COVID-19 and its Cardiac and Neurological Complications among Ontario Visible Minorities.

BACKGROUND: Due to lack of data on the epidemiology, cardiac, and neurological complications among Ontario visible minorities (Chinese and South Asians) affected by coronavirus disease (COVID-19), this population-based retrospective study was undertaken to study them systematically. METHODS: From January 1, 2020 to September 30, 2020 using the last name algorithm to identify Ontario Chinese and South Asians who were tested positive by PCR for COVID-19, their demographics, cardiac, and neurological complications including hospitalization and emergency visit rates were analyzed compared to the general population. RESULTS: Chinese (N = 1,186) with COVID-19 were found to be older (mean age 50.7 years) compared to the general population (N = 42,547) (mean age 47.6 years) (p < 0.001), while South Asians (N = 3,459) were younger (age of 42.1 years) (p < 0.001). The 30-day crude rate for cardiac complications among Chinese was 169/10,000 (p = 0.069), while for South Asians, it was 64/10,000 (p = 0.008) and, for the general population, it was 112/10,000. For neurological complications, the 30-day crude rate for Chinese was 160/10,000 (p < 0.001); South Asians was 40/10,000 (p = 0.526), and general population was 48/10,000. The 30-day all-cause mortality rate was significantly higher for Chinese at 8.1% vs 5.0% for the general population (p < 0.001), while it was lower in South Asians at 2.1% (p < 0.001). CONCLUSIONS: Chinese and South Asians in Ontario affected by COVID-19 during the first wave of the pandemic were found to have a significant difference in their demographics, cardiac, and neurological outcomes.

Role of cell death in the progression of heart failure.

All multicellular organisms develop during evolution the highly regulated and interconnected pathways of cell death. This complex network contributes to the pathogenesis of various cardiovascular disorders including ischemia/reperfusion injury, myocardial infarction, heart failure, dysrhythmias and atherosclerosis. Chronic cardiac remodeling response and transition to overt HF have been associated with modestly increased apoptosis, although the actual burden of chronic cell loss attributable to apoptosis is not clear. Central mediators of cardiomyocyte survival and death are the mitochondrial organelles. Based on its morphological characteristics, cell death can be classified into three major types: apoptosis, necrosis and autophagy. Recently, a new pathway of regulated necrosis, necroptosis, has also been reported in the failing heart. The mitochondrial (intrinsic) and the death-receptor-mediated (extrinsic) converge at mitochondria inducing release of mitochondrial apoptogens to initiate the caspase cascade and eventually degradation of the doomed cardiomyocyte. Activation of death receptors can initiate not only extrinsic apoptotic pathway, but also necrosis. On the other hand, autophagy, which is characterized by the massive formation of lysosomal-derived vesicles, containing degenerating cytoplasmic contents, is primarily a survival response to nutrient deprivation, and a selective form of autophagy, mitophagy, is also a protective mechanism that allows to eliminate damaged mitochondria and thereby to attenuate mitochondria-mediated apoptosis and necrosis in the myocardium. Further insight into the molecular mechanisms underlying cell death will increase the efficiency and repertoire of therapeutic interventions available in cardiovascular disease.

Mitochondria in heart failure: the emerging role of mitochondrial dynamics.

Over the past decade, mitochondria have emerged as critical integrators of energy production, generation of reactive oxygen species (ROS), multiple cell death, and signaling pathways in the constantly beating heart. Clarification of the molecular mechanisms, underlying mitochondrial ROS generation and ROS-induced cell death pathways, associated with cardiovascular diseases, by itself remains an important aim; more recently, mitochondrial dynamics has emerged as an important active mechanism to maintain normal mitochondria number and morphology, both are necessary to preserve cardiomyocytes integrity. The two opposing processes, division (fission) and fusion, determine the cell type-specific mitochondrial morphology, the intracellular distribution and activity. The tightly controlled balance between fusion and fission is of particular importance in the high energy demanding cells, such as cardiomyocytes, skeletal muscles, and neuronal cells. A shift toward fission will lead to mitochondrial fragmentation, observed in quiescent cells, while a shift toward fusion will result in the formation of large mitochondrial networks, found in metabolically active cardiomyocytes. Defects in mitochondrial dynamics have been associated with various human disorders, including heart failure, ischemia reperfusion injury, diabetes, and aging. Despite significant progress in our understanding of the molecular mechanisms of mitochondrial function in the heart, further focused research is needed to translate this knowledge into the development of new therapies for various ailments.

A comparison of Chinese and non-Chinese Canadian patients hospitalized with heart failure.

