Clinical epidemiology of heart failure

Atrial fibrillation and the risk of death in patients with heart failure: a literature-based meta-analysis

BACKGROUND

Heart failure (HF) and atrial fibrillation (AF) are common, associated with significant morbidity and mortality, and frequently coexist. It is uncertain from published data if the presence of AF in patients with HF is associated with an incremental adverse outcome. The aim of this study was to combine the results of all studies investigating prognosis for patients with HF and AF compared with those in sinus rhythm (SR) to asses the mortality risk associated with this arrhythmia.

METHODS

Electronic databases were searched (Biological Abstracts, Current Contents, EMBASE, Medline, Medline In-progress, PubMed and Scopus), to 31 December 2006, using the key words congestive heart failure, heart failure, ventricular dysfunction, atrial fibrillation, atrial flutter, sinus rhythm, prognosis, outcome, death and hospitalization. Bibliographies of retrieved publications were hand searched. Studies were eligible if they included a HF population and if outcomes were reported by cardiac rhythm (AF or SR). Studies were reviewed by predetermined protocol (including quality assessment). Data were pooled using a random effects model.

RESULTS

Twenty studies were included (from 3380 initially identified) representing 32946 patients (10819 deaths). Nine randomized controlled trials (RCT) were included. The prevalence of AF was 15%, crude mortality rates were 46% (AF) and 33% (SR). The odds ratio for death was 1.33 (95% confidence interval (CI) 1.12-1.59) for AF compared with SR. Eleven observational studies were included. The prevalence of AF was 23%, crude mortality rates were 38% (AF) and 25% (SR). The odds ratio for death was 1.57 (95% CI 1.20-2.05) for AF compared with SR.

CONCLUSION

This meta-analysis demonstrates that AF is associated with worse outcomes for patients with HF compared with those with SR. Further research is required to determine whether the adverse outcome associated with AF is related to the arrhythmia itself, or to variables, such as HF severity, patient age and comorbidity.

Urinary incontinence and overactive bladder in patients with heart failure

PURPOSE

We explored the nature of the relationship between heart failure and urinary symptoms, specifically urinary incontinence and overactive bladder.

MATERIALS AND METHODS

An 81-item written survey about urinary incontinence, urgency, frequency, nocturia and other symptoms was administered to hospitalized and clinic patients with heart failure. A medical records review was also conducted to determine types of medications, body mass index and documentation of the New York Heart Association Classification of heart failure.

RESULTS

Of 408 respondents 296 (average age 62.2 years) had information about heart failure stage and urinary symptoms. Of these respondents 45% and 57% reported urinary incontinence and overactive bladder, respectively. Adjusted odds ratio for having overactive bladder over no symptoms for respondents with New York Heart Association Class III or Class IV heart failure was 2.9 (95% CI 1.344-6.250) and for higher fatigue-depression composite was 2.155 (95% CI 1.206-3.860). Adjusted odds ratio for having overactive bladder over frequency/nocturia for respondents with higher body mass index was 1.458 (95% CI 1.087-1.953) and for higher fatigue-depression composite was 1.629 (95% CI 1.038-2.550).

CONCLUSIONS

Urinary incontinence and overactive bladder are prevalent in patients with heart failure. Evidence of late stage heart failure, higher fatigue-depression composite and higher body mass index were associated with overactive bladder. Sex, age and diuretic use were not associated with urinary incontinence and overactive bladder.

Risk stratification of mortality in patients with heart failure and left ventricular ejection fraction >35%

The population of patients with heart failure (HF) and mild to moderate left ventricular (LV) dysfunction is growing, and mortality remains high. There is a need for better risk stratification of patients who might benefit from primary prevention of mortality. This study aimed to evaluate the prognostic value of Holter-based parameters for predicting mortality in patients with HF with LV ejection fraction (EF) >35%. The study involved 294 patients (199 men, mean age 66 years) with HF of ischemic and nonischemic causes, New York Heart Association classes II to III, and LVEF >35%. Surface electrocardiogram and 24-hour Holter monitoring were performed at enrollment to assess traditional electrocardiographic variables, as well as heart rate variability, heart rate turbulence, and repolarization dynamics (QT/RR). Total mortality and sudden death were the primary and secondary end points. During a median 44-month follow-up, there were 43 deaths (15%). None of the traditional electrocardiographic risk parameters significantly predicted mortality. A standard deviation of all normal-to-normal RR intervals < or =86 ms, turbulence slope < or =2.5 ms/RR, and QT end/RR >0.21 at daytime were found to be independent risk predictors of mortality in multivariate analyses. The predictive score based on these 3 variables showed that patients with > or =2 abnormal risk markers were at risk of death (30% 3-year mortality rate) and sudden death (12%), similar to death rates observed in patients with LVEF < or =35%. In conclusion, increased risk of mortality and sudden death could be predicted in patients with HF with LVEF >35% by evaluating the combination of standard deviation of all normal-to-normal RR intervals, turbulence slope, and QT/RR, parameters reflecting autonomic control of the heart, baroreflex sensitivity, and repolarization dynamics.

