Survival in medically treated coronary artery disease.

Abstract

In 1214 symptomatic medically treated patients with coronary artery disease, 57 noninvasive baseline clinical characteristics and 24 catheterization descriptors were analyzed by a multivariable analysis technique to determine the characteristics that were independent predictors of survival and, in particular, to determine whether noninvasive characteristics contributed prognostic information in addition to catheteriza- tion findings.When the noninvasive characteristics were analyzed, 31 characteristics were significant (p < 0.05) univariate predictors of survival, but only 12 contained significant independent prognostic information.Fiveand 7-year survival rates in 197 patients who had none of the independently significant noninvasive characteristics were both 90%.Nineteen variables were significant when the catheterization descriptors were analyzed individually.Only seven were independently significant when they were analyzed jointly.When all 81 baseline characteristics were analyzed jointly, seven noninvasive characteristics (history of peripheral vascular disease, New York Heart Association class IV heart failure, nonspecific intraventricular conduction defect, progressive chest pain, nocturnal pain, premature ventricular complexes on the resting ECG, and left bundle branch block) and six invasive characteristics (left-main stenosis, arteriovenous oxygen difference, number of diseased vessels, abnormal left ventricular contraction, left ventricular end-diastolic pressure and anterior asynergy) were independently significant.Different survival rates may occur in subsets that are uniform with respect to only one or two important characteristics (e.g., coronary anatomy and ventricular function) because of differences in other important baseline characteristics.Both noninvasive and invasive characteristics must be taken into account to define prognosis in coronary disease fully.EARLY STUDIES of patients with clinically diagnosed coronary artery disease identified clinical characteristics such as age, sex, previous myocardial infarction, ECG abnormalities and heart failure as im- portant predictors of survival.1-5With the use of cor- onary angiography, the extent of coronary disease6-9 and the quality of left ventricular (LV) function'0' 11 were shown to be accurate predictors of survival.Although noninvasive descriptors still receive some attention,9 12 until recently the relationship between noninvasive and invasive descriptors in predicting sur- vival has not been extensively examined.Patients with coronary disease are usually classified by the number of diseased vessels and the quality of LV function.Survival within these categories is con- sidered a manifestation of the natural history of the disease.13 While such a classification produces a clinically useful stratification of the survival rates, the outcomes in each category vary significantly.For ex- ample, 2-year survival rates have varied from ap- proximately 93%14 to approximately 83%12 in patients