Chronic Heart Failure Flashcards
When does heart “failure” occur?
Heart “failure” occurs when the heart is not bale to supply sufficient oxygen-rich blood to the body, because of impaired ability of the ventricle to either fill or eject blood
What are the most common causes of heart failure?
Ischemic (due to decreased blood supply, such as from an MI) or non-ischemic, such as from long-standing uncontrolled hypertension
What are less common causes of heart failure?
Less common causes include valvular disease, excessive alcohol intake, illicit drug use, congenital heart defects, viral infections, diabetes and cardiotoxic drugs/chest radition
What are symptoms of HF generally related to?
Symptoms of HF are usually related to fluid overload, which commonly presents as shortness of breath (SOB) and edema
Why do symptoms occur with HF?
Symptoms can occur due to problems with systolic (contraction) or diastolic (relaxation) functions of the heart
What is performed when HF is suspected and why is it important?
An ultrasound of the heart (echocardiography or ECHO) is performed when HF is suspected. It provides an estimate of left ventricular ejection fraction (LVEF)
What is LVEF?
LVEF is a measurement of how much blood is pumped out of the left ventricle (the main pumping chamber of the heart) with each contraction and is used interchangeably with ejection fraction (EF)
What does an EF < 40% indicate?
An EF < 40% indicates systolic dysfunction, or heart failure with reduced ejection fraction (HFrEF)
*Impaired ability to eject blood during systole
What does an EF of 55-70% indicate?
Normal
What does an EF > 50% with diastolic dysfunction indicate?
Heart Failure with Preserved EF (HFpEF)
*Impaired ventricular relaxation and filling during diastole
What does an EF of 41-49% indicate?
Heart Failure with Mildly Reduced EF (HFmrEF)
*Likely mixed systolic and diastolic function
What does an EF < 40% at baseline, then a > 10% increased and second EF > 40% indicate?
Heart Failure with Improved EF (HFimpEF)
*EF improved with treatment; classified separately because treatments for HFrEF should be continued, despite higher EF
Describe the ACC/AHA staging system
The American Heart Association recommend categorizing patients by HF stage. The staging system is used to guide treatment in order to slow progression of structural heart disease in asymptomatic patients or in symptomatic patients
What does biomarkers refer to in the staging system?
Biomarkers in the definitions refer to BNP and NT-proBNP
Describe the NYHA classification system.
HF can also be classified by the level of limitation in physical functioning using NYHA classification system
What does AHA/ACC stage A indicate?
At risk for development of HF, but without symptoms of HF and without structural heart disease or elevated biomarkers (e.g. patients with HTN, ASCVD or DM)
What does ACC/AHA stage B indicate?
Pre-HF; structural heart disease, abnormal cardiac function or elevated biomarkers, but without signs or symptoms of HF (e.g. patients with LVH, low EF, valvular disease)
What does ACC/AHA stage C indicate?
Structural and/or functional cardiac abnormality with prior or current symptoms of HF (e.g. a patient with known structural disease plus SOB, fatigue and reduced exercise tolerance)
What does ACC/AHA stage D indicate?
Advanced HF with severe symptoms, symptoms at rest or recurrent hospitalizations despite maximal treatment (refractory HF requiring specialized interventions)
What does NYHA functional class I indicate?
No limitations of physical activity. Ordinary physical activity does not cause symptoms of HF (e.g. fatigue, palpitations, dyspnea)
What does NYHA functional class II indicate?
Slight limitation of physical activity. Comfortable at rest, but ordinary physical activity (e.g. walking up stairs) results. in symptoms of HF
What does NYHA functional class III indicate?
Marked limitation of physical activity. Comfortable at rest but minimal exertion (e.g. bathing, dressing) causes symptoms of HF
What does NYHA functional class IV indicate?
Unable to carry on any physical activity without symptoms of HF, or symptoms of HF at rest (e.g. SOB while sitting in a chair)
Describe the corresponding ACC/AHA staging system and NYHA functional class system.
- ACC/AHA stage B = NYHA stage I
- ACC/AHA stage C = NYHA stage I/II/III
- ACC/AHA stage D = NYHA stage IV
What are lab/biomarkers indicative of systolic heart failure?
- Increased BNP: normal is < 100 pg/mL
- Increased NT-proBNP: normal is < 300 pg/mL
*BNP and proBNP are used to distinguish between cardiac and non-cardiac causes of dyspnea
What are left-sided signs and symptoms of systolic heart failure?
- Orthopnea: SOB when lying flat
- Paroxysmal nocturnal dyspnea (PND): nocturnal cough and SOB
- Bibasilar rales: crackling lung sounds head on lung exam
- S3 gallop: abnormal hear sound
- Hypoperfusion (renal impairment, cool extremitiies)
What are general signs and symptoms of systolic heart failure?
