PCI Guidelines for Interventional Cardiology Boards
Joseph D. Babb MD, FACC, FAHA, FSCAI
Zoran Lasic MD, FACC, FSCAI
In November 2011, the ACCF/AHA/SCAI published updated guidelines for percutaneous coronary intervention (PCI) (1). Practice guidelines are the result of a thorough review of evidence with an aim to provide assistance to physicians in selecting the best management strategy for an individual patient. In return, physicians will have to be familiar with the guidelines to optimally manage their patients and to successfully pass the interventional cardiology board exam since the majority of questions on the board exam are derived from material contained in the guidelines.
Data on efficacy and outcomes represent the primary basis for the recommendations contained in the guidelines. The Class of Recommendation (COR) is an estimate of the size of the treatment effect, considering risks versus benefits in addition to evidence and/or agreement that a given treatment or procedure is or is not useful/effective or in some situations may cause harm.
In general, Class I recommendations are for the procedure/treatment that should be performed. Class IIa reflects a recommendation where there is likely benefit for the treatments/procedures to be performed. Class IIb recommendations are made when the benefit to risk ratio is less certain. Class III denotes those treatments/procedures, where the risks outweigh the benefits, and these therapies should not be provided.
The Level of Evidence (LOE) is an estimate of the certainty or precision of the treatment effect and each recommendation given is associated with the weight of evidence ranked as LOE A, B, or C according to number of patients’ populations evaluated.
When preparing for the interventional cardiology board, one should primarily focus on Class I and III recommendations and for that purpose, most of the recommendations listed here will be in Classes I and III. Board questions usually depict a clinical scenario looking for the correct answer that is based on the guidelines. Most of the time correct answers will be one that is based on Class I (treatment/procedure that should be performed) or Class III (treatment/procedure that should not be performed), regardless of the LOE.
This chapter summarizes many of the recommendations contained within the guideline document with focus on Class I and III COR. Most of the basis for specific recommendations are covered in many of the other chapters in this book and therefore not duplicated here.
HEART TEAM APPROACH TO REVASCULARIZATION DECISIONS
Heart Team is composed of an interventional cardiologist, cardiac surgeon, and the patient’s general cardiologist. Support for using a multidisciplinary approach is a foundation of a Heart Team approach that originates from reports that patients with complex coronary artery disease (CAD) referred specifically for PCI or coronary artery bypass grafting (CABG) in concurrent trial registries have lower mortality rates than those randomly assigned to PCI or CABG in controlled trials. Particularly in patients with stable ischemic heart disease (SIHD) and unprotected left main and/or complex CAD for whom a revascularization strategy is not straightforward, an approach has been endorsed that involves terminating the procedure after diagnostic coronary angiography is completed: this allows a thorough discussion and affords both the interventional cardiologist and cardiac surgeon the opportunity to discuss revascularization options with the patient. Calculation of the Society of Thoracic Surgeons (STS) score and the SYNTAX (2) score is often useful in making revascularization decisions, as they have been shown to predict adverse outcomes in patients undergoing CABG and PCI.
Class I
1. A Heart Team approach to revascularization is recommended in patients with unprotected left main or complex CAD. (Level of Evidence: C.)
Class II
1. Calculation of the Society of Thoracic Surgeons (STS) and SYNTAX scores is reasonable in patients with unprotected left main and complex CAD. (Level of Evidence: B.)
PCI OUTCOMES
Three interrelated components define outcome of PCI procedure: angiographic, procedural and clinical success (Table 33-1).
Angiographic Success
There are two different sets of criteria that characterize angiographic success of PCI procedures. One is related to a successful balloon angioplasty, defined as the reduction of a minimum stenosis diameter to <50%, and the other for successful deployment of coronary stents where a minimum diameter stenosis of 10% (with
optimal goal as close to 0% as possible) is a benchmark that defines success. In both procedures, there should be final Thrombolysis In Myocardial Infarction (TIMI) flow grade 3, without occlusion of a significant side branch, flow-limiting dissection, distal embolization, or angiographic thrombus.
optimal goal as close to 0% as possible) is a benchmark that defines success. In both procedures, there should be final Thrombolysis In Myocardial Infarction (TIMI) flow grade 3, without occlusion of a significant side branch, flow-limiting dissection, distal embolization, or angiographic thrombus.
