LONG-TERM SURVIVAL OF MEDICALLY TREATED PATIENTS IN THE CORONARY-ARTERY SURGERY STUDY (CASS) REGISTRY

Background This study describes the impact of clinical, angiographic, and demographic characteristics on the longterm survival of Coronary A rtery Surgery Study (CASS) patients while they were under medical trea tment. Revascularization rates for the population are also provided. M ethods and Results All CASS patients who had not received heart surger y before enrollment (23 467 patients) were included in this survival a nalysis while they were under medical treatment or surveillance. Follo w-up time ranged from 0 to 17 years (median, 12 years). Long-term vita l status is known for 95.8% of these patients. Log-rank tests, Kaplan- Meier survival curves, and Cox proportional-hazards regression are use d to describe and assess the impact of patient characteristics on surv ival. Characteristics that had a significant impact on survival, in or der of observed explanatory power, are age, number of diseased vessels , congestive heart failure score, smoking history, ejection fraction, sex, presence of left main coronary artery disease, presence of diabet es, left ventricular wall motion score, presence of other illnesses, h istory of myocardial infarction, and presence of left main equivalent disease. Overall, 12-year survival for patients with zero-, one-, two- , and three-vessel disease is 88%; 74%, 59%, and 40%, respectively. Tw elve-year survival for patients with at least one diseased vessel and ejection fractions in the ranges of 50% to 100%, 35% to 49%, and 0% to 34% is 73%, 54%, and 21%, respectively. High myocardial jeopardy, hig h anginal class, and two or three proximal diseased vessels characteri ze the profile of patients most likely to have received surgical treat ment during follow-up. Conclusions These results contribute to the und erstanding of the natural history of coronary artery disease and are a lso of historical interest: The poor survival of patients with three-v essel disease and low ejection fractions continues to emphasize the im portance of considering revascularization for these patients.