ANESTHESIA FOR NON CARDIAC
SURGERY IN PATIENTS WITH
CORONARY STENTS
Dr. Mahesh Vakamudi
Professor and Head
Department of Anesthesiology, Critical Care and Pain Medicine
(ISO 9001:2008 CERTIFIED)
Sri Ramachandra University
Chennai
Magnitude of the problem
 2 million patients undergo PCI annually
 90% of these patients receive one or more
intracoronary stents
 5% of these patients will undergo non cardiac
surgery in the first year after stenting
NUMBER
Percutaneous
coronary
interventions
Stents commonly
placed
>
Coronary artery
bypass
surgeries
Increase
procedural success
Decrease
restenosis
Why this lecture?
 In patients who have coronary stents,
perioperative coronary stent thrombosis is a
catastrophic complication
 Non cardiac surgery, especially if surgery is
performed immediately after stenting and
particularly if dual antiplatelet therapy is
discontinued – increases this risk
 Maintain balance between risk of bleeding and
stent thrombosis is our dilemma.
 What do we do? That’s what this lecture is about
Which patients are prone for
stent thrombosis?
 Patients with a suboptimal angiographic
result
 Those with high risk lesions
 Small vessels
 Bifurcation lesions
 Those with diabetes and renal failure
 Those whose dual antiplatelet therapy has
been stopped
Scoring system for LST
Risk score for prediction of LST
Renal failure
Bifurcation lesion
Diabetes
Brachytherapy
Each 20% fall in EF
Low
0
6 points
6 points
4 points
2.5 points
0.25 points
Medium
6
High
9
Very High
13
19
Why thrombosis?
Early surgery
Stents not
endothelialized
Prothrombotic
state due to
surgery
Stopping
antiplatelets
Discontinuation of Aspirin and Clopidogrel
Loss of
antiplatelet
effect
Rebound
increase in COX
1 and TXB2
Increased thrombin
and decreased
fibrinolysis
Surgery
⁺
Prothrombotic
state
Loss of antiinflammatory
protection by
clopidogrel
Stent
thrombosis
&
MI
Coronary
angioplasty
without stents
Bare metal
stents
Abrupt vessel collapse due to
acute recoil and vasospasm
Stent placement injures
vessel wall and causes scar
tissue growth inside the
stent
Drug eluting
stents
Prevent
neointimal
hyperplasia
Platform + Carrier
(Stent + Drug)
Antiproliferative and
immunosuppressive
properties
but
Stent
restenosis
Delay
endothelialization
Late stent
thrombosis
Incidence of deaths
Bare metal stents
8 out of 25 patients who underwent surgery
within 2 weeks died – 7 of MI, 1 of bleeding
None out of 15 patients who underwent
surgery after 15 days died
Kaluza GL, Joseph J, Lee JR, Raizner ME, Raizner AE.
Catastrophic outcomes of noncardiac surgery soon after coronary stenting.
J Am Coll Cardiol 2000;35:1288 –94.
Bare metal stents
The
of death,
or stent thrombosis
Of
27risk
patients
whoMI,
underwent
non cardiacwas
surgery
elevated
for 6 weeks,
forofjust
2 weeks
within
3 weeks
of BMS,not
86%
those
who stopped
antiplatelets died
Sharma
AK,Fasseas
Ajani AE,
HamwiJL,
SM,
Majoroutcome
noncardiac
surgery
Wilson SH,
P, Orford
etet
al.al.
Clinical
of patients
following
coronary
stenting:
when
is ittwo
safemonths
to operate?
Catheter
undergoing
noncardiac
surgery
in the
following
coronary
Cardiovasc
Interv
stenting. J Am
Coll2004;63:141–5.
Cardiol 2003;42:234–40.
DES
 First generation DES elute
 Sirolimus
 Paclitaxel
 Second generation DES elute
 Zotarolimus
 Everolimus
Drug eluting
stents
McFadden et al. (19) reported DES thrombosis in 3 patients
undergoing surgery late (343 to 442 days) after implantation.
Nasser et al. (20) reported sirolimus-eluting stent (SES)
thrombosis in 2 patients after surgery performed 4 and 21
months after SES implantation.