BACKGROUND: Canadians of Chinese descent, represent one of the fastest growing visible minority groups in Canada, (as well as the second largest), but relatively little is known about the clinical features of heart failure (HF) in Chinese-Canadian versus non-Chinese Canadian patients. METHODS: We conducted a population-based analysis of urban patients hospitalized in Ontario, Canada for the first time with a most responsible diagnosis of HF between April 1, 1995 and March 31, 2008. Among the 99,278 patients, 1,339 (1.3%) were classified as Chinese using a previously validated list of Chinese surnames. Through linkage to other administrative databases, we compared the clinical characteristics, pharmacological management, and outcomes of Chinese versus non-Chinese HF patients. RESULTS: Ischemic heart disease was identified as the possible etiology of HF in a greater proportion of non-Chinese patients (47.7% vs. 35.3%; p < 0.001) whereas hypertension (26.1% vs. 16.1%; p < 0.001) and valvular heart disease (11.6% vs. 7.2%; p < 0.001) were relatively more common in Chinese patients. Chinese patients were prescribed angiotensin-converting enzyme (ACE) inhibitors less frequently (57.5% vs. 66.4%, p < 0.001) and angiotensin receptor blockers (ARBs) more frequently (17.4% vs. 8.9%, p < 0.001) compared to non-Chinese patients. They were also less likely to be adherent to ACE inhibitors over a 1-year follow up period. However, the 1-year case-fatality rates were comparable between the Chinese (31.7%) and non-Chinese (30.2%) subjects (p = 0.24). CONCLUSION: There are important differences in the causes and medical management of HF in Chinese and non-Chinese patients residing in Canada. Despite these differences, the long-term outcomes of HF patients were similar.

Relationships between changes in patient-reported health status and functional capacity in outpatients with heart failure.

BACKGROUND: Heart failure trials use a variety of measures of functional capacity and quality of life. Lack of formal assessments of the relationships between changes in multiple aspects of patient-reported health status and measures of functional capacity over time limits the ability to compare results across studies. METHODS: Using data from HF-ACTION (N = 2331), we used the Pearson correlation coefficients and predicted change scores from linear mixed-effects modeling to demonstrate the associations between changes in patient-reported health status measured with the EQ-5D visual analog scale and the Kansas City Cardiomyopathy Questionnaire (KCCQ) and changes in peak VO(2) and 6-minute walk distance at 3 and 12 months. We examined a 5-point change in KCCQ within individuals to provide a framework for interpreting changes in these measures. RESULTS: After adjustment for baseline characteristics, correlations between changes in the visual analog scale and changes in peak VO(2) and 6-minute walk distance ranged from 0.13 to 0.28, and correlations between changes in the KCCQ overall and subscale scores and changes in peak VO(2) and 6-minute walk distance ranged from 0.18 to 0.34. A 5-point change in KCCQ was associated with a 2.50-mL kg(-1) min(-1) change in peak VO(2) (95% CI 2.21-2.86) and a 112-m change in 6-minute walk distance (95% CI 96-134). CONCLUSIONS: Changes in patient-reported health status are not highly correlated with changes in functional capacity. Our findings generally support the current practice of considering a 5-point change in the KCCQ within individuals to be clinically meaningful.

Nuclear-mitochondrial cross-talk in global myocardial ischemia. A time-course analysis.

Myocardial ischemia results in early and progressive damage to mitochondrial structure and function, but the molecular events leading to these changes have not been clearly established. We hypothesized that mitochondrial dysfunction and a coordinated expression of nuclear and mitochondrial genes occur in a time-dependent manner by relating the time courses of changes in parameters of mitochondrial bioenergetics after ischemia-reperfusion. Using a Langendorff rat heart model, mitochondrial bioenergetics and protein levels were assessed at different times of ischemia and ischemia/reperfusion. Mitochondrial and nuclear gene expression (super array analysis) and mitochondrial DNA levels were evaluated after late ischemia. Ischemia induced progressive and marked decreases in complex I, III, and V activities. Reperfusion (15, 30, and 60 min) after 45 min of ischemia had little further effect on enzyme activities or respiration. Super array analysis after 45 min ischemia revealed increased levels of the proteins with more pronounced increases in the corresponding mRNAs. Expression of mitochondrial and nuclear genes involved in oxidative phosphorylation increased after 45 min of ischemia but not after reperfusion. Myocardial ischemia induces mitochondrial dysfunction and differential but coordinated expression of nuclear and mitochondrial genes in a time-dependent manner. Our observations are pertinent to the search for molecular stimuli that generate mitochondrial defects and alter mitochondrial and nuclear transcriptional responses that may impact ischemic preconditioning and cardioprotection.

Epidemiology of COVID-19 and Its Cardiac and Neurologic Complications Among Chinese and South Asians in Ontario: Waves 1, 2, and 3.

