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C HAPTER 2 3 / Interventional Cardiology Techniques: Percutaneous Coronary Intervention 547
events include all types of VCD utilization. The use of VCD has patient and documented in the medical record. Patients should be
not shown superiority over manual compression or reduction in reassured that the implantation of a DES after careful consideration
groin complications. The severity of bleeding complications may with the physician remains a very effective treatment for CAD. 3
be worse after a failed VCD compared to manual compression be-
cause the VCD is deployed at maximal anticoagulation while With Noncardiac Surgery and
manual compression is delayed until the ACT is below 180 sec- Invasive Procedures
onds. Device embolism and limb ischemia require emergency vas- When noncardiac surgery or invasive procedures are performed
cular surgery for device removal. 44 early after stent placement before complete stent endothelializa-
tion has occurred, the risk of stent thrombosis is increased.
Antiplatelet therapy is discontinued in the perioperative period;
Stent Thrombosis
surgery itself creates a prothrombotic state increasing the risk of
Stent thrombosis can occur at different time intervals after im- stent thrombosis. Antiplatelet bridging strategies with DES have
68
plantation. Stent thrombosis events have been identified as early- not been well studied. The ACC/AHA has proposed several im-
acute (within 24 hours), subacute (within 30 days), late ( 30 portant points to consider and recommendations for perioperative
days to 1 year), and very late ( 1 year after stent implantation). 63 patient management with PCI.
Stent thrombosis that results in closure of the stent or threatened Perioperative management of patients with recent coronary stents
closure is a potentially life-threatening complication. It can occur and PTCA 68 is important to reduce the risk of stent thrombosis.
with all stents regardless of design or composition. The patient
■ Patients undergoing noncardiac surgery within 1 to 2 weeks af-
usually presents with severe ischemia or acute MI. Stent throm- ter a BMS are at high risk of stent thrombosis and death if an-
bosis was more commonly seen in early stenting experiences with tiplatelet therapy is discontinued in the perioperative period.
BMS, but has decreased with improved pharmacological therapy
■ Surgery should be avoided for at least 4 weeks after BMS im-
and IVUS-facilitated, stent deployment. Thrombotic events with plantation.
BMS are uncommon after 30 days with dual antiplatelet treat-
■ Perioperative stent thrombosis is associated with high mortality
ment. Complete endothelialization of the BMS has been con- and morbidity.
firmed angioscopically within 3 to 6 months.
■ Revascularization does not improve perioperative outcomes in
Since 2003 there has been a rapid increase in the use of DES. patients with stable CAD; stenting prior to noncardiac surgery
There is an increased risk of late (between 7 and 18 months) stent should be avoided.
thrombotic events with DES compared to BMS, resulting in cardiac
■ If PCI is necessary in a patient undergoing surgery, PTCA only
death and nonfatal MI in patients after discontinuation of clopido- may be a useful option. In such a case, surgery should be de-
grel at 6 months. The presumed mechanism is delayed or incomplete layed by a week to permit vascular healing.
endothelialization or localized hypersensitivity to the polymer on the ■ A patient requiring stent who may also need surgery in the fore-
64
DES. Resistance to the antiplatelet effects of aspirin and clopido- seeable future should receive a BMS.
grel has been associated with platelet hyperreactivity. A strong inde-
pendent predictor of stent thrombosis is nonresponsiveness to clopi- Perioperative management of patients with recent DESS S 68 also is
dogrel. Further assessment tools to identify nonresponders and important in prevention of DES thrombosis. The optimal delay of
alternative pharmacological strategies may be indicated for this noncardiac surgery after a DES is unknown, but a delay of 1 year
group of patients. 65,66 The incidence of very late thrombosis with is recommended. Perioperative thrombosis of DES has been re-
DES is about 0.2% events per year after 1 year and up to 0.6% at 3 ported as late as 21 months after stent implantation. Primary PCI
67
to 4 years compared to BMS. There was no significant increase of is the preferred treatment strategy for patients who develop peri-
death or MI reported at 4 years with DES compared to BMS. Sim- operative stent thrombosis. Consultation with cardiology prior to
ilar mortality and morbidity results may reflect a counter balance of surgery and disposition to the telemetry floor or surgical floor af-
an increase in late stent thrombosis with DES but a higher incidence ter surgery are at the discretion of the cardiologist. When clopi-
of restenosis with BMS and the need for repeat target vessel revascu- dogrel is continued throughout surgery, the anesthesiologist will
larization. Treatment for stent thrombosis is emergency PCI or, less be unable to perform spinal or epidural therapies.
commonly, fibrinolysis to restore vessel patency. Proposed recommendations for patients with DES who need
68
Stent thrombosis is associated with a suboptimal angiographic surgery early after stent implantations :
result and incomplete stent apposition (defined as the stent strut
■ Continue dual antiplatelet therapy in the perioperative period
not having full contact with the vessel at implantation or late af- for patients at low risk of bleeding.
ter vessel remodeling leading to thrombosis). Other risk factors for
■ Discontinue dual antiplatelet therapy; bridge with heparin and
thrombosis include specific high-risk lesion characteristics (such GP IIb/IIIa receptor inhibitors for the perioperative period, with
as small vessels and bifurcation lesions), “off-label” use of stents, early resumption of oral antiplatelet therapy postoperatively.
and high-risk patients, such as those with diabetes, renal failure,
■ Stop dual antiplatelet agents preoperatively and restart as early
ACS, and localized hypersensitivity to the stent polymer. Early as feasible with clopidogrel loading.
cessation of dual antiplatelet therapy is a major cause of stent
thrombosis. Obtaining a good angiographic result and adminis-
tering aspirin and a thienopyridine (clopidogrel or ticlopidine) are RESTENOSIS
the cornerstones of stent thrombosis prevention.
Concerns about the prolonged risk of stent thrombosis have re- Restenosis is defined as a coronary luminal re-narrowing after
sulted in the empirical practice of extending dual antiplatelet therapy PCI that is documented by repeat coronary angiography or other
for 12 months or longer. The medical decision-making process and intracoronary imaging modalities. Clinical restenosis or ischemia
risks and benefits of therapy should be thoroughly discussed with the noted on noninvasive testing frequently requires additional revas-