Myocardial infarct extension, a process involving the enlargement of infarct and border zone, leads to progressive degeneration of left ventricular (LV) function and eventually gives rise to heart failure. Despite carrying a high risk, the causation of infarct extension is still a subject of much speculation. In this study, patient-specific LV models were developed to investigate the correlation between infarct extension and impaired regional mechanics. Subsequently, sensitivity analysis was performed to examine the causal factors responsible for the impaired regional mechanics observed in regions surrounding the infarct and border zone. From our simulations, fibre strain, fibre stress and fibre stress-strain loop (FSSL) were the key biomechanical variables affected in these regions. Among these variables, only FSSL was correlated with infarct extension, as reflected in its work density dissipation (WDD) index value, with high WDD indices recorded at regions with infarct extension. Impaired FSSL is caused by inadequate contraction force generation during the isovolumic contraction and ejection phases. Our further analysis revealed that the inadequacy in contraction force generation is not necessarily due to impaired myocardial intrinsic contractility, but at least in part, due to inadequate muscle fibre stretch at end-diastole, which depresses the ability of myocardium to generate adequate contraction force in the subsequent systole (according to the Frank-Starling law). Moreover, an excessively stiff infarct may cause its neighbouring myocardium to be understretched at end-diastole, subsequently depressing the systolic contractile force of the neighbouring myocardium, which was found to be correlated with infarct extension.
Background In contrast with the setting of acute myocardial infarction, there are limited data regarding the impact of diabetes mellitus on clinical outcomes in contemporary cohorts of patients with chronic coronary syndromes. We aimed to investigate the prevalence and prognostic impact of diabetes according to geographical regions and ethnicity. Methods and results CLARIFY is an observational registry of patients with chronic coronary syndromes, enrolled across 45 countries in Europe, Asia, America, Middle East, Australia, and Africa in 2009–2010, and followed up yearly for 5 years. Chronic coronary syndromes were defined by ≥1 of the following criteria: prior myocardial infarction, evidence of coronary stenosis >50%, proven symptomatic myocardial ischaemia, or prior revascularization procedure. Among 32 694 patients, 9502 (29%) had diabetes, with a regional prevalence ranging from below 20% in Northern Europe to ∼60% in the Gulf countries. In a multivariable-adjusted Cox proportional hazards model, diabetes was associated with increased risks for the primary outcome (cardiovascular death, myocardial infarction, or stroke) with an adjusted hazard ratio of 1.28 (95% confidence interval 1.18, 1.39) and for all secondary outcomes (all-cause and cardiovascular mortality, myocardial infarction, stroke, heart failure, and coronary revascularization). Differences on outcomes according to geography and ethnicity were modest. Conclusion In patients with chronic coronary syndromes, diabetes is independently associated with mortality and cardiovascular events, including heart failure, which is not accounted by demographics, prior medical history, left ventricular ejection fraction, or use of secondary prevention medication. This is observed across multiple geographic regions and ethnicities, despite marked disparities in the prevalence of diabetes. ClinicalTrials identifier ISRCTN43070564
Heart failure is the leading cause of morbidity and mortality worldwide. Standard treatment for heart failure includes pharmacotherapy and cardiac device implants. However, supportive approaches in managing dyspnea in heart failure are limited. This study aimed to test the efficacy of 20-minute mindful breathing in reducing dyspnea among patients admitted for acute decompensated heart failure. We conducted a parallel-group, non-blinded, randomized controlled trial of a single session of 20-minute mindful breathing plus standard care versus standard care alone among patients admitted for moderate to severe dyspnea due to acute decompensated heart failure, using the dyspnea score based on the Edmonton Symptom Assessment System (ESAS), at the Cardiology Unit of University Malaya Medical Centre in Malaysia. Thirty participants were randomly assigned to a single session of 20-minute mindful breathing plus standard care (n = 15) or standard care alone (n = 15), with no difference in their demographic and clinical characteristics. There was statistically significant reduction in dyspnea in the intervention group compared to the control group at minute 20 (U = 49.5, n1 = 15, n2 =15, median reduction in ESAS dyspnea score 1 = 2, median reduction in ESAS dyspnea score 2 = 0, mean rank 1 = 11.30, mean rank 2 = 19.70, z = −2.692, r = 0.4, P = 0.007). Our results provided evidence that a single session of 20-minute mindful breathing was efficacious in reducing dyspnea for patients admitted for acute decompensated heart failure.
