Mortality in primary and secondary myocarditis.
BACKGROUND
Lymphocytic myocarditis presents as a primary disorder or in association with a systemic disease. Whether primary and secondary myocarditis have the same prognosis is unknown.


METHODS
Patients (n = 171) referred to the Johns Hopkins Cardiomyopathy service from 1984 to 1998 with newly diagnosed cardiomyopathy were observed for an average of 5.9 years after an original diagnosis of biopsy-proven myocarditis or until reaching the end point of death. Giant-cell myocarditis was excluded from this study. Myocarditis was classified as secondary when a systemic disease was present at the time of presentation; otherwise, myocarditis was classified as primary. Survival rates among patients with primary and secondary myocarditis were compared with Kaplan-Meier analysis and Cox proportional hazard models incorporating clinical variables, including baseline hemodynamics and treatment with immunosuppressive therapy.


RESULTS
The mortality rate associated with secondary myocarditis varied substantially depending on the underlying systemic disorder. Peripartum myocarditis, when compared with idiopathic myocarditis, had a reduced mortality rate (relative hazard, 0.23 [0.06-0.98]; P <.05), which was attenuated after controlling for confounding variables (relative hazard, 0.62 [0.13-2.98]; P =.55). In contrast, human immunodeficiency virus myocarditis had a particularly poor prognosis (relative hazard, 6.70 [3.51-12.79]; P <.05), even after controlling for confounding variables. Myocarditis associated with systemic inflammatory disorders showed a trend toward increased mortality rate (relative hazard, 2.46 [0.65-9.38]; P =.19). For both primary and secondary myocarditis, advanced age and pulmonary hypertension were important clinical predictors of death.


CONCLUSIONS
The prognosis of patients with secondary myocarditis, when compared with patients with idiopathic myocarditis, seems most affected by the primary disease process.
Pulerwitz
Todd C
TC
Cardiology Division, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, USA. tcp2003@columbia.edu
Cappola
Thomas P
TP
Felker
G Michael
GM
Hare
Joshua M
JM
Baughman
Kenneth L
KL
Kasper
Edward K
EK
D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000150:complications; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications; D008297:Male; D009205:Myocarditis / Q000209:etiology / Q000401:mortality* / Q000473:pathology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000401:mortality; D011379:Prognosis; D016016:Proportional Hazards Models; D011644:Puerperal Disorders / Q000401:mortality; D012189:Retrospective Studies; D012595:Scleroderma, Systemic / Q000150:complications; D015996:Survival Rate