Assessing the Cost Effectiveness of an Incremental Lipid-Lowering Therapy Approach After Coronary Artery Bypass Grafting Using Nationwide Data.

BACKGROUND

Lipid-lowering therapy (LLT) is important for risk reduction for patients after coronary artery bypass grafting. Cost limits the wider use of PCSK9 (proprotein convertase subtilsin/kexin type 9) inhibitors (PCSK9is) and newer drugs. Hence, mathematical modeling was performed on a nationwide cohort of US veterans post coronary artery bypass grafting to understand the need for expensive drugs like PCSK9is and the cost effectiveness of this model was evaluated.

METHODS

First, Monte Carlo simulations were used to model the stepwise initiation of high-intensity statins, ezetimibe, and PCSK9i therapy for each patient to lower their low-density lipoprotein cholesterol levels to recommended targets. Next, a lifetime Markov model was constructed with stroke, myocardial infarction, repeat revascularization, and mortality rates obtained our study cohort of nationwide US veterans post coronary artery bypass grafting. LLT treatment costs and quality adjusted life years were used to determine the cost effectiveness of this stepwise LLT approach versus observed clinical practice from the health care perspective. Probabilistic models were fit and results for cost effectiveness reported using incremental cost-effectiveness ratio per quality adjusted life year gained over the lifetime.

RESULTS

For 27 443 US veterans post- coronary artery bypass grafting (mean age 66 years, 10% Black) with a median low-density lipoprotein cholesterol 129 (interquartile range, 95.2-180) mg/dL, the 42% and 37% reached target LLT by statin intensification only and including ezetimibe, respectively. Only 6% required bempedoic acid or PCSK9is after the preceding steps. Such stepwise LLT reduction projected 0.8 life years gained over the 30-year period. With a median incremental cost-effectiveness ratio of percent 15 232 (interquartile range, 13 520-17 769) per quality adjusted life year gained, this stepwise approach reached 100% probability for being cost effective (compared with observed clinical practice) at willingness-to-pay thresholds >$20 000.

CONCLUSIONS

Few patients needed bempedoic acid or PCSK9is when simulating stepwise LLT with high-intensity statins and ezetimibe. Such an approach was observed as cost effective at very low willingness-to-pay thresholds.