Publications by authors named "Quan M Bui"

Background: Genetic cardiomyopathies (CMs) are increasingly recognized as causes of end-stage heart failure (ESHF). Identification of a genetic etiology in ESHF has important prognostic and family implications. However, genetic testing practices are understudied in patients with ESHF.

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Background: Breast arterial calcification (BAC) on mammograms has emerged as a biomarker of women's cardiovascular disease (CVD) risk, but there is a lack of quantification tools and clinical outcomes studies.

Objectives: This study assessed the association of BAC (both presence and quantity) with CVD outcomes.

Methods: This single-center, retrospective study included women with a screening mammogram from 2007 to 2016.

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Hypertrophic cardiomyopathy (HCM) due to thick filament variants is more common; however, HCM due to thin filament variants (HCM-Thin) may be associated with a more malignant phenotype with an increased risk of sudden cardiac death. The aim of this study was to review all the published cases of HCM-Thin to better understand the natural history and clinical outcomes of this disease. A literature review of HCM-Thin identified 21 studies with a total of 177 patients that were suitable for analysis.

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Dilated cardiomyopathy (DCM) is a common cause of heart failure and is the primary indication for heart transplantation. A genetic etiology can be found in 20-35% of patients with DCM, especially in those with a family history of cardiomyopathy or sudden cardiac death at an early age. With advancements in genome sequencing, the understanding of genotype-phenotype relationships in DCM has expanded with over 60 genes implicated in the disease.

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The effect of using donation after circulatory death (DCD) hearts on waitlist outcomes has not been substantiated. We retrospectively analyzed 184 heart transplant (HT) candidates at our institution from 2019 to 2021. Patients were stratified into 2 observation periods centered on September 12, 2020, when the adult DCD HT program officially began.

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All muscle contraction occurs due to the cyclical interaction between sarcomeric thin and thick filament proteins within the myocyte. The thin filament consists of the proteins actin, tropomyosin, Troponin C, Troponin I, and Troponin T. Mutations in these proteins can result in various forms of cardiomyopathy, including hypertrophic, restrictive, and dilated phenotypes and account for as many as 30% of all cases of inherited cardiomyopathy.

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The days and weeks preceding hospitalization are poorly understood because they transpire before patients are seen in conventional clinical care settings. Home health sensors offer opportunities to learn signatures of impending hospitalizations and facilitate early interventions, however the relevant biomarkers are unknown. Nocturnal respiratory rate (NRR) is an activity-independent biomarker that can be measured by adherence-independent sensors in the home bed.

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Home health monitoring has the potential to improve outpatient management of chronic cardiopulmonary diseases such as heart failure. However, it is often limited by the need for adherence to self-measurement, charging and self-application of wearables, or usage of apps. Here, we describe a non-contact, adherence-independent sensor, that when placed beneath the legs of a patient's home bed, longitudinally monitors total body weight, detailed respiratory signals, and ballistocardiograms for months, without requiring any active patient participation.

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Background Myocardial strain can identify subclinical left ventricular dysfunction in various cardiac diseases, but its association with clinical outcomes in genetic cardiomyopathies remains unknown. Herein, we assessed myocardial strain in patients with Danon disease (DD), a rare X-linked autophagic disorder that causes severe cardiac manifestations. Methods and Results Echocardiographic images were reviewed and used to calculate myocardial strain from a retrospective, international registry of patients with DD.

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Background: Danon disease (DD) is a rare X-linked dominant cardioskeletal myopathy caused by mutations in the lysosome-associated membrane protein-2 (LAMP-2) gene that is usually lethal without cardiac transplantation. The purpose of this study was to characterize post-transplant outcomes in a large cohort of patients with DD who underwent cardiac transplantation.

Methods: The clinical phenotype and outcome data of patients with DD who underwent cardiac transplantation (n = 38; 19 males and 19 females) were obtained from 8 centers.

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Background: Statins have anti-inflammatory and immunomodulatory effects that may reduce the severity of coronavirus disease 2019 (COVID-19), in which organ dysfunction is mediated by severe inflammation. Large studies with diverse populations evaluating statin use and outcomes in COVID-19 are lacking.

Methods And Results: We used data from 10,541 patients hospitalized with COVID-19 through September 2020 at 104 US hospitals enrolled in the American Heart Association's COVID-19 Cardiovascular Disease (CVD) Registry to evaluate the associations between statin use and outcomes.

