Adherence to guideline-directed medical therapy and its association with re-hospitalization and mortality following coronary artery bypass graft surgery

Abstract

Abstract Objectives We investigated associations with re-hospitalization, and intermediate- and long-term mortality, of cardio-thoracic surgeons' adherence to pharmacological guideline-directed medical therapy (GDMT) in discharge recommendations of coronary artery bypass graft (CABG) surgery patients. Methods In this longitudinal multicenter study, 1,131 patients who underwent elective CABG surgery in seven medical centers during 2004–2007 were interviewed in the hospital before surgery. Adherence of cardio-thoracic surgeons to GDMT was considered as prescribing medications from three families: antiplatelet therapy, beta-blockers and statins; and was determined from discharge letters. Patients were interviewed one-year after hospitalization to obtain information on re-hospitalizations and current medications. Mortality information was extracted from the Ministry of Internal Affairs registry and updated until March 2018. Results GDMT adherence was evident in the discharge recommendations of 638 patients (56.4%). A propensity score (PS)-weighted multivariate logistic regression showed a 26% lower 1-year risk of re-hospitalization/mortality among patients whose discharge recommendations reflected full adherence than among patients whose recommendations reflected partial adherence (OR=0.74, 95% CI: 0.57–0.97, p=0.03). A PS-weighted Cox proportional hazard model showed 24% lower intermediate (8 year)-term mortality hazard among patients with cardio-thoracic surgeons' adherence to GDMT, compared to other patients (HR=0.76, 95% CI: 0.59–0.98, p=0.03); however the protective effect was attenuated when examining long (14 year)-term mortality. Short- and intermediate-term protective effects were also found when considering only adherence to beta-blockers or statins. Use of GDMT increased 1-year after CABG surgery only in patients who attended cardiac rehabilitation programs after surgery and not in those who did not attend cardiac rehabilitation during that year. Conclusions The reference in CABG patients' discharge recommendations to GDMT was associated with a lower 1-y re-admissions/mortality and lower intermediate-term mortality. Cardio-thoracic surgeons should adhere closely to preventive medication guidelines. Cardiac rehabilitation is associated with better post CABG surgery patients preventive treatment. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Israel National Institute for Health Policy