Clinical features of idiopathic restrictive cardiomyopathy

Idiopathic restrictive cardiomyopathy (RCMP) has not been fully understood because this disease is difficult to diagnose. The present study aimed to assess the clinical profile and outcome of idiopathic RCMP from a multicenter cohort. This investigation is a retrospective study of consecutive patients with idiopathic RCMP at 10 centers in Korea between 1990 and 2010. We evaluated the clinical characteristics of the patients and prognostic factors associated with mortality using multivariate Cox proportional hazards regression analyses. The study included 53 patients (26 men, 49.1%). During a median follow-up of 1.7 years, 17 patients (32.1%) died and 5 patients (9.4%) received a heart transplant. The 5-year survival rate of the overall patients was 64.4%}7.8%. In multivariable analyses, the predictors of mortality were tricuspid regurgitation (TR).moderate (hazard ratio [HR] 32.55, P<001) and left ventricular enddiastolic diameter (LVEDD) (HR 0.85, P<001). Idiopathic RCMP showed unfavorable prognosis. Advanced TR and lower LVEDD are independent adverse predictors of mortality in patients with idiopathic RCMP. Abbreviations: EDP = end-diastolic pressure, EF = ejection fraction, HR = hazard ratio, LA = left atrium, LV = left ventricle, LVEDD = left ventricular end-diastolic diameter, NYHA Fc = New York Heart Association functional class, RCMP = restrictive cardiomyopathy, RV = right ventricle, RVEDP = right ventricle end-diastolic pressure, TR = tricuspid regurgitation.