Background: Although we had previously reported the cardiac and neurologic outcomes of Chinese and South Asian Ontarians in wave 1 of COVID-19, data on subsequent waves of COVID-19 remain unexamined. This is an extension study of this cohort in waves 2 and 3. Methods: We identified adult Ontarians with a positive COVID-19 polymerase chain reaction test from January 1, 2020 to June 30, 2021, and they were classified as being Chinese or South Asian using a validated surname algorithm; we compared their outcomes of mortality, and cardiac and neurologic complications with those of the general population using multivariable logistic regression models. Results: Compared to the general population (n = 439,977), the Chinese population (n = 15,208) was older (mean age 44.2 vs 40.6 years, P < 0.001) and the South Asian population (n = 46,333) was younger (39.2 years, P < 0.001). The Chinese population had a higher 30-day mortality (odds ratio [OR] 1.44; 95% confidence interval [CI] 1.28-1.61) and more hospitalization or emergency department visits (OR, 1.14; 95% CI, 1.09-1.28), with a trend toward a higher incidence of cardiac complications (OR, 1.03; 95% CI, 0.87-1.12) and neurologic complications (OR, 1.23; 95% CI, 0.96-1.58). South Asians had a lower 30-day mortality (OR, 0.88; 95% CI, 0.78-0.98) but a higher incidence of hospitalization or emergency department visits (OR, 1.17; 95% CI, 1.14-1.20) with a trend toward a lower incidence of cardiac complications (OR, 0.76; 95% CI, 0.67-0.87) and neurologic complications (OR, 0.89; 95% CI, 0.73-1.09). There was also a significant difference in these outcomes between wave 1, 2 and 3, with a greater mortality in all groups in waves 2 and 3. Conclusions: Ethnicity continues to be an important determinant of mortality, cardiac and neurologic outcomes, and healthcare use among patients with COVID-19, requiring further studies to understand factors driving these differences.

Contexte: Nous avons déjà présenté les issues cliniques cardiaques et neurologiques chez les Ontariens de descendance chinoise ou sud-asiatique pour la première vague de la pandémie de COVID-19, mais les données au sujet des vagues ultérieures n'avaient pas encore été analysées. Nous présentons ici une prolongation de cette étude de cohortes pour la seconde et la troisième vague de COVID-19. Méthodologie: Notre analyse porte sur des adultes ontariens ayant obtenu un résultat positif à un test de COVID-19 par réaction en chaîne de la polymérase entre le 1er janvier 2020 et le 30 juin 2021. Un algorithme validé pour l'analyse des noms de famille a été utilisé pour isoler les sujets de descendance chinoise ou sud-asiatique, et leur taux de mortalité de même que les complications cardiaques et neurologiques ont été comparés à ceux de la population générale à l'aide de modèles de régression logistique multivariée. Résultats: En comparaison de la population générale (n = 439 977), les personnes de descendance chinoise (n = 15 208) se sont révélées plus âgées (âge moyen de 44,2 ans contre 40,6 ans, P < 0,001), tandis que les personnes de descendance sud-asiatique (n = 46 333) étaient plus jeunes (39,2 ans, P < 0,001). Dans la population de descendance chinoise, le taux de mortalité après 30 jours était plus élevé (rapport de cotes [RC] de 1,44; intervalle de confiance [IC] à 95 % de 1,28 à 1,61), et davantage d'hospitalisations ou de consultations aux urgences sont survenues (RC de 1,14; IC à 95 % de 1,09 à 1,28). L'incidence de complications cardiaques (RC de 1,03; IC à 95 % de 0,87 à 1,12) et de complications neurologiques (RC de 1,23; IC à 95 % de 0,96 à 1,58) avait également tendance à être plus élevée. Chez les personnes de descendance sud-asiatique, le taux de mortalité après 30 jours était plus faible (RC de 0,88; IC à 95 % de 0,78 à 0,98), mais l'incidence d'hospitalisations ou de consultations aux urgences était plus élevée (RC de 1,17; IC à 95 % de 1,14 à 1,20). Elles présentaient également une tendance vers une plus faible incidence de complications cardiaques (RC de 0,76; IC à 95 % de 0,67 à 0,87) et de complications neurologiques (RC de 0,89; IC à 95 % de 0,73 à 1,09). Des différences significatives ont également été observées pour ces paramètres entre les vagues 1, 2 et 3 de la maladie, et le taux de mortalité était plus élevé pour tous les groupes des vagues 2 et 3. Conclusions: L'origine ethnique demeure un déterminant important de la mortalité, des issues cliniques cardiaques et neurologiques ainsi que de l'utilisation des ressources en santé chez les patients atteints de la COVID-19. D'autres études sont toutefois nécessaires pour mieux comprendre les facteurs qui expliquent ces différences.

Awareness of Warning Symptoms of Heart Disease and Stroke: Results of a Follow-up Study of the Chinese Canadian Cardiovascular Health Project.

