Long-term prognostic impact of therapeutic strategies in patients with idiopathic dilated cardiomyopathy: changing mortality over the last 30 years

Clinical management of dilated cardiomyopathy: current knowledge and future perspectives

Dilated cardiomyopathy (DCM) is a primary heart muscle disease characterized by a progressive dilation and dysfunction of either the left or both ventricles. The management of DCM is currently challenging for clinicians. The persistent lack of knowledge about the etiology and pathophysiology of this disease continues to determine important fields of uncertainty in managing this condition. Molecular cardiology and genetics currently represent the most crucial horizon of increasing knowledge. Understanding the mechanisms underlying the disease allows clinicians to treat this disease more effectively and to further improve outcomes of DCM patients through advancements in etiologic characterization, prognostic stratification and individualized therapy. Left ventricular reverse remodeling predicts a lower rate of major cardiac adverse events independently from other factors. Optimized medical treatment and device implantation are pivotal in inducing left ventricular reverse remodeling. Newly identified targets, such as angiotensin-neprilysin inhibition, phosphodiesterase inhibition and calcium sensitizing are important in improving prognosis in patients affected by DCM.

Arrhythmogenic Phenotype in Dilated Cardiomyopathy: Natural History and Predictors of Life-Threatening Arrhythmias

BACKGROUND

Patients with dilated cardiomyopathy (DCM) may present with ventricular arrhythmias early in the disease course, unrelated to the severity of left ventricular dysfunction. These patients may be classified as having an arrhythmogenic DCM (AR-DCM). We investigated the phenotype and natural history of patients with AR-DCM.

METHODS AND RESULTS

Two hundred eighty-five patients with a recent diagnosis of DCM (median duration of the disease 1 month, range 0 to 7 months) and who had Holter monitoring at baseline were comprehensively evaluated and followed for 107 months (range 29 to 170 months). AR-DCM was defined by the presence of ≥1 of the following: unexplained syncope, rapid nonsustained ventricular tachycardia (≥5 beats, ≥150 bpm), ≥1000 premature ventricular contractions/24 hours, and ≥50 ventricular couplets/24 hours, in the absence of overt heart failure. The primary end points were sudden cardiac death (SCD), sustained ventricular tachycardia (SVT), or ventricular fibrillation (VF). The secondary end points were death from congestive heart failure or heart transplantation. Of the 285 patients, 109 (38.2%) met criteria for AR-DCM phenotype. AR-DCM subjects had a higher incidence of SCD/SVT/VF compared with non-AR-DCM patients (30.3% vs 17.6%, P=0.022), with no difference in the secondary end points. A family history of SCD/SVT/VF and the AR-DCM phenotype were statistically significant and cumulative predictors of SCD/SVT/VF.

CONCLUSIONS

One-third of DCM patients may have an arrhythmogenic phenotype associated with increased risk of arrhythmias during follow-up. A family history of ventricular arrhythmias in DCM predicts a poor prognosis and increased risk of SCD.

Genetics of Human and Canine Dilated Cardiomyopathy

Cardiovascular disease is a leading cause of death in both humans and dogs. Dilated cardiomyopathy (DCM) accounts for a large number of these cases, reported to be the third most common form of cardiac disease in humans and the second most common in dogs. In human studies of DCM there are more than 50 genetic loci associated with the disease. Despite canine DCM having similar disease progression to human DCM studies into the genetic basis of canine DCM lag far behind those of human DCM. In this review the aetiology, epidemiology, and clinical characteristics of canine DCM are examined, along with highlighting possible different subtypes of canine DCM and their potential relevance to human DCM. Finally the current position of genetic research into canine and human DCM, including the genetic loci, is identified and the reasons many studies may have failed to find a genetic association with canine DCM are reviewed.

Gαq protein carboxyl terminus imitation polypeptide GCIP-27 improves cardiac function in chronic heart failure rats

Background

Gαq protein carboxyl terminus imitation polypeptide (GCIP)-27 has been shown to alleviate pathological cardiomyocyte hypertrophy induced by various factors. Pathological cardiac hypertrophy increases the morbidity and mortality of cardiovascular diseases while it compensates for poor heart function. This study was designed to investigate the effects of GCIP-27 on heart function in rats with heart failure induced by doxorubicin.

