Revascularization after acute myocardial infarction: impact of hospital teaching status and on-site invasive facilities.

OBJECTIVE

To investigate the influence of hospital teaching status and service availability on rates of revascularization following myocardial infarction.

DESIGN

Retrospective cohort study based on province-wide hospital discharge abstracts.

SETTING

All acute care hospitals in Ontario, Canada's most populous province (9.7 million).

PATIENTS

Patients admitted to hospital between April 1, 1991, and September 30, 1991, with a principal diagnosis of acute myocardial infarction.

MEASUREMENTS

The odds of a patient's having been referred for revascularization (angioplasty or bypass surgery) within six months of a myocardial infarction were calculated based on the type of hospital to which he or she had initially presented, defined as "teaching" or "nonteaching" or as having or not having interventional facilities on-site (cardiac catheterization and/or revascularization). Odds ratios were adjusted for potential confounding variables, and for possible joint effects of teaching status and on-site interventional capabilities.

RESULTS

The patients were more likely to have had revascularization (OR 1.79; 95% CI 1.47-2.14, p = 0.0001) when they had been admitted to a teaching hospital, and independently were more likely to have been referred for revascularization (OR 1.34; 95% CI 1.09-1.66, p = 0.0067) when they had been admitted to a hospital with on-site interventional facilities. There was no interaction between teaching status and service availability regarding referral for revascularization.

CONCLUSION

Teaching status is an important determinant of revascularization following acute myocardial infarction and is independent of service availability, which also influences revascularization rates.