Hybrid coronary revascularization (HCR) combines coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) to treat multivessel coronary artery disease. HCR aims to perform CABG on the left anterior descending artery using a left internal mammary artery graft via minimally invasive surgery while treating other vessels with PCI. This approach seeks to provide the benefits of CABG for the LAD while reducing surgical trauma compared to traditional CABG. The optimal strategy and order of CABG versus PCI, as well as antiplatelet management, are debated due to the lack of large randomized controlled trials on HCR. HCR shows promise for high surgical risk patients but further research is still needed to define appropriate patient selection

1. Hybrid Coronary
Revascularization

2.  Hybrid coronary revascularization (HCR) was
first introduced in the 1996 as a pioneering
treatment approach to multivessel coronary
artery disease (CAD), hoping to bring together
the “best of both worlds”.
 HCR aims to reduce surgical trauma while
preserving long-term survival and minimizing
adverse cardiovascular event.

3.  The intial concept was launched by Dr.Gianni
Angelini et al from Imperial College, London
and included a small number of patient
population (6pts) and received favorable
outcomes in terms of hospital stay ,duration of
extubation and 6 month survival.

4.  In the era of BMS when restenosis after PCI
was more frequent than the modern PCI
results, multiple revascularization procedures
were common, only they were staged by days,
weeks, or perhaps months.

5.  In the modern era, a hybrid procedure refers
to the combination of CABG and PCI, staged
by minutes, hours, or at most, days.
 It has gained interest as cardiac surgeons
have improved techniques for minimally
invasive surgical approaches, while
interventional cardiologists have at their
disposal improved devices and have
developed skills that have enabled them to
become more aggressive in their
percutaneous interventions.

6.  As interventional cardiologists are becoming
“surgeons” with more invasive tools, surgeons
are becoming “interventional cardiologists”
with less invasive tools.
 Hence, the division between the 2 specialties
is becoming blurred, and we are meeting in
the middle.

7.  The hybrid approach includes left internal
mammary artery (LIMA) anastomosis to the
left anterior descending coronary artery (LAD),
typically via a minimally invasive approach,
and percutaneous coronary intervention (PCI)
for the remaining (non-LAD) lesions.

9. RATIONALE ,INDICATIONS AND
CONTRAINDICATIONS
 Several trials have compared the outcomes of
CABG surgery versus PCI in multivessel
disease.
 In a review of 23 randomized studies
comparing PCI and CABG, survival at 10
years was similar even among the diabetic
population; however, the rate of repeat
revascularization rate was higher in PCI than
CABG along with lower rate of relief from
angina.

10.  LIMA–LAD graft has excellent patency rates,
which correlates with increased eventfree
survival in CABG pts and LIMA-LAD graft may
be responsible for the majority of the benefit of
CABG surgery.
 Whether the non LAD lesions are treated with
SVG or PCI, it becomes statistically less
significant than LIMA.

11. This is the premise on which the modern era of
hybrid coronary revascularization is based.
Conversely, with PCI, the location of the lesion
in the proximal LAD has been identified as an
independent risk factor for in-stent restenosis
with rates between 19% and 44%.

12.  With the advance of the stent technology it
has shown favorable clinical outcomes with
DES as compared to SVG in non LAD
territories.

13.  Indications for hybrid CABG/PCI (MIDCAB and
TECAB) include patients with multivessel
disease who have high-grade proximal
disease of the LAD along with favorable
lesions for PCI in the left circumflex and right
coronary artery territories.

14.  Other indications where PCI may represent a
superior alternative to SVG conduit are lack or
poor quality of the conduit, a nongraftable but
stentable vessel (e.g., LCX lesion in the
atrioventricular groove with small diffuse
obtuse marginal)

15.  The rationale for HCR lies in the well-
established survival benefit conferred by
LIMA-to-LAD grafts and the use of new stent
platforms featuring lower stent restenosis and
thrombosis rates compared with venous graft
stenosis and occlusion rates, respectively.
 Individually the patency rates and survival
rates of arterial conduits are better than the
venous grafts in patients undergoing CABG.

