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result(s) for
"Haddad, Haissam"
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Autonomic cardiovascular reflex control of hemodynamics during exercise in heart failure with reduced ejection fraction and the effects of exercise training
by
Tomczak, Corey R
,
Haddad, Haissam
,
Marciniuk, Darcy D
in
Ejection fraction
,
Endocrine system
,
Heart failure
2022
Heart failure with reduced ejection fraction is associated with increased exercise intolerance, morbidity, and mortality. Importantly, exercise intolerance in heart failure with reduced ejection fraction is a key factor limiting patient quality of life and survival. Exercise intolerance in heart failure with reduced ejection fraction stems from a multi-organ failure to maintain homeostasis at rest and during exercise, including the heart, skeletal muscle, and autonomic nervous system, lending itself to a system constantly trying to “catch-up”. Hemodynamic control during exercise is regulated primarily by the autonomic nervous system, whose operation, in turn, is partly regulated via reflexive information from exercise-stimulated receptors throughout the body (e.g., arterial baroreflex, central and peripheral chemoreceptors, and the muscle metabo- and mechanoreflexes). Persons with heart failure with reduced ejection fraction exhibit malfunctioning autonomic reflexes, which lead to exaggerated sympathoexcitation and attenuated parasympathetic tone. Chronic elevation of sympathetic activity is associated with increased morbidity and mortality. In this review, we provide an overview of how each main exercise-related autonomic reflex is changed in heart failure with reduced ejection fraction, and the role of exercise training in attenuating or reversing the counterproductive changes.
Journal Article
Trust in the Transplant Team Associated With the Level of Chronic Illness Management—A Secondary Data Analysis of the International BRIGHT Study
by
Mielke, Juliane
,
Dobbels, Fabienne
,
De Geest, Sabina
in
behavioral outcomes
,
Chronic Disease
,
chronic illness management
2024
A trustful relationship between transplant patients and their transplant team (interpersonal trust) is essential in order to achieve positive health outcomes and behaviors. We aimed to 1) explore variability of trust in transplant teams; 2) explore the association between the level of chronic illness management and trust; 3) investigate the relationship of trust on behavioral outcomes. A secondary data analysis of the BRIGHT study (ID: NCT01608477; https://clinicaltrials.gov/ct2/show/NCT01608477?id=NCT01608477&rank=1 ) was conducted, including multicenter data from 36 heart transplant centers from 11 countries across four different continents. A total of 1,397 heart transplant recipients and 100 clinicians were enrolled. Trust significantly varied among the transplant centers. Higher levels of chronic illness management were significantly associated with greater trust in the transplant team (patients: AOR= 1.85, 95% CI = 1.47–2.33, p < 0.001; clinicians: AOR = 1.35, 95% CI = 1.07–1.71, p = 0.012). Consultation time significantly moderated the relationship between chronic illness management levels and trust only when clinicians spent ≥30 min with patients. Trust was significantly associated with better diet adherence (OR = 1.34, 95%CI = 1.01–1.77, p = 0.040). Findings indicate the relevance of trust and chronic illness management in the transplant ecosystem to achieve improved transplant outcomes. Thus, further investment in re-engineering of transplant follow-up toward chronic illness management, and sufficient time for consultations is required.
Journal Article
Physiologic expansion of human heart-derived cells enhances therapeutic repair of injured myocardium
by
Courtman, David
,
Kanda, Pushpinder
,
Davila, Liliana
in
Adult progenitor cells
,
Biomedical and Life Sciences
,
Biomedical Engineering and Bioengineering
2019
Background
Serum-free xenogen-free defined media and continuous controlled physiological cell culture conditions have been developed for stem cell therapeutics, but the effect of these conditions on the relative potency of the cell product is unknown. As such, we conducted a head-to-head comparison of cell culture conditions on human heart explant-derived cells using established in vitro measures of cell potency and in vivo functional repair.
Methods
Heart explant-derived cells cultured from human atrial or ventricular biopsies within a serum-free xenogen-free media and a continuous physiological culture environment were compared to cells cultured under traditional (high serum) cell culture conditions in a standard clean room facility.
