Renal Dysfunction in Heart Failure

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Congestive heart failure with elevated serum creatinine and blood urea nitrogen (BUN)

GENERAL CONSIDERATIONS

• Heart failure is common in patients with chronic renal disease, and signs of renal dysfunction (rising serum creatinine) occur in about 10% of patients with heart failure

• Renal dysfunction with heart failure is directly related to the degree of left ventricular dysfunction and, generally, reduced delivery of cardiac output to the kidney

• Hemodynamically induced renal dysfunction must be differentiated from chronic renal disease (common), the adverse effects of therapy (eg, angiotensin-converting enzyme [ACE] inhibitors), and diuretic-induced hypovolemia

• Some heart failure patients present with hepatic and renal dysfunction (hepatorenal syndrome)

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Symptoms of organ hypoperfusion, such as lethargy and mental confusion

PHYSICAL EXAM FINDINGS

• Evidence of reduced perfusion:

  • – Cool extremities

  • – Low blood pressure

  • – Tachycardia

  • – Diffuse neurologic abnormalities

  • – Jaundice

DIFFERENTIAL DIAGNOSIS

• Primary renal disease, such as renovascular disease, obstructive uropathy, or urinary tract infection

• Drug-induced renal dysfunction: nonsteroidal anti-inflammatory drugs, allopurinol, ACE inhibitors

• Volume depletion from aggressive use of diuretics

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Anemia, abnormal liver function tests, increased prothrombin time

• Low serum sodium, high potassium

• Rise in BUN out of proportion to rise in creatinine

ELECTROCARDIOGRAPHY

• Signs of hyperkalemia or hypocalcemia may be present

• Nonspecific ST-T–wave changes are common

IMAGING STUDIES

• Echocardiography usually shows profound left ventricular dysfunction (ejection fraction < 0.20)

• Echocardiography may show marked left ventricular hypertrophy and diastolic dysfunction, especially in chronic kidney disease patients

DIAGNOSTIC PROCEDURES

• Right heart catheterization may be useful for defining the hemodynamic abnormality and initiating therapy

TREATMENT

CARDIOLOGY REFERRAL

• When renal dysfunction occurs during the treatment of heart failure

• Hypotension or shock

• When heart failure occurs in a patient with chronic kidney disease

HOSPITALIZATION CRITERIA

• Rising creatinine and BUN in a patient with heart failure

• Hypotension, shock

• Rising potassium levels despite diuretics

• Low serum sodium and signs of heart failure

MEDICATIONS

• Stop unnecessary drugs

• Stop ACE inhibitors if creatinine > 2.75 mg/dL

• Carefully adjust diuretic dosage

• Maximize beta-blocker therapy for heart failure

• Avoid digoxin if possible

THERAPEUTIC PROCEDURES

• Institute ultrafiltration or hemodialysis if necessary

• Percutaneous valve or coronary procedures if appropriate

• Correct anemia if hemoglobin < 10 g/dL

SURGERY

• Appropriate surgery to improve ...