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Discover the most talked about and latest scientific content & concepts.

Journal: The Canadian journal of cardiology

171

Aortic root enlargement (ARE) procedures are believed to allow implantation of larger valve prostheses; however, little evidence exists to support the specific efficacy of various techniques.

Concepts: Aorta, Ascending aorta

171

BACKGROUND: This systematic review sought to evaluate critically the health benefits of physical activity among persons with atrial fibrillation (AF). AF is increasing in Western society. While health benefits of physical activity are well established, benefits of physical activity among individuals with AF are not clearly identified. METHODS: Literature was retrieved systematically through searching electronic databases (MEDLINE, EMBASE, Cochrane), cross-referencing, and drawing on the authors' knowledge. Identified original research articles evaluated health benefits of physical activity among persons with AF or effects of physical activity on AF incidence. From 1056 individual citations, 36 eligible articles were identified. RESULTS: Moderate-intensity physical activity was found to improve exercise capacity, quality of life, and the ability to carry out activities of daily living among persons with AF (n = 6). Increased incidence of AF was not associated with physical activity among the general population (n = 2), although long-term vigorous endurance exercise may be associated with increased incidence of AF (n = 7), and greater risks may be associated with high-intensity physical activity among those with AF (n = 2). Moderate-intensity physical activity among individuals with AF does not adversely alter training outcomes, functional capacity, morbidity, or mortality compared with those in sinus rhythm (n = 12). Physical activity may improve management and treatment of AF (n = 6) and, among at-risk populations, may reduce incidence of AF (n = 3). CONCLUSIONS: In conclusion, moderate-intensity physical activity should be encouraged among persons with or at risk of AF. Further research is needed.

Concepts: Person, Population, Heart, Atrial fibrillation, Physical exercise, Exercise, Weight loss, Individual

27

Since the inception of the Canadian Cardiovascular Society heart failure (HF) guidelines in 2006, much has changed in the care for patients with HF. Over the past decade, the HF Guidelines Committee has published regular updates. However, because of the major changes that have occurred, the Guidelines Committee believes that a comprehensive reassessment of the HF management recommendations is presently needed, with a view to producing a full and complete set of updated guidelines. The primary and secondary Canadian Cardiovascular Society HF panel members as well as external experts have reviewed clinically relevant literature to provide guidance for the practicing clinician. The 2017 HF guidelines provide updated guidance on the diagnosis and management (self-care, pharmacologic, nonpharmacologic, device, and referral) that should aid in day-to-day decisions for caring for patients with HF. Among specific issues covered are risk scores, the differences in management for HF with preserved vs reduced ejection fraction, exercise and rehabilitation, implantable devices, revascularization, right ventricular dysfunction, anemia, and iron deficiency, cardiorenal syndrome, sleep apnea, cardiomyopathies, HF in pregnancy, cardio-oncology, and myocarditis. We devoted attention to strategies and treatments to prevent HF, to the organization of HF care, comorbidity management, as well as practical issues around the timing of referral and follow-up care. Recognition and treatment of advanced HF is another important aspect of this update, including how to select advanced therapies as well as end of life considerations. Finally, we acknowledge the remaining gaps in evidence that need to be filled by future research.

Concepts: Iron, Myocardial infarction, Cardiology, Heart failure, Ejection fraction, Heart, Cardiovascular system, Sleep apnea

27

BACKGROUND: Sudden infant death syndrome (SIDS) is the leading cause of death in the first 6 months after birth in the industrialized world. The genetic contribution to SIDS has been investigated intensively and to date, 14 cardiac channelopathy genes have been associated with SIDS. Newly published data from National Heart, Lung, and Blood Institute Grand Opportunity (NHLBI GO) Exome Sequencing Project (ESP) provided important knowledge on genetic variation in the background population. Our aim was to identify all variants previously associated with SIDS in ESP to improve the discrimination between plausible disease-causing mutations and variants most likely to be false-positive. METHODS: The PubMed database was searched to identify SIDS-associated channelopathy variants and the prevalence of these in the ESP population (6500 individuals) were obtained. In silico prediction tools were applied to variants present in ESP and 6 SIDS-associated variants (CAV3 p.C72W, p.T78M; KCNH2 p.R148W, and SCN5A p.S216L, p.V1951L, p.F2004L) were genotyped in our own control population. RESULTS: Nineteen different missense variants previously associated with SIDS were identified in ESP affecting 225 of 6424 alleles. This corresponds to 1:29 individuals in the ESP population being carriers of a SIDS-associated variant. Genotyping of 6 SIDS-associated variants in our own controls revealed frequencies comparable with those found in ESP. CONCLUSIONS: A very high prevalence of previously SIDS-associated variants was identified in exome data from population studies. Our findings indicate that the suggested disease-causing role of some of these variants is questionable. A cautious interpretation of these variants must be made when found in SIDS victims.

Concepts: Gene, Genetics, Mutation, Demography, Breastfeeding, Ion channel, Pacifier, Sudden infant death syndrome

27

Viability imaging might be useful to guide decisions for revascularization in patients with ischemic cardiomyopathy. Recent trial results raise important points for clinicians regarding which modalities to use and in which patients. We discuss the modalities currently used in clinical practice. We suggest that testing be reserved for complex patients in whom the risks and potential benefits from revascularization are highest, and emphasize that the results of viability testing are not the only determinant of potential outcome benefit, and should not be viewed in isolation but as an objective adjunct to decision making.

