acute heart failure (AHF)

Introduction

A sudden cardiac event resulting in an acute decline in cardiac output, insufficient perfusion of tissues & acute pulmonary & systemic venous congestion.

Etiology

• myocardial ischemia or infarction
• cardiac arrhythmias
• ventricular septal defect
• uncontrolled, severe hypertension
• pulmonary embolism
• valvular failure
  • progressive mitral stenosis
  • critical aortic stenosis
  • acute mitral regurgitation
    • ischemic papillary muscle dysfunction
    • rupture of papillary muscle
    • rupture of chordae tendinae
    • infectious endocarditis
  • acute aortic regurgitation - infectious endocarditis
• acute dilated cardiomyopathy
  • cocaine
  • myocarditis
  • chemotherapy
  • toxins
  • idiopathic
• aortic dissection
• cardiac rupture
• cardiac tamponade
• high-output states
  • anemia
  • thyrotoxicosis
  • beriberi
  • intracardiac or arteriovenous shunting
• NSAIDs may increase risk of acute on chronic heart failure

Epidemiology

• 50% of hospitalizations for acute heart failure in patients with reduced LVEF

Clinical manifestations

• pulmonary edema is the most common manifestation
  • symptoms
    • sudden, extreme dyspnea
    • pink, frothy sputum
    • diaphoresis
  • signs
    • tachycardia
    • cyanosis
    • jugular venous distension (right heart failure)
    • 3rd heart sound (S3)
    • pulmonary crackles, rales, rhonchi
• hepatic congestion mimicking an intra-abdominal process
  • less common
  • associated with jugular venous distension & right heart failure
• older patients hospitalized with acute heart failure
  • more likely to be female
  • more likely to have diastolic heart failure
  • more likely to have gradual onset of symptoms
  • more likely to have atypical presentation
    • chronic cough, insomnia, weight loss, anorexia, nausea, nocturia, syncope, abdominal pain, confusion, falls, functional decline
• heart failure may present as abdominal pain in children & adolescents due to reduced intestinal blood flow

Laboratory

• complete blood count to rule out anemia
• serum urea nitrogen, serum creatinine
  • BUN/creatinine to rule out renal failure
• arterial blood gas (ABG)
• urinalysis
• serum electrolytes
  • serum potassium > 4.5 mEq/L may be associated with worse outcomes
• low serum Mg+2, low serum Na+ portend poor prognosis
• markers of myocardial infarction
  • serum creatine kinase & serum CK-MB
  • cardiac-specific troponin-I or troponin-C may predict higher mortality
• arterial blood gas
• elevated serum BNP (ventricular pressure overload)
  • measured upon hospital admission to determine prognosis in patients with acutely decompensated heart failure
  • NT-proBNP in serum best predictor of mortality

Diagnostic procedures

• electrocardiogram
  • arrhythmias
  • conduction delays
  • non-sepcific ST-T changes
• echocardiography
  • mitral regurgitation
  • ventricular septal defect
  • focal wall motion abonormalities
  • pericardial effusion
• radionuclide ventriculography
• cardiac catheterization
  • pulmonary artery & wedge pressure
  • left to right shunt
  • coronary angiography

Radiology

• chest X-ray
  • cardiomegaly
  • pulmonary vascular redistribution
  • pulmonary edema
• lung ultrasonography outperforms chest-X-ray
  • positive predictive value: 92%
  • negative predictive value: 92%

Complications

• mortality among Medicare beneficiaries
  • 1-year mortality for hospitalization survivors:
    • 41% overall & 72% for high-risk admissions
  • in hospital mortality 2.8% (2011-2016)

Differential diagnosis

• asthma
• COPD
• pneumonia
• pneumothorax
• pulmonary edema
  • re-expansion
  • high altitude
  • neurogenic
• acute coronary syndrome
  • dyspnea, but not chest pain associated with exacerbation of heart failure
  • serum BNP may be elevated with acute coronary syndrome
• adult respiratory distress syndrome
• pulmonary embolism
• eclampsia
• heroin overdose

