Improving secondary prevention through focused adherence strategies

Although efforts to improve adherence are often patient-centric, a focus on discharge practices after acute coronary syndrome (ACS) can influence the likelihood that patients are on optimal secondary prevention therapies at six months, which is linked to improved outcomes.1,2 Speaking to the limbic, Professor David Brieger explains that multidisciplinary collaboration, hospital audits, and tailored secondary prevention regimens all play a role in improving secondary prevention post-ACS.

Post-ACS care insights from CONCORDANCE

The Cooperative National Registry of Acute Coronary care, Guideline Adherence and Clinical Events (CONCORDANCE)3 was a clinician-driven initiative designed to collect and report data related to the clinical care of ACS patients from hospitals in different regions of Australia. The prospective, observational registry involved 43 hospitals and allowed for benchmarking against best practice recommendations as well as investigation of factors that could improve patient care and outcomes.3In the CONCORDANCE study, we specifically looked at how hospitals performed at a range of indicators,” explained Prof. Brieger.

One measurement related to whether patients were receiving optimal preventive therapy six months post-ACS (namely, antiplatelet drugs, beta blockers, angiotensin converting enzyme inhibitors or angiotensin II receptor blockers and lipid lowering therapy). Patients were considered ‘adherent’ if they were receiving ≥75% of indicated therapies, which equated to either ≥4 out of 5 secondary prevention therapies (or ≥3 out of 4 if there was any contraindication). “One hospital stood out because it had consistently the best adherence, and they had a cardiology-specific pharmacist who saw every patient and audited therapies at discharge. The hospital also had protocols – a discharge list – that included all the evidence-based medications. These two factors resulted in consistent adherence,” explained Prof. Brieger.

For Prof. Brieger, this data reinforces the value of members of the multidisciplinary team beyond the cardiologist in optimising secondary prevention strategies. “There are so many things pharmacists, nurse practitioners and nurse specialists can do. They tend to prioritise the medications, too. From a cardiologists’ point of view, all the action’s happened from a clinical perspective: we’ve taken them into the cath lab, we’ve done what we’re trained to do, and the rest of it doesn’t always get the same attention,” he said.

The impact of adherence on post-ACS outcomes

A published analysis of the CONCORDANCE data found lower rates of death and major adverse cardiovascular events (MACE) in patients on optimal secondary prevention therapy compared to those who were not. However, the analysis also found that the use of such therapy diminished over time.2

The authors analysed a representative sample of 6,859 patients in the registry who had experienced an ACS and had at least 6 months’ follow-up data. They examined whether patients on ≥75% of recommended secondary prevention medications at 6 months had an association with the rate of MACE, revascularisation and all-cause or cardiovascular mortality.2

At discharge, 92% of patients were on aspirin, 93% on lipid-lowering therapy, 78% on a beta-blocker, 74% on an ACE or angiotensin receptor blocker, and 73% on a second antiplatelet agent.2

The proportion of patients taking ≥75% of medications for secondary prevention dropped from 89% at discharge to 78% at 6 months and 66% at 2 years. For those patients who had been followed up to two years, death or MACE was less frequent in patients taking ≥75% of medications compared to those who were not (8.3% versus 13.9%; adjusted OR 0.75, 95% CI 0.56 – 0.99), and was less frequent in patients who attended cardiac rehabilitation versus those who did not (4.6% versus 13.4%; adjusted OR 0.44, 95% CI 0.31 to 0.62). The authors concluded, “Improving the continued use of cardiovascular prevention in the months and years after a patient’s index event is likely to lead to direct and rapid improvements in clinical outcomes.”2

An ‘important modifiable predictor’ of treatment adherence

Another CONCORDANCE analysis assessed the relative importance of clinical and treatment factors as predictors of adherence to secondary prevention therapies 6 months post-ACS in an effort to identify improvement strategies.3

Patients (n = 6,595) were stratified according to whether they were receiving ≥75% of indicated medications (‘adherent’) or receiving <75% of indicated medications (‘non-adherent) at 6 months. Baseline characteristics, hospital and post-discharge care were compared between the two groups, and multivariable logistic analysis identified independent predictors of adherence.

It was found that 68.1% of patients were classified as adherent to secondary prevention therapy. Patients were more likely to be classified as adherent if they had previous stroke, percutaneous coronary intervention (PCI) or hypertension (ORs 1.36 – 1.56). In contrast, non-ST-segment elevation myocardial infarction (versus unstable angina) and atrial fibrillation were predictive of non-adherence (OR 0.51 and 0.59, respectively). In terms of in-hospital and post-discharge factors linked to adherence, it was found that adherence was less likely with medical management alone (OR 0.34) and coronary artery bypass graft (CABG; OR 0.5), both compared to percutaneous coronary intervention (PCI). Cardiac rehabilitation and attendance at a general practitioner were post-discharge factors linked to greater adherence.

The authors concluded, “Failure to discharge patients on indicated therapies is the most important modifiable predictor of adherence failure 6 months after an ACS. Implementing protocols to automate prescription of indicated discharge therapies has the potential to reduce non-adherence dramatically in the 6 months following discharge.”

‘Subtleties’ in secondary prevention need to be considered

“There are some subtleties around secondary prevention. I think we can overshoot,” explained Prof. Brieger. He noted that protocols need to be flexible: “Beta-blockers should be restricted for patients where there is good evidence of benefit. Similarly for the ACE inhibitors. The statins and the dual antiplatelets, on the other hand, should be central for most patients. I like to think that’s what we do at discharge,” he said.

Prof. Brieger offered some explanation as to why lower adherence to secondary prevention therapies was found in patients who had received medical management alone (versus PCI) in hospital. “We find that patients who don’t get stented tend to go home without the second antiplatelet. Whereas we have a phobia of stent thrombosis, which we know is prevented by dual antiplatelet therapy – and also we stent lower-[bleeding] risk patients,” he explained. For patients undergoing CABG – who also showed lower adherence compared to PCI – he said that part of the issue relates to the fact that the second antiplatelet is discontinued ahead of surgery and not routinely re-established following the procedure. The irony is that the data suggests the second antiplatelet does in fact confer additional benefit when restarted after [the procedure],” said Prof Brieger.

While patient factors continue to play a major role in adherence, the CONCORDANCE data are a reminder of how clinical practices impact on the likelihood that patients are on optimal secondary prevention therapies after ACS. Prof. Brieger believes that improvements in care occur as a result of continual practice review. “We really need to be auditing our practice and performance and that was what we did in CONCORDANCE,” he said.


This article was sponsored by Astra Zeneca. Any views expressed in the article are those of the expert alone and do not necessarily reflect the views of the sponsor. Before prescribing, please review the Brilinta product information via the TGA website. Treatment decisions based on these data are the responsibility of the prescribing physician.


  1. Brieger D et al. Improving patient adherence to secondary prevention medications 6 months after an acute coronary syndrome: observational cohort study. Intern Med J 2018 48;541–549
  2. Chow C et al. Secondary prevention therapies in acute coronary syndrome and relation to outcomes: observational study. Heart Asia 2019; 11. doi 10.1136/heartasia-2018-011122
  3. Aliprandi-Costa B et al. The design and rationale of the Australian Cooperative National Registry of Acute Coronary care, Guideline Adherence and Clinical Events (CONCORDANCE). Heart Lung Circ 2013;22(7):533–541




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