Cardiology

Management of Heart Failure

SUMMARY:

Heart failure (HF) is a broad term that encompasses many different etiologies and degrees of cardiac dysfunction, but generally refers to impairment of blood flow through the heart. Americans over 40 have a 20% lifetime risk of developing HF. It is associated with considerable morbidity and mortality, and accounts for approximately 1M hospitalizations annually; it is also a major cause of hospital readmission. The 2013 ACC/AHA Guideline for the Management of Heart Failure (with focused updates in 2016 and 2017) offers a comprehensive guide to treating this common condition.

Risk Factors
Diagnosis of HF
Workup at Time of Diagnosis
Key Points
Learn More – Primary Sources

Risk Factors

Hypertension is the primary modifiable risk factor
Treating chronic hypertension leads to 50% reduction in risk of developing HF
Other risk factors
- Coronary artery disease (CAD) | Diabetes | Metabolic syndrome | Smoking | Alcohol | Illicit drug use (cocaine, amphetamines)

Diagnosis of HF

Primarily a clinical diagnosis
Cardinal symptoms
- Shortness of breath | Exercise intolerance | Fatigue | Edema

Workup at Time of Diagnosis

Imaging
- Basic: EKG | Chest X-ray | Echocardiogram
- New HF with high suspicion for CAD: Coronary angiography +/- revascularization
- New HF with known CAD: Non-invasive imaging to detect myocardial ischemia (e.g. nuclear myocardial perfusion scan)
Labs
- CBC | Tests of kidney and liver function | Electrolytes | Lipids | TSH | Urinalysis | BNP
- New evidence suggests screening BNP in patients at risk for HF (i.e. with ≥1 risk factors) “can be useful” in preventing clinical HF

KEY POINTS:

Terminology

HF with reduced EF (HFrEF or ‘systolic’ HF) vs. HF with preserved EF (HFpEF or ‘diastolic’ HF)
- HFrEF: EF≤40%
- HFpEF: EF>40% | Accounts for half of all HF

Note: HFrEF and HFpEF are not mutually exclusive | Patients often have combined systolic and diastolic dysfunction

Stages and Classes of HF

Guideline-directed medical therapy (GDMT) Is Tailored According to Severity of Disease

ACC/AHA stages of HF: Considers symptoms as well as structural cardiac abnormalities
- A: At risk for HF, no structural heart disease
- B: Structural heart disease, no symptoms of HF
- C: Structural heart disease with symptoms of HF
- D: Refractory HF (not responding to standard medical therapy)

New York Heart Association (NYHA) classes of HF: Subjective, based on symptomatology
- I: No limitation of physical activity
- II: Slight limitation of physical activity (OK at rest, symptomatic with “ordinary” activity)
- III: Marked limitation of physical activity (OK at rest, symptomatic with “less than ordinary” activity)
- IV: Symptomatic at rest or with any level of physical activity

Treatment Considerations – GDMT

GDMT recommendations based on large RCTs showing morbidity and mortality benefit for Stages B-D HFrEF only
- Little evidence of benefit in HFpEF
GDMT
- Reduces morbidity and mortality
- Improves symptoms and quality of life (QOL)
- Decreases hospitalizations
Some therapies limit cardiac remodeling and lead to improvements in ejection fraction (EF) over time

ACE inhibitors (ACEI): Associated with mortality benefit

Examples
- Lisinopril | Enalapril | Fosinopril
Switch to ARB (e.g., Losartan, Valsartan) if chronic cough develops (20% of patients)
Reassess renal function and electrolytes within 1 to 2 weeks after initiation of ACEI or ARB
Do not combine ACEI and ARB
In NYHA class II to III patients tolerating ACEI/ARB, switch to Entresto (valsartan/sacubitril)

Beta blockers: Associated with mortality benefit

Examples
- Carvedilol | Bisoprolol | Metoprolol succinate (not tartrate)
General rule for dosing
- ‘Start low, go slow’ | Titrate up to maximum tolerated dose

Aldosterone antagonists: Mortality benefit for NYHA II-IV with EF≤35%

Examples
- Spironolactone | Eplerenone
Major risk is hyperkalemia
- Start only if GFR >30 ml/min and K+ <5
- Reassess renal function and electrolytes within 3 to 7 days after starting

Loop diuretics: Indicated for Stages C-D for relief of symptoms due to fluid overload; no known effect on mortality

Examples
- Furosemide | Bumetanide | Torsemide
Titration
- Largely based on symptoms and clinical assessment of volume status (e.g., weight, urine output, BNP)
- Most patients will require chronic fixed doses to maintain euvolemia

Other medications

Digoxin
- For persistent symptoms despite GDMT | Shown to decrease hospitalizations
Hydralazine + isosorbide dinitrate: For persistent symptoms despite GDMT in NYHA III-IV African American patients
Ivabridine
- Can reduce HF hospitalizations in a small subset of patients: NYHA class II-III with EF≤35% on GDMT and sinus rhythm with resting HR≥70 bpm
- Omega-3 fatty acids: “reasonable to use as adjunctive therapy” for NYHA II-IV HFrEF or HFpEF

Drugs to avoid

Calcium channel blockers
- Can worsen HF (particularly non-dihydropyridines due to their negative inotropic effect); amlodipine may be OK
- NSAIDs: Cause sodium and water retention
- Thiazolidinediones: Increased incidence of HF events

HFpEF Management

Recommendations are limited to BP control
- First line: ACEI or ARB
- Diuretics for symptom management
Mortality benefit of GDMT for HFrEF when applied to HFpEF has not been convincingly demonstrated

Dietary Recommendations

Sodium restriction
- Stages A and B: <1.5 g/day
- Stages C and D: <3 g/day
Fluid restriction: <1.5 to 2L/day only recommended in Stage D (refractory) HF

Other Considerations

Indications for CABG
- HFrEF or HFpEF with angina despite GDMT or significant multivessel disease

Indications for ICD placement for primary prevention of sudden cardiac death
- EF≤35% (NYHA II-III) or EF≤30% (NYHA I)
- On GDMT
- Expected survival ≥1 year

Repeat echocardiogram in a patient with ≥1 of the following
- Significant change in clinical status
- Experienced or recovered from a clinical event
- Received treatment, including GDMT, with potentially significant effect on cardiac function