Management

• admit to hospital (CCU) most cases
  • EHMRG scale may be used for assessment of hospitalization vs discharge from ED (see EHMRG scale for calculator)
  • Barthel Index, serum creatinine & LV hypertrophy on EKG used in calculating score for predicting prognosis
  • treat volume overload
  • fluid & sodium restriction leads to increased thirst but not better outcomes
  • special case of right heart failure
    • push normal saline even if central venous pressure elevated
    • avoid pressors until volume expansion produces pulmonary edema
• oxygen
  • ventilatory support for cardiogenic pulmonary edema
    • BiPAP is more effective than CPAP alone
      • reduces the risk of endotracheal intubation & death
• intravenous loop diuretic
  • furosemide (Lasix) has poor & variable oral availability
  • bumetanide (Bumex)
  • no clear advantage of infusion vs bolus
  • initial IV dose should be at least the outpatient daily oral dose
  • increase diuretic dose to remove excess fluid
  • high-dose vs low-dose
    • no outcome advantage
    • tradeoff of renal toxicity vs symptom relief
  • earlier diuretic administration in the emergency department associated with lower mortality
  • diuretic resistance is > 240 mg furosemide equivalent daily
    • loop diuretic + metolazone 5 mg PO BID (metolazone not available IV)
    • loop diuretic + tolvaptan 30 mg PO QD
      • in hospitalized patients with acute heart failure, addition of tolvaptan to intravenous loop diuretic did not improve dyspnea despite greater weight loss & fluid loss
• optimizing ACE inhibitor less important than removing excess fluid with diuretic
• nitrates reduce preload & dilate coronary arteries
  • sulingual nitroglycerin
  • nitroglycerin or nitroprusside drip
    • nitroprusside also reduces afterload
    • useful when patients remain in heart failure after adequate diuresis
  • nitropaste
  • hold for hypotension
  • early nitrates plus hydralazine of no benefit over usual care
• morphine reduces preload - hold for hypotension
• acetazolamide added to intravenous loop diuretic is associated with a higher rate of successful decongestion in patients with stage 3 chronic renal failure
  • worsening renal function occurs more frequently with acetazolamide, but this is not associated with adverse clinical outcomes
• antiarrhythmic agents to control ventricular response to atrial fibrillation
  • digoxin also improves cardiac contractility
    • avoid increases in digoxin with acute renal failure
  • diltiazem IV
    • rapidly effective
    • negative inotropic effect
• pressors for left heart failure (LV systolic dysfunction)
  • norepinephrine (pressor of choice)
    • heart failure with severe hypotension
    • normal to low systemic vascular resistance
    • vasoconstrictive, inotropic & chronotropic effects
    • start 1-4 ug/min
  • dopamine
    • may be inferior to norepinephrine
    • 5-10 ug/kg/min (inotropic & chronotropic)
    • 10-20 ug/kg/min (vasoconstrictive)
    • renal dose dopamine 2 ug/kg/min does not improve renal function in patients with acute heart failure
  • dobutamine
    • may be inferior to norepinephrine
      • better than milrinone in patients with renal insufficiency
      • preferable to adding metolazone for loop diuretic resistance
    • refractory heart failure with poor cardiac output
    • systolic blood pressure < 100 mm Hg
    • inotropic effects
    • decreased systemic vascular resistance
    • start 2-5 ug/kg/min
  • phosphodiesterase inhibitors
    • amrinone
    • milrinone
      • load 50 ug/kg
      • 0.375-0.75 ug/kg/min
    • effects similar to dobutamine
• avoid beta-blockers & calcium channel blockers (both negative inotropes)
  • avoid esmolol drip even with tachycardia
    • risk of negative intropic effect greater than benefit of slowing heart rate (even with short 1/2 life of esmolol)
• SGLT-2 inhibitor therapy throughout hospitalization regardless of LVEF
  • SGLT-2 inhibitors have little effect on blood pressure
  • empagliflozin
  • increases urine output 25% over 5 days without adverse renal effects
    • eGFR not affected
  • improves health-related quality of life at 90 days after acute heart failure; benefits begin at day 15
• aldosterone antagonists have little effect on blood pressure
  • initiate at any time during hospitalization & continue at discharge unless contraindicated
• natriuretic hormone
  • nesiritide 0.005 ug/kg/min does not improve renal function in patients with acute heart failure
• intra-aortic balloon pump & left ventricular assist device
  • cardiogenic shock resistant to inotropic agents
  • stabilization prior to revascularization
• coronary angiography with revascularization
  • percutaneous transluminal coronary angioplasty (PTCA)
• dialysis for heart failure complicated by anuria
  • pressures are first line unless anuria
• right heart catheterization does not improve outcomes in hospitalized patients with heart failure
• delay elective surgery until stabilization
• intravenous iron with ferric carboxymaltose may benefit stabilized hospitalized patients with iron-deficiency
• follow-up
  • close observation after stabilization
  • observe for recurrent heart failure, dehydration, electrolyte abnormalities, drug toxicity
  • telephone contact within 48 hours of discharge
  • follow-up physician visit within 1 week after hospital discharge
  • early follow-up nurse home visit
  • intensive 3-month physical rehabilitation program focusing on strength, balance, mobility, & endurance started during hospitalization or shortly after discharge improves physical function
  • early & rapid uptitration of neurohormonal blockade
    • beta-blocker
    • ACE inhibitor, ARB, or ARNI
    • aldosterone receptor antagonist
• prognosis
  • high mortality especially in the elderly
  • 33% mortality within the 1st 3 months
  • NT-proBNP in serum best short-term predictor of mortality
• heart transplantation: median survival 11 years with normal quality of life

More general terms

• heart failure (HF)
• hemodynamic instability (compromise)

More specific terms

• acute diastolic heart failure
• acute right ventricular failure; cor pumonale
• cardiorenal syndrome
• high-output heart failure

Additional terms

• right ventricular failure; right heart failure