Chronic heart failure

Background

Definition

• A syndrome of volume overload and poor tissue perfusion that is caused by cardiac dysfunction and is characterized by dyspnea, fatigue, and edema
• Two broad types:
  • Heart failure with reduced ejection fraction <40% (HFrEF or systolic dysfunction)
  • Heart failure with preserved ejection fraction (HFpEF or diastolic dysfunction)

Stages

• Stage A: no structural heart disease or symptoms but high risk for developing HF (e.g., patients with diabetes mellitus or hypertension)
• Stage B: structural heart disease without symptoms of HF (e.g., patients with a previous MI and asymptomatic LV dysfunction)
• Stage C: structural heart disease with symptoms of HF (e.g., patients with a previous MI with dyspnea and fatigue)
• Stage D: refractory HF requiring special interventions (e.g., patients with refractory HF who are awaiting cardiac transplantation).

Etiologies

By Subtype

• HFrEF
  • Coronary artery disease (most common)
  • Hypertension (most common)
  • Viral infection
  • Chronic alcohol use
  • Valvular heart disease
  • Chemotherapy, such as doxorubicin or trastuzumab
  • Peripartum cardiomyopathy
  • Idiopathic dilated cardiomyopathy
  • Genetic causes of cardiomyopathy
• HFpEF
  • Hypertension (most common)
  • Myocardial infarction

By Cardiomyopathy

• Dilated cardiomyopathy: toxins (alcohol, cocaine, chemotherapy), myocarditis, Chagas disease, peripartum cardiopmyopathy, familial cardiomyopathies
• Hypertrophic cardiomyopathy: hypertension
• Restrictive cardiomyopathy
• Arrhythmogenic right ventricular cardiomyopathy
• Unclassified cardiomyopathy: Takotsubo cardiomyopathy, non-compaction cardiomyopathy

By Risk Factor

• Common
  • Tachyarrhythmia
  • Valvular disease
  • If CAD risk factors:
    • Coronary artery disease
    • Hypertensive cardiomyopathy
• Other risks
  • Toxic agents: alcohol, amphetamines, cocaine, steroids, chemotherapy, heavy metals, radiation
  • Pregnancy: PPCM, pre-eclampsia, gestational diabetes
  • Inflammatory or infectious: myocarditis, sarcoidosis, infectious hypereosinophilia, giant celll lymphocytic, auto-immune diseases
  • Metabolic: diabetes, thyroid disease, adrenal insufficiency, pheochromocytoma, Cushing disease
  • Nutritional: thiamine deficiency, selenium deficiency, malnutrition, obesity
  • Infiltrative: amyloidosis, glycogen storage disease, Fabry disease
  • Hereditary: hypertrophic cardiomyopathy, ARVC, LV noncompaction, hemochromatosis
  • Acute respiratory distress syndrome (ARDS)

Epidemiology

• 6-10% of people over age 65

Risk Factors

• Previous episode of acute heart failure
• Prior atrial fibrillation or coronary artery bypass surgery
• Myocardial infarction
• Coronary artery disease
• Diabetes mellitus
• Hypertension

Clinical Manifestations

History

• Hx of heart failure, MI, or CAD
• Dyspnea on exertion
• Paroxysmal nocturnal dyspnea
• Orthopnea
• Fatigue
• Determine NYHA classification of functional status

Signs & Symptoms

• Cardiac exam: S3 present, abdominojugular reflux, elevated JVP
• Respiratory exam: crackles/rales
• Lower extremity edema

	Dry	Wet
Warm	Less congested Better-perfused	More congested Better-perfused
Cold	Less congested Poorly perfused	Less congested Poorly perfused

Investigations

• Lab
  • Troponins
  • Natriuretic peptide (if diagnosis uncertain)
    • NT-proBNP > 450 pg/mL if age < 50 years and > 900 pg/mL if age > 50 years; <100 pg/mL helps rule it out
• Imaging
  • Chest X-ray showing pulmonary venous or interstitial edema, cardiomegaly, or pleural effusions
• Other
  • EKG showing new atrial fibrillation, ischemic changes, or any other abnormality
  • Echocardiography
    • Systolic heart failure
      • Reduced LV ejection fraction (LVEF)
    • Diastolic heart failure
      • E/A ratio less than 1
      • MV deceleration time > 220ms

