April 2016 at a glance. Focus on cardiac remodeling, biomarkers and treatment.

Abstract

Mohamed et al. show the long-term effects of volume overload induced by aortacaval shunt in mice followed by serial echocardiography until the development of reduced left ventricular ejection fraction (LVEF) and heart failure (HF). Transition to HF was characterized by reduced sarcomeric titin phosphorylation, a cause of increased sarcomeric stiffness, activation of calcium/calmodulin-dependent protein kinase II, decreased protein kinase B (Akt) phosphorylation, high oxidative stress, and increased apoptosis. These changes were worsened in Akt-deficient mice showing the critical role of this kinase.1 Tenascin-C is a large glycoprotein which appears in the extracellular matrix following tissue injury or tumor formation. Yokokawa et al. have measured it in 123 patients with dilated cardiomyopathy undergoing endomyocardial biopsy. Patients with high myocardial tenascin had worse cardiac remodeling and poorer outcomes. Diabetes and HF severity were independent determinants of its content.2 Suematsu et al. have compared valsartan and LCZ696 with a control group in streptozotocin induced diabetic mice. Compared with control and with valsartan groups, administration of LCZ696 improved LVEF and reduced LV ANP mRNA, the LV fibrotic area and TGF-β levels.3 Atrial flutter-related tachycardiomyopathy is a specific form of cardiac remodeling. Brembilla-Perot et al. report the 6 months follow-up of 1269 patients who underwent radiofrequency ablation for atrial flutter. A marked improvement in LVEF was shown in 56% of the patients who had a reduced LVEF before ablation. An ischemic etiology and prescription of antiarrhythmic drugs were associated with a lower likelihood of LVEF improvement. Patients who improved their LVEF had similar outcomes as those with a normal LVEF at baseline whereas those with a persistent low LVEF post-ablation had an almost 3-fold higher mortality rate.4 Ovchinnikova et al. have measured circulating microRNAs in 137 patients with acute HF, 20 with chronic HF, 8 with dyspnea caused by COPD exacerbation, and 41 healthy controls. Plasma levels of miRNAs were decreased in the patients with acute HF compared with all the other groups with 15 of the 226 miRNAs measured that showed a larger than a 4-fold difference. Among them, 12 were different also in the validation cohort and a prognostic value was shown for 7 of them so that their further drop within 48 hours after admission was associated with an increased risk of 180-day mortality.5 Another study shows that liver function exams were abnormal in up to 40% of the patients with acute HF enrolled in ASCEND-HF (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure) and increased serum bilirubin had prognostic value also at multivariable analysis.6 Sleep-disordered breathing (SDB) is found in over half of the patients with HF and is associated with reduced quality of life and poor prognosis. Pearse and Cowie have reviewed the classification, pathophysiology, prognosis and treatment options for patients with HF and SDB. The results of the most recent trials, including SERVE-HF, are discussed.7 The effects of chronic subcutaneous (SQ) BNP administration were evaluated by McKie et al. in a double-blind, placebo controlled study in patients with asymptomatic LV dysfunction who underwent plasma volume expansion at baseline and after 12 weeks. Compared with placebo, chronic SQ, twice daily, BNP administration was associated with an increase in urinary sodium and cGMP excretion and in urine flow with a tendency to a different glomerular filtration rate response to volume expansion and to a lower LV mass.8