Please see also 2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines [PubMed Abstract]. Circulation. 2022 Jan 18;145(3):e4-e17.
In this post, I link to and excerpt from 2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines [PubMed Abstract] [Full-Text HTML] [Full-Text PDF]. J Am Coll Cardiol. 2022 Jan 18;79(2):e21-e129.
The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.
Structure
Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients’ interests.
Treatment decisions regarding coronary revascularization in patients with coronary artery disease should be based on clinical indications, regardless of sex, race, or ethnicity, because there is no evidence that some patients benefit less than others, and efforts to reduce disparities of care are warranted.
2.
In patients being considered for coronary revascularization for whom the optimal treatment strategy is unclear, a multidisciplinary Heart Team approach is recommended. Treatment decisions should be patient centered, incorporate patient preferences and goals, and include shared decision-making.
3.
For patients with significant left main disease, surgical revascularization is indicated to improve survival relative to that likely to be achieved with medical therapy. Percutaneous revascularization is a reasonable option to improve survival, compared with medical therapy, in selected patients with low to medium anatomic complexity of coronary artery disease and left main disease that is equally suitable for surgical or percutaneous revascularization.
4.
Updated evidence from contemporary trials supplement older evidence with regard to mortality benefit of revascularization in patients with stable ischemic heart disease, normal left ventricular ejection fraction, and triple-vessel coronary artery disease. Surgical revascularization may be reasonable to improve survival. A survival benefit with percutaneous revascularization is uncertain. Revascularization decisions are based on consideration of disease complexity, technical feasibility of treatment, and a Heart Team discussion.
5.
The use of a radial artery as a surgical revascularization conduit is preferred versus the use of a saphenous vein conduit to bypass the second most important target vessel with significant stenosis after the left anterior descending coronary artery. Benefits include superior patency, reduced adverse cardiac events, and improved survival.
6.
Radial artery access is recommended in patients undergoing percutaneous intervention who have acute coronary syndrome or stable ischemic heart disease, to reduce bleeding and vascular complications compared with a femoral approach. Patients with acute coronary syndrome also benefit from a reduction in mortality rate with this approach.
7.
A short duration of dual antiplatelet therapy after percutaneous revascularization in patients with stable ischemic heart disease is reasonable to reduce the risk of bleeding events. After consideration of recurrent ischemia and bleeding risks, select patients may safely transition to P2Y12 inhibitor monotherapy and stop aspirin after 1 to 3 months of dual antiplatelet therapy.
8.
Staged percutaneous intervention (while in hospital or after discharge) of a significantly stenosed nonculprit artery in patients presenting with an ST-segment–elevation myocardial infarction is recommended in select patients to improve outcomes. Percutaneous intervention of the nonculprit artery at the time of primary percutaneous coronary intervention is less clear and may be considered in stable patients with uncomplicated revascularization of the culprit artery, low-complexity nonculprit artery disease, and normal renal function. In contrast, percutaneous intervention of the non-culprit artery can be harmful in patients in cardiogenic shock.
9.
Revascularization decisions in patients with diabetes and multivessel coronary artery disease are optimized by the use of a Heart Team approach. Patients with diabetes who have triple-vessel disease should undergo surgical revascularization; percutaneous coronary intervention may be considered if they are poor candidates for surgery.
10.
Treatment decisions for patients undergoing surgical revascularization of coronary artery disease should include the calculation of a patient’s surgical risk with the Society of Thoracic Surgeons score. The usefulness of the SYNTAX score calculation in treatment decisions is less clear because of the interobserver variability in its calculation and its absence of clinical variables.
1.4. Scope of the Guideline
The scope of the “2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization” is to provide an update to and to consolidate the 2011 coronary artery bypass graft (CABG) surgery (1) and the 2011 and 2015 percutaneous coronary intervention (PCI) guidelines (2,3), with the added consideration of using a patient-centric disease approach. The applicable sections on revascularization from the 2012 stable ischemic heart disease (SIHD) guideline (4), as well as the 2013 ST-segment–elevation myocardial infarction (STEMI) (5) and 2014 non–ST-segment–elevation myocardial infarction (NSTEMI) guidelines (6), will also be updated. This present guideline will affect the following documents:
Replace/retire the 2015 update in PCI in STEMI guideline (3).
4.
Replace/retire the 2013 STEMI guideline, Sections 4.1, 4.2, 4.3, 4.4, 5.3 (deals with transfer after lytic with intent to do PCI), 6.2, 6.4, 7.1, and 7.2 (5).
Replace/retire the 2012 SIHD guideline, Section 5 (4).
