Effect of persistent opium consumption after surgery on the long-term outcomes of surgical revascularisation.

Background: A wrong traditional belief persists among people that opium consumption beneficially affects cardiovascular disease and its risk factors. However, no evidence exists regarding the effect of opium consumption or cessation on the long-term risk of major adverse cardio-cerebrovascular events after coronary artery bypass grafting. We therefore aimed to evaluate the effect of persistent opium consumption after surgery on the long-term outcomes of coronary artery bypass grafting.
Methods: The study population consisted of 28,691 patients (20,924 men, mean age 60.9 years), who underwent coronary artery bypass grafting between 2007 and 2016 at our centre. The patients were stratified into three groups according to the status of opium consumption: never opium consumers ( n  = 23,619), persistent postoperative opium consumers ( n  = 3636) and enduring postoperative opium withdrawal ( n  = 1436). Study endpoints were 5-year mortality and 5-year major adverse cardio-cerebrovascular events, comprising all-cause mortality, acute coronary syndrome, cerebrovascular accident and revascularisation.
Results: After surgery, 3636 patients continued opium consumption, while 1436 patients persistently avoided opium use. The multivariable survival analysis demonstrated that persistent post-coronary artery bypass grafting opium consumption increased 5-year mortality and 5-year major adverse cardio-cerebrovascular events by 28% (hazard ratio (HR) 1.28, 95% confidence interval (CI) 1.06-1.54; P  = 0.009) and 25% (HR 1.25, 95% CI 1.13-1.40; P  < 0.0001), respectively. It also increased the 5-year risk of acute coronary syndrome by 34% (sub-distribution HR 1.34, 95% CI 1.16-1.55; P  < 0.0001).
Conclusions: The present data suggest that persistent post-coronary artery bypass grafting opium consumption may significantly increase mortality, major adverse cardio-cerebrovascular events and acute coronary syndrome in the long term. Future studies are needed to confirm our findings.