Dyspnea (SOB at rest or upon exertion), cough, fatigue, weakness, reduced exercise capacity
What are some right-sided signs and symptoms of systolic heart failure?
- Peripheral edema
- Ascites: abdominal fluid accumulation
- Jugular venous distention (JVD): neck vein distention
- Hepatojugular reflux (HJR): neck vein distortion from pressure placed on the abdomen
- Hepatomegaly: enlarged liver due to fluid congestion
What is cardiac output?
Cardiac output (CO) is the volume of blood that is pumped by the heart in one minute and is determined by heart rate and stroke volume
*CO = HR x SV
What is stroke volume?
Stroke volume is the volume of blood ejected from the left ventricle during one complete heartbeat (cardiac cycle). SV depends on preload, afterload, and contractility
What is the cardiac index?
The cardiac index (CI) relates the CO to the size of the patient, using the body surface area
*CI = CO/BSA
How does the body try and compensate for HFrEF?
HFrEF is a low cardiac output state. The body compensates by activating neurohormonal pathways to increase blood volume or the force or speed of contractions. This can temporarily increase CO, but chronically leads to myocyte damage and cardiac remodeling which causes change in the size, composition and shape of the heart
What are the main pathways that are activated in HF?
The main pathways that are activated in HF are the renin-angiotensin-aldosterone system (RAAS), the sympathetic nervous system (SNS) and vasopressin, The neurohormones that normally balance these systems become insufficient
Describe the steps of RAAs and Vasopressin activation
1) Renin convert angiotensinogen to angiotensin I
2) Angiotensin I is converted to angiotensin II (Ang II) by angiotensin-converting enzyme (ACE)
3) Ang II causes vasoconstriction and stimulates release of aldosterone from the adrenal gland and vasopressin from the pituitary gland
4) Aldosterone causes sodium and water retention and increases potassium excretion
5) Vasopressin causes vasoconstriction and water retention
Describe SNS activation
Norepinephrine (NE) and epinephrine (EPI) release cause an increase in HR, contractility (positive inotropy) and vasoconstriction
What are some lifestyle management counseling points for patients with HF?
- Monitor and document body weight daily, in the morning after voiding and before eating
- Notify the provider if weight increases by 2-4 pounds in one day or 3-5 pounds in one week, or if symptoms worsen
- Restrict sodium intake to < 1500 mg/day in stage A and B HF (maintain some sodium restriction
- Restrict fluid in stage D HF
- Stop smoking. Limit alcohol intake. Do not use illicit drugs
- Obtain recommended vaccines: influenza (annually) and pneumococcal vaccines per ACIP guidelines
- Reduce weight to BMI < 30 kg/m2 to decrease the heart’s workload and preserve function
- Exercise (or perform regular physical activity, if able)
What are some natural products that can help in the management of HF?
- Omega-3 fatty acid (fish oil) supplementation is reasonable to decrease mortality and cardiovascular hospitalizations
- Hawthorn and coenzyme Q10 may improve HF symptoms
- Avoid the use of products containing ephedra (ma huang) or ephedrine
By what mechanism do drugs cause or worsen HF?
Most drugs that cause or worsen HF cause fluid retention/edema, increase blood pressure or have negative inotropic effects
What are key drugs that cause or worsen heart failure?
DPP-4 inhibitors, Immunosuppressants, Non-DHP CCBs, Antiarrhythmics, Thiazolidinediones, Itraconazole, Oncology drugs, NSAIDs
What are the initial medications recommended for all systolic heart failure patients without contraindications?
ACE inhibitors or ARBs or ARNIs, beta-blockers, loop diuretics
What are secondary medications recommended that are added on in select patients with systolic heart failure?
Aldosterone receptor antagonists (ARAs), SGLT2 inhibitors, Hydralazine and nitrates, Ivabradine
What are some additional medications that can be considered in patients with systolic heart failure?
Digoxin, Vericiguat
What is the MOA of loop diuretics?
Loop diuretics block sodium and chloride reabsorption in the thick ascending limb of the loop of Henle. They increase excretion of sodium, potassium, chloride, magnesium, calcium and water
What is the significance of loop diuretics in CHF?
The decrease in fluid volume makes it easier for the heart to pump, reduces congestive symptoms (decreases preload) and restores euvolemia (“dry” weight). They do not improve survival, but are often required for symptom control
What are some examples of loop diuretics?
Furosemide, Bumetanide, Torsemide, Ethacrynic Acid
What is a boxed warning of loop diuretics?