BACKGROUND: Our original pilot study in 2008 demonstrated a poor degree of awareness of heart disease and stroke among Chinese Canadians, warranting an updated survey of their knowledge. We sought to determine the current degree of knowledge of cardiovascular disease, including stroke, among ethnic Chinese residents of Canada. METHODS: A 35-question online survey was conducted in the fall of 2017 among 1001 Chinese Canadians (aged ≥ 18 years) in the greater Toronto area (n = 501) and Vancouver (n = 500). Knowledge of heart disease and stroke, such as signs and symptoms of stroke and heart attack, health habits, and initial response to a cardiovascular emergency were assessed. RESULTS: A total of 52.0% of the respondents were female, and 46.3% were aged <45 years. A total of 40.1% spoke Cantonese, and 23.7% spoke Mandarin; 79.5% were immigrants, and 31% had lived in Canada < 10 years. A total of 85% identified at least one heart attack symptom, and 80% identified at least one stroke symptom; 86.2% indicated that they would call 911 if experiencing a heart attack or stroke. Internet use was positively associated with the ability to identify a greater number of heart attack and stroke symptoms, compared to the number among non-Internet users (P < 0.001). Women were 14% more likely to overlook gender as a risk factor for cardiovascular disease (CVD). CONCLUSIONS: This study found that in 2017, compared to 2008, awareness of symptoms of heart disease and stroke improved among Chinese Canadians residing in Toronto and Vancouver.

CONTEXTE: Dans le cadre d'une première étude pilote menée en 2008, nous avions montré que les Canadiens d'origine chinoise connaissaient si mal les maladies cœur et l'accident vasculaire cérébral (AVC) qu'une enquête de suivi de leurs connaissances s'imposait. Nous avons donc entrepris d'évaluer les connaissances actuelles des maladies cardiovasculaires, y compris l'AVC, chez les résidents canadiens d'origine chinoise. MÉTHODOLOGIE: Un sondage en ligne comprenant 35 questions a été effectué à l'automne 2017 auprès de 1 001 Canadiens d'origine chinoise (âgés de 18 ans ou plus) de la région du Grand Toronto (n = 501) et de Vancouver (n = 500). Les connaissances relatives aux maladies cœur et à l'AVC, notamment les signes et symptômes d'AVC et de crise cardiaque, les saines habitudes de vie et la première chose à faire en cas d'urgence cardiovasculaire, ont été évaluées. RÉSULTATS: Au total, 52,0 % des répondants étaient des femmes, et 46,3 % étaient âgés de moins de 45 ans; 40,1 % parlaient cantonnais et 23,7 %, mandarin; 79,5 % étaient des immigrants, et 31 % vivaient au Canada depuis moins de 10 ans. Au total, 85 % des répondants connaissaient au moins un symptôme de crise cardiaque et 80 %, au moins un symptôme d'AVC; 86,2 % ont indiqué qu'ils composeraient le 9-1-1 s'ils subissaient une crise cardiaque ou un AVC. Les répondants qui utilisaient l'Internet étaient capables de reconnaître un plus grand nombre de symptômes de crise cardiaque et d'AVC que les répondants qui n'utilisaient pas l'Internet (p < 0,001). Les femmes avaient 14 % plus de chances de ne pas tenir compte du sexe comme facteur de risque de maladie cardiovasculaire. CONCLUSIONS: L'étude a révélé qu'en 2017, comparativement à 2008, la connaissance des symptômes de maladie cœur et d'AVC s'est améliorée chez les Canadiens d'origine chinoise vivant à Toronto et à Vancouver.

Intercountry Differences in Guideline-Directed Medical Therapy and Outcomes Among Patients With Heart Failure.

OBJECTIVES: The aim of this study was to examine patterns of care and clinical outcomes among patients with heart failure with reduced ejection fraction (HFrEF) in the United States and Canada. BACKGROUND: In the GUIDE-IT (Guiding Evidence Based Therapy Using Biomarker Intensified Treatment) trial, the use of N-terminal pro-B-type natriuretic peptide-guided titration of guideline-directed medical therapy (GDMT) was compared with usual care alone for patients with HFrEF in the United States and Canada. It remains unknown whether the country of enrollment had an impact on outcomes or GDMT use. METHODS: A total of 894 patients at 45 sites across the United States and Canada with HFrEF (ejection fraction ≤40%) were enrolled in the trial. Kaplan-Meier survival estimates stratified by country of enrollment were developed for the trial outcomes, and log-rank testing was compared between the groups. GDMT use and titration were also compared. RESULTS: U.S. patients were more likely to be younger, to be Black, to have higher body mass index, and to have histories of defibrillator placement or sleep apnea. Use of ß-blockers was significantly higher in Canada at baseline (99.3% vs. 94.0%; p = 0.01) and 6 months (99.0% vs. 94.1%; p = 0.04), and use of mineralocorticoid receptor antagonists was higher in Canada at 6 months (68.3% vs. 55.1%; p = 0.01). Canadian patients were less likely to experience the primary study endpoint (hazard ratio [HR]: 0.65; 95% confidence interval [CI]: 0.45 to 0.93; p = 0.01) due to decreased rates of HF hospitalization (HR: 0.57; 95% CI: 0.38 to 0.86; p = 0.003). The differences in outcomes were driven by increased heart failure hospitalization among U.S. Black patients. CONCLUSIONS: In GUIDE-IT, patients with HFrEF in Canada were significantly less likely to be hospitalized for heart failure. Differences in GDMT use, along with differences in sociodemographics and care delivery structures, may contribute to these differences, highlighting the importance of increasing diversity in clinical trials. (Guiding Evidence Based Therapy Using Biomarker Intensified Treatment [GUIDE-IT]; NCT01685840).

