Adherence to Guidelines for Cardiac Catheterization Referrals and Secondary Prevention Strategies in Patients with Non-ST Segment Elevation Acute Coronary Syndromes

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Michelle J. Haroun MD
Anjali Shroff MD,
Joshua J. Manolakos
Madhu K. Natarajan MD MSc
John You MD MSc,
Ameen Patel MD


Background: Previous studies have demonstrated higher referral rates for invasive procedures among patients admitted with acute coronary syndromes (ACS) to hospitals with catheterization facilities compared to those without. Studies have also reported underuse of evidence-based medical therapies and cardiac rehabilitation programs post myocardial infarction. We evaluated referral patterns for cardiac catheterization and use of secondary prevention strategies in current practice.

Methods: We conducted a retrospective study of 397 patients with non-ST segment elevation ACS, comparing angiography referrals at a hospital with on-site catheterization facilities (Site A, n = 194) versus a hospital without (Site B, n = 203). We also recorded the use of secondary prevention strategies including discharge medications, referrals to smoking cessation programs and cardiac rehabilitation.

Results: There was no significant effect of on-site angiography on the decision to manage patients invasively (adjusted OR for on-site angiography 1.49 95% CI 0.92-2.44, p = .11), or wait times for cardiac catheterization (Site A 1.9 days vs. Site B 2.2 days, difference −0.3 days, 95% CI −0.83 to 0.55, p = .70). However, at the time of hospital discharge, less than 70% of patients were prescribed dual antiplatelet therapy and only 13% of patients were referred for cardiac rehabilitation.

Conclusion: These observations suggest that in contemporary practice in a Southern Ontario community, the availability of on-site percutaneous coronary intervention does not influence referral rates or wait times for cardiac catheterization. However we did observe significant underuse of cardiac rehabilitation programs and certain medical therapies. This suggests that despite improvements in access to invasive procedures, there remain important gaps in secondary prevention of coronary artery disease, which represent opportunities to improve quality of care in these patients.

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