Implementation and prospective evaluation of the Country Heart Attack Prevention model of care to improve attendance and completion of cardiac rehabilitation for patients with cardiovascular diseases living in rural Australia: a study protocol.

INTRODUCTION: Despite extensive evidence of its benefits and recommendation by guidelines, cardiac rehabilitation (CR) remains highly underused with only 20%-50% of eligible patients participating. We aim to implement and evaluate the Country Heart Attack Prevention (CHAP) model of care to improve CR attendance and completion for rural and remote participants. METHODS AND ANALYSIS: CHAP will apply the model for large-scale knowledge translation to develop and implement a model of care to CR in rural Australia. Partnering with patients, clinicians and health service managers, we will codevelop new approaches and refine/expand existing ones to address known barriers to CR attendance. CHAP will codesign a web-based CR programme with patients expanding their choices to CR attendance. To increase referral rates, CHAP will promote endorsement of CR among clinicians and develop an electronic system that automatises referrals of in-hospital eligible patients to CR. A business model that includes reimbursement of CR delivered in primary care by Medicare will enable sustainable access to CR. To promote CR quality improvement, professional development interventions and an accreditation programme of CR services and programmes will be developed. To evaluate 12-month CR attendance/completion (primary outcome), clinical and cost-effectiveness (secondary outcomes) between patients exposed (n=1223) and not exposed (n=3669) to CHAP, we will apply a multidesign approach that encompasses a prospective cohort study, a pre-post study and a comprehensive economic evaluation. ETHICS AND DISSEMINATION: This study was approved by the Southern Adelaide Clinical Human Research Ethics Committee (HREC/20/SAC/78) and by the Department for Health and Wellbeing Human Research Ethics Committee (2021/HRE00270), which approved a waiver of informed consent. Findings and dissemination to patients and clinicians will be through a public website, online educational sessions and scientific publications. Deidentified data will be available from the corresponding author on reasonable request. TRIAL REGISTRATION NUMBER: ACTRN12621000222842.

Statin therapy alone and in combination with an acyl-CoA:cholesterol O-acyltransferase inhibitor on experimental atherosclerosis.

The ability to modify the enzymatic processes involved in promoting atherosclerotic plaque disruption and to serially monitor atherosclerotic evolution could provide novel information in the management of patients with atherosclerosis. We studied the effects of a statin (atorvastatin) and its combination with an acyl-CoA:cholesterol O-acyltransferase (ACAT) inhibitor (avasimibe) on atherosclerotic regression and plaque stability as measured by matrix metalloproteinase 1 and 3 (MMP-1 and MMP-3) levels. Watanabe Heritable Hyperlipidemic (WHHL) rabbits treated with atorvastatin alone experienced an attenuated increase in atherosclerotic burden versus controls as determined by MR imaging. The mean vessel wall area (VWA) prior to drug therapy was 5.57 +/- 0.01 mm2. The VWA increased to 6.71 +/- 0.03 and 7.16 +/- 0.03 mm2, respectively, in atorvastatin-treated and control groups (p < 0.0001 for both). The combination of atorvastatin and avasimibe induced a significant regression of the previously established atherosclerotic lesions, with the VWA decreasing to 4.54 +/- 0.04 mm2 (p = 0.009). Atorvastatin alone induced a nonsignificant reduction in the percent staining of MMP-1 in atherosclerotic lesions, but the combination treatment with avasimibe led to a significant reduction versus controls (p = 0.005). However, a reduction in MMP-3 staining was significant for rabbits treated with both atorvastatin alone (p = 0.007) and in combination with avasimibe (p = 0.04) versus controls. In this animal model, the addition of avasimibe to atorvastatin has beneficial effects on both atherosclerotic plaque regression and stabilization.

Bivalirudin: an anticoagulant for acute coronary syndromes and coronary interventions.

Heparin is a commonly used anticoagulant in patients with coronary artery disease but its use does not always result in low rates of ischaemic and bleeding events, so the search for new anticoagulants continues. Thrombin plays a key role in both thrombosis and haemostasis and direct thrombin inhibitors modelled on the hirudin molecule found in the saliva of the medicinal leech, Hirudo medicinalis, have recently been developed. To date, the only direct thrombin inhibitor shown to reduce both the ischaemic and the bleeding complications associated with percutaneous coronary intervention (PCI) is bivalirudin, which is approved for this indication in the US and New Zealand. This agent is currently being studied in patients undergoing PCI with or without glycoprotein IIb/IIIa inhibitors and stenting. Bivalirudin has been shown to significantly reduce the risk of reinfarction in patients with acute myocardial infarction (MI) treated with streptokinase, but its use for this indication is not approved in the US. It may also prove to be beneficial in patients with acute MI treated with other fibrinolytic regimens or with primary or facilitated PCI. Bivalirudin is suitable for use as an alternative to heparin in the majority of patients undergoing PCI and in patients receiving streptokinase for acute MI.