Outcome and prognostic value of N-terminal pro-brain natriuretic peptide and high-sensitivity C-reactive protein in mildly dilated cardiomyopathy vs. dilated cardiomyopathy

Abstract

Aims: Mildly dilated cardiomyopathy (MDCM) was characterized as a subset of dilated cardiomyopathy (DCM) with systolic dysfunction and modest ventricular dilatation, of which the prognostic studies were limited. We aimed to compare the prognostic value of the N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity C-reactive protein (hs-CRP) between MDCM and DCM. Methods and results: We retrospectively included hospitalized patients diagnosed with DCM and a left ventricular ejection fraction ≤ 50% at Fuwai Hospital from 2006 to 2017. MDCM was defined as left ventricular end-diastolic diameter index (LVEDDi) ≤ 33 mm/m2 in males and ≤34 mm/m2 in females. A total of 640 patients (median age 49 years, 24.8% female) were included in this study. At baseline, 110 cases (17%) were categorized as MDCM and 529 cases (83%) as DCM. Of 282 patients who had follow-up echocardiograms ≥ 6 months, 7 MDCM patients (11.1%) evolved to DCM and 70 DCM patients (32.0%) recovered to MDCM by the change of LVEDDi. Compared with DCM, patients with baseline MDCM had lower composite risks of all-cause mortality, heart transplantation, and heart failure rehospitalization [adjusted hazard ratio (HR) 0.63, 95% confidence interval (CI) 0.43–0.93, P = 0.019]. Both hs-CRP and NT-proBNP were independently associated with the composite endpoint in the overall cohort (hs-CRP: adjusted HR 1.07, 95% CI 1.00–1.15, P = 0.036; NT-proBNP: adjusted HR 1.11, 95% CI 1.02–1.22, P = 0.019). After a propensity-score matching between MDCM and DCM, higher NT-proBNP (above the median) was significantly associated with the outcome in DCM patients (HR 1.83, 95% CI 1.05–3.20, P = 0.034), but not in MDCM patients (HR 1.54, 95% CI 0.76–3.11, P = 0.227). On the contrary, higher hs-CRP (above the median) showed prognostic value for adverse events in MDCM patients (HR 3.19, 95% CI 1.52–6.66, P = 0.002), but not in DCM patients (HR 1.04, 95% CI 0.61–1.79, P = 0.88). Conclusions: In patients with MDCM, although no evidence suggested the prognostic role of NT-proBNP, higher level of hs-CRP was associated with outcome, supporting the use of hs-CRP in risk stratification for patients with MDCM.