Giant cell versus lymphocytic myocarditis. A comparison of their clinical features and long-term outcomes.

Abstract

BACKGROUND Giant cell myocarditis has rarely been diagnosed premortem, and little is known about its natural history. In addition, no comparative studies with lymphocytic myocarditis exist. METHODS AND RESULTS The clinical features, serial change in left ventricular fraction (LVEF), and outcomes of all patients with histologically verified myocarditis were retrospectively evaluated. Ten patients (22%) were found to have giant cell myocarditis (group 1), whereas the remaining 36 (78%) had lymphocytic myocarditis (group 2). Age at presentation, gender distribution, duration of symptoms, initial LVEF, and resting hemodynamics did not differ between groups. Ventricular tachycardia was detected in 90% of group 1 patients compared with only 25% of group 2 (p = 0.0007). Atrioventricular block that required pacemaker insertion was also more common in group 1 (60%) than in group 2 (8.3%) (p = 0.001). Left ventricular systolic function declined during follow-up in group 1 patients (LVEF, 0.43 +/- 0.07-0.26 +/- 0.05, p = 0.11) but increased in group 2 patients (LVEF, 0.33 +/- 0.03-0.41 +/- 0.03, p = 0.02). When the net change between initial and final LVEF was assessed, a significant difference was evident (giant cell group, -0.17 +/- 0.06; lymphocytic group, +0.07 +/- 0.03; p = 0.0008). Although a greater proportion of patients in group 1 died or required transplantation (seven of 10 versus 11 of 36, p = 0.03), actuarial survival over 4 years was not different for the giant cell group (50%) than for the lymphocytic group (62%). CONCLUSION Giant cell myocarditis was more prevalent than previously recognized and highly associated with both ventricular tachycardia and pacemaker requirement. The likelihood of an adverse event, either cardiovascular mortality or cardiac transplantation, was significantly greater for patients with giant cell myocarditis than for those with lymphocytic myocarditis, perhaps because of the progressive decline in left ventricular systolic function that was observed in those with giant cell myocarditis.

Electrical Remodeling of the Ventricular Myocardium in Myocarditis

“…[16][17][18][19][20] The EAM model shows an acute inflammatory phase evoked 2 weeks after myosin injection, and a recovery phase around the 25th day, which is followed by a dilated cardiomyopathy-like phase with chronic heart failure. In the acute phase, the heart enlarges and whitishyellow discoloration appears in the myocardium.…”

Protection Against Autoimmune Myocarditis by Gene Transfer of Interleukin-10 by Electroporation

“…Giant cell myocarditis is a fatal disease, and survivors are more likely to develop dilated cardiomyopathy than patients with lymphocytic myocarditis. 1,2 The efficiency of immunosuppressive therapy for this disease is controversial. 1,2 In a rat model in which myocarditis was induced by purified cardiac myosin, T cells were reported to play an important role in inducing myocarditis.…”

A New Scoring System to Predict the Efficacyof Steroid Therapy for Patients With Active Myocarditis

“…30 Various immunerelated systemic disorders involve myocarditis, and cardiac symptoms may precede the systemic symptoms of the primary disorder. [31][32][33][34][35][36] Some patients with myocarditis are unexpectedly diagnosed from endomyocardial biopsy performed for unexplained left ventricular dysfunction without infectious or inflammatory signs. Those are atypical cases of viral myocarditis.…”