SciCombinator

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

Concept: Ejection fraction

168

BACKGROUND: Heart failure (HF) patients have a high risk of death, and implantable cardioverter defibrillators (ICDs) are effective in preventing sudden cardiac death (SCD). However, a certain percentage of patients may not be immediate candidates for ICDs, particularly those having a short duration of risk or an uncertain amount of risk. This includes the newly diagnosed patients, as well as those on the cardiac transplant list or NYHA class IV heart failure patients who do not already have an ICD. In these patients, a wearable cardioverter defibrillator (WCD) may be used until long term risk of SCD is defined. The purpose of this study was to determine the incidence of SCD in this population, and the efficacy of early defibrillation by a WCD. METHODS: Ten enrolling centers identified 89 eligible HF patients who were either listed for cardiac transplantation, diagnosed with dilated cardiomyopathy, or receiving inotropic medications. Data collected included medical history, device records, and outcomes (including 90 day mortality). RESULTS: Out of 89 patients, final data on 82 patients has been collected. Patients wore the device for 75+/-58 days. Mean age was 56.8+/-13.2, and 72% were male. Most patients (98.8%) were diagnosed with dilated cardiomyopathy with a low ejection fraction (<40%) and twelve were listed for cardiac transplantation. Four patients were on inotropes. There were no sudden cardiac arrests or deaths during the study. Interestingly, 41.5% of patients were much improved after WCD use, while 34.1% went on to receive an ICD. CONCLUSIONS: In conclusion, the WCD monitored HF patients until further assessment of risk. The leading reasons for end of WCD use were improvement in left ventricular ejection fraction (LVEF) or ICD implantation if there was no significant improvement in LVEF.

Concepts: Myocardial infarction, Cardiology, Cardiomyopathy, Heart failure, Ejection fraction, Implantable cardioverter-defibrillator, Cardiac arrest, Ventricular fibrillation

164

Inhibition of neurohumoural pathways such as the renin angiotensin aldosterone and sympathetic nervous systems is central to the understanding and treatment of heart failure (HF). Conversely, until recently, potentially beneficial augmentation of neurohumoural systems such as the natriuretic peptides has had limited therapeutic success. Administration of synthetic natriuretic peptides has not improved outcomes in acute HF but modulation of the natriuretic system through inhibition of the enzyme that degrades natriuretic (and other vasoactive) peptides, neprilysin, has proven to be successful. After initial failures with neprilysin inhibition alone or dual neprilysin-angiotensin converting enzyme (ACE) inhibition, the Prospective comparison of angiotensin receptor neprilysin inhibitor (ARNI) with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure trial (PARADIGM-HF) trial demonstrated that morbidity and mortality can be improved with the angiotensin receptor blocker neprilysin inhibitor sacubitril/valsartan (formerly LCZ696). In comparison to the ACE inhibitor enalapril, sacubitril/valsartan reduced the occurrence of the primary end point (cardiovascular death or hospitalisation for HF) by 20% with a 16% reduction in all-cause mortality. These findings suggest that sacubitril/valsartan should replace an ACE inhibitor or angiotensin receptor blocker as the foundation of treatment of symptomatic patients (NYHA II-IV) with HF and a reduced ejection fraction. This review will explore the background to neprilysin inhibition in HF, the results of the PARADIGM-HF trial and offer guidance on how to use sacubitril/valsartan in clinical practice.

Concepts: Myocardial infarction, Hypertension, Heart failure, Ejection fraction, Renin-angiotensin system, Angiotensin II receptor antagonist, ACE inhibitor, Enalapril

157

Limited information exists on the etiology, prevalence, and significance of hyperdynamic left ventricular ejection fraction (HDLVEF) in the intensive care unit (ICU). Our aim in the present study was to compare characteristics and outcomes of patients with HDLVEF with those of patients with normal left ventricular ejection fraction in the ICU using a large, public, deidentified critical care database.

