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

Additional bypass graft or concomitant surgical ablation? Insights from the HEIST registry

BACKGROUND

Surgical ablation for atrial fibrillation at the time of isolated coronary artery bypass grafting is reluctantly attempted. Meanwhile, complete revascularization is not always possible in these patients. We attempted to counterbalance the long-term benefits of surgical ablation against the risks of incomplete revascularization.

METHODS

Atrial fibrillation patients undergoing isolated coronary artery bypass grafting for multivessel disease between 2012 to 2022 and included in the HEart surgery In atrial fibrillation and Supraventricular Tachycardia registry were divided into complete revascularization, complete revascularization with additional grafts, and incomplete revascularization cohorts; these were further split into surgical ablation and non-surgical ablation subgroups.

RESULTS

A total of 8,405 patients (78% men; age 69.3 ± 7.9) were included; of those, 5,918 (70.4%) had complete revascularization, and 556 (6.6%) had surgical ablation performed. Number of anastomoses was 2.7 ± 1.2. The median follow-up was 5.1 [interquartile range 2.1-8.8] years. In patients in whom complete revascularization was achieved, surgical ablation was associated with long-term survival benefit: hazard ratio 0.69; 95% confidence intervals (0.50-0.94); P = .020 compared with grafting additional lesions. Similarly, in patients in whom complete revascularization was not achieved, surgical ablation was associated with a long-term survival benefit of 0.68 (0.49-0.94); P = .019. When comparing surgical ablation on top of incomplete revascularization against complete revascularization without additional grafts or surgical ablation, there was no difference between the 2: 0.84 (0.61-1.17); P = .307, which was also consistent in the propensity score-matched analysis: 0.75 (0.39-1.43); P = .379.

CONCLUSION

To achieve complete revascularization is of utmost importance. However, when facing incomplete revascularization at the time of coronary artery bypass grafting in a patient with underlying atrial fibrillation, concomitant surgical ablation on top of incomplete revascularization is associated with similar long-term survival as complete revascularization without surgical ablation.

Clinical Insights to Complete and Incomplete Surgical Revascularization in Atrial Fibrillation and Multivessel Coronary Disease

Objectives

Although endorsed by international guidelines, complete revascularization (CR) with Coronary Artery Bypass Grafting (CABG) remains underused. In higher-risk patients such as those with pre-operative atrial fibrillation (AF), the effects of CR are not well studied.

Methods

We analyzed patients’ data from the HEIST (HEart surgery In AF and Supraventricular Tachycardia) registry. Between 2012 and 2020 we identified 4770 patients with pre-operative AF and multivessel coronary artery disease who underwent isolated CABG. We divided the cohort according to the completeness of the revascularization and used propensity score matching (PSM) to minimize differences between baseline characteristics. The primary endpoint was all-cause mortality.

Results

Median follow-up was 4.7 years [interquartile range (IQR) 2.3–6.9]. PSM resulted in 1,009 pairs of complete and incomplete revascularization. Number of distal anastomoses varied, accounting for 3.0 + –0.6 vs. 1.7 + –0.6, respectively. Although early (< 24 h) and 30-day post-operative mortalities were not statistically different between non-CR and CR patients [Odds Ratio (OR) and 95% Confidence Intervals (CIs): 1.34 (0.46–3.86); P = 0.593, Hazard Ratio (HR) and 95% CIs: 0.88 (0.59–1.32); P = 0.542, respectively] the long term mortality was nearly 20% lower in the CR cohort [HR (95% CIs) 0.83 (0.71–0.96); P = 0.011]. This benefit was sustained throughout subgroup analyses, yet most accentuated in low-risk patients (younger i.e., < 70 year old, with a EuroSCORE II < 2%, non-diabetic) and when off-pump CABG was performed.

Conclusion

Complete revascularization in patients with pre-operative AF is safe and associated with improved survival. Particular survival benefit with CR was observed in low-risk patients undergoing off-pump CABG.

The Role of Angiogenesis and Arteriogenesisin Myocardial Infarction and Coronary Revascularization

Surgical myocardial revascularization is associated with long-term survival benefit in patients with multivessel coronary artery disease. However, the exact biological mechanisms underlying the clinical benefits of myocardial revascularization have not been elucidated yet. Angiogenesis and arteriogenesis biologically leading to vascular collateralization are considered one of the endogenous mechanisms to preserve myocardial viability during ischemia, and the presence of coronary collateralization has been regarded as one of the predictors of long-term survival in patients with coronary artery disease (CAD). Some experimental studies and indirect clinical evidence on chronic CAD confirmed an angiogenetic response induced by myocardial revascularization and suggested that revascularization procedures could constitute an angiogenetic trigger per se. In this review, the clinical and basic science evidence regarding arteriogenesis and angiogenesis in both CAD and coronary revascularization is analyzed with the aim to better elucidate their significance in the clinical arena and potential therapeutic use.

What does complete revascularization mean in 2021? - Definitions, implications, and biases

PURPOSE OF REVIEW

Coronary revascularization is known to be an excellent treatment for coronary artery disease. However, whether incomplete myocardial revascularization compromises long-term outcomes, as compared to complete revascularization (CR), remains contentious. Herein, we review the concept of and evidence on CR/incomplete revascularization (ICR) and discuss future perspectives.

RECENT FINDINGS

When possible, achieving CR in coronary artery bypass grafting is desirable; nonetheless, ICR is also a reasonable option to balance the therapeutic benefits against the risks.

SUMMARY

Although angiography-based assessment currently remains the standard of care, fractional flow reserve guidance may reduce the number of lesions requiring revascularization, which may be helpful for an appropriate surgical revascularization strategy. In particular, utilizing this approach may refine hybrid revascularization procedures, especially among high-risk patients.