Vein Graft Failure Following Vein Graft Failure Following Coronary Artery Bypass Surgery: Coronary Artery Bypass Surgery:

Does it Matter?Does it Matter?

Renato D. LopesRenato D. Lopes • John H. Alexander • Rajendra H. Mehta • Gail • John H. Alexander • Rajendra H. Mehta • Gail E. Hafley • Michael J. Mack • Keith B. Allen • Eric D. Peterson • E. Hafley • Michael J. Mack • Keith B. Allen • Eric D. Peterson • Robert A Harrington • C. Michael Gibson • Robert M. Califf • Robert A Harrington • C. Michael Gibson • Robert M. Califf • Nicholas T. Kouchoukos • T. Bruce FergusonNicholas T. Kouchoukos • T. Bruce Ferguson

- ACC- Atlanta, 2010 -- ACC- Atlanta, 2010 -

DisclosuresDisclosuresDisclosuresDisclosures

None of the authors has any disclosures related to this studyNone of the authors has any disclosures related to this study

BackgroundBackground

Saphenous vein grafts (SVG) are the most common conduit used in coronary artery bypass graft (CABG) surgery

Per patient rates of vein graft failure (VGF): 25-45%

Depends on: Population When measured How defined

Alexander JH. JAMA 2005; 16;294(19):2446-2454

Widimsky P. Circulation 2004 30;110(22):3418-3423

Vein Graft FailureVein Graft Failure

Pathogenesis of VGFPathogenesis of VGF Intimal injuryIntimal injury Smooth muscle Smooth muscle

migrationmigration Neointimal hyperplasiaNeointimal hyperplasia AtherosclerosisAtherosclerosis ThrombosisThrombosis

BackgroundBackground

Predictors of Vein Graft Failure:

Location

Diameter

Quality

Number of anastomoses

Time since implantation of the SVG

Cataldo G,Circulation 2003

Shah PJ. J Thorac Cardiovasc Surg 2003

Roth JA, Ann Thorac Surg 1979

native target vessel

BackgroundBackground

Little is know about the relationship between vein graft failure and subsequent clinical outcomes

ObjectivesObjectives

To assess long-term (5 years) clinical outcomes of patients enrolled in the PREVENT-IV trial

To assess the relationship between vein graft failure assessed by coronary angiography 12-18 months post-CABG and 5-year clinical outcomes

EDIFOLIGIDE(n=1508)

PLACEBO(n=1506)

Angiography Cohort(n=1197)

5-year Clinical Endpoint (N=1430, 94.8%)

Angiography Cohort(n=1203)

5-year Clinical Endpoint (N=1435, 95.3%)

Non-Angiography(n=311)

1-year Angiographic Endpoint (81%)

1-year Angiographic Endpoint (79%)

Non-Angiography(n=303)

Enrolled PatientsEnrolled Patients

(n=3014)(n=3014)

PREVENT-IVPREVENT-IVStudy Design & Study Design & Follow-UpFollow-Up

MethodsMethodsMethodsMethods

We assessed the long-term clinical outcomes of patients enrolled in the PREVENT-IV trial

Follow-up was performed by mail or telephone survey

Clinical outcomes included death, MI, and repeat revascularization through 5 years

All events were confirmed by review of medical records

MethodsMethods

Vein graft failure was assessed by quantitative coronary angiography and defined as a ≥75% stenosis anywhere in the vein graft

Vein graft failure was classified both per patient and per graft

Patients who had clinical events or died before angiographic follow-up were excluded from these analyses

Statistical AnalysisStatistical Analysis

Cumulative event rates for clinical outcomes were calculated using the Kaplan-Meier method

Covariate adjusted analyses of outcomes were assessed using the Cox proportional hazards model

Logistic regression was used to assess per patient graft failure outcomes

Statistical AnalysisStatistical Analysis

Individual graft failure rates were adjusted for intrapatient correlation using general estimating equation techniques

The Cox proportional hazards model (with covariates for the number of grafts implanted and the proportion failed) was used to assess the relationship between graft failure and clinical outcomes

Time to 1-Year AngiogramTime to 1-Year AngiogramAngiography CohortAngiography Cohort

Alexander JH. JAMA 2005; 16;294(19):2446-2454

Death, MI, or RevascularizationDeath, MI, or Revascularization

0.0

0.1

0.2

0.3

0 1 2 3 4 5

Ev

ent

Ra

te

Years

Placebo

Edifoligide

HR 1.03 (95% CI: 0.89-1.18)

Death or MIDeath or MI

0.0

0.1

0.2

0.3

0 1 2 3 4 5

Ev

ent

Ra

te

Years From Angiogram

Placebo

EdifoligideHR 1.01 (95% CI: 0.83-1.23)

DeathDeath

0.0

0.1

0.2

0.3

0 1 2 3 4 5

Ev

ent

Ra

te

Years

Placebo

EdifoligideHR 1.10 (95% CI: 0.89-1.36)

Results: VGF and OutcomesResults: VGF and Outcomes

The composite of death, MI, or revascularization occurred more frequently among patients who had vein graft failure compared with those who had did not

Adjusted HR 1.79, 95% CI 1.40-2.28; P<0.001

There was no relationship between vein graft failure and death / MI or death in either per patient or per graft analyses

0.0

0.1

0.2

0.3

0 1 2 3 4

Ev

ent

Ra

te

Years From Angiogram

DD D/MID/MI D/MI/RevascD/MI/Revasc

Vein Graft FailureVein Graft Failure

No Vein Graft FailureNo Vein Graft Failure

Post Angiogram EventsPost Angiogram Events

HR 1.79, 95% CI 1.40-2.28; P<0.001

NSNS

Vein Graft Failure and OutcomesVein Graft Failure and Outcomes““Subgroups”Subgroups”Vein Graft Failure and OutcomesVein Graft Failure and Outcomes““Subgroups”Subgroups”

There was no impact on the relationship between vein graft failure and 5-year clinical outcomes based on:

Graft Target (LAD vs other)

Target Artery Quality (Good vs other)

Graft Quality (Good vs other)

IMA Failure (Yes vs no)

LimitationsLimitations

A causal relationship between vein graft failure and clinical outcomes cannot be proven. We assessed only associations

Angiographic follow-up was protocol driven and may have influence revascularization rates

ConclusionsConclusions

Vein graft failure 1 year after CABG is strongly associated with an increased risk of death, MI, or revascularization at 5 years

This association is driven by early revascularization with no association between vein graft failure and death or MI

Further investigation of the appropriate management of patients with angiographic VGF post-CABG is needed

Thank youThank you

Back up slidesBack up slides

MI Prior to 1-Year AngiogramMI Prior to 1-Year Angiogram

No Vein Graft Failure

Vein Graft Failure

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0.01

0.02

0.03

0.04

0.05

0.06

0 2 4 6 8 10 12

Ev

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Months From Enrollment

Revascularizations Prior to 1-Year AngiogramRevascularizations Prior to 1-Year Angiogram

No Vein Graft Failure

Vein Graft Failure

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0 2 4 6 8 10 12

Ev

ent

Ra

te

Months From Enrollment