CCS/CHFS Heart Failure Guidelines Update: Defining a New Pharmacologic Standard of Care for Heart Failure With Reduced Ejection Fraction.

In this update of the Canadian Cardiovascular Society heart failure (HF) guidelines, we provide comprehensive recommendations and practical tips for the pharmacologic management of patients with HF with reduced ejection fraction (HFrEF). Since the 2017 comprehensive update of the Canadian Cardiovascular Society guidelines for the management of HF, substantial new evidence has emerged that has informed the care of these patients. In particular, we focus on the role of novel pharmacologic therapies for HFrEF including angiotensin receptor-neprilysin inhibitors, sinus node inhibitors, sodium glucose transport 2 inhibitors, and soluble guanylate cyclase stimulators in conjunction with other long established HFrEF therapies. Updated recommendations are also provided in the context of the clinical setting for which each of these agents might be prescribed; the potential value of each therapy is reviewed, where relevant, for chronic HF, new onset HF, and for HF hospitalization. We define a new standard of pharmacologic care for HFrEF that incorporates 4 key therapeutic drug classes as standard therapy for most patients: an angiotensin receptor-neprilysin inhibitor (as first-line therapy or after angiotensin converting enzyme inhibitor/angiotensin receptor blocker titration); a ß-blocker; a mineralocorticoid receptor antagonist; and a sodium glucose transport 2 inhibitor. Additionally, many patients with HFrEF will have clinical characteristics for which we recommended other key therapies to improve HF outcomes, including sinus node inhibitors, soluble guanylate cyclase stimulators, hydralazine/nitrates in combination, and/or digoxin. Finally, an approach to management that integrates prioritized pharmacologic with nonpharmacologic and invasive therapies after a diagnosis of HFrEF is highlighted.

Heart failure in the ethnic minorities.

PURPOSE OF REVIEW: Ethnic minority groups constitute increasing proportions of the population in western countries. Heart failure is increasingly prevalent worldwide and is associated with significant morbidity and mortality. The purpose of this review is to discuss the limited data on heart failure in the ethnic minority groups. RECENT FINDINGS: South Asians have more coronary risk factors that may increase the risk for premature coronary heart disease leading to development of heart failure at a younger age. In the Chinese, hypertension remains an important cause of heart failure and recent data suggest that heart failure with preserved systolic function is common. African-Americans have a higher prevalence of heart failure than whites, present with heart failure at younger ages, and heart failure in them is less likely to be due to coronary heart disease. Findings from a randomized controlled trial conducted specifically on African-Americans support the addition of the combination of isosorbide dinitrate and hydralazine to standard medical regimen for black patients with heart failure. Aboriginal people are more likely than nonaboriginal people to have less access to healthcare and to have a higher disease burden for atherosclerosis. Heart failure is more prevalent in aboriginal than in the nonaboriginal counterparts. SUMMARY: There are important differences across ethnic groups in the causes of heart failure and response to treatment. Given the likely increasing frequency of heart failure in these populations and an increasingly multiethnic world, additional studies on heart failure across different ethnic groups are warranted.

The Status of Specialized Ambulatory Heart Failure Care in Canada: A Joint Canadian Heart Failure Society and Canadian Cardiovascular Society Heart Failure Guidelines Survey.

This joint Canadian Heart Failure Society and the CCS Heart Failure guidelines report has been developed to provide a pan-Canadian snapshot of the current state of clinic-based ambulatory heart failure (HF) care in Canada with specific reference to elements and processes of care associated with quality and high performing health systems. It includes the viewpoints of persons with lived experience, patient care providers, and administrators. It is imperative to build on the themes identified in this survey, through engaging all health care professionals, to develop integrated and shared care models that will allow better patient outcomes. Several patient and organizational barriers to care were identified in this survey, which must inform the development of regional care models and pragmatic solutions to improve transitions for this patient population. Unfortunately, we were unsuccessful in incorporating the perspectives of primary care providers and internal medicine specialists who provide the majority of HF care in Canada, which in turn limits our ability to comment on strategies for capacity building outside the HF clinic setting. These considerations must be taken into account when interpreting our findings. Engaging all HF care providers, to build on the themes identified in this survey, will be an important next step in developing integrated and shared care models known to improve patient outcomes.

