Heart failure with reduced ejection fraction

Heart failure with reduced ejection fraction (HFrEF)is is a type of heart failure due to left ventricular dysfunction (left heart failure) classified by the presence of ana left ventricular ejection fraction of 40% or less. Heart failure with reduced ejection fraction occurs when the left ventricle is unable to contract and effectively pump blood (also known as systolic heart failure), thus decreasing cardiac output and ejection fraction.

Epidemiology

The prevalence of heart failure in the US alone worldwide is 6.523 million casespeople, and 50% of which 50% are caused byclassified as heart failure with reduced ejection fraction ¹. The number of cases is expected to rise due to the ageing population. Compared to women, men are more likely to have heart failure with reduced ejection fraction. 

OtherRisk factors

Comorbid risk factors include the following ²:

• hypertension
• cigarette smoking
• alcoholism 
• recreational drug abuse 
• diabetes mellitus
• obesity 

Clinical presentation

Clinical presentations of heartHeart failure with reducedis a clinical syndrome that has a similar clinical presentation regardless of ejection fraction. Symptoms can be conceptualized as those related to fluid overload (congestion) and heartthose related to poor cardiac output (pump failure with preserved ejection fraction are similar) ³. Nonspecific symptoms of heart failureThe former include palpitationsdyspnoea, orthopnoea, peripheral oedema, and abdominal discomfort. The latter include loss of appetite, fatigue,oedema and weakness. Some patients have palpitations.

On physical exam, weakness, dyspnoea, etc.  ³. 

Patientsdisplaced apical impulse is the best predictor of reduced left ventricular ejection fraction due to its association with heart failure, cardiac biomarkers such as NP-proBNP and BNP are abnormally elevateddilated cardiomyopathy¹⁰. However, levelsThe palpated point of NP-proBNP and BNP are more significantmaximal impulse is displaced lateral to the midclavicular line.

ECG is usually abnormal in heart failure with reduced ejection fraction ¹¹. For example, there may be evidence of prior or ongoing myocardial infarction.

Cardiac biomarkers such as NT-proBNP (N-terminal pro-B-type natriuretic peptide) and BNP are usually abnormally elevated in heart failure. Levels are more elevated in heart failure with reduced ejection fraction in particular as the left ventricular cavity is larger with thinner wallsenlarges, causing greater wall stress ⁴.

Pathology 

A significant initial insult to the heartAcute myocardial injury or chronic overload of pressure or volume can lead to reduced cardiac output, triggering a compensated cascade. Compensatory myocardial remodelling occurs in an attempt to restore blood flow but may progress to become maladaptive ⁵. However, the condition gets progressively worse as reduced cardiac output is caused by loss of leftLeft ventricular contractility decreases, which leads to high preservationfurther diminished blood flow, retention of end-diastolic volume, diminished blood flow, andand increased regurgitation. As a result, most patients with heart failure with reduced ejection fraction develop eccentric left ventricular remodelling. 

Aetiology¹

Common causes of heart failure with reduced ejection fraction include the following ^12,13: 

• ischaemic (coronary) heart disease (most common)
• idiopathic dilated cardiomyopathy
• arrhythmias 
• coronary arteryhypertensive heart disease
• valvular heart disease

Other causes are less common ^12,13:

• infective cardiomyopathy/myocarditis
• alcoholic cardiomyopathy
• atrial fibrillation drug-induced cardiomyopathy (eg, anthracyclines, trastuzumab)
• peripartum cardiomyopathy

Radiographic features 

Echocardiography Plain radiograph

Chest radiographs show the presence of nonspecific findings of heart failure including cardiomegaly, pulmonary oedema, and pleural effusions.

Ultrasound

Echocardiography is is the initial test for evaluating left ventricular structure, mass, and ejection fraction. Heart failure with reduced ejection fraction typically shows an increase in end-diastolic volume and and end-systolic volume with, an eccentric hypertrophy pattern, and low ejection fraction.Doppler echocardiography can can also be used to analyseevaluate for aortic and mitral valvular regurgitation, thus assisting with heart failure diagnosisdysfunction ⁶. 

Plain chest radiograph CT

Chest X-ray shows the presence of nonspecific findingsCoronary CTA is a noninvasive alternative to coronary catheter angiography to help distinguish ischaemic and nonischemic aetiologies of heart failure include cardiomegaly, enlargement.  Cardiac CT can also evaluate the left ventricular function and regional wall motion to corroborate findings on echocardiography.

Angiography

Coronary angiography (left heart catheterisation) is indicated when ischaemic cardiomyopathy may be the aetiology of left ventricle, and parasternal heave, whichheart failure. Invasive angiography is an indicationthe gold standard for detection of pulmonary hypertension assignificant steno-occlusive disease in the forward movement of blood decreases ⁷coronary arteries that supply the left ventricular myocardium.

Cardiac magnetic resonance MRI

When echocardiographic images are suboptimal, cardiac magnetic resonance should be considered as it is capable of presentingevaluating ejection fraction, segmental dysfunction, valvular lesions, and myocardial fibrosis. However, utilisation of cardiac magnetic resonance is challenging in patients with implantable cardioverter defibrillatorcardiac devices ⁷.

Computed TomographyNuclear medicine

Radionuclide myocardial perfusion and myocardial perfusion, respectively ⁷imaging can risk stratify patients as a first step in evaluating for ischaemic heart disease as the possible aetiology of heart failure.

Treatment and prognosis

Pharmacologic therapy ¹

Drug therapy

Substantial evidence-based treatment exists for symptomatic heart failure with reduced ejection involvesfracture, including both pharmacotherapy and device-based therapies ^1,8,9. First-line pharmacotherapy is a combination of diuretics (typically a loop diuretic) and neurohormonal therapy consisting of a beta blockers, vasodilators, diuretics such as blocker and a renin-angiotensin system blocker (angiotensin-converting enzyme inhibitors inhibitor, angiotensin II receptor blockersblocker, loop diuretics, etc. 

Device therapyor angiotensin receptor-neprilysin inhibitor) ¹

Implantable cardioverter defibrillator can beA cardiac implantable electronic device is indicated for certain eligible patients who are eligiblewith heart failure with reduced ejection fracture, consisting of either an implantable cardioverter defibrillator or cardiac resynchronization pacemaker⁹. Additional interventions include coronary artery revascularisation (surgical coronary artery bypass grafting or percutaneous coronary stenting) and valvular intervention (surgical or transcatheter aortic valve replacement for critical aortic stenosis, and surgical or transcatheter mitral valve repair may be considered for patients with severe mitral regurgitation secondary to) ⁹.

In general, the prognosis of heart failure with reduced ejection fraction is worse than that with preserved ejective fraction. Cardiac resynchronization therapy might also be prescribed to help pace the heart.