Management

• See also Acute heart failure management

Non-Pharmacologic Management

• Regular exercise 3-5 times a week for 30-45 min per session (after stress test)
• No-added-salt diet (2-3 g/day); 1-2g/day if severe fluid retention
• Fluid limited to 1.5 L/day to 2 L/day from all sources, if diuretics fail
• Consider referral to multidisciplinary outpatient clinic

Manage Comorbidities

• Replace iron-deficiency with IV iron (improves quality of life)
• Avoid treating diabetes with glitazones, prefer SGLT-2 inhibitors
• Treat hypertension, especially in HFpEF

Pharmacologic Treatments

• Treat cardiovascular risk factors (hypertension, dyslipidemia, atherosclerotic disease)
  • Previous MI: ASA 81mg po daily if indicated for secondary prevention
  • Atrial fibrillation: warfarin or other anticoagulation
• Overall approach is triple therapy: ACEi, beta-blockers, aldosterone agonists
• Reassess NYHA class after maximizing treatment
  • NYHA I: continue
  • NYHA II-IV and sinus rhythm with HR ≥70: add ivabradine and switch ACEi to ARNI (Entresto)
  • NYHA II-IV and sinus rhythm with HR < 70bpm or AF or pacemaker: switch ACEi to ARNI (Entresto)
• Reassess LVEF
  • If NYHA I-III and LVEF ≤35%: consider ICD/CRT
  • NYHA IV: consider hydralazine/nitrates, referral for mechanical support or transplant, refer to palliative care
• HFrEF:
  • First-line: ACE inhibitor (second-line: ARB)
  • First-line: beta-blocker (second-line: CCB)
    • Titrate slowly, doubling dose q2-4 weeks
    • Objective improvement may take 6-12 months
  • If severe symptoms and LVEF<30%: aldosterone antagonist
  • If African-American: consider adding ISDN
  • If congestive symptoms:
    • First-line: loop diuretic at lowest minimal dose required to control symptoms
    • Second-line: consider adding thiazide or low-dose metolazone
    • Last-line: consider adding digoxin if severe symptoms or poorly-controlled atrial fibrillation
• Monitor blood pressure while titrating up medication

Procedures

• Cardiac resynchronization therapy is indicated when LVEF<30%, LBBB, and QRS > 150ms
• Devices
  • ICD if EF <35%
  • CRT +/- ICD if reduced EF and LBBB
• Implantable hemodynamic monitor (CardioMEMS)
  • Pulmonary artery pressure sensor
  • Better than daily weights for predicting heart failure exacerbations
  • Reduces hospitalizations by 30%
  • Studied in HFpEF and HFrEF
  • Expensive! $20k
• Surgery: see advanced therapies, below

Advanced Therapies

• Consider advanced therapies such as ventricular assist device or cardiac transplantation when heart failure is severe and refractory
• Possible indications include:
  • LVEF <25%
  • End-organ dysfunction
  • Recurrent hospitalizations 2x/12months unexplained
  • Unable to tolerate medical therapies, including hypotension
  • Diuretic refractory
  • Inotropic support
  • Pulmonary hypertension and right heart failure
  • Six-minute walk test <300m
  • Increased 1yr mortality >20%
  • Renal or hepatic dysfunction
  • Chronic hyponatremia <134 chronically
  • Cardiac cachexia
  • Unable to tolerate ADLs

Prognosis

• 30-40% of patients die within 1 year of diagnosis and 60-70% die within 5 years
• NYHA II have a 5-10% annual mortality rate
• NYHA IV have a 30--70% annual mortality rate
• MAGGIC risk score
  • Estimates 1 and 3 year survival

Further Reading

• Harrison's 19e (Ch 234)
• CCS Heart Failure Guidelines Update 2006
• Does this dyspneic patient in the emergency department have congestive heart failure? JAMA RCE 2005