Spontaneous regression of coronary artery obstructions: incidence in 313 consecutive repeat angiograms

Five-year angiographic follow-up of factors associated with progression of coronary artery disease in the Coronary Artery Surgery Study (CASS). CASS Participating Investigators and Staff

OBJECTIVES

The Coronary Artery Surgery Study (CASS) required participants to undergo follow-up angiography at 5 years to identify clinical and angiographic features associated with progression of coronary artery disease.

BACKGROUND

The CASS randomized 780 patients at 11 participating clinical centers between an initial strategy of medical therapy versus bypass surgery. Five clinical sites accomplished follow-up angiography in > 50% of their randomized subjects within a 42- to 66-month period after the entry arteriogram (n = 314).

METHODS

Qualified clinical site angiographers, using side by side film review, evaluated an average of 13 segments/patient on both arteriograms for initial stenosis severity, morphologic features, lesion location and occurrence of disease progression or occlusion. Progression was defined as further definite narrowing by > or = 15% and occlusion as lesion progression to > or = 98%. Lesions were subcategorized as to whether they were univariate and had or had not been treated with bypass surgery. Multivariate logistic regression analyses were performed.

RESULTS

For nonbypassed segments, right coronary artery and left anterior descending artery proximal and midlocations were associated with disease progression. For stenosis-containing segments, the initial severity, a non-left anterior descending artery location and increased treadmill duration predicted progression. Segment occlusion was associated with initial lesion severity, right coronary artery location and subsequent interval myocardial infarction. There were few predictors of progression or occlusion in bypassed arteries, other than initial lesion severity.

CONCLUSIONS

Univariate and multivariate associations with lesion progression and occlusion included diabetes, lesion location, elevated cholesterol level, interval infarction and lesion morphology. These angiographic results, collected in a prospective trial, are consistent with known risk factors.

The dynamics of progression of coronary atherosclerosis studied in 168 medically treated patients who underwent coronary arteriography three times

To study the dynamics of progression of coronary atherosclerosis we analyzed findings in 168 patients who underwent coronary arteriography three times without undergoing coronary surgery or percutaneous transluminal coronary angioplasty. Of 66 patients who had progression in interval 1 (from first to second coronary arteriogram), 32 also had progression in interval 2 (from second to third coronary arteriogram); of 102 patients who had no progression in interval 1, 37 had progression in interval 2. In only 9 of the 32 patients who had progression during both intervals was the same lesion involved, and in six of these patients other lesions were also involved. Progression correlated with the duration of the interval between catheterizations, an increase in symptoms, and the occurrence of myocardial infarction. Analysis of variance showed no significant differences in mean values for age, blood pressure, total serum cholesterol, and serum triglycerides in the four main progression groups. Progression of coronary atherosclerosis is a highly unpredictable process. It follows a nonlinear course, and information derived from sequential coronary arteriograms is of little value in predicting future progression.

Design features of a controlled clinical trial to assess the effect of a calcium entry blocker upon the progression of coronary artery disease

This report presents the design and methodological features of a double-blind, randomized, placebo-controlled, trial in 383 patients with coronary artery disease. The study's principal objective is to determine whether chronic treatment with a calcium entry blocker can retard the progression of coronary artery disease. The study population consists of patients with coronary artery disease and a baseline coronary arteriogram that qualifies them as being at high risk for disease progression. After satisfying all entry criteria, patients were randomized to receive either the calcium entry blocker nicardipine or placebo. All indicated concomitant medications except calcium entry blockers are permitted. Patients are being followed clinically for 24 months before undergoing a second coronary arteriogram. The effect of the treatments on a variety of clinical and angiographic parameters will be determined.

Myocardial preservation with alternate coronary artery occlusion and reversal of flow through collateral vessels

In 1980, a 46-year-old man suffered occlusion of his left anterior descending coronary artery with preservation of myocardium due to collateral flow from a patent right coronary artery. Six years later, unstable angina recurred, this time due to right coronary occlusion but with myocardial preservation due to reversal of collateral flow from his now recanalized left anterior descending artery.