TABLE 33-1 PCI Outcomes | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Procedural Success
Procedural success consists of angiographic success without associated in-hospital major clinical complications (e.g., death, myocardial infarction [MI], stroke, emergency CABG).
Clinical Success
Clinically successful PCI mandates both anatomic and procedural success along with relief of signs and/or symptoms of myocardial ischemia. Duration of clinical success determines short- and longterm success, with the cutoff point of 9 months. Primary driving force behind lack of long-term success is restenosis.
COMPLICATIONS
In spite of refinement of PCI, in-hospital mortality still occurs in an average of 1.27% patients undergoing PCI, ranging from 0.65% in elective PCI to 4.81% in ST-segment elevated myocardial infarction (STEMI) (3). It is more common in patients with risk factors, primarily advanced age, comorbidities (e.g., diabetes, chronic kidney disease [CKD], congestive heart failure), multivessel CAD, high-risk lesions, and the setting of PCI (e.g., STEMI, urgent or emergency procedure, cardiogenic shock).
Procedural and periprocedural MI after PCI occur in >15% based on the 2007 universal definition of MI which states that after PCI, elevations of cardiac biomarkers above the 99th percentile upper reference limit indicate periprocedural myocardial necrosis. Increases of biomarkers >3 times the 99th percentile upper reference limit were designated as defining PCI-related MI. Most common causes for MI include acute artery closure, embolization and no-reflow, side branch occlusion, and acute stent thrombosis. It is critical to differentiate between myonecrosis and a clinical MI. All MIs involve myonecrosis, but not all myonecroses are clinical MI.
Incidence of emergency CABG after PCI has dramatically decreased to current level of 0.4%. In-hospital mortality associated with it remains high with ranges from 7.8% to 14%. Similarly, the incidence of PCI-related stroke is relatively low — 0.22%, but in-hospital mortality in patients with PCI-related stroke is 25% to 30%.
Access related complications are the most common cause of vascular complications from PCI. With technique refinement incidence has decreased over time. The most commonly encountered complications are access site hematoma, retroperitoneal hematoma, pseudoaneurysm, arteriovenous fistula, and arterial dissection and/or occlusion. Their incidence varies on the basis of different definitions from 2% to 6%.
Radial artery access and ultrasound-guided access could potentially decrease bleeding complications, but vascular closure devices have not been clearly demonstrated to decrease vascular complication rates.
Periprocedural bleeding is associated with subsequent mortality, with higher risk in patients with advanced age, low body mass index, CKD, baseline anemia, as well as the degree of platelet and thrombin inhibition, vascular access site, and sheath size.
TABLE 33-2 PCI Complications | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ||||||||||||||||||
Coronary perforation occurs in 0.2% PCI, most commonly by wire perforation during PCI for chronic total occlusion (CTO) or by ablative or oversized devices during PCI of heavily diseased or tortuous coronary arteries. Table 33-2 lists frequency of complications (4, 5, 6, 7, 8, 9, 10, 11, 12 and 13).
PREDICTORS OF CLINICAL OUTCOME AFTER PCI
Several models have been developed to predict procedural success and mortality after PCI. For inpatient mortality, the best accepted system is the ACC National Cardiovascular Data Registry (NCDR) CathPCI Risk Score system (14), with C statistic (probability of placing a patient in the right order, giving the higher probability to the one who develops the disease than to the one who does not) of 0.90.
For procedural success the modified ACC/AHA score (15) and the SCAI score (16) are both in use with discrimination by the C statistic of (0.70-0.82 respectively).