Methods and Results

Forty-eight rats were randomly divided into the following six groups receiving vehicle (control), doxorubicin (Dox), losartan (6 mg/kg, i.g.) and three doses of GCIP-27 (10, 30, 90 μg/kg; i.p., bid), respectively. Heart failure was induced by Dox, which was administered at a 20 mg/kg cumulative dose. After 10 weeks of treatment, we observed that GCIP-27 (30, 90 μg/kg) significantly increased ejection fraction, fraction shortening, stroke volume and sarcoplasmic reticulum Ca²⁺ ATPase activity of Dox-treated hearts. Additionally, GCIP-27 decreased myocardial injury, heart weight index and left ventricular weight index, fibrosis and serum cardiac troponin-I concentration in Dox-treated mice. Immunohistochemistry, western blotting and real-time PCR experiments indicated that GCIP-27 (10–90 μg/kg) could markedly upregulate the protein expression of myocardial α-myosin heavy chain (MHC), Bcl-2, protein kinase C (PKC) ε and phosphorylated extracellular signal-regulated kinase (p-ERK) 1/2 as well as the mRNA expression of α-MHC, but downregulated the expression of β-MHC, Bax and PKC βII, and the mRNA expression levels of β-MHC in Dox-treated mice. It was also found that GCIP-27 (30, 90 μg/L) decreased cell size and protein content of cardiomyocytes significantly in vitro by comparison of Dox group.

Conclusions

GCIP-27 could effectively ameliorate heart failure development induced by Dox. PKC–ERK1/2 signaling might represent the underlying mechanism of the beneficial effects of GCIP-27.

Persistent recovery of normal left ventricular function and dimension in idiopathic dilated cardiomyopathy during long‐term follow‐up: does real healing exist?

Background

An important number of patients with idiopathic dilated cardiomyopathy have dramatically improved left ventricular function with optimal treatment; however, little is known about the evolution and long‐term outcome of this subgroup, which shows apparent healing. This study assesses whether real healing actually exists in dilated cardiomyopathy .

Methods and Results

Persistent apparent healing was evaluated among 408 patients with dilated cardiomyopathy receiving tailored medical treatment and followed over the very long‐term. Persistent apparent healing was defined as left ventricular ejection fraction ≥50% and indexed left ventricular end‐diastolic diameter ≤33 mm/m² at both mid‐term (19±4 months) and long‐term (103±9 months) follow‐up. At mid‐term, 63 of 408 patients (15%) were apparently healed; 38 (60%; 9% of the whole population) showed persistent apparent healing at long‐term evaluation. No predictors of persistent apparent healing were found. Patients with persistent apparent healing showed better heart transplant–free survival at very long‐term follow‐up (95% versus 71%; P=0.014) compared with nonpersistently normalized patients. Nevertheless, in the very long term, 37% of this subgroup experienced deterioration of left ventricular systolic function, and 5% died or had heart transplantation.

Conclusions

Persistent long‐term apparent healing was evident in a remarkable proportion of dilated cardiomyopathy patients receiving optimal medical treatment and was associated with stable normalization of main clinical and laboratory features. This condition can be characterized by a decline of left ventricular function over the very long term, highlighting the relevance of serial and individualized follow‐up in all patients with dilated cardiomyopathy, especially considering the absence of predictors for long‐term apparent healing.

Epidemiology, pathophysiology, and prognosis of heart failure in the elderly

Heart failure (HF) represents the quintessential disorder of cardiovascular aging, reflecting the convergence of age-related changes in the cardiovascular system and other organ systems and the increasing prevalence of cardiovascular diseases at older age. The prevalence and incidence of HF increase progressively with advancing age, and HF imposes an enormous burden on society in mortality, morbidity, and associated health care costs. Despite major advances in treatment of HF over the last 25 years, the prognosis remains poor, with median survival rates of less than 5 years in older adults. As the population ages, it is anticipated that the number of older people with HF will increase dramatically over the next several decades.