What is the diagnosis and treatment for dilated cardiomyopathy (DCM)?

From the Guidelines

Dilated cardiomyopathy (DCM) should be diagnosed and treated with a comprehensive approach that includes optimal medical therapy with ACE inhibitors, beta-blockers, and mineralocorticoid receptor antagonists (MRAs), as well as device therapy and lifestyle modifications, to reduce morbidity, mortality, and improve quality of life. The diagnosis of DCM involves identifying the underlying cause of the condition, which can range from genetic to infectious causes, and assessing the severity of the disease through echocardiography and other diagnostic tests 1. Treatment typically includes medications such as:

• ACE inhibitors (like enalapril or lisinopril at 2.5-40mg daily)
• Beta-blockers (such as carvedilol 3.125-25mg twice daily or metoprolol 12.5-200mg daily)
• Diuretics (furosemide 20-80mg daily) to reduce fluid retention
• Aldosterone antagonists (spironolactone 25-50mg daily) may be added for moderate to severe cases
• For patients with reduced ejection fraction below 35%, SGLT2 inhibitors like dapagliflozin (10mg daily) have shown benefit 1. Device therapy, including implantable cardioverter-defibrillators, may be recommended for patients at risk of sudden cardiac death, while cardiac resynchronization therapy helps when there's electrical dyssynchrony 1. Lifestyle modifications are crucial, including:
• Sodium restriction (<2g daily)
• Fluid restriction if needed
• Regular moderate exercise as tolerated
• Avoiding alcohol and tobacco These treatments aim to slow disease progression, improve heart function, relieve symptoms, and extend survival by reducing the workload on the heart, blocking harmful neurohormonal pathways, and preventing dangerous arrhythmias 1. It is essential to individualize treatment and target the underlying cause of DCM, in addition to standard systolic heart failure therapies, to achieve the best possible outcomes 1.

From the FDA Drug Label

In two placebo controlled, 12-week clinical studies compared the addition of lisinopril up to 20 mg daily to digitalis and diuretics alone. The combination of lisinopril, digitalis and diuretics reduced the following signs and symptoms of heart failure: edema, rales, paroxysmal nocturnal dyspnea and jugular venous distention A large (over 3,000 patients) survival study, the ATLAS Trial, comparing 2. 5 mg and 35 mg of lisinopril in patients with systolic heart failure, showed that the higher dose of lisinopril had outcomes at least as favorable as the lower dose

The diagnosis of dilated cardiomyopathy (DCM) is not directly addressed in the provided drug label. However, the treatment for heart failure, which can be a result of DCM, may include lisinopril in combination with digitalis and diuretics to reduce signs and symptoms of heart failure, such as edema, rales, paroxysmal nocturnal dyspnea, and jugular venous distention 2. Lisinopril has been shown to have a dose-dependent antihypertensive effect and has been used to treat systolic heart failure. The ATLAS Trial compared two doses of lisinopril (2.5 mg and 35 mg) in patients with systolic heart failure and found that the higher dose had outcomes at least as favorable as the lower dose 2. Key points for treatment include:

• Lisinopril in combination with digitalis and diuretics may be used to treat heart failure
• The ATLAS Trial supports the use of lisinopril in patients with systolic heart failure
• Lisinopril has a dose-dependent antihypertensive effect 2

From the Research

Diagnosis of Dilated Cardiomyopathy (DCM)

• The diagnosis of DCM involves determining the underlying cause, defining the hemodynamic character, and recognizing complicating factors such as atrial fibrillation and renal dysfunction 3.
• Diagnostic tests should consider both genetic and acquired factors, as 5-15% of patients with acquired DCM may harbor a likely pathogenic or pathogenic gene variant 4.
• The definition of DCM has been recognized as overly restrictive, and left ventricular hypokinesis without dilation could be the initial presentation of DCM 4.

Treatment of Dilated Cardiomyopathy (DCM)

• The treatment of DCM overlaps with the treatment of heart failure, and the primary objective is to slow the progression of disease and improve quality and length of life 5.
• Angiotensin-converting enzyme inhibitors, beta-blocking agents, digoxin, and judicious diuretic administration make up the therapeutic plan for patients with symptomatic DCM heart failure 3.
• Other treatment options include:
  • Spirolactone for patients with more advanced stages of heart failure 3.
  • Biventricular pacing (cardiac resynchronization therapy) for patients with DCM and a left ventricular or intraventricular conduction defect and a QRS duration of longer than 140 msec 3.
  • Thoracic epidural blockade to improve ventricular function 6.
  • Omecamtiv mecarbil, a heart myosin activator, as a potential future treatment option 5.
• Nonpharmacologic approaches, including dietary measures, exercise conditioning, and dedicated heart failure programs, are also important in the management of DCM 3.

Anesthetic Management of Patients with DCM

• Anesthetic management of patients with DCM is a challenge due to poor left systolic function, ventricular enlargement, risk of malignant arrhythmias, and sudden cardiac death 6.
• Preoperative assessment and appropriate anesthetic management are important in patients with DCM, and advanced monitoring devices such as transesophageal echocardiography and cardiac resynchronization therapy can be used to assess ventricular function and myocardial fibrosis 6.
• Close perioperative monitoring, suitable anesthetic, optimization fluid management, and stable hemodynamic status are crucial in the anesthetic management of patients with DCM 6.