Results
Transitioning from traditional high serum cell culture conditions to serum-free xenogen-free conditions had no effect on cell culture yields but provided a smaller, more homogenous, cell product with only minor antigenic changes. Culture within continuous physiologic conditions markedly boosted cell proliferation while increasing the expression of stem cell-related antigens and ability of cells to stimulate angiogenesis. Intramyocardial injection of physiologic cultured cells into immunodeficient mice 1 week after coronary ligation translated into improved cardiac function and reduced scar burden which was attributable to increased production of pro-healing cytokines, extracellular vesicles, and microRNAs.
Conclusions
Continuous physiological cell culture increased cell growth, paracrine output, and treatment outcomes to provide the greatest functional benefit after experimental myocardial infarction.
Journal Article
Isolation of human explant derived cardiac stem cells from cryopreserved heart tissue
2017
The value of preserving high quality bio specimens for fundamental research is significant as linking cellular and molecular changes to clinical and epidemiological data has fueled many recent advances in medicine. Unfortunately, storage of traditional biospecimens is limited to fixed samples or isolated genetic material. Here, we report the effect of cryopreservation of routine myocardial biopsies on explant derived cardiac stem cell (EDC) culture outcomes. We demonstrate that immediate cryopreservation or delayed cryopreservation after suspension within cardioplegia for 12 hours did not alter EDC yields, proliferative capacity, antigenic phenotype or paracrine signature. Cryopreservation had negligible effects on the ability of EDCs to adopt a cardiac lineage, stimulate new vessel growth, attract circulating angiogenic cells and repair injured myocardium. Finally, cryopreservation did not influence the ability of EDCs to undergo genetic reprogramming into inducible pluripotent stem cells. This study establishes a means of storing cardiac samples as a retrievable live cell source for cardiac repair or disease modeling.
Journal Article
Assessment of the Sensitivity of a Smartphone App to Assist Patients in the Identification of Stroke and Myocardial Infarction: Cross-Sectional Study
2025
Most people do not recognize symptoms of neurological and cardiac emergencies in a timely manner. This leads to delays in hospital arrival and reduced access to therapies that can open arteries. We created a smartphone app to help patients and families evaluate if symptoms may be high risk for stroke or heart attack (myocardial infarction, MI). The ECHAS (Emergency Call for Heart Attack and Stroke) app guides users to assess their risk through evidence-based questions and a test of weakness in one arm by evaluating finger-tapping on the smartphone.
This study is an initial step in the accuracy evaluation of the app focused on sensitivity. We evaluated whether the app provides appropriate triage advice for patients with known stroke or MI symptoms in the Emergency Department. We designed this study to evaluate the sensitivity of the app, since the most dangerous output of the app would be failure to recognize the need for emergency evaluation. Specificity is also important, but the consequences of low specificity are less dangerous than those of low sensitivity.
In this single-center cross-sectional study, we enrolled patients presenting with symptoms of possible stroke or MI. The ECHAS app assessment consisted of a series of evidence-based questions regarding symptoms and a test of finger-tapping speed and accuracy on the phone's screen to detect unilateral arm weakness. The primary outcome was the sensitivity of the ECHAS app in detecting the need for ED evaluation. The secondary outcome was the sensitivity of the ECHAS app in detecting the need for hospital admission. Two independent and blinded board-certified physicians reviewed the medical record and adjudicated the appropriateness of the ED visit based on a 5-point score (ground truth). Finally, we asked patients semistructured questions about the app's ease of use, drawbacks, and benefits.
We enrolled 202 patients (57 with stroke and 145 with MI). The ECHAS score was strongly correlated with the ground truth appropriateness score (Spearman correlation 0.41, P<.001). The ECHAS app had a sensitivity of 0.98 for identifying patients in whom ED evaluation was appropriate. The app had a sensitivity of 1.0 for identifying patients who were admitted to the hospital because of their ED evaluation. Patients completed an app session in an average of 111 (SD 60) seconds for the stroke pathway and 60 (SD 33) seconds for the MI pathway. Patients reported that the app was easy to use and valuable for personal emergency situations at home.
The ECHAS app demonstrated a high sensitivity for the detection of patients who required emergency evaluation for symptoms of stroke or MI. This study supports the need for a study of specificity of the app, and then a prospective trial of the app in patients at increased risk of MI and stroke.
