Definition and Classification

Heart failure (HF) is a clinical syndrome characterized by symptoms and signs caused by a structural or functional cardiac abnormality, resulting in reduced cardiac output or elevated intracardiac pressures.

Stages (ACC/AHA)

Common Causes

HFrEF

• Ischemic cardiomyopathy (most common in US)
• Dilated cardiomyopathy (idiopathic, viral, toxic)
• Myocarditis, peripartum cardiomyopathy
• Prolonged tachycardia, anthracycline toxicity

HFpEF

• Hypertension (most common cause)
• Obesity, diabetes, metabolic syndrome
• Hypertrophic or restrictive cardiomyopathy
• Atrial fibrillation, aging

Clinical Presentation

Diagnostic Workup

Initial Labs

• BNP > 100 pg/mL or NT-proBNP > 300 pg/mL suggests HF
• CBC, CMP (BUN/Cr), TFTs, lipids, HbA1c
• Iron studies (iron deficiency common in HF)
• Urinalysis

Imaging and Studies

• ECG: assess rhythm, LVH, ischemia, QRS widening
• Chest X-ray: cardiomegaly, Kerley B lines, cephalization, pleural effusions
• Echocardiogram: essential to classify EF, assess wall motion, valves
• Coronary angiography if ischemia suspected

Pharmacologic Management — HFrEF (GDMT)

Goal-directed medical therapy (GDMT) — all four pillars shown to reduce mortality.

The Four Pillars

• ACEi/ARB or ARNi (sacubitril-valsartan preferred if tolerated)
• Beta-blocker: carvedilol, metoprolol succinate, or bisoprolol
• MRA (mineralocorticoid receptor antagonist): spironolactone or eplerenone
• SGLT2 inhibitor: dapagliflozin or empagliflozin (proven mortality benefit)

Additional Agents

• Loop diuretics (furosemide) for symptom relief of congestion — not mortality benefit
• Hydralazine + nitrate: if ACEi/ARB/ARNi not tolerated (especially Black patients)
• Ivabradine: if HR ≥ 70 bpm on max beta-blocker, sinus rhythm, EF ≤ 35%
• Digoxin: consider for persistent symptoms, AF (Class IIa)

Management — HFpEF

Fewer mortality-reducing agents proven; focus on symptom control and comorbidities.

• SGLT2 inhibitors: now recommended (empagliflozin — EMPEROR-Preserved trial)
• Diuretics for congestion relief
• Aggressive BP control (< 130/80 mmHg)
• Rate control for AF; anticoagulation if indicated
• Treat underlying causes: obesity, DM, sleep apnea, HTN
• ARB (candesartan) or MRA may reduce hospitalizations (Class IIb)

Device Therapy

• ICD: EF ≤ 35%, NYHA II-III, on GDMT ≥ 3 months, expected survival > 1 year
• CRT (cardiac resynchronization): EF ≤ 35%, LBBB with QRS ≥ 150 ms, sinus rhythm, NYHA II-IV
• LVAD: Stage D HF as bridge-to-transplant or destination therapy
• Heart transplant: Stage D refractory to all therapies

Acute Decompensated HF (ADHF)

Presentation

• Rapid worsening dyspnea, hypoxia, severe edema
• Elevated BNP, chest X-ray with pulmonary congestion

Management (LMNOP)

• Lasix (IV furosemide) — aggressive diuresis
• Morphine (use cautiously) — reduces preload/anxiety
• Nitrates — venodilation, preload reduction
• Oxygen — supplemental O2, CPAP/BiPAP if needed
• Position — sit upright, legs dependent

Hemodynamic Profiles

• Wet-warm: congested, adequate perfusion — diurese
• Wet-cold: congested, poor perfusion — inotropes + diuresis
• Dry-cold: no congestion, poor perfusion — IV fluids cautiously, inotropes

Monitoring and Follow-Up

• Daily weights; instruct patient to call if > 2-3 lb gain in 24 hrs or > 5 lb in 1 week
• Electrolytes and renal function (BMP) within 1–2 weeks of starting/adjusting diuretics
• BNP/NT-proBNP to trend disease burden
• Repeat echo after 3–6 months of GDMT to reassess EF
• Fluid restriction (1.5–2 L/day) in moderate-severe HF
• Sodium restriction < 2 g/day
• Cardiac rehab for stable NYHA II–III

Red Flags / When to Refer or Admit

• SpO2 < 90%, respiratory distress at rest
• SBP < 90 mmHg or signs of hypoperfusion (cool, clammy, altered mental status)
• New arrhythmia or acute ischemia
• Acute cardiogenic pulmonary edema
• Failure of outpatient diuresis

• EF < 40%, newly diagnosed HF
• Advanced HF stage C/D, considering devices or transplant
• Unexplained or refractory HF

Key Teaching Points

• HFrEF (EF < 40%) has proven mortality-reducing GDMT — start all four pillars when able
• SGLT2 inhibitors now benefit both HFrEF and HFpEF
• ARNi (sacubitril/valsartan) is preferred over ACEi in chronic HFrEF if tolerated
• Diuretics relieve symptoms but do not reduce mortality
• Daily weight monitoring is a cornerstone of outpatient HF management
• BNP helps diagnose HF but also guides prognosis and response to therapy
• HF with preserved EF is increasingly recognized; SGLT2i now first-line