Endomyocardial miR-133a levels correlate with myocardial inflammation, improved left ventricular function, and clinical outcome in patients with inflammatory cardiomyopathy

Serially measured circulating miR-22-3p is a biomarker for adverse clinical outcome in patients with chronic heart failure: The Bio-SHiFT study

BACKGROUND

Several studies have suggested circulating microRNAs (miRs) are associated with heart failure, but these studies were small, and limited to single miR measurements. We examined 7 miRs which were previously linked to heart failure, and tested whether their temporal expression level predicts prognosis in a prospective cohort of chronic heart failure (CHF) patients.

METHODS AND RESULTS

In 2011-2013, 263 CHF patients were included. At inclusion and subsequently every 3months, we measured 7miRs. The primary endpoint (PE) comprised heart failure hospitalization, cardiovascular mortality, cardiac transplantation and LVAD implantation. Associations between temporal miR patterns and the PE were investigated by joint modelling, which combines mixed models with Cox regression. Mean age was 67±13years, 72% were men and 27% NYHA classes III-IV. We obtained 873 blood samples (median 3 [IQR 2-5] per patient). The PE was reached in 41 patients (16%) during a median follow-up of 0.9 [0.6-1.4] years. The temporal pattern of miR-22-3p was independently associated with the PE (HR [95% CI] per doubling of level: 0.64 [0.47-0.77]). The instantaneous change in level (slope of the temporal miR pattern) of miR-22-3p was also independently associated with the PE (HR [95% CI] per doubling of slope: 0.33 [0.20-0.51]). These associations remained statistically significant after adjustment for temporal patterns of NT-proBNP, Troponin T and CRP.

CONCLUSIONS

The temporal pattern of circulating miR-22-3p contains important prognostic and independent information in CHF patients. This concept warrants further investigation in larger series with extended follow-up.

Relevance of cardiac parvovirus B19 in myocarditis and dilated cardiomyopathy: review of the literature

Over the last decade, parvovirus B19 (B19V) has frequently been linked to the pathogenesis of myocarditis (MC) and its progression towards dilated cardiomyopathy (DCM). The exact role of the presence of B19V and its load remains controversial, as this virus is also found in the heart of healthy subjects. Moreover, the prognostic relevance of B19V prevalence in endomyocardial biopsies still remains unclear. As a result, it is unclear whether the presence of B19V should be treated. This review provides an overview of recent literature investigating the presence of B19V and its pathophysiological relevance in MC and DCM, as well as in normal hearts. In brief, no difference in B19V prevalence is observed between MC/DCM and healthy control hearts. Therefore, the question remains open whether and how cardiac B19V may be of pathogenetic importance. Findings suggest that B19V is aetiologically relevant either in the presence of other cardiotropic viruses, or when B19V load is high and/or actively replicating, which both may maintain myocardial (low-grade) inflammation. Therefore, future studies should focus on the prognostic relevance of the viral load, replicative status and virus co-infections. In addition, the immunogenetic background of MC/DCM patients that makes them susceptible to develop heart failure upon presence of B19V should be more thoroughly investigated.