Circulating microRNAs and cardiomyocyte proliferation in heart failure patients related to 10 years survival

Abstract Aims Mechanochemical signalling drives organogenesis and is highly conserved in mammal evolution. Regaining recovery in myocardial jeopardy by inducing principles linking cardiovascular therapy and clinical outcome has been the dream of scientists for decades. Concepts involving embryonic pathways to regenerate adult failing hearts became popular in the early millennium. Since then, abundant data on stem cell research have been published, never reaching widespread application in heart failure therapy. Another conceptual access, using mechanotransduction in cardiac veins to limit myocardial decay, is pressure‐controlled intermittent coronary sinus occlusion (PICSO). Recently, we reported acute molecular signs and signals of PICSO activating regulatory miRNA and inducing cell proliferation mimicking cardiac development in adult failing hearts. According to a previously formulated hypothesis, ‘embryonic recall’, this study aimed to define molecular signals involved in endogenous heart repair during PICSO and study their relation to patient survival. Methods and results We previously reported a study on the acute molecular effects of PICSO in an observational non‐randomized study. Eight out of the thirty‐two patients with advanced heart failure undergoing cardiac resynchronization therapy (CRT) were treated with PICSO. Survival was monitored over 10 years, and coronary sinus blood samples were collected during intervention before and after 20 min and tested for miRNA signalling and proliferation when co‐cultured with cardiomyocytes. A numerically lower death rate post‐CRT and PICSO as compared with control CRT only, and a non‐significant reduction in all‐cause mortality risk of 42% was observed (37.5% vs. 54.0%, relative risk = 0.58, 95% confidence interval: 0.17–2.05; P = 0.402). Four miRNAs involved in cell cycle, proliferation, morphogenesis, embryonic development, and apoptosis significantly increased concomitantly in survivors and PICSO compared with a decrease in non‐survivors (hsa‐miR Let7b, P