Can cause profound diuresis resulting in fluid and electrolyte depletion
What is a contraindication of loop diuretics?
Anuria
What are some warnings of loop diuretics?
Sulfa allergy (not likely to cross-react); warning does not apply to ethacrynic acid
What are some side effects associated with loop diuretics?
- Decreased electrolytes: K, Mg, Na, Cl, Ca
- Increased electrolytes/labs: HCO3 (metabolic alkalosis), UA, BG, TGs, total cholesterol
- Ototoxicity including hearing loss, tinnitus and vertigo (more with ethacrynic acid or rapid IV administration of any loop diuretic)
- Orthostatic hypotension, photosensitivity, myalgias
What are some monitoring parameters of loop diuretics?
Renal function, fluid status (input/output, weight), BP, electrolytes, audiology testing (with high doses or rapid IV administration), s/sx of HF
What are some notes associated with loop diuretics?
- Take early in the day to avoid nocturia
- Furosemide injection: store at room temperature (refrigeration causes crystals to form, which may dissolve upon warning); solution must be clear, do not use if yellow in color
- Bumetanide and furosemide injections are light-sensitive (store in amber bottles); IV admixtures do not require light protection
What is the oral equivalent dosing of loop diuretics?
Furosemide 40 mg = torsemide 20 mg = bumetanide 1 mg = ethacrynic acid 50 mg
What is the conversion ratio between Furosemide IV to PO?
Furosemide IV:PO 1:2
What is the conversion of Bumetanide and ethacrynic acid IV to PO?
1:1
What are some important loop diuretic drug interactions?
- Avoid NSAIDs; the increased sodium and water retention can decrease the effect of loop diuretics and cause renal impairment
- Use caution with other drugs that decrease blood pressure
- Watch for additive diuresis and electrolyte abnormalities when used in combination with thiazide-type diuretics
- Additive risk for ototoxicity when used with other ototoxic drugs, especially in patients with impaired renal function
- Diuretics can decrease lithium renal clearance and increase risk of lithium toxicity
How do ACE inhibitors work?
ACE inhibitors block the conversion of angiotensin I to Ang II, resulting in decreased vasoconstriction and decreased aldosterone secretion. They block the degradation of bradykinin, which may contribute to the vasodilatory effects and the side effects of cough and angioedema
How do ARBs work?
ARBs block Ang II from binding to the angiotensin II type-1 (AT1) receptor. These drugs decrease RAAS activation, resulting in decreased preload and afterload. They decrease cardiac remodeling, improve left ventricular function and decreased morbidity and mortality
What is the dose recommendation for ACE inhibitors and ARBs when treating HF?
The goal is to titrate to the target dose (which is different for every medication), as tolerated, not to target BP
What is the recommendation of the combination of ACE inhibitor, ARBs and ARAs?
Combining an ACE inhibitor or ARB with an ARA has added survival benefits. Triple combination of an ACE inhibitor + ARB + ARA is not recommended due to a higher risk of hyperkalemia and renal insufficiency
Between ACE inhibitors, ARBs and ARAs, which class of medications tend to cause angioedema more frequently?
Angioedema occurs more frequently with ACE inhibitors (than with ARBs) and in black patients. For testing purposes, do not use an ACE inhibitor or ARB in patients with a history of angioedema from use of any of these medications
What are the ACE inhibitors mentioned in the HF guidelines?
Captopril, Enalapril, Fosinopril, Lisinopril, Perindopril, Quinapril, Ramipril, Trandolapril
What are some boxed warnings of ACE inhibitors?
Can cause injury and death to the developing fetus when used in the 2nd and 3rd trimesters; discontinue as soon as pregnancy is detected
What are some contraindications of ACE inhibitors?
- Do not use with history of angioedema
- Do not use within 36 hours of Entresto
- Do not use with aliskiren in diabetes
What are some warnings about ACE inhibitors?
Angioedema, hyperkalemia, hypotension, renal impairment, bilateral renal artery stenosis (avoid use)
What are some side effects of ACE inhibitors?
Generally well-tolerated, can cause cough, hyperkalemia, increased SCr, hypotension/dizziness [increases risk if volume-depleted (e.g. with concurrent diuretic)], headache
What are monitoring parameters of ACE inhibitors?
BP, K, renal function, s/sx of HF and angioedema
What are the ARBs mentioned in the HF guidelines?
Candesartan, Losartan, Valsartan
What are some differences in side effects between ACE inhibitors and ARBs?
ARBs have less cough, less angioedema and no washout period required with sacubitril/valsartan (Entresto)
What is Entresto a combination of?
Entresto is a combination of a neprilysin inhibitor (sacubitril) and an ARB (valsartan)
