Early and late mortality after surgery for unstable angina in relation to Braunwald class

Background The prognostic value of the preoperative Braunwald doss of unsta ble angina to predict early and longterm outcome after urgent coronary arte ry bypass grafting (CABG) has not been studied previously. Methods Deaths were recorded after all primary isolated CABG performed for unstable (n = 992) and stable In = 5376) angina pectoris during 1980-1995. Severity of symptoms in the unstable patients was classified according to B raunwald. Results Death within 30 days of surgery occurred in 4.6% of the patients ha ving unstable angina and in 1.6% of those with stable angina. Early mortali ty was 2.5% in Braunwald class II, 4.9% in class IIIB, and 6.2% in class II IC unstable patients. The risk of early death, after adjustment for risk Fa ctors, was about four times higher in Braunwald class IIB (odds ratio [OR] 4.3, 95% confidence interval [CI] 2.4-7.7) and IIIC (OR 4,7, 95% CI 2.2-10. 3) patients than in stable patients, The risk of death during postoperative months 1 to 6 tended to be higher (relative risk 2.4, 95% CI 0.8-7.1) in B raunwald class IIIC patients than in stable patients. After the first 6 mon ths vp to 5 years, survival rates in all Braunwald classes were similar to those in patients operated on for stable angina. Conclusions There was a higher risk of early death after urgent bypass surg ery in patients with Brounwald class III unstable angina than after electiv e CABG. The long-term survival rates after the first 6 postoperative months was similar in stable and unstable patients, regardless of preoperative Br aunwald closs.