Ce rapport conjoint des lignes directrices de la Société canadienne d'insuffisance cardiaque et de la Société canadienne de cardiologie (SCC) sur l'insuffisance cardiaque a été élaboré pour fournir un aperçu pancanadien de l'état actuel des soins ambulatoires de l'insuffisance cardiaque (IC) en clinique au Canada, en se référant spécifiquement aux éléments et aux processus de soins associés à des systèmes de santé très performants et de qualité. Il comprend les points de vue de personnes ayant une expérience vécue de l'IC, de prestataires de soins aux patients et d'administrateurs. Il est impératif de s'appuyer sur les thématiques identifiées dans cette enquête, en y engageant tous les professionnels de la santé, pour développer des modèles de soins intégrés et partagés qui permettront de meilleurs pronostics pour les patients. Plusieurs obstacles relatifs aux patients et organisationnels dont il faudra se soucier ont été identifiés dans cette enquête, qui doit servir de base à l'élaboration de modèles de soins régionaux et de solutions pragmatiques pour améliorer les transitions pour cette population de patients. Malheureusement, nous n'avons pas réussi à intégrer les points de vue des prestataires de soins primaires et des spécialistes en médecine interne qui fournissent la majorité des soins en IC au Canada, ce qui limite notre capacité à commenter les stratégies de renforcement des capacités en dehors du cadre des cliniques d'IC. Ces considérations doivent être prises en compte lors de l'interprétation de nos conclusions. L'engagement de tous les prestataires de soins de santé en IC à s'appuyer sur les thématiques identifiées dans cette enquête constituera une prochaine étape importante dans le développement de modèles de soins intégrés et partagés connus pour améliorer le pronostic des patients.

CCS/CHFS Heart Failure Guidelines: Clinical Trial Update on Functional Mitral Regurgitation, SGLT2 Inhibitors, ARNI in HFpEF, and Tafamidis in Amyloidosis.

In this update, we focus on selected topics of high clinical relevance for health care providers who treat patients with heart failure (HF), on the basis of clinical trials published after 2017. Our objective was to review the evidence, and provide recommendations and practical tips regarding the management of candidates for the following HF therapies: (1) transcatheter mitral valve repair in HF with reduced ejection fraction; (2) a novel treatment for transthyretin amyloidosis or transthyretin cardiac amyloidosis; (3) angiotensin receptor-neprilysin inhibition in patients with HF and preserved ejection fraction (HFpEF); and (4) sodium glucose cotransport inhibitors for the prevention and treatment of HF in patients with and without type 2 diabetes. We emphasize the roles of optimal guideline-directed medical therapy and of multidisciplinary teams when considering transcatheter mitral valve repair, to ensure excellent evaluation and care of those patients. In the presence of suggestive clinical indices, health care providers should consider the possibility of cardiac amyloidosis and proceed with proper investigation. Tafamidis is the first agent shown in a prospective study to alter outcomes in patients with transthyretin cardiac amyloidosis. Patient subgroups with HFpEF might benefit from use of sacubitril/valsartan, however, further data are needed to clarify the effect of this therapy in patients with HFpEF. Sodium glucose cotransport inhibitors reduce the risk of incident HF, HF-related hospitalizations, and cardiovascular death in patients with type 2 diabetes and cardiovascular disease. A large clinical trial recently showed that dapagliflozin provides significant outcome benefits in well treated patients with HF with reduced ejection fraction (left ventricular ejection fraction ≤ 40%), with or without type 2 diabetes.

Regional distribution of mitochondrial dysfunction and apoptotic remodeling in pacing-induced heart failure.

BACKGROUND: Specific myocardial mitochondrial enzymatic dysfunction and apoptotic remodeling occur in pacing-induced heart failure. We sought to define their regional distribution and molecular basis in the failing heart. METHODS AND RESULTS: Enzyme dysfunction was assessed in mitochondrial subpopulations and immunoblot analysis was performed using homogenate proteins from the left atria (LA) and left ventricle (LV) of paced and control mongrel dogs. A greater range of enzymatic defects (complex I, III, and V) was found in mitochondria subpopulations from the LV as compared with the LA (where only complex V was defective). Analysis of paced LV proteins demonstrated a downregulated expression of both mitochondrial genes (eg, cytochrome b) and nuclear genes (eg, ATP synthase beta subunit, mitochondrial creatine kinase). Protease-activated products of both mitochondrial (eg, apoptosis inducing factor) and cytosolic (eg, caspase-3) apoptogenic proteins were increased in both the LA and LV. Nuclear-localized apoptotic markers (eg, p53, p21) were also significantly increased in the LV of paced dogs. CONCLUSION: Abnormal activity of several mitochondrial enzymes and increased apoptogenic pathway appear to be mediated, at least in part, by an orchestrated shift in expression (both nuclear and mitochondrial DNA) of respiratory chain subunits (eg, cyt b, ATP-beta), mitochondrial bioenergetic enzymes (eg, mitochondrial creatine kinase), global transcription factor (eg, PGC-1), and apoptotic proteins (eg, p53, p21) with distinct differences in their regional distribution and in the subpopulations of mitochondria affected.

