Effect of PCI on Long-Term Survival in Patients with Stable Ischemic Heart Disease

Abstract

Background: Percutaneous coronary intervention (PCI) relieves angina in patients with stable ischemic heart disease, but clinical trials have not shown that it improves survival. Between June 1999 and January 2004, we randomly assigned 2287 patients with stable ischemic heart disease to an initial management strategy of optimal medical therapy alone (medical-therapy group) or optimal medical therapy plus PCI (PCI group) and did not find a significant difference in the rate of survival during a median follow-up of 4.6 years. We now report the rate of survival among the patients who were followed for up to 15 years.

Methods: We obtained permission from the patients at the Department of Veterans Affairs (VA) sites and some non-VA sites in the United States to use their Social Security numbers to track their survival after the original trial period ended. We searched the VA national Corporate Data Warehouse and the National Death Index for survival information and the dates of death from any cause. We calculated survival according to the Kaplan-Meier method and used a Cox proportional-hazards model to adjust for significant between-group differences in baseline characteristics.

Results: Extended survival information was available for 1211 patients (53% of the original population). The median duration of follow-up for all patients was 6.2 years (range, 0 to 15); the median duration of follow-up for patients at the sites that permitted survival tracking was 11.9 years (range, 0 to 15). A total of 561 deaths (180 during the follow-up period in the original trial and 381 during the extended follow-up period) occurred: 284 deaths (25%) in the PCI group and 277 (24%) in the medical-therapy group (adjusted hazard ratio, 1.03; 95% confidence interval, 0.83 to 1.21; P=0.76).

Conclusions: During an extended-follow-up of up to 15 years, we did not find a difference in survival between an initial strategy of PCI plus medical therapy and medical therapy alone in patients with stable ischemic heart disease. (Funded by the VA Cooperative Studies Program and others; COURAGE ClinicalTrials.gov number, NCT00007657.).

Figure 1. Patient Selection Process for the Extended Follow-up Analysis

Patients at U.S. sites were asked, as part of the initial informed-consent process, to provide their Social Security number for survival tracking. The use of identifiers for long-term survival tracking was not permitted by the institutional review boards in Canada and at some non-VA enrolling sites in the United States. Patients who consented to the use of their Social Security numbers for survival tracking were included in the extended follow-up cohort. PCI denotes percutaneous coronary intervention.

Figure 2. Kaplan–Meier Estimates of Survival in the Two Treatment Groups

Panel A shows the number of patients at risk in the whole study cohort. It also shows the expected survival (without censoring of data) of 2287 persons who were matched by age and sex to the COURAGE population according to data from the U.S. vital statistics report for 2009. Panel B shows the number of patients at risk in the cohort of patients with extended follow-up. The curves in both panels have been truncated at 12 years, which is the approximate median duration of follow-up in the extended follow-up cohort.

Figure 3. Forest Plot of the Treatment Effect with Respect to Death from Any Cause in Various Subgroups

The treatment effect compared PCI plus optimal medical therapy with optimal medical therapy alone. The median duration of follow-up for all patients (including those with and those without extended follow-up) was 6.2 years. CAD denotes coronary artery disease, and LVEF left ventricular ejection fraction.