The intended primary target audience consists of cardiovascular clinicians who are involved in the care of patients for whom revascularization is considered or indicated. Coronary artery disease (CAD) is to be approached with the most current treatment options and treated as a “condition.” Recommendations are stated in reference to the patients and their condition. The focus is to provide the most up-to-date evidence to inform the clinician during shared decision-making with the patient. Although the document is not intended to be a procedural-based manual of recommendations that outlines the best practice for coronary revascularization, there are certain techniques that surgeons or interventional cardiologists might use that are associated with improved clinical outcomes.
In developing the 2021 coronary artery revascularization guideline, the writing committee reviewed previously published guidelines and related statements. Table 1 contains a list of these publications and statements deemed pertinent to this writing effort and is intended for use as a resource, thus obviating the need to repeat existing guideline recommendations.
Table 2. Applying ACC/AHA Class of Recommendation and Level of Evidence to Clinical Strategies, Interventions, Treatments, or Diagnostic Testing in Patient Care (Updated May 2019)∗
1.6. Abbreviations
Abbreviation
Meaning/Phrase
ACS
acute coronary syndrome
AKI
acute kidney injury
AMI
acute myocardial infarction
AVR
aortic valve replacement
BIMA
bilateral internal mammary artery
BMS
bare-metal stent
CABG
coronary artery bypass graft
CAD
coronary artery disease
CKD
chronic kidney disease
COR
Class of Recommendation
CTO
chronic total occlusion
CVD
cardiovascular disease
DAPT
dual antiplatelet therapy
DES
drug-eluting stent
ECG
electrocardiogram
FFR
fractional flow reserve
GDMT
guideline-directed medical therapy
iFR
instantaneous wave-free ratio
IMA
internal mammary artery
ISR
in-stent restenosis
IVUS
intravascular ultrasound
LAD
left anterior descending
LIMA
left internal mammary artery
LOE
Level of Evidence
MACE
major adverse cardiovascular events
MI
myocardial infarction
NSTE-ACS
non–ST-segment–elevation acute coronary syndrome
NSTEMI
non–ST-segment–elevation myocardial infarction
OCT
optical coherence tomography
PCI
percutaneous coronary intervention
RCT
randomized controlled trial
SCAD
spontaneous coronary artery dissection
SIHD
stable ischemic heart disease
STEMI
ST-segment–elevation myocardial infarction
SVG
saphenous vein graft
SYNTAX
Synergy Between PCI With TAXUS and Cardiac Surgery
TAVR
transcatheter aortic valve replacement
UFH
unfractionated heparin
VT
ventricular tachycardia
2. Improving Equity of Care in Revascularization and Shared Decision-Making
Figure 1. Shared Decision-Making Algorithm
Table 3. Ideal Components of the Shared Decision-Making and Informed Consent Process
Patient-Centered Care
Assess a patient’s ability to understand complex health information
Seek support of family/others
Elicit and respect cultural, racial, ethnic, or religious preferences and values
Evaluate social determinants of health (education, income, access to health care)
Improve telephone/telemedicine access
Discuss treatment alternatives and how each affects the patient’s quality of life
Shared Decision-Making
Encourage questions and explain the patient’s role in the decision-making partnership
Clearly and accurately communicate the potential risks and benefits of a particular procedure and alternative treatments
Ensure that patients have a key role in deciding what revascularization approach is appropriate
Spend sufficient time to engage in shared decision-making; allow for a second opinion
Work with a chaplain, social worker, or other team members to facilitate shared decision-making
Encourage patients to share their fears, stress, or other emotions, and address appropriately
Negotiate decision in partnership with the patient and family members
Respect patient’s autonomy to decline recommended treatment
Consent Procedures
Use plain language, avoiding jargon, and adopt the patient’s words; integrate pictures to teach
Document teach-back of patient’s knowledge and understanding
Conduct conversations with a trained interpreter, as needed
Provide patient-specific short- and long-term risks, benefits, and alternative treatments
Provide unbiased, evidence-based, reliable, accessible, and relevant information to patient
Discuss specific risks and benefits with regard to survival, relief of angina, quality of life, and potential additional intervention, as well as uncertainties associated with different treatment strategies
Provide patient time to reflect on the trade-offs imposed by the outcome estimates
Provide information on the level of operator expertise, volume of the facility, and local results in the performance of coronary revascularization options
Clearly inform of the need for continued medical therapy and lifestyle modifications
In patients for whom the optimal treatment strategy is unclear, a Heart Team approach that includes representatives from interventional cardiology, cardiac surgery, and clinical cardiology is recommended to improve patient outcomes (1, 2, 3, 4, 5, 6, 7).
Figure 2. Phases of Patient-Centric Care in the Treatment of Coronary Artery Disease
In patients who are being considered for CABG, calculation of the STS risk score is recommended to help stratify patient risk (1,2).