16. THE SURVIVAL BENEFIT OF A
SURGICAL LIMA-TO-LAD GRAFT
A unique conduit, the LIMA powerfully resists
thrombosis and atherosclerosis.
Furthermore, a LIMA graft protects the native
coronary tree from the deleterious effects of
disease progression

17.  Because of the higher arterial pressures and
unfavorable venous wall anatomy it is not
suitable to carry blood at such higher
pressures and hence is vulnerable to
reocclusion.
 Some studies suggest 75.9% 5 yr survival
rates in SVG grafts as compared to 86.6% in
LIMA grafts. While patency being 96% in LIMA
as compared to 81.1% in SVG.(NEJM 1986)

18. WHAT FAVOURS LIMA OVER
SVG
 LIMA even has a superior thrombotic profile in
terms of thrombosis when compared to DES.
 It is termed as relatively resistant to
atherosclerosis and has a protective role on
native coronary tree.
WHY???
 Endothelial layer has fewer fenestrations.
 Intercellular junctions have lower permeability.
 Higher eNOS activity
 Resistant to transfer of lipoproteins.

19.  Thus, PCI and stenting provide strong
competition for SVG revascularization
because, unlike an LIMA-LAD graft, disease
progression in the proximal native coronary
segment occurs alongside SVG deterioration

20.  Moreover, significant angiographic SVG stenosis
occurs at least twice as frequently as in-stent
restenosis using the latest technology platforms.
 However, ischemia-driven revascularization rates
are considerably higher in stented patients with
treated multivessel CAD.
 Furthermore, even though SVG occlusion occurs
at a higher rate compared with stent thrombosis ,
the clinical consequences of the latter are more
dramatic, as it is more frequently associated with
major adverse clinical events.

21. CONTRAINDICATIONS
1. LAD is non graftable.
2. LAD is intramyocardial.
3. Previous surgery involving left chest cavity.
4. Left SCA stenosis causing LIMA graft
unsuitable.
5. Lack of tolerance of single lung ventilation.

22. PATIENT SELECTION FOR
HCR
CONCEPT OF HEART TEAM

23. HEART TEAM
 First introduced in ESC 2013 as a followup of
tumour boards of 1968.
 While decision-making for patients with acute
indications or less complex coronary disease may
be straightforward, for patients with stable
complex (e.g. left main and/or multivessel)
coronary artery disease (CAD), a Heart Team
consisting of a clinical/non-invasive cardiologist,
interventional cardiologist, and cardiac surgeon is
considered optimal to best assess the advantages
and disadvantages of the various treatment
strategies.

24.  The Heart Team has recently become a class
1C recommendation in European and
American guidelines on myocardial
revascularization.

25.  A study from Circulation 2010 done in New
York suggests that in patients with an
indication for coronary artery bypass grafting
(CABG), only 53% received such treatment,
34% underwent percutaneous coronary
intervention (PCI), 12% received medical
management, and 1% did not receive any
treatment.

26.  Following consultation with the institutional
heart team the decision should be taken for
HCR
 Factors to consider are the coronary tree
anatomy,proximal LAD lesion, renal status and
history of previous cardiopulmonary
interventions.

27.  Important anatomical feature favoring HCR should be
plaque burden in the proximal LAD well characterized
by the SYNTAX (SYNergy Between PCI With TAXUS
and Cardiac Surgery) score.
The classic indication for HCR is multivessel CAD
including:
1) a proximal complex LAD lesion with optimal distal
anatomy amenable to LIMA-to-LAD grafting;
2) non- LAD lesions amenable to PCI, in a patient with
no contraindications to dual antiplatelet therapy
(DAPT)
3) a high likelihood of achieving “reasonable incomplete
revascularization” with such an approach.

28.  Complex distal left main lesions are also ideal
for HCR if the circumflex artery territory is
amenable for PCI.
 HCR appears particularly appealing for
patients with the aforementioned coronary
anatomy and others considered too high risk
for open cardiopulmonary bypass surgery via
midline sternotomy.

29. HIGH RISK CASES FOR
CABG
 High risk of deep sternal wound infection (e.g.,
diabetics, morbidly obese)
 Severely impaired left ventricular function
 Chronic kidney disease
 Significant carotid or neurological disease
 Severe aortic calcification
 Prior sternotomy.

30.  The 2011 American College of Cardiology
Foundation/American Heart Association
guidelines for CABG state that the “primary
purpose of performing HCR is to decrease the
morbidity rate of traditional CABG in high-risk
patients”

31.  In ESC/EACTS latest guidelines HCR has a
Class IIb recommendation for specific patient
subsets and only at experienced centers.
 The lack of several large randomized
controlled trials (RCTs) involving different risk
groups, hinders the identification of an HCR
target group.

