What are the key differences between constrictive pericarditis and restrictive cardiomyopathy (CM)?

From the Guidelines

Constrictive pericarditis should be treated with pericardiectomy in patients with persistent and prominent symptoms, while restrictive cardiomyopathy management focuses on treating the underlying cause and heart failure symptoms. The key to differentiating constrictive pericarditis and restrictive cardiomyopathy lies in their distinct causes, diagnostic features, and treatments. Constrictive pericarditis is characterized by a thickened, fibrotic pericardium that restricts cardiac filling, often resulting from inflammation due to infections, radiation, surgery, or autoimmune diseases 1. In contrast, restrictive cardiomyopathy involves stiffening of the myocardium itself, typically due to infiltrative diseases, storage disorders, or fibrosis.

Diagnostic Differences

Key diagnostic differences between the two conditions include:

• Pericardial calcification and thickening on imaging in constrictive pericarditis
• Ventricular septal bounce with respiration in constrictive pericarditis versus its absence in restrictive cardiomyopathy
• Hemodynamic findings like equalization of diastolic pressures and discordant respiratory variation in ventricular pressures in constrictive pericarditis 1

Treatment Approaches

Treatment for constrictive pericarditis is primarily surgical, with pericardiectomy being the accepted standard of treatment in patients with persistent and prominent symptoms, such as NYHA class III or IV 1. However, surgery should be considered cautiously in patients with either mild or very advanced disease and in those with radiation-induced constriction, myocardial dysfunction, or significant renal dysfunction. On the other hand, restrictive cardiomyopathy management focuses on treating the underlying cause and heart failure symptoms with diuretics, ACE inhibitors, and beta-blockers.

Prognosis

Prognosis is generally better for constrictive pericarditis when treated surgically, with complete normalization of cardiac hemodynamics reported in 60% of patients 1. However, constrictive pericarditis patients with prior ionizing radiation, worse renal function, higher pulmonary artery systolic pressure, abnormal left ventricular systolic function, lower serum sodium level, and older age have a poor long-term outcome 1. In contrast, restrictive cardiomyopathy often has a progressive course with poorer outcomes unless the underlying cause can be effectively treated. Pericardiectomy should be performed by experienced surgeons, and referral to a center with a special interest in pericardial disease may be warranted in centers with limited experience in this surgery 1.

From the Research

Constrictive Pericarditis vs Restrictive Cardiomyopathy

• Constrictive pericarditis is characterized by marked thickening and dense scarring of the pericardium, leading to impaired diastolic filling and reduced cardiac output 2, 3.
• Restrictive cardiomyopathy, on the other hand, is a condition where the myocardium becomes stiff, leading to impaired diastolic filling and reduced cardiac output.
• The diagnosis of constrictive pericarditis can be challenging, as it shares similar symptoms and clinical findings with restrictive cardiomyopathy and other syndromes associated with right-sided pressure abnormalities 3.
• Pericardiectomy is considered the treatment of choice for constrictive pericarditis, and has been shown to improve hemodynamics and overall heart function in symptomatic patients 2, 3, 4, 5, 6.

Key Differences

• Constrictive pericarditis is characterized by pericardial thickening and scarring, whereas restrictive cardiomyopathy is characterized by myocardurnal stiffness.
• Pericardiectomy is a surgical procedure that involves the removal of the pericardium, and is used to treat constrictive pericarditis 2, 3, 4, 5, 6.
• The outcome of pericardiectomy for constrictive pericarditis is generally good, with improved functional capacity and reduced symptoms 2, 3, 4, 5, 6.

Diagnostic Challenges

• The diagnosis of constrictive pericarditis can be challenging, as it requires the exclusion of other conditions that may present with similar symptoms and clinical findings, such as restrictive cardiomyopathy 3, 6.
• Cardiac catheterization, transthoracic echocardiography, computed tomography, and cardiac magnetic resonance imaging can be used to confirm the diagnosis of constrictive pericarditis and exclude other conditions 6.