Recommendation-Specific Supporting Text
The STS risk score has been validated in several studies and demonstrates excellent predictive value for estimating risk of adverse events (2, 3, 4). The STS risk score serves as a useful tool when a choice is being made among various treatment strategies because it allows the clinician, the patient, and the patient’s family to have a reasonable estimate of operative risk. The STS risk score performs better than the EuroSCORE II for the patient population with CABG, particularly at higher (>5%) predicted mortality rates (1,2). Commonly used cardiac surgery risk models, such as the STS and EuroSCORE II, are limited in assessing the influence of risk factors, including cirrhosis, frailty, and malnutrition, on outcome. Patients with liver cirrhosis, frailty, and malnutrition have increased risk of perioperative morbidity and mortality after cardiac surgery (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17) and may be assessed by other tools (Table 5).
Table 5. Assessment of Risk Factors Not Quantified in the STS Score
Risk Factor
Assessment Tool
Cirrhosis
Model for End-Stage Liver Disease (MELD) score (1, 2, 3, 4, 5, 6)
4.1. Angiography to Define Anatomy and Assess Lesion Severity
Coronary angiography remains the default method to define coronary anatomy and characterize the severity of coronary arterial stenoses. A visually estimated diameter stenosis severity of ≥70% for non–left main disease and ≥50% for left main disease has been used to define significant stenosis and to guide revascularization strategy. Although the length of a lesion may contribute to physiological lesion severity (i.e., a longer moderate lesion may result in more ischemia than a focal severe lesion), there are no standard cutoffs for lesion length used to classify a severe stenosis. An angiographically intermediate coronary stenosis is defined as a diameter stenosis severity of 40% to 69%, and generally warrants additional investigation to assess physiological significance. There is controversy over whether visually estimated diameter stenosis or quantitative coronary angiography better predicts the functional significance of a coronary stenosis (1,2). The difference in mean diameter stenosis between quantitative coronary angiography and visual estimation varies from 10% to 20% and is dependent on stenosis severity (3, 4, 5). The use of optimal angiographic projections, multiple angiographic views, and adjunct imaging or physiology may aid in the assessment of coronary anatomy when coronary angiography is used.
1. In patients with multivessel CAD, an assessment of CAD complexity, such as the SYNTAX score, may be useful to guide revascularization (1, 2, 3, 4).
Synopsis
The anatomic complexity of lesions, expected completeness of revascularization, predicted risk of death, and other adverse outcomes are important factors to consider for determining the type of revascularization for patients with CAD. Many factors contribute to the estimation of the complexity of CAD (Table 6). The SYNTAX score was prospectively derived from the SYNTAX trial to aid in this decision-making process by providing an objective measure to grade the anatomic complexity of CAD in patients with multivessel disease (1). Its value as an independent predictor of long-term major adverse cardiac and cerebrovascular events and death was established in the SYNTAX trial cohort and subsequently validated in external studies of patients treated with PCI but not CABG (2, 3, 4). The SYNTAX II score and the revised SYNTAX Score II 2020 was retrospectively developed from the SYNTAX trial cohort (5,6) to incorporate clinical variables in addition to the anatomic variables. These scores demonstrate modest discrimination in predicting adverse clinical events after revascularization (6).
Recommendation-Specific Supporting Text
1. The SYNTAX score remains the most widely used and validated risk score to guide the choice of revascularization in patients with multivessel disease. Important limitations of this score include the cumbersome scoring system required for each lesion and the interobserver variability in its calculation (7,8). Additionally, the absence of clinical variables limits its use in estimating the risk of clinical events after CABG. When estimating a patient’s complexity of disease, it is important to consider variables that contribute to disease complexity which might impact the success and outcomes of revascularization (Table 6).
Table 6. Angiographic Features Contributing to Increasing Complexity of CAD
Multivessel disease
Left main or proximal LAD artery lesion
Chronic total occlusion
Trifurcation lesion
Complex bifurcation lesion
Heavy calcification
Severe tortuosity
Aorto-ostial stenosis
Diffusely diseased and narrowed segments distal to the lesion
Thrombotic lesion
Lesion length >20 mm
CAD indicates coronary artery disease; and LAD, left
anterior descending.
4.3. Use of Coronary Physiology to Guide Revascularization With PCI
Recommendations for the Use of Coronary Physiology to Guide Revascularization With PCI
1. In patients with angina or an anginal equivalent, undocumented ischemia, and angiographically intermediate stenoses, the use of fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) is recommended to guide the decision to proceed with PCI (1, 2, 3, 4, 5, 6).
3: No benefit
B-R
2. In stable patients with angiographically intermediate stenoses and FFR >0.80 or iFR >0.89, PCI should not be performed (7, 8, 9, 10).
