A Comprehensive Evidence-Based Decision Algorithm for Assisting Clinicians and Patients With Stable Ischemic Heart Disease in Selecting Revascularization Strategy in Multivessel Disease

Abstract: We propose an evidenced-based algorithm for the selection of revascularization strategy (coronary artery bypass surgery, percutaneous coronary intervention, or optimal medical therapy) to be applied in multivessel, non-acute coronary syndrome presentations. This algorithm provides a highly effective tool that is comprehensible to both physicians and patients. 

J INVASIVE CARDIOL 2018;30(5):182-185.

Key words: revascularization decision algorithm, multivessel disease, CABG vs PCI vs optimal medical therapy

Choosing the best revascularization strategy in multivessel coronary artery disease (CAD) is a complex process in which clinical trial results, guidelines, appropriate use criteria, local expertise, and professional experience all have weight.^1-3 Despite over 40 years of study, individual patients and their physicians are often confronted with non-definitive evidence, divergent opinions, and a thicket of overlapping considerations. Further complicating matters, many patients seen in practice would not fit into the inclusion criteria for the various trials often cited.

Formal evidence-based revascularization evaluations are rarely performed in the patient care setting, despite the best intentions, leading to substantial health-care delivery variations. Only by putting into practice what has been learned from clinical investigations can medical outcomes be optimized. Ensuring the application of clinical trial evidence in individual cases is difficult, and requires strategies that are effective at the time of the patient encounter. The adoption and consistent use of evidence-based information, rather than reliance on subjective judgment and its inherent biases, requires considerable effort and tools that are easily utilized in the clinical environment.

A decision algorithm can be one highly effective method to ensure implementation. By constructing a visual picture of the pathway, simplifying the early stages of the assessment, and sequentially introducing each key element shown to be critical to the selection of revascularization strategy, the clinician (and potentially the patient) can be certain that all relevant factors are taken into account. Nuances and individual exceptions are easily incorporated later in the process. 

In this paper, we propose such an evidenced-based algorithm to be applied in non-acute coronary syndrome presentations that is comprehensible to both physicians and patients.

Decision Algorithm 

Rationale. The purpose of the schematic algorithm is to provide an evidence-based foundation that allows the introduction of individual-specific considerations and choices. Unlike professional guidelines, which do an excellent job of summarizing clinical trial evidence for population-based strategies but are not easily applied in individual patients, or appropriate use criteria, which determine appropriateness on the basis of just a few clinical variables, the concept of this algorithm is to provide a means for physicians and patients to take into account all appropriate individual circumstances, which guidelines are insufficiently granular to incorporate. 

\Use of the decision tool (Figure 1). The broad concept of this tool is not to “force” any particular result in any case; rather, it is intended as an outline to ensure that all of the factors that might properly influence the selection of various revascularization strategies are overtly taken into consideration at some point in the decision-making process. The structure is based on a full assessment of the number and location of significant stenoses, and includes symptoms, coronary angiography, and functional testing. Once this assessment is made, the various factors shown in clinical trials are positioned in a logical sequence. 

The pathways at the end do not come to a final conclusion, but instead remain open ended and are intended to stimulate further discussion of the alternatives, until a result acceptable to all is reached. Although a “preferred” strategy is initially identified, further evidence-based factors of the pros and cons of that strategy (Table 1) must be considered, and may well lead to discarding that strategy in favor of an alternative. Reaching the table in the algorithm is not the end; instead, that particular box is queried for further concerns. The table lists specific considerations for coronary artery bypass graft (CABG), percutaneous coronary intervention (PCI), and optimal medical therapy (OMT). Only after these issues and those of alternative strategies are overtly considered should a decision be made regarding the best option. 

Again, the point is to guarantee that all relevant factors are taken into account, not to lead to any particular outcome. Table 1 is included to further fine-tune the decision-making process. Patient preference should be considered in every case.

Obviously, gradations and distinctions in interpretation and specific considerations in individual cases, including but not limited to lesion severity and morphology, symptomatology, technical feasibility, and risk-to-benefit ratio evaluation, cannot be incorporated simply into an algorithmic scheme, and no attempt is made to do so. 

Discussion

Revascularization decisions for stable ischemic heart disease patients are exceedingly complex, and the choice of strategy depends on multiple factors, many of them highly nuanced. Any notion that a simplistic decision-tree algorithm could incorporate all the features of a single patient would be absurd, and that is not the intention. Rather, the concept is to take those characteristics that tend to be influential (ie, symptoms, extent of disease) and systematically arrange them in such a way as to make their consideration overt and to clarify their relative roles. 

The process of decision-making is highly complex, and must take into account numerous factors, including clinical trials. The physician must balance the relative roles of comorbidity, concurrent medications, disability, overall prognosis, and patient preference. An algorithm may be valuable in ensuring that the decisions are aligned with existing guidelines. However, good judgment and sharp insight remain essential elements. Physicians and patients alike seek a primer into the decision-making process; this algorithm is offered not as a complete or final rendering but as an introductory, entry-level phase of a multifaceted process. There is no existing algorithm to assist physicians, patients, or third parties in placing all of the existing information in context, making the decision process at times appear random and subjective. 

We present an evidence-based decision tool (Appendix 1) with no intent to influence any particular result; rather, the idea is to give organization to the process and ensure that no critical factor has been forgotten or its significance under- or over-valued. Intentionally, the final decision is always left open ended; the tool is intended to assist in the decision-making, not to take away from the importance of tailoring the selection of revascularization strategy to the specific case.

References

1.    Levine GN, Bates ER, Blankenship JC, et al. 2011 ACCF/AHA/SCAI guideline for percutaneous coronary intervention: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Society for Cardiovascular Angiography and Interventions. J Am Coll Cardiol. 2011;58:2550-2583.

2.    Fihn SD, Gardin JM, Abrams J, et al. 2012 ACCF/AHA/ACP/AATS/PCNA/ SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, and the American College of Physicians, American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol. 2012;60:e44-e164.

3.    ACCF/SCAI/STS/AATS/AHA/ASNC 2012 appropriateness criteria for coronary revascularization focused update. J Am Coll Cardiol. 2012;59:857-881.

From ¹Rush Medical College, Chicago lllinois; and ²MedStar Washington Hospital Center, Washington D.C.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted February 13, 2018, provisional acceptance given February 19, 2018, final version accepted March 12, 2018.

Address for correspondence: Lloyd W. Klein, MD, Rush Medical College, 3000 North Halsted Ave, Suite 625, Chicago, IL 60614. Email: lloydklein@comcast.net