Journal Article
Comparison of Transesophageal and Transthoracic Echocardiographic Measurements of Mechanism and Severity of Mitral Regurgitation in Ischemic Cardiomyopathy (from the Surgical Treatment of Ischemic Heart Failure Trial)
2015
Mitral regurgitation (MR) is common in ischemic heart disease and contributes to symptoms and mortality. This report compares the results of baseline transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) imaging of the mechanism and severity of functional MR in patients with ischemic cardiomyopathy in the Surgical Treatment for Ischemic Heart Failure (STICH) trial. Independent core laboratories measured both TTE and TEE images on 196 STICH participants. Common measurements to both models included MR grade, mitral valve tenting height and tenting area, and mitral annular diameter. For each parameter, correlations were assessed using Spearman rank correlation coefficients. A modest correlation was present between TEE and TTE for overall MR grade (n = 176, r = 0.52). For mechanism of MR, modest correlations were present for long-axis tenting height (n = 152, r = 0.35), tenting area (n = 128, r = 0.27), and long-axis mitral annulus diameter (n = 123, r = 0.41). For each measurement, there was significant scatter. Potential explanations for the scatter include different orientation of the imaging planes between TEE and TTE, a mean temporal delay of 6 days between TEE and TTE, and statistically significant differences in heart rate and blood pressure and weight between studies. In conclusion, TEE and TTE measurements of MR mechanism and severity correlate only modestly with enough scatter in the data that they are not interchangeable.
Journal Article
Mechanisms of Functional Mitral Regurgitation in Ischemic Cardiomyopathy Determined by Transesophageal Echocardiography (from the Surgical Treatment for Ischemic Heart Failure Trial)
by
Holly, Thomas A.
,
Velazquez, Eric J.
,
Kron, Irving
in
Aged
,
Cardiology
,
Cardiomyopathies - diagnostic imaging
2013
The mechanisms underlying functional mitral regurgitation (MR) and the relation between mechanism and severity of MR have not been evaluated in a large, multicenter, randomized controlled trial. Transesophageal echocardiography (TEE) was performed in 215 patients at 17 centers in the Surgical Treatment for Ischemic Heart Failure (STICH) trial. Both 2-dimensional (n = 215) and 3-dimensional (n = 81) TEEs were used to assess multiple quantitative measurements of the mechanism and severity of MR. By 2-dimensional TEE, leaflet tenting area, anterior and posterior leaflet angles, mitral annulus diameter, left ventricular (LV) end-systolic volume index, LV ejection fraction (LVEF), and sphericity index (p <0.05 for all) were significantly different across MR grades. By 3-dimensional TEE, mitral annulus area, leaflet tenting area, LV end-systolic volume index, LVEF, and sphericity index (p <0.05 for all) were significantly different across MR grades. A multivariate analysis showed a trend for annulus area (p = 0.069) and LV end-systolic volume index (p = 0.071) to predict effective regurgitant orifice area and for annulus area (p = 0.018) and LV end-systolic volume index (p = 0.073) to predict vena contracta area. In the STICH trial, multiple quantitative parameters of the mechanism of functional MR are related to MR severity. The mechanism of functional MR in ischemic cardiomyopathy is heterogenous, but no single variable stands out as a strong predictor of quantitative severity of MR.
Journal Article
Alternative Imaging Modalities in Ischemic Heart Failure (AIMI-HF) IMAGE HF Project I-A: study protocol for a randomized controlled trial
2013
Background
Ischemic heart disease (IHD) is the most common cause of heart failure (HF); however, the role of revascularization in these patients is still unclear. Consensus on proper use of cardiac imaging to help determine which candidates should be considered for revascularization has been hindered by the absence of clinical studies that objectively and prospectively compare the prognostic information of each test obtained using both standard and advanced imaging.
Methods/Design
This paper describes the design and methods to be used in the Alternative Imaging Modalities in Ischemic Heart Failure (AIMI-HF) multi-center trial. The primary objective is to compare the effect of HF imaging strategies on the composite clinical endpoint of cardiac death, myocardial infarction (MI), cardiac arrest and re-hospitalization for cardiac causes.
