Statin Initiation Following Coronary Artery Bypass Grafting: Outcome of a Hospital Discharge Protocol

Abstract

<h3>Study objectives</h3> To evaluate the outcome of a hospital discharge statin drug therapy initiation protocol following coronary artery bypass graft (CABG) surgery. Our goal was to measure the percentage of patients receiving statin drugs at hospital discharge and at a post-hospital discharge assessment following the implementation of the statin drug therapy initiation protocol. We also evaluated low-density lipoprotein cholesterol (LDL-C) goal attainment (<i>ie</i>, < 100 mg/dL), safety monitoring, and tolerability of the statin drug. <h3>Design</h3> Single-center, observational study with a historical control group. <h3>Setting</h3> University-affiliated health system with a comprehensive heart care program that included a 14-bed cardiac surgery ICU. Approximately 400 CABG procedures are performed annually. <h3>Patients</h3> Patients who underwent CABG surgery were eligible for inclusion in the study. The exclusion criteria were as follows: contraindications to statin therapy; refusal to take a statin drug; refusal to give informed consent; and age < 18 years. <h3>Intervention</h3> A protocol was implemented to recommend treatment with a statin drug at hospital discharge in all post-CABG surgery patients if the presurgical LDL-C level was > 100 mg/dL or the patient was receiving a statin prior to hospital admission. The protocol also included a presurgical assessment of lipoprotein levels and hepatic function. All cardiac surgery staff were educated regarding the specifics of the protocol. <h3>Results</h3> A total of 403 patients were included in the study. The historical control group (202 subjects) and the intervention group (201 subjects) were similar with respect to gender, age, and baseline lipoprotein levels. The follow-up assessment interval was approximately 6 months in both groups. Overall, patients were more likely to receive a statin at hospital discharge in the intervention group compared to the control group (relative risk [RR], 1.6; 95% confidence interval [CI], 1.3 to 2.0). Attainment of the goal for LDL-C level was similar between the intervention and control groups in the overall sample. Patients who were not at their LDL-C goal at baseline were more likely to have a follow-up LDL-C level of < 100 mg/dL in the intervention group (RR, 1.9; 95% CI, 1.0 to 3.5). The rate of liver function assessment was similar in the control and intervention groups. No patients in either group experienced elevations of alanine aminotransferase levels that were more than three times the upper limit of normal, and no cases of muscle toxicity were noted. <h3>Conclusion</h3> The initiation of therapy with a statin drug at hospital discharge following CABG surgery was associated with increased utilization rates. The LDL-C goal attainment improved in patients who were not at their goal prior to surgery. However, the persistence of medication use declined within 6 months. Statin therapy initiation was well-tolerated in this cohort of patients.