N-terminal pro-B-type natriuretic peptide testing improves the management of patients with suspected acute heart failure: primary results of the Canadian prospective randomized multicenter IMPROVE-CHF study.

BACKGROUND: The diagnostic utility of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in heart failure has been documented. However, most of the data were derived from countries with high healthcare resource use, and randomized evidence for utility of NT-proBNP was lacking. METHODS AND RESULTS: We tested the hypothesis that NT-proBNP testing improves the management of patients presenting with dyspnea to emergency departments in Canada by prospectively comparing the clinical and economic impact of a randomized management strategy either guided by NT-proBNP results or without knowledge of NT-proBNP concentrations. Five hundred patients presenting with dyspnea to 7 emergency departments were studied. The median NT-proBNP level among the 230 subjects with a final diagnosis of heart failure was 3697 compared with 212 pg/mL in those without heart failure (P<0.00001). Knowledge of NT-proBNP results reduced the duration of ED visit by 21% (6.3 to 5.6 hours; P=0.031), the number of patients rehospitalized over 60 days by 35% (51 to 33; P=0.046), and direct medical costs of all ED visits, hospitalizations, and subsequent outpatient services (US $6129 to US $5180 per patient; P=0.023) over 60 days from enrollment. Adding NT-proBNP to clinical judgment enhanced the accuracy of a diagnosis; the area under the receiver-operating characteristic curve increased from 0.83 to 0.90 (P<0.00001). CONCLUSIONS: In a universal health coverage system mandating judicious use of healthcare resources, inclusion of NT-proBNP testing improves the management of patients presenting to emergency departments with dyspnea through improved diagnosis, cost savings, and improvement in selected outcomes.

Matrix metalloproteinase inhibition attenuates atrial remodeling and vulnerability to atrial fibrillation in a canine model of heart failure.

BACKGROUND: Atrial structural remodeling occurs in evolving heart failure (HF) and is an important substrate for the development of atrial fibrillation (AF). The matrix metalloproteinases (MMPs) play a role in extracellular remodeling, and recent studies have demonstrated increased atrial MMP activity in HF. Whether increased MMP activity directly contributes to atrial remodeling and AF in the setting of HF remains unclear. The current study examined the effects of MMP inhibition on atrial structural remodeling and AF vulnerability during HF progression. METHODS AND RESULTS: Three groups of dogs (n = 5 each)--control normal dogs (controls) and 10 dogs subjected to simultaneous atrioventricular pacing (SAVP) for 2 weeks to induce HF and randomly assigned to treatment with placebo (SAVP-placebo) or a MMP inhibitor PGE-7113313, a MMP-1-sparing MMP inhibitor, 6 mg/kg orally twice daily (SAVP-MMPi)--were studied. SAVP-MMPi dogs had less AF inducibility (percent of burst attempts leading to AF episodes: 1.7 +/- 2.9 seconds vs. 23+/-19 seconds, mean +/- SD, P < .05) and maintenance (AF duration: 253 [105 to 326] vs. 1932 [1296 to 2724] seconds, median [25th-75th quartile], P < .05) than SAVP-placebo dogs. The SAVP-MMPi dogs had significantly smaller increases in atrial myocyte cross sectional area, collagen area fraction, and MMP-9 activity relative to controls than SAVP-placebo. There were, however, no significant differences in the changes in chamber dimension and function in the left atrium. CONCLUSIONS: This unique finding of an attenuation of the vulnerability to AF in conjunction with reduced myocyte hypertrophy and fibrosis after MMP inhibition suggests that heightened MMP activity in the atria contributes to atrial structural remodeling and AF promotion during evolving HF.

Simultaneous right atrioventricular pacing: a novel model to study atrial remodeling and fibrillation in the setting of heart failure.

BACKGROUND: Atrial fibrillation (AF) is a common arrhythmia which contributes to morbidity and mortality in patients with heart failure (HF). Atrial remodeling is a key substrate for the development of AF in HF. However, experimental models that study AF in the setting of HF have important limitations. We evaluated a new dog model of atrial remodeling and AF. METHODS AND RESULTS: Twenty-two mongrel dogs were randomized into 2 groups: 14 dogs with simultaneous atrioventricular pacing (SAVP) for 2 weeks (220 beats/min, no AV delay) and 8 control dogs with no pacing. SAVP for 2 weeks induced marked changes in atrial mechanical function and conduction. Left atrial area fractional shortening decreased 61 +/- 17%, whereas left ventricular area fractional shortening decreased by 38 +/- 18% from baseline (both P < .05). Conduction slowed and conduction heterogeneity increased. AF was induced in 83% of SAVP dogs, lasting a median of 1600 seconds, versus no dogs with induced AF in the controls. SAVP significantly increased nonfibrillar collagen in the mid-myocardium of both atrial appendages and matrix metalloproteinase-9 activity. CONCLUSIONS: SAVP in dogs induces structural and electrical remodelling that form the substrate for reproducibly inducible AF. This novel model may be useful for studies of the pathophysiology and treatment of AF in heart failure.

