Prognostic significance of transient ischemic episodes: Response to treatment shows improved prognosis Results of the total ischemic burden bisoprolol study (TIBBS) follow-up

Objectives. The Total Ischemic Burden Bisoprolol Study (TIBBS) follow-up examined cardiac event rates in relation to translent ischemi and its treatment. Background. It is nuclear whether transient ischemi on the ambulatory electrocardiogram has prognostic implications in stable angin and whether medical treatment can improve the prognosis. Methods. The TIBBS trial was an 8-week, randomized, controlled comparison of the effects of bisoprolol and nifedipine on transient ischemic episodes in patients with stable angin pectoris. Of the 545 patients screened, 520 (95.4%) could be followed up. Rates of cardiac and noncardiac death, nonfatal acute myocardial infarction, hospital admission for unstable angin and need for coronary artery bypass graft surgery or percutaneous transluminal coronary angioplasty were recorded. Results. total of 145 events occurred in 120 (23.1%) of 520 patients. Patients with more than six episodes had an event rate of 32.5% compared with 25.0% for patients with two to six episodes and 13.2% for patients with less than two episodes (p < 0.001). Hard events (death, acute myocardial infarction, hospital admission for unstable angin pectoris) were more frequent in patients with two or more ischemic episodes (12.1% vs. 4.7%, P = 0.0049). Patients with 100% response rate of transient ischemic episodes during the TIBBS trial had 17.5% event rate at 1 year compared with 32.3% for non-100% responders (p = 0.008). Patients receiving bisoprolol during the TIBBS trial had lower event rate (22.1%) at 1 year than patients randomized to nifedipine (33.1%, P = 0.033). Conclusions. In patients with stable angin pectoris, frequent episodes of transient ischemi are marker for an increased event rate. 100% response to medical treatment reduces the event rate. The greater reduction of ischemi with bisoprolol than nifedipine during the TIBBS trial translated into animproved outcome at 1 year.