Off-Pump Coronary Artery Bypass Grafting in Acute Coronary Syndrome: Focus on Safety and Completeness of Revascularization

Coronary artery bypass surgery for acute coronary syndrome: A network meta-analysis of on-pump cardioplegic arrest, off-pump, and on-pump beating heart strategies

BACKGROUND

Coronary artery bypass grafting (CABG) in the setting of an acute coronary syndrome is a high-risk procedure, and the best strategy for myocardial revascularisation remains debated. This study compares the 30-day mortality benefit of on-pump CABG (ONCAB), off-pump CABG (OPCAB), and on-pump beating heart CABG (OnBHCAB) strategies.

METHODS

A systematic search of three electronic databases was conducted for studies comparing ONCAB with OPCAB or OnBHCAB in patients with acute coronary syndrome (ACS). The primary outcome, 30-day mortality, was compared using a Bayesian hierarchical network meta-analysis (NMA). A random effects consistency model was applied, and direct and indirect comparisons were made to determine the relative effectiveness of each strategy on postoperative outcomes.

RESULTS

One randomised controlled trial and eighteen observational studies fulfilling the inclusion criteria were identified. A total of 4320, 5559, and 1962 patients underwent ONCAB, OPCAB, and OnBHCAB respectively. NMA showed that OPCAB had the highest probability of ranking as the most effective treatment in terms of 30-day mortality (odds ratio [OR], 0.50; 95% credible interval [CrI], 0.23-1.00), followed by OnBHCAB (OR, 0.62; 95% CrI, 0.20-1.57), however the 95% CrI crossed or included unity. A subgroup NMA of nine studies assessing only acute myocardial infarction (AMI) patients demonstrated a 72% reduction in likelihood of 30-day mortality after OPCAB (CrI, 0.07-0.83). No significant increase in rate of stroke, renal dysfunction or length of intensive care unit stay was found for either strategy.

CONCLUSIONS

Although no single best surgical revascularisation approach in ACS patients was identified, the significant mortality benefit with OPCAB seen with AMI suggests high acuity patients may benefit most from avoiding further myocardial injury associated with cardiopulmonary bypass and cardioplegic arrest.

Long-Term Follow-Up of Device-Assisted Clampless Off-Pump Coronary Artery Bypass Grafting Compared with Conventional On-Pump Technique

STUDY OBJECTIVE

To evaluate the long-term outcomes of clampless off-pump coronary artery bypass grafting (C-OPCAB) compared with conventional on-pump double clamping coronary artery bypass grafting (C-CABG).

METHODS

From October 2006 to December 2011, 366 patients underwent isolated coronary artery bypass grafting. After propensity score matching of preoperative variables, 143 pairs were selected who received C-OPCAB with the use of device-assisted PAS-Port proximal venous graft anastomoses or C-CABG, performed by the same surgeon experienced in both techniques. Data of the two groups of patients were retrospectively analyzed up to 14 years of follow-up.

RESULTS

As compared with C-OPCAB, in the C-CABG patients, the performed number of grafts per patient was higher (2.9 ± 0.5 vs. 2.6 ± 0.6, p-value 0.0001). At 14 years, overall survival, including in-hospital death, was 64 ± 4.7% for the C-OPCAB vs. 55 ± 5.5% for the C-CABG, freedom from overall MACCEs 51 ± 6.2% vs. 41 ± 7.7%, and from late cardiac death 94 ± 2.4% vs. 96 ± 2.2% (p-value not significant, for all comparisons). No significant statistical differences were observed in the actual rates of adverse events during follow-up. Independent predictors of survival were advanced age at operation (p-value 0.001) and a lower mean value of preoperative left ventricular ejection fraction (p-value 0.015).

CONCLUSIONS

Our single-center study analysis suggests that clampless OPCAB using device-assisted proximal anastomoses proved to be not inferior to double-clamping CABG in the long-term follow-up, provided that involved surgeons are familiar with both techniques. These conclusions are supported by a large and long-term follow-up period, eliminating potential bias, i.e., by means of the propensity score matching and analyzing single-surgeon experience.

Graft patency and completeness of revascularization in minimally invasive multivessel coronary artery bypass surgery

OBJECTIVES

Graft patency and completeness of revascularization were analyzed in patients who underwent off-pump minimally invasive coronary artery bypass grafting via a left small thoracotomy.

METHODS

We retrospectively reviewed the invasive angiography findings and clinical data of 186 consecutive patients who underwent off-pump minimally invasive coronary artery bypass grafting via a left small thoracotomy. The left internal thoracic artery and saphenous vein were used to bypass two or more of three coronary artery systems: the left anterior descending artery, left circumflex artery, or right coronary artery. Before hospital discharge, invasive angiography was performed to assess graft patency. Clinical variables during hospitalization and follow-up were collected and analyzed.

RESULTS

All 186 patients successfully underwent off-pump minimally invasive coronary artery bypass grafting without conversion to sternotomy or assistance of cardiopulmonary bypass. The mean graft number was 2.81 per patient (range, 2-5), and the total number of grafts was 522. The in-hospital mortality rate was 1.6% (3 of 186). A total of 181 of 186 (97.3%) patients underwent postoperative invasive angiography. Among the 510 grafts assessed by angiography, the total graft patency rate was 96.3% (491 of 510) (98.3% [171 of 174] for left internal thoracic artery grafts and 95.2% [318 of 334] for saphenous vein grafts). The rate of complete revascularization was 99.5% (185 of 186).

CONCLUSIONS

Minimally invasive coronary artery bypass grafting using left internal thoracic artery and saphenous vein grafts provides acceptable graft patency and completeness of revascularization for selected patients with multivessel disease.