Previous research hasn't shown a decrease in the incidence of death or myocardial infarction after revascularization in patients with stable coronary disease. Researchers conducted an international study to determine the effect of adding cardiac catheterization and revascularization to medical therapy in patients with stable coronary disease and moderate or severe ischemia.

A total of 5,179 patients were randomly assigned to either invasive (medical therapy plus cardiac catherization and revascularization) or conservative management (medical therapy alone). Baseline characteristics of the patients were similar in the two groups, as were risk factor control and medication use.

Over a median follow-up of 3.2 years, the primary outcome (a composite of death from cardiovascular causes; myocardial infarction; or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest) occurred in 318 patients in the invasive-strategy group and 352 patients in the conservative-strategy group. At six months, the estimated cumulative event rate was 5.3% in the former and 3.4% in the latter; at five years, it was 16.4% and 18.2%. During follow-up, the researchers noted more procedural infarctions in the invasive-strategy group and fewer nonprocedural infarctions. The incidence of all-cause mortality was similar and low in both groups.

The researchers also examined angina-related symptoms, function, and quality of life in the two groups. At baseline, 20% of all patients had daily or weekly angina, 44% had angina one to three times per month, and 35% had no angina. Health-status scores improved in both groups but were higher in the invasive-strategy group throughout the follow-up period. The modest differences favoring the invasive strategy in the overall study population reflected differences among patients, with the greatest benefits in those who had daily or weekly angina at randomization and the least in those who were asymptomatic.

The authors caution that the findings apply only to patients who met the inclusion criteria of this trial, which excluded people with unacceptable angina despite maximal medical therapy and those with left main coronary artery disease, acute coronary syndromes, or depressed ejection fraction.