Avoid preoperative
coronary stenting
Stent selection (BMS
vs DES)
Delay surgery
Optimize
antiplatelet therapy
Education and
collaboration
Avoid preoperative
Choose BMS
coronary
if
revascularization,
Surgery neededunless
from 6
thereweeks
exists to
a strong
12 months
and
proven
Bleeding
indication
diathesis
Patient unable or unwilling
to
receiveballoon
long term
Consider
clopidogrel
angioplasty
if surgery
is BMS
needed
Choose
DES
if 6
– 6within
weeks
weeks.
stents
surgery
needed
DES –Avoid
12ismonths
after 12 months
Continue
antiplatelet therapy
during surgery
Surgeons
anesthesiologists
cardiologists
Avoiding revascularization
 CARP trial
 510 stable patients with CAD undergoing
major vascular surgery
 Randomized to revascularization (by CABG or
PCI) or no revascularization
 Similar incidence of postoperative MI and 27
month survival in both the groups
So, first ask the question: Is
revascularization necessary?
Revascularization without
stents (Balloon only)
 Patients with acute coronary syndrome and
those with profound ischemia on non invasive
testing do need revascularization
 Can be done without stents: Percutaneous
balloon angioplasty
 In this study, when surgery was done 11 days
after PCI, only 1 patient died and 1 had an AMI
Gottlieb A, Banoub M, Sprung J, Levy PJ, Beven M, Mascha EJ.
Perioperative cardiovascular morbidity in patients with coronary artery
disease undergoing vascular surgery after percutaneous transluminal
coronary angioplasty. J Cardiothorac Vasc Anesth 1998;12:501– 6.
When surgery after Balloon
angioplasty?
 2002 ACC AHA guidelines
 Delaying noncardiac surgery for 6 to 8 weeks
was discouraged because restenosis could have
occurred
 Performing noncardiac surgery too early after
the PCI also may be risky because acute or
subacute closure after balloon angioplasty
usually occurs within hours to days after the
procedure.
 Delay surgery for 1 week after balloon
angioplasty
If stenting can’t be avoided
 Complex lesion or inability to achieve optimal
result with balloon angioplasty
 Choose the right stent
 Surgery needed with 12 months: Choose BMS
 Surgery can be delayed for > 12 mth: DES
 BMS endothelialize more rapidly than DES
 Sirolimus eluting stent preferable as it requires 3
mths of antiplatelet therapy than a paclitaxel
eluting stent that requires 6 mths of clopidogrel
Delay surgery
 6 weeks BMS
 12 months DES
Major
adverse
cardiac
events 10
(%)
Bare metal
stents
Drug eluting
stents
8
6
4
2
0
0
2
4
6
8
10
12
14
Time from stent until surgery (months)
16
18
RISK OF PERIOPERATIVE STENT THROMBOSIS WITH DES
Stents implanted in left main coronary artery
Stents implanted in bifurcations
Greater total stent length (multiple/overlapping stents)
Heightened platelet activity (surgery, DM, malignancy)
In stent restenosis
Left ventricular dysfunction
Localized hypersensitivity vasculitis
Penetration by stent into necrotic core
Plaque disruption into non stented segment
Renal failure
Diabetes mellitus
Resistance to antiplatelets
Inappropriate discontinuation of antiplatelet medications
What are the steps to
prevent stent
thrombosis in these
patients coming for
non cardiac surgery?
Periop antiplatelet therapy
 Continue dual antiplatelet thearpy during and
after surgery
 Discontinue clopidogrel but “bridge” the
patient to surgery with Glycoprotein IIb/IIIa
inhibitor or an antithrombin, and restart
clopidogrel as soon as possible after surgery
 Discontinue clopidogrel before surgery and
restart it as soon as possible after surgery
Impact of aspirin on bleeding
 Most studies in cardiac and vascular surgery
 Safe in doses of 75 – 150 mg
 Increases bleeding by a factor of 1.5, no effect
on morbidity and mortality
 Avoid in TURP and intracranial surgery (as
bleeding in these situations can be life
threatening)
Option 1 : Continue therapy
 Dental extractions
 Cataract surgery
 Dermatologic surgery
Option 2: Bridging therapy
 Bridge using short acting antiplatelet or an
anticoagulant
 Platelet inhibitors are the more logical choice
as stent thrombosis is a platelet mediated
phenomenon
 Cessation of heparin in a patient not on
antiplatelets can cause rebound effect and
stent thrombosis
Bridging therapy
 A shortacting GP IIb/IIIa inhibitor (tirofiban or
eptifibatide) or thrombin inhibitor, or both, is
substituted for clopidogrel during the
perioperative period
 Role
 Prevent platelet aggregation
 Displace fibrinogen from GP IIb/IIIa receptors
 Block signaling processes
Bridging therapy
 Tirofiban and eptifibatide are administered




parenterally
Have half-lives 2 h
Eliminated by renal clearance.
