Circulating miR-30d Predicts Survival in Patients with Acute Heart Failure.

BACKGROUND/AIMS: Identification of novel biomarkers to identify acute heart failure (AHF) patients at high risk of mortality is an area of unmet clinical need. Recently, we reported that the baseline level of circulating miR-30d was associated with left ventricular remodeling in response to cardiac resynchronization therapy in advanced chronic heart failure patients. However, the role of circulating miR-30d as a prognostic marker of survival in patients with AHF has not been explored. METHODS: Patients clinically diagnosed with AHF were enrolled and followed up for 1 year. Quantitative reverse transcription polymerase chain reactions were used to determine serum miR-30d levels. The univariate logistic regression analysis and multivariate logistic regression analysis were used to determine the predictors for all-cause mortality in AHF patients. Kaplan-Meier survival analysis was used to analyze the role of miR-30d in prediction of survival. RESULTS: A total of 96 AHF patients were enrolled and followed up for 1 year. Serum miR-30d was significantly lower in AHF patients who expired in the one year follow-up period compared to those who survived. Univariate logistic regression analysis yielded 18 variables that were associated with all-cause mortality in AHF patients, while the multivariate logistic regression analysis identified 4 variables including heart rate, hemoglobin, serum sodium, and serum miR-30d level associated with mortality. ROC curve analysis showed that hemoglobin, heart rate and serum sodium displayed poor prognostic value for AHF (AUCs not higher than 0.700) compared to miR-30d level (AUC = 0.806). Kaplan-Meier survival analysis confirmed that patients with higher serum miR-30d levels had significantly lower mortality (P=0.001). CONCLUSION: In conclusion, this study shows evidence for the predictive value of circulating miR-30d as 1-year all-cause mortality in AHF patients. Large multicentre studies are further needed to validate our findings and accelerate the transition to clinical utilization.

Exercise Training Protects Against Acute Myocardial Infarction via Improving Myocardial Energy Metabolism and Mitochondrial Biogenesis.

BACKGROUND/AIMS: Acute myocardial infarction (AMI) represents a major cause of morbidity and mortality worldwide. Exercise has been proved to reduce myocardial ischemia-reperfusion (I/R) injury However it remains unclear whether, and (if so) how, exercise could protect against AMI. METHODS: Mice were trained using a 3-week swimming protocol, and then subjected to left coronary artery (LCA) ligation, and finally sacrificed 24 h after AMI. Myocardial infarct size was examined with triphenyltetrazolium chloride staining. Cardiac apoptosis was determined by TUNEL staining. Mitochondria density was checked by Mito-Tracker immunofluorescent staining. Quantitative reverse transcription polymerase chain reactions and Western blotting were used to determine genes related to apoptosis, autophagy and myocardial energy metabolism. RESULTS: Exercise training reduces myocardial infarct size and abolishes AMI-induced autophagy and apoptosis. AMI leads to a shift from fatty acid to glucose metabolism in the myocardium with a downregulation of PPAR-α and PPAR-γ. Also, AMI induces an adaptive increase of mitochondrial DNA replication and transcription in the acute phase of MI, accompanied by an activation of PGC-1α signaling. Exercise abolishes the derangement of myocardial glucose and lipid metabolism and further enhances the adaptive increase of mitochondrial biogenesis. CONCLUSION: Exercise training protects against AMI-induced acute cardiac injury through improving myocardial energy metabolism and enhancing the early adaptive change of mitochondrial biogenesis.