Heart failure highlights in 2012-2013

The cost-effectiveness of B-type natriuretic peptide-guided care in compared to standard clinical assessment in outpatients with heart failure in Tehran, Iran

BACKGROUND

B-type natriuretic peptide (BNP) is commonly used as a diagnostic method for patients with heart failure. This study was designed to evaluate the cost-effectiveness of BNP compared to standard clinical assessment in outpatients with heart failure with reduced ejection fraction (HFrEF) in Tehran, Iran.

METHODS

This study was a cost-effectiveness analysis carried on 400 HFrEF outpatients > 45 years who were admitted to Rasoul Akram General Hospital of Tehran, Iran. A Markov model with a lifetime horizon was developed to evaluate economic and clinical outcomes for BNP and standard clinical assessment. Quality-adjusted life-years (QALYs), direct, and indirect costs collected from the patients.

RESULTS

The results of this study indicated that mean QALYs and cost were estimated to be 2.18 QALYs and $1835 for BNP and 2.07 and $2376 for standard clinical assessment, respectively. In terms of reducing costs and increasing QALYs, BNP was dominant compared to standard clinical assessment. Also, BNP had an 85% probability of being cost-effective versus standard clinical assessment if the willingness to pay threshold is higher than $20,800/QALY gained.

CONCLUSION

Based on the results of the present study, measuring BNP levels represents good value for money, decreasing costs and increasing QALYs compared to standard clinical assessment. It is suggested that the costs of the BNP test be covered by insurance in Iran. The result of the current study has important implications for policymakers in developing clinical guidelines for the diagnosis of heart failure.

IRX1 hypermethylation promotes heart failure by inhibiting CXCL14 expression

To identify the mechanism and functions of IRX1 in heart failure (HF) and provide evidence for new therapies. Bioinformatic analysis was performed to select target genes in HF cells compared to normal groups. Experimental rats were treated in a controllable manner to explore how IRX1 methylation accounted for this disease in vivo. Cardiac ultrasonic and morphologic examinations were conducted to test the mouse heart and evaluate the degree of cardiac impairment at in the level of organization. GSEA analysis revealed the relative enrichment of functions. Immunofluorescent assays, western blotting and qRT-PCR were used to determine the DNA methylation and expression levels. IRX1 was hypermethylated in heart failure and identified as a target gene by bioinformatic analysis. Transverse aortic constriction (TAC) induced heart failure in rats, while 5-aza-2'-deoxycytidine (5-Aza) alleviated heart failure in rats according to medical cardiac indexes. Western blotting and qRT-PCR revealed that a conspicuous difference in the expression of IRX1 and CXCL14 between HF and normal cardiac cells. As a result of gene methylation, left ventricular hypertrophy and cardiac fibrosis is usually accompanied by heart failure. Moreover, is the results implied that the demethylation of IRX1 improves heart failure in vivo and in vitro. IRX1 methylation induced damaged cardiac function and even heart failure, which has important implications for HF treatment and diagnosis.

Risk factors for heart failure in a cohort of patients with newly diagnosed myocardial infarction: a matched, case-control study in Iran

OBJECTIVES:

Risk factors for heart failure (HF) have not yet been studied in myocardial infarction (MI) patients in Iran. This study was conducted to determine these risk factors.

METHODS:

In this nationwide, hospital-based, case-control study, the participants were all new MI patients hospitalized from April 2012 to March 2013 in Iran. The data on 1,691 new cases with HF (enrolled by census sampling) were compared with the data of 6,764 patients without HF as controls. We randomly selected four controls per one case, matched on the date at MI and HF diagnosis, according to incidence density sampling. Using conditional logistic regression models, odds ratios (ORs) with a 95% confidence interval (CI) were calculated to identify potential risk factors.

RESULTS:

The one-year in-hospital mortality rate was 18.2% in the cases and higher than in the controls (12.1%) (p<0.05). Significant risk factors for HF were: right bundle branch block (RBBB) (OR, 2.86; 95% CI, 1.95 to 4.19), stroke (OR, 2.00; 95% CI, 1.39 to 2.89), and coronary artery bypass grafting (CABG) (OR, 2.03; 95% CI, 1.34 to 3.09). Diabetes, hypertension, percutaneous coronary intervention (PCI), atrial fibrillation, ventricular tachycardia, and age were determined to be the factors significantly associated with HF incidence (p<0.05). The most important factor in women was diabetes (OR, 1.41; 95% CI, 1.05 to 1.88). Age, hypertension, PCI, CABG, and RBBB were the most important factors in men.

CONCLUSIONS:

Our findings may help to better identify and monitor the predictive risk factors for HF in MI patients. The pattern of risk factors was different in men and women.

Regulation of PP2Cm expression by miRNA-204/211 and miRNA-22 in mouse and human cells

AIM

The mitochondrial targeted 2C-type serine/threonine protein phosphatase (PP2Cm) is encoded by the gene PPM1K and is highly conserved among vertebrates. PP2Cm plays a critical role in branched-chain amino acid catabolism and regulates cell survival. Its expression is dynamically regulated by the nutrient environment and pathological stresses. However, little is known about the molecular mechanism underlying the regulation of PPM1K gene expression. In this study, we aimed to reveal how PPM1K expression is affected by miRNA-mediated post-transcriptional regulation.

