Clinical and Echocardiographic Risk Factors of Adverse Outcomes in Young Patients With Dilated Cardiomyopathy

Purpose: This study is aimed at identifying clinical and echocardiographic factors associated with all-cause mortality or heart transplantation (HTx) in young patients with dilated cardiomyopathy (DCM). Methods: We conducted a retrospective analysis of hospitalized patients (aged 18-45 years) diagnosed with DCM between January 2012 and December 2022. All patients underwent a 2-year medical therapy for heart failure, followed by at least 1 year of follow-up. Clinical and echocardiographic data were collected at baseline and after the 2-year treatment period. Multivariate Cox proportional hazards regression with a backward stepwise method was used to identify risk factors for all-cause mortality or HTx. Results: The study cohort comprised 67 patients. Over a median follow-up of 38 months (range 18-50), 15 patients died and 24 underwent HTx. Significant risk factors for all-cause mortality/HTx included smoking, digoxin use, elevated N-terminal pro-brain natriuretic peptide (NT-proBNP, ≥ 5678 pg/mL), higher C-reactive protein (CRP, ≥ 3.0 mg/L), higher uric acid (UA, ≥ 570 μmol/L), lower left ventricular ejection fraction (LVEF, ≤25%), and enlarged end-diastolic left ventricular diameter (LVD, ≥ 65 mm). Among these, elevated CRP (hazard ratio, HR = 6.727, p < 0.001) and enlarged LVD (HR = 3.038, p = 0.007) were the strongest independent risk factors, irrespective of other risk factors. Moreover, each 5 mm annual increase in end-systolic left atrial diameter (LAD, HR = 3.641, p < 0.001) and each unit annual increase in Ln(NT-proBNP) (HR = 4.069, p < 0.001) were the strongest predictors of all-cause mortality/HTx, even after accounting for the effects of body mass index, duration of treatment, and baseline CRP level. Conclusions: Intensive monitoring and medical care may be beneficial for young adult DCM patients with defined risk factors such as smoking, elevated NT-proBNP and CRP, lower LVEF, and enlarged LV diameter. Our findings suggest that personalized intensive monitoring and medical care based on identified risk factors may improve outcomes in young adult DCM patients.