Complete versus Incomplete Revascularization and Influence of Postoperative Antiplatelet Therapy in Coronary Artery Bypass Grafting: Results from the TiCAB Study

Objectives: The recently published results of the TiCAB trial showed no significant differences of outcomes, regarding major cardiovascular events or bleeding, in patients receiving aspirin or ticagrelor adjunctive to coronary artery bypass grafting (CABG). We herein aimed to analyze subgroups of patients who received complete (CR) or incomplete revascularization (ICR) during CABG and determine possible impact of the different antiplatelet therapies.

Methods: In this randomized controlled trial (RCT), 1,859 patients were enrolled between April 2013 and April 2017 and randomly assigned to aspirin or ticagrelor therapy adjunctive to CABG. Of these, 1,550 patients (83.4%; 14.9% female, age 60–75 years: 60.8%) received CR and 309 patients (16.6%; 15.9% female, age 60–75: 57.9%) received ICR. Outcomes were evaluated based on the primary outcomes of cardiovascular death, myocardial infarction (MI), repeat revascularization, PTCA, and stroke 12 months after CABG.

Results: Baseline parameters revealed significant differences regarding clinical presentation (stable angina pectoris [AP]: CR 68.9 vs. ICR 71.2%, instable AP: 14.1 vs. 7.8%, NSTEMI: 17.0 vs. 21.0%, p = 0.005), lesion characteristics (chronic total occlusion [CTO]: CR 91.3 vs. ICR 96.8%, p = 0.001), operative technique (off-pump coronary artery bypass grafting [OPCAB]: CR 3.0 vs. ICR 6.1%, p = 0.005) and number of utilized grafts (venous grafts: CR 1.02/patient vs. ICR 0.86/patient, p = 0.01; total number of grafts: 2.69/patient vs. 2.49/patient, p = 0.0002). Patients with ICR presented with significantly higher rates of PTCA (CR: 3.3% vs. ICR: 6.3%, p = 0.02) and repeat revascularization (CR: 3.9% vs. ICR: 7.3%, 0.01) up to 12 months after the index procedure. No significant differences were found regarding stroke, MI, cardiovascular death, or BARC-adjudicated clinical endpoints. Also, no differences were found between subgroups receiving aspirin or ticagrelor.

Conclusion: In this large RCT, patients who received ICR for coronary vessel disease were significantly more frequently exposed to repeat revascularization or PTCA up to 12 months following the index procedure. Patients who were incompletely revascularized presented more stable at the time of admission and received less grafts, highly likely due to the presence of significantly more CTO of coronary arteries and were significantly more often provided with OPCAB. Although mortality presented no differences between groups, our results suggest that patients benefit from CR with regards to prevention of re-revascularization. Therefore, concept of CR should be taken into consideration even if CTO or challenging operative circumstances are present.