Integrating cost-effectiveness evidence into clinical practice guidelines in Australia for acute myocardial infarction.

A teaching hospital is working with the Victorian State Government and universities, integrating cost-effectiveness evidence into clinical practice guidelines (CPGs), protocols and pathways for respiratory and cardiology interventions. Acute myocardial infarction (AMI) findings are reported. Results will stimulate cost-effective practice and inform medical associations, federal and state governments and international organisations developing CPGs. Published CPGs by the American College of Cardiology/American Heart Foundation for AMI in 1999 are reviewed by a large interdisciplinary hospital-based committee given cost-effectiveness evidence. Levels of evidence criteria rating on methodological rigor for effectiveness and costs are applied. National Health and Medical Research Council (NHMRC) grades of recommendation criteria for combinations of relative effectiveness versus relative costs and cut-off points are used. Extrapolating results between countries was addressed by applying the OECD's health purchasing power parity series. Recommendations for revisions to United States guidelines and for local application are formulated. United States Guidelines require updating: Regarding angioplasty, percutaneous transluminal coronary angioplasty (PTCA) is cost-effective for men aged 60 years relative to recombinant tissue plasminogen activator (tPA), with additional cost per life year saved of 274 ecu. PTCA with discharge after 3 days is cost-effective in low-risk AMI. Regarding GP IIb/IIIa drugs, Abciximab during intervention incurred equal mean hospital costs for placebo, abciximab bolus, and abciximab bolus+infusion with incremental 6-month cost for the latter treatment costing 293 US dollars per patient. Agent recouped almost all initial therapy costs with significant benefits. Incremental cost of abciximab per event prevented is 3,258 US dollars. Tirofiban was compared to placebo after high-risk angioplasty for AMI or unstable angina. Tirofiban decreased the rate of hospital deaths, myocardial infarction, revascularisation at 2 days by 36% relative to placebo (8% vs. 12%) without increased cost. Clinical benefits were similar at 30 days. Tirofiban+heparin+aspirin was compared to heparin+aspirin. Tirofiban arm resulted in net savings of 33,418 ecu per 100 patients for the first 7 days of treatment. Regarding thrombolytics, tPA is more cost-effective than streptokinase. Incremental costs for each life saved when streptokinase is substituted by recombinant tissue plasminogen are 31%, 45%, 97% higher in Germany, Italy and the United States than in the United Kingdom. Regarding anticoagulants, enoxaparin is a promising alternative to unfractionated heparin for hospitalised patients with non-Q-wave myocardial infarction or unstable angina, saving 1,485 Canadian dollars per patient over 12 months with 10% reduction in 1 year risk of death, myocardial infarction or recurrent angina. Regarding antiarrhymics, the cost-effectiveness of no amiodarone, amiodarone for patients with depressed heart rate variability (DHRV), and amiodarone for patients with DHRV plus positive programmed ventricular stimulation (PPVS) for high-risk post-AMI was investigated. Amiodarone for DHRV+PPVS patients was dominated by a blend of the two alternatives. Compared to no amiodarone, the incremental cost-effectiveness of amiodarone for DHRV patients was 39,422 US dollars per quality adjusted life year gained. Amiodarone for DHRV is the most appropriate. Other CPG updates concern serum markers, for example, cardiac troponin I assay (c-Tnl), cost advantages of ad hoc angioplasty and secondary prevention through antioxidants and pravastatin. Australian costs are reported later in the paper.