Synopsis
FFR and iFR are 2 of the most commonly used physiological methods of assessing lesion significance. FFR is defined as the ratio of maximal blood flow in a region distal to a lesion compared with the normal maximal blood flow of an artery. iFR, an index of lesion severity, is the instantaneous wave-free ratio (in diastole) of coronary pressure distal to the coronary lesion (Pd) to the aortic pressure (Pa) The potential advantage of iFR, which is a resting physiological index, is that it obviates the use of adenosine because it does not require a state of maximal hyperemia. These 2 measures—FFR and iFR—have been studied in randomized trials with clinical endpoints of death, myocardial infarction (MI), or repeat revascularization (1, 2, 3, 4, 5). There are other resting indices that have been compared with iFR or FFR in observational studies (9,10). These resting indices have varying degrees of accuracy relative to FFR and iFR but have not been studied in randomized trials with clinical endpoints. The FAME 2 (Fractional Flow-Reserve-Guided PCI versus Medical Therapy in Stable Coronary Disease) trial (2) tested a strategy of PCI for all lesions with abnormal FFR compared with optimal medical therapy alone. Recruitment into the trial was stopped early because of a significant benefit of PCI over medical therapy in patients with an abnormal FFR with respect to death, MI, or urgent revascularization, with the benefit derived largely from a reduction in ischemia-driven revascularization.
The role of FFR in guiding surgical revascularization is uncertain. Multiple small observational studies, as well as RCTs and meta-analyses of these trials, suggest that fewer distal anastomoses are performed, and off-pump CABG is more often chosen in patients undergoing CABG with FFR-guided revascularization than in those undergoing CABG with angiogram-guided revascularization (11, 12, 13, 14). However, in these studies, no differences were found in clinical outcomes in patients undergoing CABG with FFR guidance compared with patients undergoing CABG with angiogram guidance (11, 12, 13, 14). Additionally, not all studies included an angiogram-guided comparison group. Large, randomized trials that are appropriately powered are warranted to guide the use of FFR in patients undergoing surgical revascularization.
Recommendation-Specific Supportive Text
1. In the FAME trial, PCI for a stenosis ≥50% with an abnormal FFR reduced the risk of the composite endpoint at 1 year as compared with PCI guided by angiography only (1), a benefit that was maintained at 2 years (9) but not at 5 years. The DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation and the Instantaneous Wave-free Ratio versus Fractional Flow Reserve in Patients with Stable Angina Pectoris or Acute Coronary Syndrome) (4) and the iFR-SWEDEHEART (Instantaneous Wave-free Ratio versus Fractional Flow Reserve in Patients with Stable Angina Pectoris or Acute Coronary Syndrome) trials (6) compared outcomes with the use of iFR- or FFR-guided PCI. In these trials, iFR-guided PCI was found to be noninferior to FFR-guided PCI. As compared with FFR, the use of iFR was associated with lower rates of procedure-related chest pain and shorter procedural time. In randomized trials, the rates of short- and long-term MACE were lower among patients who had PCI guided by physiology with either FFR or iFR (4,6).
2. Deferral of PCI when the FFR is >0.80 or the iFR is >0.89 is associated with low rates of long-term MACE (8, 9, 10). The DEFER (Deferral of Percutaneous Intervention) trial demonstrated similar rates of MACE in follow-up when PCI for angiographic intermediate lesions and FFR >0.75 was deferred, rather than performed, at 2 and 5 years of follow-up (8). Additionally, there were lower rates of MI in the deferred group at long-term follow-up (7). In patients enrolled in the FAME trial who had an FFR >0.80, 2-year rates of MI and revascularization were low, at 0.2% and 3.2%, respectively (9). Finally, in the DEFINE-FLAIR and the iFR-SWEDEHEART trials, rates of MACE in patients who had PCI deferred on the basis of an FFR >0.80 or an iFR >0.89 were 4.05% and 4.12%, respectively (10), with unplanned revascularization being the most frequent cause of MACE. The cutoffs of FFR and iFR provided were those used in the clinical trials. On occasion, borderline values may warrant further ischemia testing or additional investigations.1.
4.4. Intravascular Ultrasound to Assess Lesion Severity
Recommendation for Intravascular Ultrasound to Assess Lesion Severity
In patients with intermediate stenosis of the left main artery, intravascular ultrasound (IVUS) is reasonable to help define lesion severity (1, 2, 3, 4, 5).
Synopsis
IVUS can offer important anatomic information beyond what is seen on coronary angiography. IVUS is particularly useful in lesions involving the left main artery where there may be limitations in coronary angiography due to overlapping vessels or foreshortening. IVUS offers significantly greater spatial resolution than angiography alone (IVUS axial resolution is 100 to 150 μm, and coronary angiography axial resolution is 300 μm). Detailed cross-sectional images provide accurate evaluation of lesion characteristics, including lumen dimensions, lesion length, plaque morphology and location, thrombus, dissection, and stent apposition and expansion. Additionally, minimal lumen area on IVUS has been shown to correlate with physiological indices (6).