Concepts: Game theory, Clinical trial, Decision making, Cardiomyopathy, Risk, Decision theory, Decision making software, Cardiovascular system

27

BACKGROUND: Chronic drug interactions that exist between symptomatic congestive heart failure (CHF) therapy and pharmacologic agents used for hyperuricemia and gout are a challenging problem in clinical practice. Recent observational studies showed that prednisone can induce a potent diuresis and lower serum uric acid concentration (SUA) in CHF. We therefore designed a randomized study to compare the effect of prednisone with allopurinol on SUA in symptomatic CHF patients with hyperuricemia. METHODS: Thirty-four symptomatic CHF participants with hyperuricemia (≥ 565 μmol/L) were randomized to receive prednisone (1 mg/kg/d, orally) or allopurinol (100 mg, thrice daily, orally) for 4 weeks. The primary outcome measure was change from baseline in SUA. The secondary outcome measures were change from baseline in serum creatinine levels, estimated glomerular filtration rate, daily urine output, body weight, N-terminal pro-B-type natriuretic peptide levels, physician-assessed global clinical status, and New York Heart Association functional class. RESULTS: Both prednisone and allopurinol greatly lowered SUA rapidly. The overall SUA-lowering effect did not differ between treatment groups during the study period (P = 0.48, 2-way repeated measures analysis of variance). However, prednisone increased estimated glomerular filtration rate and daily urine output, and lowered body weights and N-terminal pro-B-type natriuretic peptide. Consequently, participants treated with prednisone had an improvement in clinical status. CONCLUSIONS: The study showed that the SUA-lowering effect of prednisone and allopurinol is similar in symptomatic CHF patients. Prednisone might be useful for short-term SUA-lowering in CHF patients with hyperuricemia.

Concepts: Heart failure, Blood urea nitrogen, Creatinine, Gout, Urea, Uric acid, Hyperuricemia, Hyperuricosuria

25

We present Hypertension Canada’s inaugural evidence-based Canadian recommendations for the management of hypertension in pregnancy. Hypertension in pregnancy is common, affecting approximately 7% of pregnancies in Canada, and requires effective management to reduce maternal, fetal, and newborn complications. Because of this importance, these guidelines were developed in partnership with the Society of Obstetricians and Gynaecologists of Canada with the main common objective of improving the management of women with hypertension in pregnancy. Guidelines for the diagnosis, assessment, prevention, and treatment of hypertension in adults and children are published separately. In this first Hypertension Canada guidelines for hypertension in pregnancy, 7 recommendations for the management of nonsevere and severe hypertension in pregnancy are presented. For nonsevere hypertension in pregnancy (systolic blood pressure 140-159 mm Hg and/or diastolic blood pressure 80-109 mm Hg), we provide guidance for the threshold for initiation of antihypertensive therapy, blood pressure targets, as well as first- and second-line antihypertensive medications. Severe hypertension (systolic blood pressure ≥ 160 mm Hg and/or diastolic blood pressure ≥ 110 mm Hg) requires urgent antihypertensive therapy to reduce maternal, fetal, and newborn adverse outcomes. The specific evidence and rationale underlying each of these guidelines are discussed.

25

The role of tachycardia-induced cardiomyopathy vs tachycardia-related short diastolic filling period and reduced atrial contraction in decline of left ventricular ejection fraction (LVEF) in atrial fibrillation (AF) is uncertain. We aimed to characterize left heart changes over time in patients with AF who undergo electrical cardioversion (ECV).

Concepts: Myocardial infarction, Cardiology, Heart failure, Ejection fraction, Heart, Atrial fibrillation, Ventricle

24

Despite improved surgical techniques, preoperative and postoperative care, patients with functionally univentricular hearts (UVH) continue to have high morbidity and mortality and a decreased lifespan. Ventricular systolic and diastolic dysfunction is a major contributing factor to Fontan patient outcome. The evaluation of ventricular function in patients with UVH is particularly challenging. At a cellular and ultrastructural level, there are inherent differences between single and biventricular right and left ventricles. In addition, there are variable loading conditions throughout the stages of single ventricle palliation as well as variable ventricular remodelling in response to these changes. We will discuss the traditional and newer, advanced echocardiographic techniques that have been applied to evaluate ventricular function in patients with UVH. Each method has inherent advantages and disadvantages when applied to this population. The use of novel techniques including deformational imaging and 3-dimensional echocardiography will hopefully provide a more comprehensive understanding of the performance of the single ventricle, and how ventricular dysfunction affects the clinical status of patients after Fontan palliation.

Concepts: Cardiology, Heart, Blood pressure, Ventricle, Programming language, Systole, Ventricular system, Diastole

24

The primary prevention of atherosclerotic disease is on the basis of optimal management of the major risk factors. For the major risk factors of diabetes, hypertension, and dyslipidemia, management for most patients is on the basis of well developed and extensive evidence-based diagnostic and therapeutic guidelines. However, for a growing segment of the population who are at the highest risk for atherosclerotic disease (ie, older adults), the application of these guidelines is problematic. First, few studies that form the evidence base for these primary prevention guidelines actually include substantial numbers of elderly subjects. Second, elderly patients represent a special population from multiple perspectives related to their accumulation of health deficits and in their development of frailty. These patients with frailty and multiple comorbidities have been mostly excluded from the primary prevention studies upon which the guidelines are based yet comprise a very significant proportion of the very elderly population. Third, elderly people are at most risk from adverse drug reactions because of the increasing number of medications prescribed in this patient population. When applying the existing guidelines to elderly people the limitations of our knowledge must be recognized regarding how best to mitigate the high risk of heart disease in our aging population and how to generalize these recommendations to the management of the largest subgroup of elderly patients (ie, those with multiple comorbidities and frail older adults).

Concepts: Death, Middle age, Gerontology, Old age, Ageing, Aging, Adverse drug reaction, Retirement