Hypertension Canada's 2018 Guidelines for Diagnosis, Risk Assessment, Prevention, and Treatment of Hypertension in Adults and Children.

Hypertension Canada provides annually updated, evidence-based guidelines for the diagnosis, assessment, prevention, and treatment of hypertension in adults and children. This year, the adult and pediatric guidelines are combined in one document. The new 2018 pregnancy-specific hypertension guidelines are published separately. For 2018, 5 new guidelines are introduced, and 1 existing guideline on the blood pressure thresholds and targets in the setting of thrombolysis for acute ischemic stroke is revised. The use of validated wrist devices for the estimation of blood pressure in individuals with large arm circumference is now included. Guidance is provided for the follow-up measurements of blood pressure, with the use of standardized methods and electronic (oscillometric) upper arm devices in individuals with hypertension, and either ambulatory blood pressure monitoring or home blood pressure monitoring in individuals with white coat effect. We specify that all individuals with hypertension should have an assessment of global cardiovascular risk to promote health behaviours that lower blood pressure. Finally, an angiotensin receptor-neprilysin inhibitor combination should be used in place of either an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in individuals with heart failure (with ejection fraction < 40%) who are symptomatic despite appropriate doses of guideline-directed heart failure therapies. The specific evidence and rationale underlying each of these guidelines are discussed.

Canadian Cardiovascular Society Consensus Conference recommendations on heart failure update 2007: Prevention, management during intercurrent illness or acute decompensation, and use of biomarkers.

Heart failure is common, yet it is difficult to treat. It presents in many different guises and circumstances in which therapy needs to be individualized. The Canadian Cardiovascular Society published a comprehensive set of recommendations in January 2006 on the diagnosis and management of heart failure, and the present update builds on those core recommendations. Based on feedback obtained through a national program of heart failure workshops during 2006, several topics were identified as priorities because of the challenges they pose to health care professionals. New evidence-based recommendations were developed using the structured approach for the review and assessment of evidence adopted and previously described by the Society. Specific recommendations and practical tips were written for the prevention of heart failure, the management of heart failure during intercurrent illness, the treatment of acute heart failure, and the current and future roles of biomarkers in heart failure care. Specific clinical questions that are addressed include: which patients should be identified as being at high risk of developing heart failure and which interventions should be used? What complications can occur in heart failure patients during an intercurrent illness, how should these patients be monitored and which medications may require a dose adjustment or discontinuation? What are the best therapeutic, both drug and nondrug, strategies for patients with acute heart failure? How can new biomarkers help in the treatment of heart failure, and when and how should BNP be measured in heart failure patients? The goals of the present update are to translate best evidence into practice, to apply clinical wisdom where evidence for specific strategies is weaker, and to aid physicians and other health care providers to optimally treat heart failure patients to result in a measurable impact on patient health and clinical outcomes in Canada.

Is There a Role for Ivabradine in the Contemporary Management of Patients with Chronic Heart Failure in Academic and Community Heart Failure Clinics in Canada?

INTRODUCTION: In patients with heart failure (HF) and reduced ejection fraction, increased heart rate (HR) is an independent risk factor for adverse outcomes. In systolic HF treatment with the If inhibitor ivabradine trial (SHIFT), Ivabradine improved survival when added to conventional treatment including ß-blockers. However, the extent of benefit in the real world is unclear. We examined the characteristics of patients on guideline-directed therapy and determined who had SHIFT-like characteristics. METHODS: A total of 1096 patients with chronic HF were reviewed from June 2014 to April 2015 in two HF clinics in Toronto: an academic institution (AI), and a community hospital (CH) clinic. SHIFT-like characteristics [left ventricular ejection fraction (LVEF) ≤35%; sinus rhythm; and HR ≥ 70 bpm] were described. RESULTS: For all patients, mean age was 75 ± 13 years, overall LVEF was 44 ± 15%, AI less than CH (41.9 ± 14.0% vs. 45.7 ± 15.0%; p < 0.0001). More than two-thirds of patients in both groups were on ß-blockers; with less than one-third at target dose. The proportion of patients with SHIFT-like characteristics was 8.4% AI and 11.7% CH, respectively (p = 0.0658). CONCLUSION: In HF clinics from both academic and community hospitals in Toronto, up-titration in the dose of ß-blockers and other guideline therapy can be improved on. A small proportion of patients with HF and SHIFT-like characteristics may potentially benefit from the addition of Ivabradine, just approved in Canada; this number will be further reduced if target dosage for ß-blockers is achieved. FUNDING: Servier Inc.