Heart failure

Despite advances in management of heart failure, the condition remains a major public-health issue, with high prevalence, poor clinical outcomes, and large health-care costs. Risk factors are well known and, thus, preventive strategies should have a positive effect on disease burden. Treatment of established systolic chronic heart failure includes use of agents that block the renin-angiotensin-aldosterone and sympathetic nervous systems to prevent adverse remodelling, to reduce symptoms and prolong survival. Diuretics are used to achieve and maintain euvolaemia. Devices have a key role in management of advanced heart failure and include cardiac resynchronisation in patients with evidence of cardiac dyssynchrony and implantation of a cardioverter defibrillator in individuals with low ejection fraction. Approaches for treatment of acute heart failure and heart failure with preserved ejection fraction are supported by little clinical evidence. Emerging strategies for heart failure management include individualisation of treatment, novel approaches to diagnosis and tracking of therapeutic response, pharmacological agents aimed at new targets, and cell-based and gene-based methods for cardiac regeneration.

Chronic left ventricular failure: the role of imaging in diagnosis and planning of conventional and novel therapies

Heart failure is the leading cause of hospitalisation in the UK, and its prevalence is expected to increase further in the future due partly to an aging population. Although pharmacological agents remain the mainstay of therapy, an increasing number of surgical and novel minimally invasive interventions have been developed for the treatment of both acute and chronic heart failure. Imaging is essential for diagnosis, guiding therapeutic options, and monitoring therapy and its complications. As a result, radiologists should be familiar with the pathogenesis, treatment options, and imaging-related issues pertaining to the management of these patients.

Autologous bone marrow-derived stem cells for ischemic heart failure: REGENERATE-IHD trial

The field of autologous stem/progenitor cell transplantation for cardiovascular diseases has moved rapidly from basic science research to clinical trials. To date, only a handful of pilot studies have reported the use of this novel strategy for heart failure patients. Most of these studies have demonstrated encouraging safety and efficacy data. However, this will need to be validated in large, randomized trials. Here, we introduce the ongoing REGENERATE-IHD trial, which is the largest randomized, placebo-controlled trial in the UK investigating the use of granulocyte-colony stimulating factor and autologous bone marrow-derived stem/progenitor cells to improve cardiac function and symptoms in heart failure patients.

Tele-guidance of chronic heart failure patients enhances knowledge about the disease. A multi-centre, randomised controlled study

BACKGROUND

New strategies are required to optimize care in increasing numbers of chronic heart failure patients. The aim of this randomised trial was to evaluate a remote guidance system.

METHODS

Intervention group patients received a home TV-channel providing educational materials. Tele-guidance was performed by a Medical Service Centre. Control group patients were followed by cardiologists and HF-nurses. Primary endpoints were total days in hospital for all causes and days alive and out of hospital. Secondary endpoints were: quality of life and knowledge of disease and self care.

RESULTS

214 patients were enrolled, median age was 66 years, 89% had systolic LV dysfunction, and 90% were in NYHA class II or III. The mean LVEF was 31%. Over a mean follow-up duration of 288 days, there were 199 hospital admissions in 105 patients. Comparison of the groups revealed no differences for the primary outcomes or for QoL or self care behaviour. Knowledge about heart failure however, increased significantly more in the Intervention group (p<0.001).

CONCLUSION

Tele-guidance may play a role in the management of heart failure patients since it takes over some of the tasks of HF-nurses. This may facilitate delivery of optimal care to more patients with the same level of experienced staff.

Comparing Type D personality and older age as correlates of tumor necrosis factor-alpha dysregulation in chronic heart failure

Tumor necrosis factor-alpha (TNF-alpha) and its soluble receptors 1 (sTNFR1) and 2 (sTNFR2) have been shown to be implicated in the pathogenesis of chronic heart failure (CHF). Ageing is accompanied by increased plasma levels of pro-inflammatory cytokines. We hypothesized that Type D personality (joint tendency to experience negative emotions and to inhibit self-expression) and age may have similar pro-inflammatory effects in the context of CHF. Participants in this study were 130 consecutive outpatients with CHF (76% men); there were 70 relatively younger (<or=59 years) and 60 relatively older (>or=60 years) patients. They all completed the 14-item Type D Scale (DS14); 43 patients (33%) had a Type D personality. A multivariate model of cytokine levels indicated an independent overall effect of both older age [F(1,128)=9.11, p=.003] and Type D personality [F(1,128)=8.28, p=.005]. Stratifying patients in age/personality subgroups showed that younger non-Type D patients had the lowest and older Type D patients the highest sTNFR1 and sTNFR2 levels (986+/-318 vs 1661+/-1128 pg/ml and 1838+/-777 vs 2823+/-1439 pg/ml, p<.0001). Importantly, the mean sTNFR1 level in younger Type D patients (1359+/-660 pg/ml) was equivalent to that in older non-Type D patients (1360+/-440 pg/ml, p=.99) who were on average 18 years older. Younger Type D and older non-Type D patients also had similar sTNFR2 levels (2406+/-1329 vs 2448+/-812 pg/ml, p=.88). Only older Type D patients had a higher mean TNF-alpha level as compared to patients who were younger or who were not Type D (5.4+/-2.9 vs 3.9+/-2.4 pg/ml, p=.008). A logistic regression model including sex, severity of CHF, systolic heart failure and ischemic etiology indicated that the combined risk category of older age or Type D was independently associated with substantially increased sTNFR1 and sTNFR2 levels. Hence, Type D personality was associated with increased TNF-alpha activity. This disease-promoting effect of Type D matched the pro-inflammatory effect of ageing.

MicroRNA and cardiac pathologies

MicroRNA has been shown to be essential for correct cardiovascular development and physiology in a number of recent reports. Studies have also started to characterize the link between specific microRNAs and aspects of pathogenesis--such as chamber morphogenesis, conduction, and contraction--and between microRNA expression signatures and pathological cardiac phenotypes--such as hypertrophy, ischemic cardiomyopathy, dilated cardiomyopathy, and aortic stenosis. Congenital anomalies of the heart may also be associated with the dysregulation of specific microRNAs. Here we report on the latest findings.

Integration target site selection for retroviruses and transposable elements

When a retrovirus infects a cell, its RNA genome is reverse transcribed into a double-stranded DNA, which is then permanently integrated into the host chromosome. Integration is one of the essential steps in the retroviral life cycle. Many transposable elements also move around and integrate into the host genome as part of their life cycle, some through RNA intermediates and some through 'cut and paste' mechanisms. Integration of retroviruses and transposable elements into 'sensitive areas' of the genome can cause irreparable damage. On the other hand, because of their ability to integrate permanently, and the relatively efficient rates of transgenesis, retroviruses and transposable elements are widely used as gene delivery tools in basic research and gene therapy trials. Recent events in gene therapy treatments for X-linked severe combined immunity deficiencies (X-SCID) have highlighted both the promise and some of the risks involved with utilizing retroviruses. Nine of 11 children were successfully treated for X-SCID using a retrovirus carrying the gene mutated in this disease. However, later two of these children developed leukemias because of retroviral integrations in the putative oncogene LMO2 [1]. A third child has also been demonstrated to have an integration in LMO2, but is as of yet nonsymptomatic [2]. It is a bit difficult to explain the high frequency of integrations into the same gene using a random model of retroviral integration, and there has been evidence for decades that retroviral integrations may not be random. But the data were somewhat limited in their power to determine the precise nature of the integration biases. The completion of the human genome sequence coupled with sensitive polymerase chain reaction techniques and an ever-decreasing cost of sequencing has given a powerful new tool to the study of integration site selection. In this review, we describe the findings from several recent global surveys of target site selection by retroviruses and transposable elements, and discuss the possible ramifications of these findings to both mechanisms of action and to the use of these elements as gene therapy vectors.