METHODS

Computational analysis based on conserved miRNA binding motifs was applied to predict the candidate miRNAs that potentially affect PPM1K expression. Dual-luciferase reporter assay was performed to verify the miRNAs' binding sites in the PPM1K gene and their influence on PPM1K 3'UTR activity. We further over-expressed the mimics of these miRNAs in human and mouse cells to examine whether miRNAs affected the mRNA level of PPM1K.

RESULTS

Computational analysis identified numerous miRNAs potentially targeting PPM1K. Luciferase reporter assays demonstrated that the 3'UTR of PPM1K gene contained the recognition sites of miR-204 and miR-211. Overexpression of these miRNAs in human and mouse cells diminished the 3'UTR activity and the endogenous mRNA level of PPM1K. However, the miR-22 binding site was found only in human and not mouse PPM1K 3'UTR. Accordingly, PPM1K 3'UTR activity was suppressed by miR-22 overexpression in human but not mouse cells.

CONCLUSION

These data suggest that different miRNAs contribute to the regulation of PP2Cm expression in a species-specific manner. miR-204 and miR-211 are efficient in both mouse and human cells, while miR-22 regulates PP2Cm expression only in human cells.

1,25-Dihydroxyvitamin D to PTH(1-84) Ratios Strongly Predict Cardiovascular Death in Heart Failure

Objectives

Vitamin D deficiency and hyperparathyroidism are common in patients with heart failure (HF). There is a growing body of evidence supporting the role of vitamin D and parathyroid hormone (PTH) in cardiac remodeling and worsening of HF. Lack of reliable automated testing of 1,25-dihydroxyvitamin D (1,25(OH)₂D), the biologically active metabolite of vitamin D, has limited its contribution to the prognostic assessment of HF. Here, the association of 1,25(OH)₂D and PTH(1–84) levels was evaluated for prediction of cardiovascular death in chronic HF patients.

Methods

We conducted a single center prospective cohort including 170 chronic HF patients (females n = 36; males n = 134; NYHA II-IV; mean age: 67 years; etiology: ischemic n = 119, dilated cardiomyopathy n = 51; mean LVEF: 23%). The primary outcome was cardiovascular death.

Results

Serum levels of 1,25(OH)₂D decreased markedly with increased HF severity. Medians were 33.3 pg/mL for NYHA-II patients, 23.4 pg/mL for NYHA-III, and 14.0 pg/mL for NYHA-IV patients (p<0.001). Most patients had levels of 25(OH)D below 30ng/mL, and stratification by NYHA functional class did not show significant differences (p = 0.249). The 1,25(OH)₂D to PTH(1–84) ratio and the (1,25(OH)₂D)² to PTH(1–84) ratio were found to be the most significantly related to HF severity. After a median follow-up of 4.1 years, 106 out of 170 patients reached the primary endpoint. Cox proportional hazard modeling revealed 1,25(OH)₂D and the 1,25(OH)₂D to PTH(1–84) ratios to be strongly predictive of outcomes.

Conclusions

1,25(OH)₂D and its ratios to PTH(1–84) strongly and independently predict cardiovascular mortality in chronic HF.

Efficacy of mineralocorticoid receptor antagonism in the acute myocardial infarction phase: eplerenone versus spironolactone

AIMS

The selective mineralocorticoid receptor (MR) antagonist eplerenone given early in patients with acute myocardial infarction (MI) improves clinical outcome, whereas little is known about the effectiveness of early spironolactone therapy. We aimed to compare the ability of eplerenone and spironolactone to promote cardiac repair after experimental MI.

METHODS AND RESULTS

Starting immediately after coronary artery ligation, C57BL/6J mice were treated with placebo, eplerenone, or spironolactone. At 7 days, treatment with eplerenone or spironolactone reduced thinning and expansion of healing infarct and improved early left ventricular chamber enlargement. Remarkably, eplerenone therapy resulted in significantly greater improvement than spironolactone of left ventricular contractile function and relaxation, associated with a more considerable leftward and downward shift of the pressure volume curve. Seven-day survival rate was significantly increased only in eplerenone treated mice. Moreover, eplerenone was superior to spironolactone in ameliorating neovessel formation in the injured myocardium. Optimized flow cytometry analysis of the monocyte differentiation marker Ly6C revealed predominant accumulation of Ly6C^high monocytes/macrophages at the site of ischemic injury during the early inflammatory phase in placebo-treated mice. In contrast, MR antagonism, especially by eplerenone, led to a skewing of the monocyte/macrophage population toward a higher frequency of healing promoting Ly6C^low cells.

CONCLUSION

The MR antagonist eplerenone versus spironolactone showed superior efficacy during the acute MI phase with more beneficial effects on survival, early cardiac dilation, and functional decline. Modulation of monocyte maturation and enhanced infarct neovessel formation appears to play a pivotal role.