32.  According to STS database at present .48% of
patients ideal for HCR actually undergo the
procedure and primarily that is because of the
lack of RCTs and proper identification of the
patient group.

33. TECHNICAL ISSUES
1- VERSUS 2-STAGED APPROACH.
HCR can be performed either simultaneously
or as a “2-staged” procedure.
The former implies concurrent CABG and PCI
in a single operative suite, with PCI following
CABG within minutes.
In the “2-staged” approach, the optimal order
PCI first versus CABG first is debated because
each approach has advantages and
disadvantages.

34.  A simultaneous approach is only feasible in
hybrid suites featuring state-of-the-art surgical
and interventional equipment.
 Often, CABG is performed first, allowing the
interventional cardiologist to study the LIMA-
LAD graft before stent implantation.
 Thus, PCI to high-risk, non-LAD lesions is
performed with a protected LAD territory. In
case of unsuccessful stent implantation,
surgical bailout graft implantation remains an
option.

35.  Additionally, the simultaneous HCR approach
can be cost effective by reducing hospital
length of stay, the risk of lesion destabilization,
and recurrent hospital admissions between
staged procedures.
 An additional advantage is improved patient
satisfaction, as it condenses revascularization
into 1 patient encounter.

36.  But the challenge is balancing the need for
appropriate antiplatelet therapy, to avoid stent
thrombosis, with surgical bleeding risk.
 Performing the LIMA-LAD anastomosis under
DAPT can be difficult, particularly when a
minimally invasive approach and video-
assisted LIMA take-down are used.
 Also The response of DES to protamine
administration at the end of CABG has not
been fully investigated

37.  When DAPT is not administered to reduce
surgical bleeding risk, PCI becomes risky and
is not recommended.
 Another challenging scenario for “1-stop”
HCR is the patient with chronic kidney
disease, who is exposed in a short period of
time to the dual nephrotoxic insult of surgery
and contrast media.

38.  When the HEART TEAM favors a 2-step
procedure, the sequence of PCI and CABG
should be guided by clinical presentation and
coronary anatomy.
 2011 ACC/AHA guidelines favor performing
CABG first followed by PCI.

39.  This strategy allows
1. Angiographic visualization of the LIMA-LAD
graft
2. complete antiplatelet inhibition following CABG
with no perioperative bleeding risk
3. Provides a protected anterior wall, lowering
procedural risks during PCI of non-LAD
vessels.

40.  On some occasions after minimally invasive
LIMA to LAD, patients become asymptomatic
in the immediate post-operative period.
 In these cases, when the residual non-LAD
lesions are angiographically intermediate,
optimal medical therapy and watchful waiting
may be in the patients’ best interest

41.  The disadvantages of a CABG-first approach
include the risk of ischemia of non-LAD
territories during the LIMA-LAD grafting and
the potential for a high risk surgical
reintervention following unsuccessful PCI.

42.  However, a PCI-first approach is reasonable in
patients presenting with acute coronary
syndrome (ACS) who undergo non-LAD culprit
lesion PCI followed by CABG of the LAD.

44. ANTIPLATELET
MANAGEMENT
 Balancing the risk of perioperative bleeding
with that of stent thrombosis.
 In the majority of HCR registries following the
“CABG-first” approach CABG was performed
on aspirin; a second antiplatelet agent was
started >4 h post-bypass after ensuring that
no bleeding complications had occurred

45.  In the “PCI-first” approach, DAPT is typically
commenced ahead of the PCI procedure and
is continued uninterrupted during CABG.
 In most series of simultaneous HCR, patients
are not pre medicated with clopidogrel and
undergo the LIMA LAD graft taking only
aspirin, followed by a single loading dose of
clopidogrel 300 mg either when the LIMA-LAD
graft is completed, just before its completion,
or immediately post-PCI.

46.  Newer antiplatelet agents like prasugrel,
ticagrelor, or cangrelor(an investigational
agent with rapid onset and reversal) could
prove to be safer alternatives for HCR;
however, this remains an “evidence-free”
zone.

