Circulation November 03, 2026

Long-Term Outcomes of Endoscopic or Open Vein Harvesting for Coronary Artery Bypass Grafting: A 10-Year Follow-Up of the REGROUP Randomized Clinical Trial

Marco A. Zenati et al. (REGROUP Trial Investigators)

Bottom Line

At 10 years of follow-up, endoscopic vein harvesting for CABG demonstrated similar long-term rates of major adverse cardiac events and survival compared to open harvesting when performed by experienced operators.

Key Findings

1. Over a 10-year follow-up period, there was no significant difference in the primary composite outcome of major adverse cardiac events (MACE)—comprising all-cause mortality, nonfatal myocardial infarction, or repeat revascularization—between the endoscopic vein harvesting (EVH) and open vein harvesting (OVH) groups.

2. Long-term overall survival was comparable between the two arms (approximately 66.7% at 10 years across the cohort), aligning with expected mortality rates for this predominantly veteran demographic undergoing CABG.

3. Rates of repeat revascularization and nonfatal myocardial infarction showed no statistically significant divergence over a decade, affirming the long-term durability and patency of EVH grafts compared to traditional open grafts.

Study Design

Design

RCT

Single-Blind

Sample

1,150

Patients

Duration

10 yr

Median

Setting

16 US VA centers

Population Adult patients (predominantly male veterans) undergoing elective or urgent coronary artery bypass grafting (CABG) via median sternotomy requiring at least one saphenous vein graft.

Intervention Endoscopic vein harvesting (EVH) of the greater saphenous vein, performed by experienced harvesters (>100 prior EVH cases).

Comparator Traditional open vein harvesting (OVH) of the greater saphenous vein.

Outcome Composite of major adverse cardiac events (MACE), including death from any cause, nonfatal myocardial infarction, and repeat revascularization.

Study Limitations

• The study cohort consisted almost entirely of male US veterans (over 99%), substantially limiting the generalizability of the findings to female patients and broader civilian populations.

• The trial rigorously mandated that all vein harvesting be performed by highly experienced operators (defined as having completed >100 EVH procedures with low conversion rates); therefore, these non-inferior outcomes may not translate to centers with lower procedural volumes or operators early in their learning curve.

• As a 10-year follow-up, natural attrition and non-cardiac competing risks of death within an aging veteran population may marginally affect the precision of long-term, graft-specific failure estimates.

Clinical Significance

This 10-year landmark update definitively refutes older observational concerns (most notably from the ROOBY trial) that endoscopic vein harvesting intrinsically damages the saphenous graft and compromises long-term survival. It solidifies EVH as a safe, standard-of-care approach that offers the known short-term benefits of reduced leg wound morbidity without exacting a long-term cardiovascular penalty, provided the procedure is performed by experienced harvesters.

Historical Context

Endoscopic vein harvesting (EVH) was widely adopted to minimize the severe leg wound infections and delayed healing associated with traditional open harvesting (OVH). However, the 2009 ROOBY trial unexpectedly reported higher rates of graft failure and adverse clinical outcomes with EVH, sparking intense clinical debate. In response, the VA commissioned the REGROUP trial (initially published in the NEJM in 2019), which corrected for operator experience by requiring expert harvesters. The initial 2.78-year and subsequent 4.7-year results showed no difference in MACE. This 10-year update serves as the definitive final word on the long-term safety of EVH in modern cardiac surgery.

Guided Discussion

High-yield insights from every perspective

Med Student

Medical Student

What is the proposed pathophysiological mechanism by which endoscopic vein harvesting was historically hypothesized to cause earlier graft failure compared to open harvesting?

Key Response

Endoscopic harvesting involves insufflation, traction, and thermal energy, which can cause endothelial injury, vasospasm, and adventitial damage. Endothelial dysfunction in a vein graft predisposes to thrombosis and accelerated intimal hyperplasia, explaining the historical concern for reduced graft patency before the REGROUP trial proved its long-term safety in experienced hands.

Resident

When discussing operative risks and benefits with a patient scheduled for CABG, how do the outcomes and complications of endoscopic versus open vein harvesting compare based on the REGROUP 10-year data and general surgical principles?

Key Response

The REGROUP 10-year data shows no difference in MACE or long-term survival between the techniques when performed by experienced operators. However, endoscopic harvesting significantly reduces leg wound complications (such as infections, dehiscence, and severe pain), making it the preferred approach to reduce postoperative morbidity and improve patient comfort.