Infusion rate is reduced by half in patients
with reduced renal function
Platelet function returns to 60%–90% of
normal after the infusion is stopped for 6–8 h.
When bridging therapy?
 Surgeries with high risk of bleeding
 Intracranial
 Spinal
 Retinal
Other drugs
 Reversible P2Y12 receptor antagonists are
undergoing clinical trials
 Cangrelor is a parenteral, reversible direct P2Y12
inhibitor
 Half-life of 5–9 min allows 100% recovery of
platelet function 1 h after the infusion is
discontinued
 4 mcg/kg/min infusion achieves complete
platelet inhibition when measured at 4 min
 AZD6140 is an oral, reversible direct P2Y12
receptor antagonist with a half life of 12 hrs.
Problems with bridging
therapy
 Expensive
 Logistically difficult
 Exposes patients to risks associated with a
prolonged hospitalization
 Some claim that it confers no protection
against intraoperative stent thrombosis
Option 3: Stop antiplatelets
 Neurosurgery
 Restart clopidogrel after surgery
 600 mg loading dose – Maximal inhibition of
platelet aggregation in 2 – 4 hours (takes 6
hrs with 300 mg)
 Reduces the incidence of hyporesponsiveness
to platelets (which are activated due to
surgery)
Steps: Preoperative evaluation
 Determine the type of stent: BES, SES, PES
 When were stents implanted?
 Determine location of stent in coronary
circulation
 How complicated was the revascularization?
 Is there a previous history of stent thrombosis?
 What antiplatelet regimen is being followed?
 Determine co-morbidities?
 What is the recommended duration of
antiplatelet therapy for this patient?
 Co-ordinate with cardiologist
Steps
 Perform procedure in centers where there is
24 hr interventional cardiology coverage for
emergency PCI
Intraop management
 Tight hemodynamic control
 Use of beta blockers
 Good HR control
 Good BP control
 Decrease sympathetic outflow and therefore
decrease platelet activation
Regional anesthesia in
patients on antiplatelets
 Advantages
 Attenuation of hypercoagulable state
 Systemically absorbed LA have antiplatelet effect
 Follow ASRA guidelines
 For patients receiving bridging therapy with
eptifibatide or tirofiban, 8 h must elapse
before a neuraxial blockade can be performed
Management of stent
thrombosis
 ST segment elevation acute myocardial
infarction
 Reperfusion
 Thrombolytic therapy less effective than
primary PCI
 Platelet mediated phenomenon
 Risk of bleeding
 All that is required during PCI is aspirin and
one dose of heparin or bivalirudin
Role of platelet transfusion
 Transfused platelets are not inhibited by
serum therapeutic levels of antiplatelets
 The thrombogenic surface of stents may
attract and activate donor platelets to an
even greater extent than endogenous
platelets
Platelet transfusions to be avoided except
in instances of life threatening bleeding
Algorithm for patients with DES for NCS
Emergency
Semi emergency
Elective
DES
> 1 yr
Assess risk of bleeding
Low
Intermediate
Length of DAPT
Continue
DAPT
< 1 yr
High
STOP
Stop Anti PLT
> 1 yr
Stop clopidogrel
Continue LD aspirin
Proceed with
surgery
DES
< 1 yr
Assess risk of
thrombosis
Low
High
Hosp Admn
? IV Anti PLT
Education
 In a survey of anesthesiologists, 63% were
not aware of recommendations about the
appropriate length of time between stent
placement and a subsequent surgical
procedure, and one-third recommended no
delay or a delay of only 1 to 2 weeks, which is
insufficient for BMS, and even more so for
DES
Patterson L, Hunter D, Mann A. Appropriate waiting time for
noncardiac surgery following coronary stent insertion: views of Canadian
anesthesiologists. Can J Anaesth 2005;52:440 –1
Take home points
 Many patients come for non cardiac surgery
after PCI
 Stent thrombosis is a catastrophe
 Remember the stepwise approach to the
issue
Avoid preoperative
coronary stenting
Stent selection (BMS
vs DES)
Delay surgery
Optimize
antiplatelet therapy
Education and
collaboration
Thank
you