Surgical Revascularization of Chronically Occluded Coronary Arteries—What You See Is What You Get?

Revascularization of Occluded Right Coronary Artery and Outcome After Coronary Artery Bypass Grafting

OBJECTIVES

The aim of the present study was to evaluate the results of isolated coronary artery bypass grafting (CABG) with or without revascularization of the occluded right coronary artery (RCA).

METHODS

Patients undergoing isolated CABG were included in a prospective European multicenter registry. Outcomes were adjusted for imbalance in preoperative variables with propensity score matching analysis. Late outcomes were evaluated with Kaplan-Meier's method and competing risk analysis.

RESULTS

Out of 2,948 included in this registry, 724 patients had a total occlusion of the RCA and were the subjects of this analysis. Occluded RCA was not revascularized in 251 (34.7%) patients with significant variability between centers. Among 245 propensity score-matched pairs, patients with and without revascularization of occluded RCA had similar early outcomes. The nonrevascularized RCA group had increased rates of 5-year all-cause mortality (17.7 vs. 11.7%, p = 0.039) compared with patients who had their RCA revascularized. The rates of myocardial infarction and repeat revascularization were only numerically increased but contributed to a significantly higher rate of MACCE (24.7 vs. 15.7%, p = 0.020) at 5 year among patients with nonrevascularized RCA.

CONCLUSION

In this multicenter study, one-third of totally occluded RCAs was not revascularized during isolated CABG for multivessel coronary artery disease. Failure to revascularize an occluded RCA in these patients increased the risk of all-cause mortality and MACCEs at 5 years.

Why and How Should We Treat Chronic Total Occlusion? Evolution of State-of-the-Art Methods and Future Directions

Chronic total occlusions are considered the most complex coronary lesion in interventional cardiology. The absence of visible lumen on angiography obscures the vessel course and makes vessel wiring unlikely with conventional techniques. Often a source of severe ischemia, chronic occlusions are also markers of advanced atherosclerosis that brings other complex features including lesion length, bifurcations, calcification, adverse vessel remodelling, distal disease, and anatomic distortion from previous bypass grafting. Often advanced atherosclerosis is associated with patient characteristics like left ventricular dysfunction, previous coronary bypass surgery, or multivessel disease that increase procedural demands and hazards. To accommodate these challenges new techniques and dedicated technologies have been developed. When applied to appropriate patients, these advances have improved procedural success, safety, and outcomes. Our aim is to provide the general cardiologist with an overview of these advances that can serve as a basis for counselling patients considered for revascularization.

Coronary artery bypass grafts to chronic occluded right coronary arteries

Background

The benefit of revascularizing chronically occluded coronary arteries remains debatable, and available long-term outcome reports are sparse. Current guidelines recommend revascularization of chronically occluded arteries only in patients with myocardial ischemia and/or symptoms associated with angina. We investigated outcome of patients with total chronic occlusion of the right coronary artery (RCA) receiving coronary artery bypass grafting (CABG) surgery with and without revascularization of the RCA.

Methods

We retrospectively analyzed all patients with chronically occluded RCAs receiving CABG with (group 1 = RCA-CABG; n = 487) and without (group 2 = No-RCA-CABG; n = 100) revascularization of the RCA. In total, 587 patients with complete follow-up of a minimum of 6 years were included (92%).

Results

In total, 82% in group 1 versus 86% in group 2 were male (P = .38). European System for Cardiac Operative Risk Evaluation II was comparable between both groups (4.35 ± 7.09% vs 4.80 ± 5.77%, P = .56) with no major differences regarding preoperative characteristics between groups. Patients in group 1 received 3.24 ± 0.79 distal anastomoses, whereas group 2 received 2.45 ± 0.83 distal anastomoses (P < .001). Although in-hospital mortality was comparable (2.9% in group 1 vs 5.0% in group 2, P = .27), long-term survival was significantly better in group 1 (P = .002). No difference in the incidence of further major adverse cardiac and cerebrovascular events was found.

Conclusions

Patients with a chronically occluded RCA undergoing CABG who did not receive an RCA graft showed a significantly reduced long-term survival. Given the herein presented data, revascularization of chronically occluded right arteries during CABG should be recommended whenever technically feasible.

Clinical outcomes of complete versus incomplete revascularization in patients treated with coronary artery bypass grafting: insights from the TiCAB trial

OBJECTIVES

In this post hoc analysis of the Ticagrelor in coronary artery bypass grafting (CABG) trial, we aimed to analyse patients treated with CABG receiving either complete revascularization (CR) or incomplete revascularization (ICR) independent from random allocation to either ticagrelor or aspirin.

METHODS

Of 1859 patients enrolled in the Ticagrelor in CABG trial, 1550 patients (83.4%) received CR and 309 patients (16.6%) ICR. Outcomes were evaluated regarding all-cause mortality, cardiovascular death, myocardial infarction (MI), repeat revascularization, stroke and bleeding within 12 months after CABG.

RESULTS

Baseline parameters revealed significant differences regarding clinical presentation (stable angina pectoris: CR 68.9% vs ICR 71.2%, instable angina pectoris: 14.1% vs 7.8%, non-ST elevation MI: 17.0% vs 21.0%, P ˂ 0.01), lesion characteristics (chronic total occlusion: CR 91.3% vs ICR 96.8%, P ˂ 0.01), operative technique [off-pump coronary artery bypass surgery (OPCAB): CR 3.0% vs ICR 6.1%, P ˂ 0.01] and number of utilized grafts (total number of grafts: 2.69/patient vs 2.49/patient, P ˂ 0.001). ICR patients displayed a significantly increased risk of repeat revascularization [hazard ratio (HR) 1.91, 95% confidence interval (CI) 1.16-3.16; P < 0.01] and percutaneous coronary intervention (HR 1.95, 95% CI 1.13-3.35; P < 0.05) within 12 months after CABG. Higher risk for repeat revascularization in ICR patients was independent from random allocation to either ticagrelor or aspirin and persisted after adjustment for baseline imbalances.

CONCLUSIONS

Patients with ICR presented more stable at the time of admission, but received less grafts, highly likely due to a higher rate of chronic total occlusion lesions and performed OPCAB. Although mortality presented no difference between groups, our results suggest that patients benefit from CR with regard to prevention of repeat revascularization.