Optimising pharmacotherapy for secondary prevention of non-invasively managed acute coronary syndrome

About half of all patients who experience an acute coronary syndrome (ACS) in Australia have their conditions managed non-invasively - that is, they do not undergo coronary angiography and revascularisation in hospital. ACS patients whose conditions are managed non-invasively may not receive the same level of evidence-based care as those who receive coronary revascularisation. This article reviews the optimal pharmacological management of ACS managed non-invasively. There is strong evidence to support the prescription of dual antiplatelet therapy (DAPT; aspirin with a P2Y12 inhibitor). DAPT should continue for 12 months after an ACS, then aspirin should be continued indefinitely. Anticoagulation with warfarin or a novel oral anticoagulant may be needed if atrial fibrillation occurs; the combination with DAPT increases the risk of bleeding. Unless contraindicated, high-intensity statin therapy should be prescribed for all post-ACS patients irrespective of their cholesterol level. Non-statin lipid therapy has not been shown to improve outcomes. Use of β-adrenergic blockers is recommended in most guidelines, but the clinical trials to support this recommendation were performed more than 30 years ago, and routine long-term use may not be relevant to modern treatment, except when there is cardiac failure or left ventricular dysfunction. Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers are also widely recommended, but the evidence for benefit is stronger when there is left ventricular dysfunction. Calcium-channel blockers, nitrates, antiarrhythmic drugs, digoxin and diuretics do not improve outcomes in post-ACS patients.