Among patients with complex coronary artery disease, coronary artery bypass grafting (CABG), as compared to percutaneous coronary intervention (PCI), is associated with a greater risk of periprocedural stroke, but not long-term stroke, according to a new analysis of the SYNTAX trial published on March 20 in JACC Cardiovascular Interventions. At four-year follow-up, there was no difference in stroke incidence between treatments.

The SYNTAX trial randomized 1,800 patients with de novo three-vessel and/or left main coronary disease to CABG or PCI. Overall, 33 and 20 strokes occurred at four years in the CABG and PCI groups, respectively. In the CABG group, nine of the 33 strokes occurred within 30 days of the procedure, whereas 18 of the 20 strokes in the PCI arm occurred more than 30 days after intervention. However, in a multivariate analysis, CABG was not significantly associated with an increased stroke risk (p=0.089).

Lead investigator Michael J. Mack, MD, FACC, Baylor Healthcare System, Plano, Texas, and colleagues concluded, "The overall incidence of stroke was low at four years in the SYNTAX trial in both CABG- and PCI-treated patients. Though more strokes occurred in the CABG arm than in the PCI arm early in the study, no significant differences were found at four years."

In an accompanying editorial, Jesse Weinberger, MD, Mount Sinai School of Medicine, New York, and Craig Smith, MD, FACC, Columbia University School of Medicine, New York, noted that this analysis reports different stroke rates than the original study where rates were higher with CABG than with PCI (2.2 vs. 0.6 percent, p=0.003). The current analysis, "focused specifically on stroke, reports a stroke difference of 1 percent (CABG) vs. 0.2 percent (PCI) at 0 to 30 days by intent-to-treat (p=0.037), and three of the nine strokes in the CABG group occurred pre-operatively, so a statistically meaningful difference in an as-treated analysis is doubtful," they wrote.

"The SYNTAX trial was not specifically designed to determine the etiology of stroke in patients treated with CABG or PCI. It is imperative to establish the causes of stroke during CABG and develop strategies to prevent these strokes," the editorialists concluded. "A prospective study may be warranted."

Keywords: Incidence, Coronary Artery Disease, Stroke, Multivariate Analysis, Texas, Coronary Disease, Coronary Artery Bypass, New York, Universities, Percutaneous Coronary Intervention