PREDICTORS OF DISEASE SEVERITY AND SURVIVAL IN PATIENTS WITH CORONARY-ARTERY DISEASE

Background: The objective of this study was to determine whether coron ary angiographic findings and survival could be predicted using standa rd clinical and exercise-test data. Methods: Five hundred and ninety-f ive men who had undergone both exercise treadmill testing and cardiac catheterization were followed for up to 5 years. Left main (LM) diseas e (greater-than-or equal-to 50% stenosis) was present in 42 patients, whereas 30 patients had LM equivalent disease (greater-than-or-equal-t o 70% stenosis of both the proximal left anterior descending and circu mflex coronary arteries). Patients were divided into six exclusive gro ups using angiography: no coronary artery disease (n = 152), one-vesse l disease (n = 186), two-vessel disease (n = 11 8), three-vessel disea se (n = 67), LM or LM equivalent disease without significant (greater- than-or-equal-to 70%) right coronary artery involvement (n = 26), and LM or LM equivalent disease with right coronary artery involvement (n = 46). Results: ST-segment depression was more marked, whereas ejectio n fraction, maximal heart rate, maximal systolic blood pressure, and e xercise capacity were lower in each group as disease severity worsened . Using Kaplan-Meier analysis, the subgroup with the poorest survival was found to be those with LM or LM equivalent disease with right coro nary artery disease, and the next worse was the three-vessel disease g roup, in which survival was poorer than in all other subgroups (P<0.01 ). Stepwise regression analysis revealed that the most powerful predic tor for coronary artery disease severity was exercise-induced ST depre ssion (P<0.001), but it predicted survival poorly. History of congesti ve heart failure, low ejection fraction (50% or lower), and poor exerc ise capacity (5 metabolic equivalents or less) emerged as strong predi ctors of survival using stepwise Cox regression analysis (P<0.001). Co nclusion: Exercise-induced ST depression predicted the severity of ang iographic disease but not survival, whereas the strongest predictors o f survival were history of congestive heart failure, low ejection frac tion, and poor exercise capacity.