Concepts: Ejection fraction, Intensive care medicine

148

Phase contrast (PC) cine-magnetic resonance imaging (MRI) of the coronary sinus allows for noninvasive evaluation of coronary flow reserve (CFR), which is an index of left ventricular microvascular function. The objective of this study was to investigate coronary flow reserve in patients with heart failure with preserved ejection fraction (HFpEF).

Concepts: Myocardial infarction, Cardiology, Heart failure, Ejection fraction, Heart, Magnetic resonance imaging, Coronary circulation, Sinus venosus

137

According to current ESC Guidelines for the diagnosis and treatment of heart failure cardiac resynchronization therapy (CRT) is indicated in patients suffering from heart failure (HF) with reduced ejection fraction (EF) with significantly widened QRS complexes. Presence of vital myocardium proved by dobutamine stress echocardiography (DSE) is considered as a good prognostic factor for responsiveness to this treatment. Chronotropic incompetence is on the other hand known factor of unfavorable outcome in HF.

Concepts: Myocardial infarction, Cardiology, Heart failure, Ejection fraction, Echocardiography, Heart disease, QRS complex, Purkinje fibers

94

Background - Poor fitness in middle age is a risk factor for heart failure, particularly heart failure with a preserved ejection fraction. The development of heart failure with a preserved ejection fraction is likely mediated through increased left ventricular (LV) stiffness, a consequence of sedentary aging. In a prospective, parallel group, randomized controlled trial, we examined the effect of 2 years of supervised highintensity exercise training on LV stiffness. Methods - Sixty-one (48% male) healthy, sedentary, middle-aged participants (53±5 years) were randomly assigned to either 2 years of exercise training (n=34) or attention control (control; n=27). Right heart catheterization and 3-dimensional echocardiography were performed with preload manipulations to define LV end-diastolic pressure-volume relationships and Frank-Starling curves. LV stiffness was calculated by curve fit of the diastolic pressure-volume curve. Maximal oxygen uptake (Vo2max) was measured to quantify changes in fitness. Results - Fifty-three participants completed the study. Adherence to prescribed exercise sessions was 88±11%. Vo2max increased by 18% (exercise training: pre 29.0±4.8 to post 34.4±6.4; control: pre 29.5±5.3 to post 28.7±5.4, group×time P<0.001) and LV stiffness was reduced (right/downward shift in the end-diastolic pressure-volume relationships; preexercise training stiffness constant 0.072±0.037 to postexercise training 0.051±0.0268, P=0.0018), whereas there was no change in controls (group×time P<0.001; pre stiffness constant 0.0635±0.026 to post 0.062±0.031, P=0.83). Exercise increased LV end-diastolic volume (group×time P<0.001), whereas pulmonary capillary wedge pressure was unchanged, providing greater stroke volume for any given filling pressure (loading×group×time P=0.007). Conclusions - In previously sedentary healthy middle-aged adults, 2 years of exercise training improved maximal oxygen uptake and decreased cardiac stiffness. Regular exercise training may provide protection against the future risk of heart failure with a preserved ejection fraction by preventing the increase in cardiac stiffness attributable to sedentary aging. Clinical Trial Registration - URL: https://clinicaltrials.gov. Unique identifier: NCT02039154.

Concepts: Epidemiology, Middle age, Cardiology, Heart failure, Ejection fraction, Heart, Avicenna, Frank-Starling law of the heart

83

Background The benefit of an implantable cardioverter-defibrillator (ICD) in patients with symptomatic systolic heart failure caused by coronary artery disease has been well documented. However, the evidence for a benefit of prophylactic ICDs in patients with systolic heart failure that is not due to coronary artery disease has been based primarily on subgroup analyses. The management of heart failure has improved since the landmark ICD trials, and many patients now receive cardiac resynchronization therapy (CRT). Methods In a randomized, controlled trial, 556 patients with symptomatic systolic heart failure (left ventricular ejection fraction, ≤35%) not caused by coronary artery disease were assigned to receive an ICD, and 560 patients were assigned to receive usual clinical care (control group). In both groups, 58% of the patients received CRT. The primary outcome of the trial was death from any cause. The secondary outcomes were sudden cardiac death and cardiovascular death. Results After a median follow-up period of 67.6 months, the primary outcome had occurred in 120 patients (21.6%) in the ICD group and in 131 patients (23.4%) in the control group (hazard ratio, 0.87; 95% confidence interval [CI], 0.68 to 1.12; P=0.28). Sudden cardiac death occurred in 24 patients (4.3%) in the ICD group and in 46 patients (8.2%) in the control group (hazard ratio, 0.50; 95% CI, 0.31 to 0.82; P=0.005). Device infection occurred in 27 patients (4.9%) in the ICD group and in 20 patients (3.6%) in the control group (P=0.29). Conclusions In this trial, prophylactic ICD implantation in patients with symptomatic systolic heart failure not caused by coronary artery disease was not associated with a significantly lower long-term rate of death from any cause than was usual clinical care. (Funded by Medtronic and others; DANISH ClinicalTrials.gov number, NCT00542945 .).