Background Oral anticoagulant therapy is indicated for the prevention of stroke or other thromboembolic events. Premature discontinuation of oral anticoagulants may increase the risk of thromboembolism resulting in adverse sequelae. There are sparse data on the prevalence and the predictors of dabigatran discontinuation in Malaysian patients with atrial fibrillation. Objectives Determine the reasons and identify associated factors for abrupt discontinuation of dabigatran, assess the switching pattern and the occurrence of thromboembolic events after dabigatran discontinuation. Setting A university-affiliated tertiary hospital in Kuala Lumpur, Malaysia. Methods The clinical and demographic data of a cohort who were initiated with dabigatran between 2010 and 2012 at the University of Malaya Medical Centre were reviewed until the date of death or on 31st December 2013. Those patients who discontinued dabigatran were further followed up until 31st December 2015 to determine the occurrence of any thromboembolic event. Main outcome measure Permanent discontinuation of dabigatran for more than 8 weeks. Results 26 (14 %) of a cohort of 192 patients discontinued dabigatran therapy during a median follow-up period of 20 (range 3-45) months. About one-half of the discontinuation occurred within the first 6 months of dabigatran use. The three most cited reasons for discontinuation are bleeding events (19 %), high out-of-pocket drug payment (19 %) and cardioversion (19 %). Heart failure [adjusted odds ratio 3.699 (95 % confidence interval 1.393-9.574)] or chronic kidney disease [adjusted odds ratio 5.211 (95 % confidence interval 1.068-23.475)] were found to be independent risk factors for abrupt dabigatran discontinuation. Patients who discontinued dabigatran received warfarin (38 %), antiplatelet agents (16 %) or no alternative antithrombotic therapy (46 %). Five of the 26 patients who discontinued dabigatran developed an ischaemic stroke within 3-34 months after discontinuation. Conclusion Abrupt dabigatran discontinuation without an alternative oral anticoagulant increases the risk of thromboembolic events. As adverse drug events and renal impairment contribute substantially to the premature discontinuation of dabigatran, it is important to identify and monitor patients at risk to reduce dabigatran discontinuation rate especially during the first six months of dabigatran therapy.
Obstructive sleep apnea (OSA) is a growing health hazard in the United States and worldwide. OSA is now recognized as a disorder with systemic manifestations and its association with obesity and adverse cardiovascular consequences. There is increasing evidence that OSA may be associated with systemic hypertension and an increased incidence of stroke, heart failure, myocardial infarction, and arrhythmias. Less information is available about the association between OSA and pulmonary hypertension (PH). We therefore conduct this study to look at the prevalence of the pulmonary hypertension in obstructive sleep apnea patient and to identify risk factors leading to pulmonary hypertension among OSA patient. We studied and analyzed all OSA patient confirmed by polysomnograph in the year 2015. Twenty-five patients with OSA were included in this study with prevalence of pulmonary hypertension of 16%. Univariate analysis of various factors revealed a statistically significant association between having the lowest SpO of <70% and pulmonary hypertension (p = 0.016). There were no statistically significant associations between age, gender, smoking status, hypertension, body mass index (BMI), or apnea-hypopnea index (AHI) with occurrence of pulmonary hypertension. AHI is not a good predictor for pulmonary hypertension. The real value of using AHI to predict the health risk of OSA is doubtful. We recommend routine echocardiogram among OSA patient. The objective information in the echocardiogram provides evidence for counseling of patient with disease of OSA and hence hopefully can improve compliance of patient to treatment especially usage of CPAP.
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