Twelve years of coronary artery surgery in South Australia

Return to Work After Coronary Artery Bypass Surgery in a Population of Long-Term Survivors

BACKGROUND

Return to paid employment may be facilitated by coronary artery bypass graft (CABG) surgery. We assessed work status in a population-based study of long-term outcomes of CABG.

AIM

To determine the association between returning to work after CABG and clinical and socio-demographic factors.

METHODS

A postal survey of 2,500 randomly selected patients 6-20 years post-CABG. The outcomes assessed were work status in the year before and after CABG and health-related quality of life (HRQOL) measured with SF-36.

RESULTS

Response was 82% (n = 2,061). Employment fell from 56% in the year prior to CABG to 42% in the year after. Workers in 'blue-collar' occupations were more likely to reduce their work status than those in 'white collar' occupations (46% versus 29%, p < 0.001). Independent predictors of reducing employment were increasing age (9% per year, 99% CI: 1.06-1.11, p < 0.001), 'blue-collar' versus 'white collar' occupation (OR: 2.1, 99% CI: 1.4-3.1) and female sex (OR: 2.1, 99% CI: 1.1-3.6). HRQOL among participants under 60 years of age at follow-up was better for those who returned to work after CABG surgery.

CONCLUSION

CABG surgery is followed by a net loss to paid employment of working age patients which increases with age, and is more likely for those in blue-collar occupations and women.

Mortality and recurrent cardiac events after coronary artery bypass graft: long term outcomes in a population study

OBJECTIVE

To determine 30 day mortality, long term survival, and recurrent cardiac events after coronary artery bypass graft (CABG) in a population.

DESIGN

Follow up study of patients prospectively entered on to a cardiothoracic surgical database. Record linkages were used to obtain data on readmissions and deaths.

PATIENTS

8910 patients undergoing isolated first CABG between 1980 and 1993 in Western Australia.

MAIN OUTCOME MEASURES

30 day and long term survival, readmission for cardiac event (acute myocardial infarction, unstable angina, percutaneous transluminal coronary angioplasty or reoperative CABG).

RESULTS

There were 3072 deaths to mid 1999. 30 day and long term survival were significantly better in patients treated in the first five years than during the following decade. The age of the patients, proportion of female patients, and number of grafts increased over time. An urgent procedure (odds ratio 3.3), older age (9% per year) and female sex (odds ratio 1.5) were associated with increased risk for 30 day mortality, while age (7% per year) and a recent myocardial infarction (odds ratio 1.16) influenced long term survival. Internal mammary artery grafts were followed by better short and long term survival, though there was an obvious selection bias in favour of younger male patients.

CONCLUSIONS

This study shows worsening crude mortality at 30 days after CABG from the mid 1980s, associated with the inclusion of higher risk patients. Older age, an acute myocardial infarction in the year before surgery, and the use of sephenous vein grafts only were associated with poorer long term survival and greater risk of a recurrent cardiac event. Female sex predicted recurrent events but not long term survival.

Early and late survival after coronary-artery surgery

Between 1970 and 1985, 1801 patients underwent coronary-artery surgery without associated valvular surgery. Eighty-four per cent of patients were male and the mean (+/- SD) age was 55.7 +/- 8.3 years. Of the patients, 18.7% were from the Coronary Care Unit and 6.5% had diabetes. The hospital mortality rate for the whole group was 3.5%. Patients from the Coronary Care Unit had the highest (8.9%) hospital mortality rate compared with those patients who were not from the Coronary Care Unit (2.1%; P less than 0.001). Other factors which increased the hospital mortality rate significantly were the number of diseased vessels (P less than 0.01), the degree of left main coronary-artery stenosis (P less than 0.001), an earlier year of surgery (P less than 0.01) and female sex (P less than 0.01). After these were taken into account, no other factors (for example, age, preoperative infarction, presence of left-ventricular aneurysm, left-ventricular end-diastolic pressure, diabetes, use of mammary-arterial grafts or the need for endarterectomy) affected the mortality rate. Patients were followed-up for a mean (+/- SD) of 4.4 +/- 2.8 years. The five-year survival rate for all patients was 88% and the 10-year survival rate was 65%. Cox regression analysis showed that the significant indicators of decreased long-term survival were undergoing operation directly from the Coronary Care Unit (P less than 0.001), left main coronary-artery stenosis (P less than 0.01), the number of grafted vessels (P less than 0.01), concomitant surgery for aneurysm (P less than 0.001), year of surgery (P less than 0.01). Seventy-nine per cent of patients were free of angina pectoris at five years after operation. The year of surgery (P less than 0.001) and preoperative myocardial infarction (P less than 0.05) were the best predictors of recurrent angina. In the long term, recurrent angina remains a problem, although this may change with the increased use of mammary-arterial grafts.

Coronary risk factor outcomes following coronary artery bypass surgery

The coronary risk factor status of patients prior to and following coronary artery bypass surgery (CABG) has been poorly investigated. Two consecutive series of CABG patients were surveyed following CABG. One hundred and thirty patients were assessed immediately following CABG and 530 patients were assessed 12-30 months following CABG. For the long-term post-CABG group, over 80% of those who had ever smoked had ceased. Sixty-four per cent of these males and 50% of females were classified as being overweight. Twenty-five per cent of males and 34% of females reportedly had high serum cholesterol (i.e. greater than or equal to 6.5 mmol/L). Comparing these CABG data with age-adjusted National Heart Foundation Risk Factor Prevalence Survey data, there was a higher prevalence of ex-smokers, overweight, hypertension, and elevated cholesterol. It was concluded that on most coronary risk factors, except for smoking, these CABG patients had a worse profile than the general Australian community. This problem warrants further research and the development of appropriate treatment programs.

The place of coronary artery bypass surgery: an appraisal

The enthusiasm for performing coronary artery bypass graft (CABG) surgery in Australia is increasing. The results of a number of careful trials which have compared surgical with medical treatment have now appeared. While there is agreement on both the increased survival provided by CABG surgery in those with left main coronary artery stenosis and the relief of symptoms in patients in whom medical therapy has failed to control severe angina, there is debate about the value of surgery in other types of disease. With improvements in medical therapy, the most recent trials have failed to show a significant overall survival benefit from surgery, although it is generally considered that surgery can relieve angina and that, in at least some groups of persons with stenosis of all three main coronary vessels (triple-vessel disease), surgery may prolong life. Alternative methods of prolonging survival among people with ischaemic heart disease include the reduction of risk factors (such as hypertension, raised blood cholesterol levels and cigarette smoking), as well as treating patients with beta-blocking agents after a myocardial infarction. We suggest it is likely that a combination of these approaches could be more effective in terms of lives saved than is CABG and may be less expensive. The current expansion of CABG surgery in Australia should be viewed in this light.