Concepts: Blood, Myocardial infarction, Cardiology, Ejection fraction, Heart, Implantable cardioverter-defibrillator, Artery, Coronary circulation

71

Current European and American guidelines recommend the perioperative initiation of a course of β-blockers in those at risk of cardiac events undergoing high- or intermediate-risk surgery or vascular surgery. The Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography (DECREASE) family of trials, the bedrock of evidence for this, are no longer secure. We therefore conducted a meta-analysis of randomised controlled trials of β-blockade on perioperative mortality, non-fatal myocardial infarction, stroke and hypotension in non-cardiac surgery using the secure data.

Concepts: Epidemiology, Myocardial infarction, Atherosclerosis, Hypertension, Cardiology, Ejection fraction, Randomized controlled trial, Stroke

62

-Small studies have suggested that high intensity interval training (HIIT) is superior to moderate continuous training (MCT) in reversing cardiac remodeling and increasing aerobic capacity in heart failure patients with reduced ejection fraction (HFrEF). The present multicenter trial compared 12 weeks supervised interventions of HIIT, MCT, or a recommendation of regular exercise (RRE).

Concepts: Myocardial infarction, Cardiology, Heart failure, Ejection fraction, Exercise, Topology, Exercise physiology, High-intensity interval training

60

Background Nitrates are commonly prescribed to enhance activity tolerance in patients with heart failure and a preserved ejection fraction. We compared the effect of isosorbide mononitrate or placebo on daily activity in such patients. Methods In this multicenter, double-blind, crossover study, 110 patients with heart failure and a preserved ejection fraction were randomly assigned to a 6-week dose-escalation regimen of isosorbide mononitrate (from 30 mg to 60 mg to 120 mg once daily) or placebo, with subsequent crossover to the other group for 6 weeks. The primary end point was the daily activity level, quantified as the average daily accelerometer units during the 120-mg phase, as assessed by patient-worn accelerometers. Secondary end points included hours of activity per day during the 120-mg phase, daily accelerometer units during all three dose regimens, quality-of-life scores, 6-minute walk distance, and levels of N-terminal pro-brain natriuretic peptide (NT-proBNP). Results In the group receiving the 120-mg dose of isosorbide mononitrate, as compared with the placebo group, there was a nonsignificant trend toward lower daily activity (-381 accelerometer units; 95% confidence interval [CI], -780 to 17; P=0.06) and a significant decrease in hours of activity per day (-0.30 hours; 95% CI, -0.55 to -0.05; P=0.02). During all dose regimens, activity in the isosorbide mononitrate group was lower than that in the placebo group (-439 accelerometer units; 95% CI, -792 to -86; P=0.02). Activity levels decreased progressively and significantly with increased doses of isosorbide mononitrate (but not placebo). There were no significant between-group differences in the 6-minute walk distance, quality-of-life scores, or NT-proBNP levels. Conclusions Patients with heart failure and a preserved ejection fraction who received isosorbide mononitrate were less active and did not have better quality of life or submaximal exercise capacity than did patients who received placebo. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT02053493 .).

Concepts: Clinical trial, Myocardial infarction, Medical terms, Cardiology, Heart failure, Ejection fraction, Atrial natriuretic peptide, Isosorbide mononitrate