Fellow

The REGROUP trial mandated that surgeons have significant prior experience with EVH. How does the 'learning curve' of EVH impact graft patency, and how should a cardiothoracic surgery fellowship program balance trainee education with the strict requirement for experienced operators?

Key Response

EVH has a steep learning curve; early, inexperienced harvesting correlates with macroscopic and microscopic graft trauma, leading to early graft failure. Fellowship training must incorporate intensive simulation and graduated, closely proctored clinical experience to mitigate the risk of creating inferior conduits during the learning phase, ensuring trainee outcomes eventually match REGROUP standards.

Attending

Given that the REGROUP trial demonstrated equivalent 10-year MACE only when performed by 'experienced operators', how should CT surgery departments define and monitor quality control for EVH in their routine clinical practice?

Key Response

Experience cannot be defined solely by lifetime case volume; it requires ongoing continuous quality improvement (CQI). Attendings must establish institutional protocols to monitor harvest times, vein repair rates, leg wound complication rates, and intermediate-term graft patency (via clinical outcomes or angiography) to ensure real-world EVH outcomes mirror high-stakes trial environments.

Scholarly Review

Critical appraisal through the lens of expert reviewers and guideline development

PhD

In extending the follow-up of a randomized trial like REGROUP to 10 years, what are the primary methodological challenges regarding missing data and competing risks, and how should statistical models adjust for non-cardiovascular mortality over a decade?

Key Response

Over a 10-year period, loss to follow-up and non-cardiovascular deaths become significant competing risks. Standard Kaplan-Meier estimates might overestimate the risk of MACE. Researchers should employ competing risk models (e.g., Fine-Gray subdistribution hazards) and robust multiple imputation methods to accurately estimate the long-term cumulative incidence of cardiovascular endpoints.

Journal Editor

As a peer reviewer evaluating the 10-year follow-up cohort of the REGROUP trial, how would you evaluate the reliance on clinical MACE as an endpoint rather than protocol-driven angiographic patency?

Key Response

A critical editor would flag that clinical MACE is an imperfect surrogate for structural graft failure. Asymptomatic graft occlusion is common and might theoretically differ between EVH and OVH cohorts despite similar clinical event rates due to collateralization or competitive flow. The lack of routine follow-up angiography is a limitation in definitively proving anatomical equivalence of the conduits.

Guideline Committee

Current ACC/AHA guidelines for CABG recommend endoscopic vein harvesting to reduce wound complications, provided it is performed by experienced operators. How does the 10-year REGROUP data impact the Level of Evidence for this recommendation?

Key Response

The REGROUP 10-year data elevates the Level of Evidence for EVH from B-R (moderate-quality randomized data) to A (high-quality randomized data with long-term follow-up). By proving that the previously feared long-term mortality and MACE signals from older observational data (e.g., PREVENT IV) do not exist with experienced operators, guidelines can confidently maintain a Class I recommendation for EVH to minimize morbidity, explicitly cementing 'operator experience' as a formal prerequisite.

Clinical Landscape

Noteworthy Related Trials

2009

PREVENT IV Trial

n = 3,014 · NEJM

Tested

Endoscopic vein harvesting

Population

Patients undergoing first-time CABG

Comparator

Open vein harvesting

Endpoint

Vein-graft failure and adverse clinical outcomes

Key result: Endoscopic harvesting was associated with higher rates of vein-graft failure at 12-18 months and higher rates of death, MI, or repeat revascularization at 3 years.

2019

REGROUP Trial

n = 1,150 · NEJM

Tested

Endoscopic vein harvesting

Population

Patients undergoing CABG

Comparator

Open vein harvesting

Endpoint

Major adverse cardiac events (MACE)

Key result: Endoscopic harvesting was non-inferior to open harvesting for MACE at a median follow-up of 2.78 years.

2019

ART Trial

n = 3,102 · NEJM

Tested

Bilateral internal thoracic artery (ITA) grafting

Population

Patients with multivessel coronary artery disease undergoing CABG

Comparator

Single ITA grafting

Endpoint

10-year all-cause mortality

Key result: At 10 years, there was no significant difference in survival or event-free survival between single and bilateral ITA grafting.

Tailored to your role

Want this tailored to you?

Add your specialty or training stage to get role-specific takeaways and more questions.

Personalize this analysis