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[Coronary bypass surgery in 1971-80 and 1995-96: increased age and comorbidity, unchanged survival rates and fewer early reoperations 1 and 5 years postoperatively].

OBJECTIVE
To describe the characteristics of patients undergoing coronary bypass surgery (CABG) over the past 30 years and the outcome after 1 and 5 years.


DESIGN
Retrospective.


METHOD
All 1041 patients who had undergone a first CABG in the Thorax centre of the Erasmus Medical Centre in Rotterdam during the period from 1 July 1971 through 31 May 1980 (group I) were compared with all patients who had also undergone such a first operation during the period between 1 September 1995 and 31 December 1996 (group II). Data on the patients, the operations, any reoperations and the mortality were obtained from patient records, from general practitioners and from municipal archives. Cumulative percentages of survival and of not having reCABG or percutaneous transluminal coronary angioplasty (PTCA) were analysed by using the Kaplan-Meier-method.


RESULTS
The patients in group I were 11 years younger on average than those in group II and there were more men (group I: 88%, group II: 76%). The patients in group II had more comorbidity than those in group I. The actuarial perioperative mortality was 1.2% in group I and 1.6% in group II. The overall 5-year mortality was significantly lower in group I than in group II (9.1% vs. 11.0%). After adjustment for the baseline characteristics, however, the patients in group II had a lower risk of mortality. Coronary revascularisation in the first 5 years was required more often in group I than in group II (7.4% vs. 4.2%). Independent predictors of a higher 5-year mortality were: a reduced ejection fraction (both groups), more extensive vascular disease (group I), chronic pulmonary disease, renal function disorders and diabetes mellitus (all group II), while treatment for hyperlipidaemia had a favourable effect on survival.


CONCLUSION
The age and comorbidity of the operated patients had increased over the years, while the chance of survival was no less than before and there was less chance of an early reoperation.