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Background: A subset of patients with takotsubo cardiomyopathy will develop significant dynamic left ventricular outflow tract (LVOT) obstruction leading to cardiogenic shock. However, traditional therapies for cardiogenic shock that focus on increased inotropy and afterload reduction can be detrimental in this situation.

Case Summary: We describe a 71-year-old woman who presented to the emergency department with typical, substernal chest pain found to be hypotensive with ST-elevations in the lateral leads.

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Background: Coronavirus Disease-2019 (COVID-19) is associated with cardiovascular injury, but left ventricular (LV) function is largely preserved. We aimed to evaluate for subclinical LV dysfunction in patients with COVID-19 through myocardial strain analysis.

Methods: We performed a single-center retrospective cohort study of all patients hospitalized with COVID-19 who underwent echocardiography.

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Background: Geographic variations in management and outcomes of individuals supported by continuous-flow left ventricular assist devices (CF-LVAD) between the United States (US) and Europe (EU) is largely unknown.

Methods: We created a retrospective, multinational registry of 524 patients who received a CF-LVAD (either HVAD or Heartmate II) between January 2008 and April 2017. Follow up spanned from date of CF-LVAD implant to post-HTx period with a median follow up of 44.

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The impact of statins, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) on coronavirus disease 2019 (COVID-19) severity and recovery is important given their high prevalence of use among individuals at risk for severe COVID-19. We studied the association between use of statin/angiotensin-converting enzyme inhibitors/ARB in the month before hospital admission, with risk of severe outcome, and with time to severe outcome or disease recovery, among patients hospitalized for COVID-19. We performed a retrospective single-center study of all patients hospitalized at University of California San Diego Health between February 10, 2020 and June 17, 2020 (n = 170 hospitalized for COVID-19, n = 5,281 COVID-negative controls).

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Advanced heart failure therapies, including heart transplantation and durable mechanical circulatory support, are available to a limited number of patients because of the scarcity of donors, expense, and large burden of care. The importance of psychological and social determinants of health, including cognitive status, health literacy, psychopathology, social support, medical adherence, and substance abuse, are emphasized in advanced heart failure and further amplified in the context of mechanical circulatory support and heart transplantation. The psychosocial assessment of advanced heart failure therapy candidates remains largely subjective, requiring a multidisciplinary evaluation, which may include psychiatrists, social workers, case managers, financial coordinators, pharmacists, and clinicians.

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Cardiovascular disease continues to be the leading cause of death among women in the United States. One of the barriers to improving cardiovascular disease outcomes in women is the lack of reliable, effective screening modalities. Breast arterial calcification has emerged as a potential risk stratification tool.

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Pulmonary arterial hypertension (PAH) is characterized by increased pulmonary artery pressure and vascular resistance, typically leading to right heart failure and death. Current therapies improve quality of life of the patients but have a modest effect on long-term survival. A detailed transcriptomics and systems biology view of the PAH lung is expected to provide new testable hypotheses for exploring novel treatments.

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Background: The Stanford integrated psychosocial assessment for transplantation (SIPAT) is a validated psychosocial evaluation tool in the transplant population.

Objective: We evaluated SIPAT in predicting post-left ventricular assist device (LVAD) outcomes, including cumulative re-admissions, driveline infections, pump malfunction, pump thrombosis, gastrointestinal bleeding, major bleeding, stroke and right ventricular failure.

Methods: This retrospective study included 50 LVAD patients at an academic institution in the United States who had a pre-implant SIPAT score during the years 2015-2017.

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Background: The optimal advanced heart failure (HF) therapy strategy for patients aged 60 or older with end-stage HF refractory to optimal medical therapy remains uncertain. This study compares outcomes of three advanced HF therapy strategies in this patient population.

Methods: A single-center retrospective study was conducted in 95 patients aged 60-73 years who had undergone isolated heart transplantation (HTx) or continuous flow left ventricular assist device (LVAD) implantation from 2010 to 2017.

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Lynch syndrome is an autosomal-dominant hereditary cancer syndrome. Mutations in mismatch repair genes, including MLH1, MSH2, MSH6, and PMS2, are implicated in the pathogenesis of the syndrome through microsatellite instability (MSI) and a rapid adenoma-carcinoma sequence. The primary methodologies for diagnosis include clinical criteria (Amsterdam I/II, Revised Bethesda Guidelines), computational models, and genetic testing (MSI, immunohistochemistry, germline testing).

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