CORONARY-ARTERY BYPASS-SURGERY IN WOMEN AND IN MEN - EARLY AND LONG-TERM RESULTS - A STUDY OF THE NORWEGIAN POPULATION ADJUSTED BY AGE AND SEX

Objective: We wished to analyse early mortality, postoperative low-out put syndrome needing intra-aortic balloon pumping support (IABP), tota l mortality, recurrent angina pectoris and total non-fatal myocardial infarction in women compared with men. Also, the standard mortality ra tio (SMR) was estimated to compare the mortality data to the general N orwegian population of comparable sex and age. Methods: A total of 102 5 patients; 113 women and 912 men, were submitted to coronary artery b ypass surgery at Rikshospitalet, Oslo between August 1982 and December 1986. The patients were followed up until the Ist of January 1993, re presenting a mean follow-up time of 7.4 years. An exposed/non-exposed cohort study design was used. A power study was carried out. The stand ardized mortality ratios for women and men were calculated after adjus ting for age and sex. Results: Crude odds ratio (OR,) of early mortali ty was 2.0 with a 95% confidence limit (CL(95%)) of 0.7-5.4. Odds rati o of low output syndrome needing intra-aortic balloon support was 1.7 (CL(95%)=0.8-4.2). Statistical significance was not achieved for these end-points. Women did not run an increased hazard of total mortality (OR(C)=0.9; CL(95%)=0.5-1.5), recurrent angina pectoris (OR(C)=1.4, CL (95%)=0.8-2.4) or of total non-fatal myocardial infarction (OR(C)=0.8; CL(95%)=0.4-1.6) when compared with men. Adjusting for confounders di d not significantly alter the results. When matched on sex and age and compared to the normal Norwegian population, we found an increased SM R in both men (2.5; CL(95%)=2.2-2.9) and women (4.1; CL(95%)=2.2-4.9). Conclusion: The risk of early mortality and low-output syndrome needi ng intra-aortic balloon support tended to be higher in women compared with men. Women did not run an increased risk of total mortality, recu rrent angina or of total non-fatal myocardial infarction. The standard mortality ratio was increased in both men and women, but in particula r higher in women, suggesting a more aggressive course of coronary art ery disease in operated women than in operated men. However, this diff erence did not show in the long term follow-up, due to the beneficial effect of coronary artery bypass surgery in both men and women. (C) 19 97 Elsevier Science B.V.