor Inhibition With Tezosentan in Acute Heart Failure Studies, 2 independent, identical, and concurrent randomized, double-blind, placebo-controlled, parallel-group trials conducted from April 2003 through January 2005 at sites in Australia, Europe, Israel, and North America. Patients admitted within the previous 24 hours with persisting dyspnea and a respiratory rate of 24/min or greater were eligible provided they fulfilled 2 of 4 criteria: (1) elevated plasma concentrations of B-type or N-terminal pro–B-type natriuretic peptide, (2) clinical pulmonary edema, (3) radiologic pulmonary congestion or edema, or (4) left ventricular systolic dysfunction.InterventionInfusion of tezosentan (5 mg/h for 30 minutes, followed by 1 mg/h for 24 to 72 hours [n = 730]) or placebo (n = 718).Main Outcome MeasuresThe coprimary end points were change in dyspnea (measured at 3, 6, and 24 hours using a visual analog scale from 0-100) over 24 hours (as area under the curve) in the individual trials and incidence of death or worsening heart failure at 7 days in both trials combined.ResultsOf the 1435 patients who received treatment as assigned, 855 (60%) were men; mean age was 70 years. Mean left ventricular ejection fraction (measured in 779 patients [54%]) was 29% (SD, 11%). Baseline dyspnea scores were similar in the 2 treatment groups. Tezosentan did not improve dyspnea more than placebo in either trial, with a mean treatment difference of −12 (95% confidence interval [CI], −105 to 81) mm · h (P = .80) in the first trial and −25 (95% CI, −119 to 69) mm · h (P = .60) in the second. The incidence of death or worsening heart failure at 7 days in the combined trials was 26% in each treatment group (odds ratio, 0.99; 95% confidence interval, 0.82-1.21; P = .95).ConclusionThe endothelin receptor antagonist tezosentan did not improve symptoms or clinical outcomes in patients with acute heart failure.Trial Registrationclinicaltrials.gov Identifiers: NCT00525707 (VERITAS-1) and NCT00524433 (VERITAS-2).

Guidelines for the Echocardiographic Assessment of the Right Heart in Adults: A Report from the American Society of Echocardiography Endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography

Abstract: on Statement: Society of Echocardiography is accreditedby theAccreditationCouncil for edical Education to provide continuingmedical education for physicians. n Society of Echocardiography designates this educational activity for of 1.0 AMA PRA Category 1 Credits . Physicians should only claim credit te with the extent of their participation in the activity. CCI recognize ASE’s certificates and have agreed to honor the credit hours registry requirements for sonographers. Society of Echocardiography is committed to ensuring that its educational ll sponsored educational programs are not influencedby the special interests ation or individual, and itsmandate is to retain only those authors whose fists canbeeffectively resolved tomaintain thegoals andeducational integrity y. While a monetary or professional affiliation with a corporation does not fluence an author’s presentation, the Essential Areas and policies of the ire that any relationships that could possibly conflict with the educational activity be resolved prior to publication and disclosed to the audience. f faculty and commercial support relationships, if any, have been indicated. ience: is designed for all cardiovascular physicians and cardiac sonographers with erest and knowledge base in the field of echocardiography; in addition, reschers, clinicians, intensivists, and other medical professionals with a spein cardiac ultrasound will find this activity beneficial.

Guidelines for the Echocardiographic Assessment of the Right Heart in Adults: A Report from the American Society of Echocardiography

Abstract: on Statement: Society of Echocardiography is accredited by the Accreditation Council for edical Education to provide continuing medical education for physicians. n Society of Echocardiography designates this educational activity for of 1.0 AMA PRA Category 1 Credits . Physicians should only claim credit te with the extent of their participation in the activity. CCI recognize ASE’s certificates and have agreed to honor the credit hours registry requirements for sonographers. Society of Echocardiography is committed to ensuring that its educational ll sponsored educational programs are not influenced by the special interests ation or individual, and its mandate is to retain only those authors whose fists can be effectively resolved to maintain the goals andeducational integrity y. While a monetary or professional affiliation with a corporation does not fluence an author’s presentation, the Essential Areas and policies of the ire that any relationships that could possibly conflict with the educational activity be resolved prior to publication and disclosed to the audience. f faculty and commercial support relationships, if any, have been indicated. ience: is designed for all cardiovascular physicians and cardiac sonographers with erest and knowledge base in the field of echocardiography; in addition, reschers, clinicians, intensivists, and other medical professionals with a spein cardiac ultrasound will find this activity beneficial.

Recommendations for the evaluation of left ventricular diastolic function by echocardiography

Abstract: Recommendations for the evaluation of left ventricular diastolic function by echocardiography

Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging

Abstract: Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography : An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging