Cardiac Cachexia in Advanced Heart Failure

Overview

Heart failure is a condition in which the heart stops pumping effectively, causing symptoms such as breathlessness or leg swelling. It affects around 900,000 people in the United Kingdom. As our population gets older, this number will continue rise. It is a condition with poor overall survival - nearly 50% of patients die within 5 years of being diagnosed with heart failure. Cardiac cachexia is a complex condition associated with heart failure. There is general loss of muscle with or without loss of fat in cardiac cachexia. The main feature of cardiac cachexia is therefore unintentional weight loss in heart failure patients. The reason why it develops is poorly understood currently. Importantly, some studies have shown that cardiac cachexia is more likely to lead to poorer outcomes (such as death) in the patients who develop it. However, there have been no studies, to our knowledge, that look at this condition in those patients who have very weak hearts ('advanced heart failure'). The investigators are looking to clarify how common cardiac cachexia is within advanced heart failure patients, and secondly how outcomes compare to those advanced heart failure patients that do not have the condition. With this in mind, the investigators will be able to establish the fuller impact cardiac cachexia has on survival and outcomes in patients with advanced heart failure. This study will involve assessing a group of \~200 advanced heart failure patients for cardiac cachexia to establish an estimate of how common it is overall. The investigators will then follow up the patients over a year, to see if we can assess the impact of cardiac cachexia on survival and outcomes. Overall, the investigators therefore hope this study will give a more robust picture on the true impact of cardiac cachexia in advanced heart failure. By doing so, the investigators will firstly highlight its importance to other clinicians who will better be able to monitor and or diagnose it, and secondly pave way for more research on a potential treatment strategy for this condition.

Cardiac cachexia (CC) is a complex metabolic syndrome associated with chronic heart failure, characterised by loss of muscle with or without loss of fat. The prominent clinical feature of CC is unintentional weight loss in adults. Anorexia, inflammation, insulin resistance and increased muscle protein breakdown are frequently associated with wasting disease. Cachexia is associated with increased morbidity, is infrequently identified or diagnosed and rarely treated. Using an older definition of CC, previous studies have found its presence to confer a poorer overall prognosis (50% mortality at 18 months follow-up in a cohort of general heart failure patients). Depending on the definition used, the prevalence of CC in heart failure has been described in literature as anywhere between 10 - 37%. The pathogenesis of CC is poorly understood, but is likely to be multi factorial, driven by a low cardiac output resulting in an increase in catabolic versus anabolic metabolism. A consensus definition from 2008 now states that CC is present when a patient has non-oedematous weight loss of at least 5% in ⩽12 months or body mass index \<20 kg/m2, plus three out of five other criteria including: (i) Decreased muscle strength (ii) Fatigue (iii) Anorexia (iv) Low fat-free mass index (v) Abnormal biochemistry e.g. Increased inflammatory markers (C-reactive protein, interleukin-6), anaemia, or low serum albumin. The prevalence of CC in advanced heart failure (AHF), however, has not been described. In this cohort of patients, independent prognosticators are vitally important given the overall propensity towards deterioration and morality. AHF refers to those patients at the end of the clinical spectrum of heart failure. There are a number of criteria to identify patients with AHF, one of which being the 'I NEED HELP' criteria. The investigators hypothesise that the prevalence of CC in AHF confers a poorer prognosis when compared to the general heart failure population. By establishing its true prevalence and prognostic impact in AHF, the group aim to highlight the need to diagnose cardiac cachexia in AHF earlier, so patients can undergo the appropriate level of closer monitoring and/or escalation in terms of potential invasive therapies or cardiac transplantation where appropriate. This study will involve participants with AHF being recruited from a single tertiary cardiac centre, via both inpatient and outpatient settings. Participants will be assessed for CC using the aforementioned 2008 CC criteria. After study enrollment, eligible participants will undergo follow up over 12 months'. This will allow the investigators to evaluate the prevalence and 12-month prognosis of cardiac cachexia in an advanced heart failure population in a hospital setting.