48. PROCEDURAL STEPS FOR
SINGLE STAGED APPROACH

49. INDIVIDUAL COMPONENTS OF
HCR
THE LIMA-LAD ANASTOMOSIS
In most cases, the LIMA-LAD anastomosis can
be performed using the minimally invasive
approach, which aims to avoid cardiopulmonary
bypass and the sternotomy incision.
Minimally invasive direct coronary artery bypass
grafting (MIDCAB) is performed on the beating
heart through a small, left-sided thoracotomy in
the 4th
/5th interspace via direct visualization.

50. To avoid the significant chest wall manipulation
associated with MIDCAB and to improve post-
operative pain control, thoracoscopic and robotic
techniques have been developed.
These include the endoscopic atraumatic
coronary artery bypass (Endo-ACAB), which
allows thoracoscopic/robotic LIMA identification
and mobilization followed by a direct non–rib
spreading thoracotomy permitting hand-sewn
anastomosis on the beating heart

51. Totally endoscopic coronary artery bypass
grafting either on- or off-pump, in which the
anastomosis is performed intracorporeally using
a robot.
The latter, although challenging, produces a
reported clinical freedom from graft failure as
high as 98.6% at 13 months in experienced
hands

52. EVIDENCE BASED
APPROACH
 Since its inception in 1996 a limted number of
large studies have been conducted regarding
the efficacy of HCR.
 Majority of the registries are published
between 2008-2013.
 Various aspects of HCR due to lack of RCTs
are still under debate.

53.  In a recent metaanalysis by Harskamp et al.
comprising 1,190 no significant differences
were found for the composite of death,
myocardial infarction, stroke, or repeat
revascularization at 1 year.
 In the most recent registries, CABG was
performed before PCI in about one-half of the
HCR procedures,whereas PCI was performed
first in quarter of the pts.

54.  One-stop HCR proved the least popular,
highlighting the practical difficulties of setting
up and running a hybrid operating room.
 However, among cohort studies comparing
HCR with conventional CABG, 1-stop HCR
appears to be the most popular strategy,
highlighting that the simultaneous approach is
considered the gold standard for comparisons
with other revascularization strategies.

55.  The majority of HCR patients are just over 60
years of age, are predominantly male, and
have a diabetes prevalence varying from 23%
to 40.7%.
 The presentation mode varied across the
studies, with ACS prevalence as low as 0% to
as high as 74%.
 In the majority of HCR cases, left ventricular
ejection fraction was preserved or, at most,
mildly impaired.

56.  Most reports focus on the lower morbidity
related to the minimally invasive nature of the
procedure’s surgical component as compared
with conventional CABG.
 Low morbidity is mirrored by reduced blood
transfusion requirements, shorter intensive
care and hospital length of stay, and faster
recovery

57. PATENCY RATES
 Fitzgibbon A or B LIMA patency rates (A
[excellent], B [fair], or O [occluded]) have
been reported in a high percentage of
patients: ranging from 93% to 100% of
patients in the perioperative period ,90% and
94% of patients at 6 months and 91% of HCR
patients at 2 years post-grafting.

58.  Only 2 studies in the last 5 years reported
angiographic follow-up of patients who
underwent HCR.
 In a study of 60 patients, Kiaii et al reported 2-
year angiographic follow up in 54 (90%)
patients. In-stent restenosis rates were 13%,
whereas in-stent thrombosis was observed in
3.7% of patients.

59.  In another study of 94 HCR patients with 6-
month angiographic follow-up , instent
restenosis was reported in 9% of patients,
whereas in-stent thrombosis was seen in
2.2%.
 These figures concur with those reported from
studies using first-generation DES

65. CONTROVERSIES
 Why should institutes adopt a complex, costly
procedure when similar survival and morbidity
outcomes can be obtained with a well-
established, safe procedure available in most
hospitals

66. FIRST a recent study, shows signals of
improved MACE outcomes in the HCR versus
conventional CABG group for patients in the
highest EuroSCORE tertile (>6), suggesting a
potential target population that would benefit the
most from this complex procedure

67.  SECOND, the use of HCR in lower- to
intermediate risk groups could be justified by
improved patient satisfaction, shorter intensive
care and hospital stays, faster return to work
and quicker return to normal daily activities.

68.  For patients who undergo LIMA to LAD first as
part of an intended staged HCR, and who
become asymptomatic postprocedure, the
benefits of PCI to residual intermediate non-
LAD lesions should be questioned.
 Optimal medical therapy watchful waiting
alongside ischemia testing when
symptomatology is unclear provides a
reasonable alternative, albeit not evidence
based.