Background: Strategies to limit adverse cardiac events after vascular surgery continue to evolve. Early recognition and treatment of myocardial ischemia may be a key to improving postoperative survival rates. Cardiac troponin I (cTnI) screening is an effective means of surveillance for postoperative myocardial ischemic injury and has long-term prognostic value.
Methods: We designed a Markov-based decision analysis model to determine the cost-effectiveness of routine surveillance with cTnI on postoperative Days 0, 1, 2, and 3, with an aim to institute tight heart rate control (60-65 bpm) with close monitoring and coronary care in the intensive care unit for 5 days in patients with cTnI >1.5 ng/mL. The key input variables obtained from published literature were as follows: probability of myocardial infarction, 0.049; cost of cTnI surveillance, $357; cost and efficacy of interventions, $13,145 and 0.55, respectively. The time horizon was lifetime and the target population being individuals aged 65 yr (median) undergoing elective open abdominal aortic surgery. The perspective for analysis was third-party payer.
Results: The incremental cost-effectiveness ratio for cTnI surveillance was $12,641 per quality-adjusted life year compared with standard care without cTnI surveillance. During one-way sensitivity analysis, probability of myocardial infarction and efficacy of interventions were found to influence the cost-effectiveness. Multivariate sensitivity analysis with second-order Monte Carlo simulation revealed that cTnI surveillance was favored in 90.75% of simulations at a commonly used threshold of $50,000 per quality-adjusted life year.
Conclusions: In patients presenting for elective open abdominal aortic surgery, intensive surveillance with cTnI and early institution of aggressive beta-blockade is cost-effective.