The cost-effectiveness of percutaneous coronary intervention as a function of angina severity in patients with stable angina.

BACKGROUND

The COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial compared percutaneous coronary intervention (PCI) plus optimal medical therapy (OMT) to OMT alone in reducing the risk of cardiovascular events in 2287 patients with stable coronary disease. We examined the cost-effectiveness of PCI as a function of angina severity at the time of randomization.

METHODS AND RESULTS

Angina severity was assessed with the Seattle Angina Questionnaire (SAQ). Patients were grouped into tertiles based on the distribution of baseline scores such that higher tertiles represented better health status. Clinically significant improvement from baseline within individual patients was defined as score increases of >8 for physical limitation, >20 for angina frequency, and >16 for quality-of-life domains. The incremental cost-effectiveness ratio for PCI was calculated as the difference in costs divided by the difference in proportion of patients with clinically significant improvement. Improvement in angina severity was significantly greater for PCI patients in the lowest and middle tertiles. The number of patients needed to treat was much larger for the highest tertile. The added in-trial cost of PCI ranged from $7300 to $13 000. Incremental cost-effectiveness ratios ranged from $80 000 to $330 000 for the lowest and middle tertiles and from $520 000 to >$3 million for the highest tertile for 1 additional patient to achieve significant clinical improvement in health status.

CONCLUSIONS

The incremental cost of PCI to provide meaningful clinical benefit above that achieved by OMT alone was lower for patients with severe angina than for those with mild or no angina. However, it is uncertain that at any level of angina severity that PCI as an initial strategy would achieve a socially acceptable cost threshold. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00007657.