What Are the Role and Management of Percutaneous Coronary Intervention for Noncardiac Surgery?

Introduction

Percutaneous coronary intervention (PCI) has revolutionized the management of coronary artery disease (CAD), initially with balloon angioplasty (BA) and subsequently with coronary stenting both with bare-metal stents (BMSs) and with drug-eluting stents (DESs). The high incidence of coronary restenosis from neointimal coronary endothelial growth after BA prompted the clinical development and introduction of BMS placement. Although they represented a significant therapeutic advance, BMSs were still associated with coronary restenosis rates in excess of 10%. The second major significant reduction in coronary restenosis after PCI resulted from DESs that pharmacologically retard stent endothelialization and neointimal growth with antimitotic agents such as sirolimus, paclitaxel, everolimus, and zotarolimus. Because of slow release of these cytostatic agents, the risk of coronary restenosis with DESs has been significantly reduced to less than 10%. The newer generations of DESs have extended the outcome benefits even further as compared with the first generation of DESs with a 38% lower risk of clinically significant coronary restenosis, a 43% lower risk of stent thrombosis (ST), and a 23% lower risk of death.

Since the introduction of DESs, millions of these devices have been implanted worldwide. The prevention of coronary ST is of paramount importance because this complication has a high mortality rate. The risk of ST is particularly high before the coronary stent has been coated with endothelium (approximately 4 to 6 weeks for BMSs and at least 1 year for DESs). As a result, dual antiplatelet therapy with aspirin and clopidogrel has been recommended for at least 1 month after BMS placement and for at least 12 months after DES placement. Although premature discontinuation of antiplatelet therapy is a major risk for ST, there are multiple identified clinical and angiographic risk factors for ST ( Table 12-1 ).

TABLE 12-1

Identified Risk Factors for Coronary Stent Thrombosis

Clinical Risk Factors	Angiographic Risk Factors
Cessation of platelet blockade	Thrombus-containing coronary lesions
Advanced age	Multiple coronary lesions
Diabetes	Overlapping coronary stents
Low ejection fraction	Coronary ostial lesions
Renal failure	Small-caliber coronary vessels
Acute coronary syndrome	Complicated stent deployment
Perioperative period	Coronary bifurcation lesions
Malignancy	Inflow lesion proximal to coronary stent
Peripheral arterial disease	Outflow lesion distal to coronary stent
Smoking	Development of neoatheroma within coronary stent

The perioperative period qualifies as a major risk factor for ST because noncardiac surgery (NCS) activates platelets and induces hypercoagulability. The significant risk of perioperative ST for BMSs was highlighted in a small case series that documented a 20% mortality rate in NCS within 6 weeks after BMS deployment. Furthermore, NCS after recent BA is not without risk of myocardial ischemia and perioperative mortality. In a case series of 350 patients who had NCS within 2 months after BA, the perioperative mortality rate was 0.9% (95% confidence interval [CI], 0.2% to 2.5%).

Given that up to 20% of patients with coronary stents require NCS within 3 years after PCI, the perioperative management of patients with recent PCI (BA, BMSs, DESs) is important because it concerns millions of patients who may be at significant perioperative risk of major adverse cardiovascular events. This chapter reviews the options, latest evidence, and current expert recommendations concerning the perioperative risk of recent PCI in NCS.

Options to Minimize Stent Thrombosis after Recent Percutaneous Coronary Intervention and Noncardiac Surgery

The perioperative options for limiting coronary thrombosis after recent PCI are presented in Table 12-2 . The evidence for each option will be reviewed. Recent expert recommendations will be presented according to the schema of the American Heart Association (AHA) and American College of Cardiology (ACC), as outlined in Tables 12-3A (classes of recommendations) and 12-3B (levels of evidence). The expert recommendations and corresponding levels of evidence have been summarized in Table 12-4 (class I recommendations), Tables 12-5A and 12-5B (classes IIa and IIb recommendations), and Table 12-6 (class III recommendations). The AHA/ACC guidelines for PCI (2011) and perioperative cardiovascular care for NCS surgery (2007) are available at www.americanheart.org (section on statements and practice guidelines; last accessed June 12, 2012.)

TABLE 12-2

Options for Limiting Coronary Thrombosis after Noncardiac Surgery and Recent Percutaneous Coronary Intervention (PCI)

Options	Considerations within the Option
Minimize preoperative PCI	1. Limit preoperative PCI in stable coronary disease 2. PCI for unstable coronary syndromes
Consider type of PCI	1. Balloon angioplasty 2. Bare-metal stents 3. Drug-eluting stents
Optimize platelet blockade	1. Continue aspirin and clopidogrel 2. Perioperative bridging with intravenous platelet blockade 3. Continue aspirin only
Education and collaboration	1. Surgeon 2. Cardiologist 3. Surgery at center with primary PCI availability

TABLE 12-3A

Definition of Classification Scheme for Clinical Recommendations

Clinical Recommendations	Definition of Recommendation Class
Class I	The procedure/treatment should be performed (benefit far outweighs the risk)
Class IIa	It is reasonable to perform the procedure/treatment (benefit still clearly outweighs the risk)
Class IIb	It is not unreasonable to perform the procedure/treatment (benefit probably outweighs the risk)
Class III	The procedure/treatment should not be performed because it is not helpful and may be harmful (risk may outweigh the benefit)