Success of Revascularization Vs Clinical Outcomes
If the mechanism of cardiac event-free and overall survival with CABG is due to revascularization, then the technical success in achieving revascularization should predict the clinical outcomes. Studies purporting to show a significant relationship between completeness of revascularization and symptomatic outcomes and survival have several methodologic problems. These include:
Variable definitions of revascularization;
Using exercise tolerance as the end point without documenting the extent of exercise rehabilitation post surgery; and
Defining complete vs incomplete revascularization by follow-up angiograms taken 2-12 months after the CABG.
Jones and colleagues reported an 8% survival advantage with complete revascularization compared with incomplete revascularization at 8 years. However, at entry into the study, the incompletely revascularized patients had a greater percentage of 3-vessel disease (P < .001), more previous AMIs (P < .001), and lower ejection fractions (P < .001).
The CASS registry involved more patients with 3-vessel CAD who received CABG than all of the other studies combined (n = 3372) and followed them for cardiac-event-free and overall survival. This study demonstrated no difference in survival or cardiac-event-free survival at 6 years related to the success of revascularization.
In the Bypass Angioplasty Revascularization Investigation (BARI), which randomized patients with multivessel disease to CABG or angioplasty, the practice of intended incomplete revascularization in the angioplasty group did not result in a lower mortality.
© 2002 Medscape
Cite this: Coronary Artery Bypass Grafting (CABG): Reassessing Efficacy, Safety, and Cost - Medscape - Jun 19, 2002.