Early invasive strategy for acute cardiac ischemia is cost effective

,; Stevermer, James

Q&A

Early invasive strategy for acute cardiac ischemia is cost effective

J Fam Pract. 2003 January;52(1):12-31

By

Anthony Kory Jackson, MD

James J. Stevermer, MD, MSPH

BACKGROUND: Is an early invasive strategy (routine catheterization or revascularization) cost effective in the treatment of unstable angina and non–ST segment elevation MI? Earlier studies showed that a conservative strategy was safer after less severe myocardial infarcts. However, therapeutic advances with glycoprotein IIb/IIIa inhibitors and coronary artery stenting have changed this finding. The TACTIC trial demonstrated that an early invasive strategy for unstable angina and non–ST segment elevation myocardial infarction is superior to a more conservative approach in reducing major cardiac events at 6 months. This study examined initial hospitalization and total 6-month costs and estimated the long-term cost effectiveness of these 2 strategies.
POPULATION STUDIED: This study enrolled 2220 men and women with unstable angina or non–ST segment elevation myocardial infarction. Subjects were enrolled if they presented within 24 hours of symptom onset and were candidates for coronary angiography and revascularization. The researchers excluded patients with persistent ST segment elevation, secondary angina, percutaneous coronary revascularization, or coronary bypass surgery within 6 months, increased risk of bleeding, left bundle branch block, severe congestive heart failure, serious systemic disease, or an elevated serum creatinine. Primary cost analysis included only patients recruited at US non–Veterans Affairs hospitals (n=1722).
STUDY DESIGN AND VALIDITY: The study was a single-blinded, randomized, controlled trial that used concealed allocation to randomize patients to an early invasive or conservative treatment strategy. All patients were treated with 325 mg of aspirin daily, intravenous heparin, and tirofiban (a glycoprotein IIb/IIIa inhibitor). Subjects randomized to the early invasive strategy underwent a coronary angiogram within 4 to 48 hours and subsequent revascularization as indicated. In the conservative treatment group, subjects received catheterization only if their routine stress test was positive or if they developed recurrent ischemia.
OUTCOMES MEASURED: The primary economic endpoint was total 6-month costs for all patients recruited at US non–Veterans Affairs hospitals. Other outcomes measured were initial hospitalization costs, costs per death prevented, and costs per year of life gained. Direct costs associated with hospitalizations, emergency department visits, outpatient visits and procedures, nursing home and rehabilitation stays, cardiac medications, and costs from lost productivity were considered within a 6-month follow-up. Inpatient, emergency department, and outpatient charges were obtained from Medicare billing data. Drug costs were obtained from Red Book average wholesale prices. Complete cost data were available for 86% of patients, with missing data equally distributed between groups.
RESULTS: Although the initial hospitalization costs were significantly higher for the invasive strategy group, these costs were nearly offset at the 6-month follow-up. The average total costs at 6 months were almost equivalent for the invasive and conservative strategies ($21,813 vs $21,277, respectively). The absolute difference in costs was $586 (95% confidence interval, –1087 to 2486). No significant difference was found for any subgroup except for patients with diabetes, for whom costs were significantly higher in the invasive group. The estimated cost per death or myocardial infarction prevented for the invasive strategy was $17,758, whereas the cost per year of life gained ranged from $8371 to $25,769, depending on model assumptions.

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Early invasive strategy for acute cardiac ischemia is cost effective

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