SYNTAX score is based on the location, severity, and extent of coronary stenoses, and is able to predict long-term risk of major adverse cardiac events (MACE) (defined as a composite of death, stroke, MI, or repeat revascularization) after multivessel intervention (17). Low score indicates less complicated anatomic CAD. In post hoc analyses, a low score was defined as <22; intermediate, 23 to 32; and high, >33. The occurrence of MACE correlated with the SYNTAX score for drug-eluting stents (DES) patients but not for those undergoing CABG. At 12-month follow-up, the primary endpoint was similar for CABG and DES in those with a low SYNTAX score. In contrast, MACE occurred more often after DES implantation than after CABG in those with an intermediate or high SYNTAX score.
PCI IN HOSPITALS WITHOUT ON-SITE SURGICAL BACKUP
Both primary and elective PCI can be performed at hospitals without on-site cardiac surgical backup with a high success rate, low in-hospital mortality rate, and low rate for emergency CABG, only when performed by experienced operators with complication rates and outcomes equivalent or superior to national benchmarks. Hospitals should provide around a clock services for STEMI patients to achieve the best outcomes in lowering in-hospital mortality and shortening door-to-balloon times (18). Quality control and improvement measures have to include comparison of outcomes with regional and national date registries, which include accepted benchmarks.
Specific requirements for PCI programs without on-site surgical backup in regards to strategy for surgical backup based on patient and lesion characteristics are listed in Table 33-3A and B.
TABLE 33-3A Requirements for Primary PCI and Emergency Aortocoronary Bypass Surgery at Hospitals without On-Site Cardiac Surgery | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ||||||||||||||||||
Class IIa
1. Primary PCI is reasonable in hospitals without on-site cardiac surgery, provided that appropriate planning for program development has been accomplished. (LOE: B)
Class III: Harm
1. Primary or elective PCI should not be performed in hospitals without on-site cardiac surgery capabilities without a proven plan for rapid transport to a cardiac surgery operating room in a nearby hospital or without appropriate hemodynamic support capability for transfer. (LOE: C)
OPERATOR AND INSTITUTIONAL COMPETENCY AND VOLUME RECOMMENDATIONS
Outcome of PCI is dependent on volume, both on institutional and operator level. However, data supporting the evidence are from older observational studies and are increasingly recognized as uncertain, particularly with regarding to low-volume institutions and operators and below recommendations are therefore categorized as LOE C. In more recent studies it appears that operator experience may modify the volume-outcome relationship at the institutional level so for the quality measures risk-adjusted outcomes remain preferable to institutional and individual operator volumes.
TABLE 33-3B Patient and Lesion Selection and Backup Strategy for Nonemergency PCI by Experienced Operators at Hospitals without On-Site Cardiac Surgery | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
TABLE 33-3C Strategy for Surgical Backup Based on Lesion and Patient Risk | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Class I
1. Elective/urgent PCI should be performed by operators with an acceptable annual volume (>75 procedures) at high-volume centers (>400 procedures) with on-site cardiac surgery. (Level of Evidence: C.)
2. Elective/urgent PCI should be performed by operators and institutions whose current risk-adjusted outcomes statistics are comparable to those reported in contemporary national data registries. (Level of Evidence: C.)
3. Primary PCI for STEMI should be performed by experienced operators who perform more than 75 elective PCI procedures per year and, ideally, at least 11 PCI procedures for STEMI per year. Ideally, these procedures should be performed in institutions that perform more than 400 elective PCIs per year and more than 36 primary PCI procedures for STEMI per year. (Level of Evidence: C.)
Class IIa
1. It is reasonable that operators with acceptable volume (>75 PCI procedures per year) perform elective/urgent PCI at low-volume centers (200 to 400 PCI procedures per year) with on-site cardiac surgery. (Level of Evidence: C.)
2. It is reasonable that low-volume operators (<75 PCI procedures per year) perform elective/urgent PCI at high-volume centers (>400 PCI procedures per year) with on-site cardiac surgery. Ideally, operators with an annual procedure volume of fewer than 75 procedures per year should only work at institutions with an activity level of more than 600 procedures per year. Operators who perform fewer than 75 procedures per year should develop a defined mentoring relationship with a highly experienced operator who has an annual procedural volume of at least 150 procedures per year. (Level of Evidence: C.)
Class IIb
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
