The adherence to guideline-directed therapy post-surgical revascularisation in coronary artery disease and its effect on postoperative outcomes

Author(s): Eric Yu Wei Lo, Billy McWilliams, and Rebecca Dignan

Background: The American Heart Association (AHA) in 2015 released a scientific statement with regards to secondary prevention after Coronary Artery Bypass Graft surgery (CABG) [1] where advice around antiplatelet, antihypertensives, beta-blockers, and anti-lipids post CABG for secondary prevention is prescribed. This paper reviewed adherence at a single center after discharge with AHA guidelines for secondary prevention after CABG [1] and the effect this had on outcomes.

Methods: All CABG patients at Liverpool Hospital, NSW, Australia from 2016-2018 were retrospectively analyzed using the cardiac surgery database. Univariate and multivariate analysis to thirty-day mortality was performed (STATA v16.1). Secondary outcomes of morbidity were reviewed.

Results: Adherence to AHA Guidelines in nine hundred and sixteen patients who underwent CABG was analyzed. Antiplatelet therapy (96.9%), beta-blocker (88.3%), anti-lipid (90.1%), antihypertensive (38.4%), and total adherence (33.62%). Adherence influenced outcomes of thirty-day mortality and post-operative Myocardial Infarction (MI) but not in post-operative stroke or revascularization rates. Multivariate analysis found that antiplatelet (OR 0.06, 95% CI 0.02-0.25, p<0.001) and anti-lipid therapy (OR 0.26, 95% CI 0.08-0.89, p=0.032) were protective factors against thirty-day mortality, with Peripheral Vascular Disease (PVD) (OR 7.98, 95% CI 2.00-31.80, p=0.003) predicting mortality in this cohort.

Conclusion: Adherence rates to AHA guidelines for secondary prevention post-surgical revascularisation were found to be comparable to that reported in the literature at discharge from the hospital. The independent importance of adherence to antiplatelet therapy and anti-lipid therapy was shown in this cohort in addition to the independent negative effects of PVD on thirty-day mortality. This highlights the importance of adherence to guideline-directed therapies.