In AIMI-HF, patients with HF of ischemic etiology (n = 1,261) will follow HF imaging strategy algorithms according to the question(s) asked by the physicians (for example, Is there ischemia and/or viability?), in agreement with local practices. Patients will be randomized to either standard (SPECT, Single photon emission computed tomography) imaging modalities for ischemia and/or viability or advanced imaging modalities: cardiac magnetic resonance imaging (CMR) or positron emission tomography (PET). In addition, eligible and consenting patients who could not be randomized, but were allocated to standard or advanced imaging based on clinical decisions, will be included in a registry.
Discussion
AIMI-HF will be the largest randomized trial evaluating the role of standard and advanced imaging modalities in the management of ischemic cardiomyopathy and heart failure. This trial will complement the results of the Surgical Treatment for Ischemic Heart Failure (STICH) viability substudy and the PET and Recovery Following Revascularization (PARR-2) trial. The results will provide policy makers with data to support (or not) further investment in and wider dissemination of alternative ‘advanced’ imaging technologies.
Trial registration
NCT01288560
Journal Article
Hemothorax due to Ruptured Mycotic Aneurysm of Intercostal Arteries Associated with Infective Endocarditis
2017
We present a case of hemothorax due to ruptured mycotic aneurysm in three intercostal arteries in a 40-year-old male with methicillin-resistant Staphylococcus aureus infective endocarditis (IE) due to intravenous drug use. Microcoil embolization and thoracotomy successfully achieved hemostasis. Mycotic aneurysm is a rare complication of IE and is usually found in the intracranial vessels. Ruptured mycotic aneurysm in the intercostal arteries can be associated with IE and can present as acute hemothorax.
Journal Article
18F-FDG PET imaging of myocardial viability in an experienced center with access to 18F-FDG and integration with clinical management teams: the Ottawa-FIVE substudy of the PARR 2 trial
by
Chow, Benjamin
,
DaSilva, Jean
,
Nichol, Graham
in
Canada
,
Coronary Artery Disease - diagnostic imaging
,
Coronary Artery Disease - physiopathology
2010
(18)F-FDG PET may assist decision making in ischemic cardiomyopathy. The PET and Recovery Following Revascularization (PARR 2) trial demonstrated a trend toward beneficial outcomes with PET-assisted management. The substudy of PARR 2 that we call Ottawa-FIVE, described here, was a post hoc analysis to determine the benefit of PET in a center with experience, ready access to (18)F-FDG, and integration with clinical teams.
Included were patients with left ventricular dysfunction and suspected coronary artery disease being considered for revascularization. The patients had been randomized in PARR 2 to PET-assisted management (group 1) or standard care (group 2) and had been enrolled in Ottawa after August 1, 2002 (the date that on-site (18)F-FDG was initiated) (n = 111). The primary outcome was the composite endpoint of cardiac death, myocardial infarction, or cardiac rehospitalization within 1 y. Data were compared with the rest of PARR 2 (PET-assisted management [group 3] or standard care [group 4]).
In the Ottawa-FIVE subgroup of PARR 2, the cumulative proportion of patients experiencing the composite event was 19% (group 1), versus 41% (group 2). Multivariable Cox proportional hazards regression showed a benefit for the PET-assisted strategy (hazard ratio, 0.34; 95% confidence interval, 0.16-0.72; P = 0.005). Compared with other patients in PARR 2, Ottawa-FIVE patients had a lower ejection fraction (25% +/- 7% vs. 27% +/- 8%, P = 0.04), were more often female (24% vs. 13%, P = 0.006), tended to be older (64 +/- 10 y vs. 62 +/- 10 y, P = 0.07), and had less previous coronary artery bypass grafting (13% vs. 21%, P = 0.07). For patients in the rest of PARR 2, there was no significant difference in events between groups 3 and 4. The observed effect of (18)F-FDG PET-assisted management in the 4 groups in the context of adjusted survival curves demonstrated a significant interaction (P = 0.016). Comparisons of the 2 arms in Ottawa-FIVE to the 2 arms in the rest of PARR 2 demonstrated a trend toward significance (standard care, P = 0.145; PET-assisted management, P = 0.057).
In this post hoc group analysis, a significant reduction in cardiac events was observed in patients with (18)F-FDG PET-assisted management, compared with patients who received standard care. The results suggest that outcome may be benefited using (18)F-FDG PET in an experienced center with ready access to (18)F-FDG and integration with imaging, heart failure, and revascularization teams.
Journal Article