Mortality and morbidity during a period of 2 years after coronary artery bypass surgery in patients with and without a history of hypertension.

OBJECTIVE

To describe mortality and morbidity during a period of 2 years after coronary artery bypass grafting (CABG) in relation to a history of hypertension.

PATIENTS

All patients in western Sweden in whom CABG was undertaken between June 1988 and June 1991 and in whom simultaneous valve surgery was not performed were included in the study.

DESIGN

A prospective 2-year follow-up study.

RESULTS

Patients with a history of hypertension (n = 777) differed from patients without such a history (n = 1348) in that the proportion of women was higher, they were older and more frequently had a history of congestive heart failure, diabetes mellitus, renal dysfunction, cerebro-vascular disease, intermittent claudication and obesity, and the number of smokers and patients with previous CABG was lower. They were also more likely to develop post-operative cerebrovascular complications and signs of myocardia damage. Patients with hypertension tended to have increased mortality during the first 30 days after CABG and the late mortality (between day 30 and 2 years) was significantly higher than in non-hypertensive participants. Whereas the development of myocardial infarction was similar in both groups, the hypertensive study participants more frequently developed stroke during 2 years of follow-up. In a multivariate analysis including age, sex, history of different cardiovascular diseases, smoking, ejection fraction, and the occurrence of three-vessel disease, hypertension did not emerge as an independent predictor of death in the early or late phase or during a total of 2 years of follow-up.

CONCLUSION

Among CABG patients, those with a history of hypertension have a different pattern of risk factors. They have a higher mean age, include a higher proportion of women and have a higher prevalence of congestive heart failure, diabetes mellitus, renal dysfunction, cerebro-vascular disease, intermittent claudication, and obesity. They also have an increased frequency of immediate post-operative complications and an increased 2-year mortality, even if a history of hypertension was not an independent predictor of death during 2 years of follow-up.