Found in translation: metoprolol improves survival more than carvedilol in a mouse model of inherited dilated cardiomyopathy

Over the past two decades, many mutations responsible for inherited forms of dilated cardiomyopathy (DCM) have been identified, providing important pathogenic insights. The first paradigm for explaining the role of genes in the mechanisms of ventricular dilation and dysfunction was elaborated after the identification of mutant proteins of the cytoskeleton that were implicated in defects of transmission of contractile force.1 In the year 2000, a mutation of a sarcomeric protein causally linked to DCM, a deletion (ΔLys210 or ΔK210 ) of the gene TNNT2 resulting in the loss of a lysine residue within a portion of the Ca2+-sensitive binding domain of troponin T (TnT), was described for the first time.2 Two years latter, in isolated cardiac muscle fibres,3 it was demonstrated that the functional consequence of this mutation is a decrease in the Ca2+ sensitivity of cardiac muscle contraction, suggesting a deficiency of force generation by the sarcomere as the primary mechanism of this type of DCM. The idea was proposed that both mechanisms, cytoskeletal and sarcomeric, may be implicated in the origin of DCM. Either the reduction of contractile force or its transmission leads to ventricular dilation as a compensatory mechanism for the decrease in stroke volume.In recent years, new evidence about clinical characteristics, prevalence, and risks of different mutations in patients with inherited DCM has been collected.4–7 TnT mutations (e.g. ΔLys210) seem to be particularly prevalent in cases with early-onset ventricular dilatation and dysfunction, leading to severe heart failure (HF) with poor outcome and, … *Corresponding author. Tel: +34 93 2746212; fax: +34 93 2746244. E-mail address : rioaguilar{at}pulso.com