© J PIONEER MED SCI.www.jpmsonline.com Volume 5, Issue 3. July-September, 2015. Page | 79
Should We Use Left Internal Thoracic Artery to
Graft Left Anterior Descending Coronary Artery
at Re-operative CABG?
Mehwish Zehra
1
, Sajjad Raza
2
1
Medical student, Karachi Medical & Dental College, Karachi, Pakistan
2
Research Fellow, Thoracic and Cardiovascular Surgery, Cleveland Clinic, Ohio, USA
Conflict of Interest: None
declared
This article has been
peer-reviewed
Article Submitted on: 13
th
April 2015
Article Accepted on: 17
th
April 2015
Funding Sources: None
declared
Correspondence to: Dr
Sajjad Raza
Address: Department of
Thoracic and
Cardiovascular Surgery,
Cleveland Clinic, Ohio,
USA
Email: razas@ccf.org
raza.sajjad@outlook.com
Cite this article: Zehra M,
Raza S. Should we use left
internal thoracic artery to
graft left anterior
descending coronary
artery at re-operative
CABG? J Pioneer Med Sci
2015; 5(3):79
Coronary artery bypass grafting (CABG) has
prolonged the life of a number of patients with
coronary artery disease (CAD) [1, 2]. Today, in
addition to patients undergoing first-time CABG,
cardiac surgeons are faced with many patients
who need coronary reoperations. The benefit of
left internal thoracic artery (LITA) to left anterior
descending artery (LAD) grafting is well-proven
by the study published in the NEJM in 1986 by
Loop et al [3]. This study showed significant
improvement in survival at 10 years in patients
who received LITA to LAD as compared to the
patients who received saphenous vein graft
(SVG) to LAD at primary CABG. Therefore,
LITA to LAD grafting is considered the gold
standard in primary coronary revascularization.
However, it was not known if this is also true for
re-operative CABG. Therefore, to find whether
LITA to LAD grafting at coronary reoperation is
safe and beneficial, researchers at Cleveland
Clinic conducted a study which they published in
the Journal of American College of Cardiology
(JACC) [4].
They found that from 1985 to 2007, re-operative
CABG was performed in 3473 patients who did
not receive LITA during their primary CABG
and who now had anterior wall ischemia. Of the
patients who underwent re-operative CABG,
1084 received SVG graft to LAD and the
remaining received LITA to LAD. Propensity-
matching was done for fair comparison of
outcomes. End-points of study were in-hospital
outcomes and long-term mortality. Median
follow-up was 14 years (mean 11±8.2). Total
available follow-up was 37,638 patient-years and
ten-percent of the patients were followed for
more than twenty-two years.
The outcomes in 908 matched patient-pairs
showed that in-hospital death, stroke, and
respiratory failure were significantly lower in the
LITA to LAD group (p-values for all
comparisons were <.05) compared to SVG to
LAD group. Long-term survival was also better
with LITA to LAD grafting (p=0.005). The
instantaneous risk of death overtime showed that
there was a high early risk lasting for about 6
months followed by gradually increasing risk
over 20 years. This rate of increase was higher
for the SVG group than for the LITA group. The
difference in survival across time showed
absolute risk reduction of 6% at 20 years with
maximum survival advantage of LITA grafting
becoming evident at around 12 years after re-
operative CABG. The number needed to treat to
save one life with LITA as compared to SVG
over a period of 20 years was 16.
Some of the limitations of this study include that
it was a non-randomized, observational study and
patient selection could have influenced its
findings. To account for this the investigators
used propensity score-matching. Deaths in the
study represent all-cause mortality and, therefore,
we don’t know how many deaths were cardiac-
related.
REFERENCES
1. CABG information. The Society of Thoracic Surgeons.
Available at: http://www.sts.org/patient-
information/adult-cardiac-surgery/cabg-information
Accessed on April 12, 2015
2. Hillis L, Smith PK, Anderson JL, et al. 2011
ACCF/AHA Guideline for Coronary Artery Bypass
Graft Surgery: A Report of the American College of
Cardiology Foundation/American Heart Association
Task Force on Practice Guidelines Developed in
Collaboration With the American Association for
Thoracic Surgery, Society of Cardiovascular
Anesthesiologists, and Society of Thoracic Surgeons. J
Am Coll Cardiol. 2011; 58(24):e123-e210.
3. Loop FD, Lytle BW, Cosgrove DM, et al. Influence of
the internal-mammary-artery graft on 10-year survival
and other cardiac events. N Engl J Med. 1986; 314: 1–6
4. Sabik JF, Raza S, Blackstone EH, Houghtaling PL,
Lytle BW. Value of Internal Thoracic Artery Grafting to
the Left Anterior Descending Coronary Artery at
Coronary Reoperation. J Am Coll
Cardiol. 2013;61(3):302-310.