Title: Inequities in heart-kidney care: Why are people with kidney disease at increased risk of death and disability after a heart attack?
Funder: Department of Health and Social Care

Abstract: Background Coronary artery disease results in significant morbidity and mortality in people with chronic kidney disease (CKD).[1,2] The incidence of heart attack ('acute myocardial infarction' (AMI)) is four times greater in people with advanced CKD than in the general population[3] and mortality is increased by up to 15-fold.[4, 5] People with CKD have frequently been excluded from randomised controlled trials in cardiovascular medicine[6] so evidence for the optimal treatment of AMI in this population is lacking. Evidence from observational studies and subgroup analyses of randomised controlled trials supports the use of standard secondary preventative medications for AMI in people with CKD.[9-9] This is reflected in current guidelines.[10,11] Prescribing practice has not been studied in England, however research from the US and Europe demonstrates widespread underuse of such medications.[4, 12] The risk benefit balance for procedures to improve blood flow to the heart ('revascularisation') following AMI for people with CKD is less clearly understood and guidelines recommend individualised decision-making.[10, 11] In England and elsewhere, people with CKD are much less likely to undergo invasive imaging of their heart ('angiography') as well as to receive revascularisation.[13, 14] Reasons for these differences have not been investigated. Variation in care may be appropriate if it reflects the specific needs of a population, however increasingly evidence suggests that differences in AMI care for people with CKD may be an inappropriate restriction of access to effective treatment ('healthcare inequity').[14, 15] Aim To investigate whether people with CKD experience equitable AMI management in England, and the barriers and facilitators to the provision of optimal care. Objectives 1. To identify the evidence base for equity of AMI care for people with CKD. 2a. To describe AMI care for people with CKD in England . 2b. To compare sensitivity and specificity of CKD algorithms in UK datasets. 2c. To investigate equity of AMI care for people with CKD in England. 3. To identify barriers and facilitators to the provision of optimal AMI care for people with CKD. Methods Phase 1 A systematic review will be conducted to identify the evidence base for equity of AMI care for people with CKD (objective 1). Phase 2 Linked data from the Clinical Practice Research Datalink and Hospital Episode Statistics will be used to describe AMI care for people with and without CKD in England (objective 2a) and determine specificity and sensitivity of CKD algorithms in these datasets (objective 2b). Equity will be assessed by comparing cardiovascular medication prescription against evidence-based guidelines and analysing outcomes of those who do and do not undergo angiography (objective 2c). Phase 3 Semi-structured interviews with patients and clinical staff will enable identification of facilitators and barriers to providing optimal AMI care for patients with CKD in England (objective 3). Timelines for delivery Three years. Anticipated impact and dissemination This research will provide the evidence base for equity of AMI care for people with CKD in the UK, forming the foundations for post-doctorate work in which I intend to develop intervention(s) to optimise AMI care for this population.

Lay abstract: Aims To find out whether we can reduce death and disability after heart attack for people with kidney disease. Background Kidney disease is common. In the UK kidney disease affects one in six people, rising to one in three over the age of 75 years. The most common causes of kidney disease are diabetes and high blood pressure. These conditions cause damage to blood vessels throughout the body, including the tiny ones within the kidney. As a result, these people are at increased risk of diseases caused by poor blood supply, such as blindness, stroke and heart attack and die at a younger age than people without kidney disease. Heart attacks are caused by lack of blood flow to the heart muscle, and can be fatal. In the UK, one person is admitted to hospital with a heart attack every five minutes. As many as one in three will have kidney disease. There have been major advances in heart attack treatment over the past 50 years, and 'gold-standard' (best practice) treatments now include a cocktail of medications as well as procedures to improve the blood supply to the heart. As a result of these advances, six out of seven people will now be alive one year after their heart attack. Amongst people with kidney disease however, only one in two will survive this long. We do not know why people with kidney disease have such poor survival after heart attack. Research from outside England has shown that doctors are less likely to give these people 'gold standard' treatments for heart attack than those without kidney disease. This probably an attempt to avoid treatment side effects which are more common in this population. However, some evidence suggests that despite increased side effects, people with kidney disease who do receive 'gold-standard' treatments do better. Doctors could therefore by accident be underusing treatments that could help people with kidney disease live longer. Use of 'gold-standard' heart attack treatments in people with kidney disease has not yet been studied in England. This research will find out whether underuse of such treatments could contribute to death and disability in this population. I will also find out why these treatments may not be given to people with kidney disease. This will help me design interventions to improve heart attack care and outcomes for people with kidney disease. Methods I will address this important question in three ways: By identifying and assessing all previous research in this area. By reviewing English GP and hospital data to compare heart attack care between people with and without kidney disease and find out whether underuse of 'gold-standard' treatments may contribute to poor survival in people with kidney disease. I will interview doctors and people with kidney disease to investigate their experiences of giving or receiving treatment for heart attack.Patient and public involvement Advice from people with kidney and heart disease from across the UK has ensured that study findings will be important to individuals living with these conditions. Patient volunteers will oversee the research, helping for example with participant recruitment, understanding interview recordings and spreading results to patients and the public. Time and travel costs will be reimbursed. Sharing findings I will keep interested patients and members of the public up-to-date via an emailed newsletter. Results will be shared with participants, patient volunteers and patient groups including the National Kidney Foundation, the UK Renal Registry Patient Council and the British Heart Foundation. I will present my findings to healthcare professionals, researchers and patients at Kidney and Heart conferences and publish in leading scientific journals.

Research activity codes: 7.3 MANAGEMENT AND DECISION MAKING
Health categories: RENAL AND UROGENITAL;CARDIOVASCULAR