Clinical and angiographic outcomes associated with surgical revascularization of angiographically borderline 50–69% coronary artery stenoses

CASS includes a multicenter patient registry and a randomized controlled clinical trial. It is designed to assess the effect of coronary artery bypass surgery on mortality and selected nonfatal end points. From August 1975 to May 1979, 780 patients with stable ischemic heart disease were randomly assigned to receive surgical (n = 390) or nonsurgical (n = 390) treatment and were followed through April 15, 1983. At 5 years, the average annual mortality rate in patients assigned to surgical treatment was 1.1%. The annual mortality rate in those receiving medical therapy was 1.6%. Annual mortality rates in patients with single-, double-, and triple-vessel disease who were in the surgical group were 0.7%, 1.0%, and 1.5%; the corresponding rates in patients in the medical group were 1.4%, 1.2%, and 2.1%. The differences were not statistically significant. Nearly 75% of the patients had entry ejection fractions of at least 0.50. The annual mortality rates in patients in the surgical group in this subgroup with single-, double-, and triple-vessel disease were 0.8%, 0.8%, and 1.2% and corresponding rates in the medical group were 1.1%, 0.6%, and 1.2%. The annual rate of bypass surgery in patients who were initially assigned to receive medical treatment was 4.7%. The excellent survival rates observed both in CASS patients assigned to receive medical and those assigned to receive surgical therapy and the similarity of survival rates in the two groups of patients in this randomized trial lead to the conclusion that patients similar to those enrolled in this trial can safely defer bypass surgery until symptoms worsen to the point that surgical palliation is required.

The prognostic value of a coronary artery jeopardy score was evaluated in 462 consecutive nonsurgically treated patients with significant coronary artery disease, but without significant left main coronary stenosis. The jeopardy score is a simple method for estimating the amount of myocardium at risk on the basis of the particular location of coronary artery stenoses. In patients with a previous myocardial infarction, higher jeopardy scores were associated with a lower left ventricular ejection fraction. When the jeopardy score and the number of diseased vessels were considered individually, each descriptor effectively stratified prognosis. Five year survival was 97% in patients with a jeopardy score of 2 and 95, 85, 78, 75 and 56%, respectively, for patients with a jeopardy score of 4, 6, 8, 10 and 12. In multivariable analysis when only jeopardy score and number of diseased vessels were considered, the jeopardy score contained all of the prognostic information. Thus, the number of diseased vessels added no prognostic information to the jeopardy score. The left ventricular ejection fraction was more closely related to prognosis than was the jeopardy score. When other anatomic factors were examined, the degree of stenosis of each vessel, particularly the left anterior descending coronary artery, was found to add prognostic information to the jeopardy score. Thus, the jeopardy score is a simple method for describing the coronary anatomy. It provides more prognostic information than the number of diseased coronary arteries, but it can be improved by including the degree of stenosis of each vessel and giving additional weight to disease of the left anterior descending coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

After coronary bypass surgery, occlusion or narrowing of bypass grafts may occur over time. The present study prospectively evaluated the angiographic patency of bypass grafts after 1 year in relation to the preoperative angiographic and functionally severity of the coronary lesion assessed by fractional flow reserve measurement to test the hypothesis that grafting of less critical stenosis may be a risk factor for early dysfunction of the graft. The study comprised 164 patients eligible for coronary artery bypass surgery who were not suitable for percutaneous intervention and with at least one intermediate lesion. Fractional flow reserve was measured in all lesions to be grafted to establish if a lesion was functionally significant. The surgeon was blinded to the results of these measurements. One year after surgery, coronary angiography was performed to establish bypass graft patency. At coronary angiography after 1 year, 8.9% of the bypass grafts on functionally significant lesions were occluded, and 21.4% of the bypass grafts on functionally nonsignificant lesions were occluded. There was no difference in angina class or repeat interventions between patients with or without occluded bypass grafts. The patency of bypass grafts on functionally significant lesions is significantly higher than the patency of bypass grafts on nonsignificant lesions; however, this finding has no clinical relevance because patients with patent or occluded bypass grafts on nonsignificant lesions did not experience an excess of angina or repeat interventions.