Treatment of Patients with Diabetes (Type I & II) with Coronary Artery Disease in British Columbia: An Outcomes Analysis of the Past, Present and Future

Nickname: FREEDOM Real World

Principal Investigators

Dr. Krishnan Ramanathan, Clinical Assistant Professor, UBC Division of Cardiology, St. Paul’s Hospital
Dr. James Abel, Clinical Associate Professor, UBC Division of Cardiovascular Surgery, St. Paul’s Hospital

Co-investigators

Dr. Eve Aymong, Dr. Jamil Bashir, Dr. Carolyn Taylor, Dr. Daniel Wong, Dr. Anthony Della Siega, Dr. Richard Townley, Dr. Colleen Hennessy and Dr. Michael Farkouh. 

Background

The prevalence of diabetes mellitus (DM) in British Columbia was 7.4% in 2010 and this number is expected to increase to 10.3% by 2020. Patients with DM are prone to a diffuse and rapidly progressive form of atherosclerosis, which increases their likelihood of requiring revascularization.  Selection of the optimal myocardial revascularization strategy for patients with DM and coronary artery disease (CAD) is crucial to reducing the high rate of thrombotic complications and improving quality of life outcomes in high-risk patients.

In 2012, the results of the Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multi-vessel Disease (FREEDOM) trial demonstrated superiority of coronary artery bypass grafting (CABG) over percutaneous coronary intervention (PCI) using drug eluting stents during a 5-year follow up period. However, the real world applicability of the FREEDOM trial results is uncertain given the restrictive nature of clinical studies. Furthermore, the long-term (i.e. > 5-years) outcome of these procedures in a chronic disease setting is unknown.

Objective

  1. To assess the impact of the FREEDOM trial on clinical practice in British Columbia.
  2. To assess the conclusion of the FREEDOM trial in the real-world patient population of British Columbians.
  3. To evaluate the independent and combined effects of DM and multi-vessel CAD on the selection of CAD treatment strategy and subsequent patient outcomes in British Columbia.

Methodological Approach

This is an analysis of retrospectively collected, linked administrative and clinical data. Patient risk factors, coronary anatomy, coronary revascularization strategy and subsequent revascularization data will be obtained from the Cardiac Services BC Heart Information System (HEARTis). Details of clinical events (myocardial infarction, congestive heart failure, arrhythmias and stroke) and all-cause mortality will be requested via Population Data BC from the Discharge Abstract Database and the Vital Statistics Deaths File, respectively. Analyses will be performed at the BC Centre for Improved Cardiovascular Health.

Relevance

As the prevalence of DM continues to increase in epidemic proportions, further knowledge is needed in the management of CAD. In BC, the availability of HEARTis, a standardized registry for all diagnostic and interventional catheterization and open heart surgery procedures, offers a unique opportunity to further extend the findings from the international FREEDOM trial.

Reference: Farkouh ME, et al. for the FREEDOM Trial Investigators. Strategies for multivessel revascularization in patients with diabetes. N Engl J Med. 2012 Dec 20;367(25):2375-84. Epub 2012 Nov 4.