Myocarditis medical therapy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Varun Kumar, M.B.B.S.; Maliha Shakil, M.D. [2] Homa Najafi, M.D.[3]

Overview[edit | edit source]

Symptomatic treatment is the mainstay of therapy for patients with viral myocarditis. Supportive therapy includes diuretics and inotropes for left ventricular failure. ACE inhibitor therapy may aid in left ventricular remodeling. Among patients with fulminant myocarditis, placement of either an intra-aortic balloon pump or a left ventricular assist device may be necessary as bridge to recovery. Administration of antimicrobial therapy is recommended for bacterial myocarditis. Immunosuppressive therapy may be effective in the management of giant cell myocarditis, autoimmune myocarditis, and eosinophilic myocarditis. In patients with arrythmias, treatment should be initiated only if arrhythmias are symptomatic or sustained. Myocarditis patients presenting with conduction abnormalities, particularly Mobitz type II and complete heart block require temporary pacemaker usually during the acute phase.

Medical Therapy[edit | edit source]

Lymphocytic/Viral Myocarditis[edit | edit source]

• The mainstay of therapy for viral myocarditis is supportive care and standard management of CHF.^{[1][2][3][4][5][6][5][7] [8][9][10][11][12][13][14][15][16][17][18]}
• The Heart Failure Society of America recommends against the routine use of immunosuppressive agents in treatment of myocarditis.

• Animal studies have demonstrated better outcomes in viral myocarditis with the use of antiviral agents and interferon early in the course of infection prior to inoculation. The use of antiviral therapy may be limited since patients with viral myocarditis are usually not seen in the early stages. However, it may be used in acute, fulminant myocarditis and in institutional outbreaks. In a series, 6 months of beta interferon in patients with myocarditis secondary to enterovirus or adenovirus infection resulted in the elimination of viral genomes in all patients and improvement of LV function in 68% of the patients.

• Immunotherapy was thought to be a treatment option for myocarditis as they suppress the activity of immunologic agents mediating myocardial inflammation. There is no significant change in mortality rate with immunotherapy. However, improvement in LV function is seen in patients with chronic inflammatory dilated cardiomyopathy.

• Intravenous immunoglobulin (IVIG) is known to have both antiviral and immunologic properties. Therefore, it can be used in both viral and autoimmune types of myocarditis.
• Temporary pacemaker insertion is indicated in patients with symptomatic bradycardia and/or heart block during the acute phase of myocarditis.
• ICD implantation is not indicated during the acute phase of myocarditis.
• Antiarrhythmic therapy can be useful in patients with symptomatic NSVT or sustained VT during the acute phase of myocarditis.

Giant Cell Myocarditis[edit | edit source]

• Giant cell myocarditis is a rare form of myocarditis and is generally associated with a poor prognosis. In a non-randomized series, 22 patients with giant cell myocarditis who were treated with corticosteroids and cyclosporine/azathioprine, survived for an average of 12.3 months. In contrast, those patients who were not treated with immunosuppressants survived for an average of 3 months. Use of immunosuppressive therapy was further strengthened by a prospective, multicenter observational study which reported an improved survival of 6 years among patients receiving high dose steroids and cyclosporine with or without muromonab-CD3. Of the 11 patients studied, two patients underwent cardiac transplantation early in the course of the study and one patient died. The study also reported that withdrawal of immunosuppression was associated with a recurrence of giant cell myocarditis in some patients which in some cases was fatal. Immunosuppressive therapy directed at T-cells may be beneficial as T-cells mediate myocardial inflammation.^[19][20][21]

• Cardiac transplantation is sometimes required to treat refractory giant cell myocarditis. However, the condition can recur in post-transplant patients. Recurrence of biopsy proven giant cell myocarditis between 3 weeks to 9 years was observed in 9 of 34 cardiac transplant patients.

Eosinophilic Myocarditis[edit | edit source]

• Eosinophilic myocarditis can occur secondary to hypersensitivity to drugs, parasitic infestation, or hypereosinophilic syndrome. The eosinophils which infiltrate the myocardium, degenerate leading to extracellular release of eosinophil granules which can contribute to death of myocytes. Usage of immunosuppressants such as high dose steroids (after excluding infections) and removal of offending drug (in drug induced hypersensitivity) is known to be beneficial in treatment of eosinophilic myocarditis. Immunosuppressive therapy may be tapered gradually after one year if normal cardiac function and cardiac enzymes levels are restored.^[22][23]

Autoimmune Myocarditis[edit | edit source]

• Myocarditis can develop in autoimmune diseases such as celiac disease and sarcoidosis. Treatment with gluten-free diet and immunosuppressants in celiac disease improves cardiac function. Corticosteroids are found to be beneficial in patients with sarcoidosis related myocarditis, particularly during initial stages of the disease before development of extensive fibrosis of myocardium.^[24][25]

Treatment of Heart Failure[edit | edit source]

• As heart failure in patients with myocarditis has poor prognosis, it is important to prevent progression or worsening of cardiac dysfunction. These patients should be treated with low sodium intake, diuretics and ACE inhibitors. Few animal studies report that mortality rate is high with digoxin in comparison to beta blocker in viral myocarditis. Studies have also demonstrated that usage of carvedilol during recovery phase decreases expression of several histochemicals and subsequently myocardial inflammation and there by improving survival. The beta-blockers should however be avoided in the acutely decompensating phase of illness. If heart failure or cardiogenic shock does not respond to medical therapy, circulatory support with an intraaortic balloon pump should be considered which could be used in fulminant myocarditis as a bridge to spontaneous recovery. Implantation of ICD in severe heart failure should be deferred for several months to allow sufficient time for recovery of ventricular function. Following the initial circulatory stabilization, further treatment of cardiac dysfunction should follow current ACC/AHA recommendations. Anticoagulation may be considered in patients with severe/chronic heart failure as they are at risk for developing thromboembolic complications.^{[26][27][28][29][30][31][32]}

• For more information on heart failure treatment, click here.

Treatment of Arrhythmia[edit | edit source]

• Arrhythmias or conduction abnormalities can occur in patients with myocarditis. Treatment should be initiated only if arrhythmias are symptomatic or sustained. Caution should be observed while using antiarrhythmics as majority of these agents have negative inotropic property which may worsen heart failure. Regular monitoring with ECG is important as it enables early detection and treatment of asymptomatic yet life threatening arrhythmias.
• Supraventricular tachycardia (SVT) can aggravate heart failure. Symptomatic and sustained SVT should be immediately converted electrically. While, patients with recurrent sustained SVT should be treated with antiarrhythmics and rate controlling agents. Implantation of ICD should be considered in patients with recurrent ventricular arrhythmia refractory to medical therapy. Myocarditis patients presenting with conduction abnormalities, particularly Mobitz type II and complete heart block require temporary pacemaker usually during the acute phase. Implantation of permanent pacemaker or ICD may be necessary in few patients.^[33]

2006 ACC/AHA/ESC Guidelines for Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death - Myocarditis, Rheumatic Disease, and Endocarditis^[34][edit | edit source]

2013 ESC Guideline for Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death - Myocarditis, Rheumatic Disease, and Endocarditis^[36][edit | edit source]

References[edit | edit source]

Template:WH Template:WS