Adjudicating Coronary Revascularization: Appropriate Use
In the 2009 publication of the 'Appropriateness Criteria for Coronary Revascularization,' (hereafter referred to as Appropriate Use Criteria or AUC), Patel et al. noted that the "appropriateness criteria are designed to examine the use of diagnostic and therapeutic procedures to support efficient use of medical resources during the pursuit of quality medical care". Thus, the intent of such criteria is to establish best practice standards, thereby improving quality of care, reducing its variability and possibly reducing its costs. These criteria were specifically designed to extend beyond the guidelines to delineate management of the more common scenarios encountered in clinical practice.
This effort was driven by limitations of practice guidelines that were potently underscored by Tricoci et al. in a study evaluating the evolution of recommendations in the American College of Cardiology (ACC)/American Heart Association (AHA) practice guidelines based on level of evidence. The preponderance of guidelines was found to be supported by level of evidence C, formulated by expert opinion and not trial-based evidence.
This role for AUC, as a valuable supplement to guideline-derived heuristics, was derived from studies of the application of RAND-University of California at Los Angeles necessity criteria for revascularization. A retrospective study of 671 patients performed by Kravitz et al. studied these clinical criteria adjudicating necessity of revascularization (coronary artery bypass grafting [CABG] or percutaneous transluminal coronary angioplasty [PTCA]) based on the opinions of nine panelists representing internal medicine, cardiology, and cardiothoracic surgery. A variety of clinical scenarios were assessed that scored appropriateness of revascularization from 1 (designated as inappropriate) to 9 (designated as most appropriate) after a two-round modified Delphi process These panelists were "chosen from a list of nationally recognized leaders nominated by medical specialty societies." Validation for these published criteria was derived from the fact that patients who received necessary revascularization within 1 year of angiography had lower mortality than those who did not (8.7 vs 15.8%, p = 0.01). Thus, performing appropriate intervention based on these criteria manifested in positive results, and supported the validity of the RAND-University of California at Los Angeles criteria for detecting underuse of appropriate intervention.
In a prospective study of clinical outcomes, enrolling over 2500 patients followed for a median of 30 months after angiography, Hemingway et al. furthered the notion that implementation of AUC would lead to less underuse of coronary revascularization, and improved clinical outcomes. In 908 patients with indications for PTCA graded as appropriate (score 7–9), over a third were treated medically. These medically treated patients were more likely to have angina at follow-up than those who underwent PTCA (OR 1.97; 95% CI: 1.29–3.00). In 1353 patients within indications for CABG graded as appropriate, over a quarter were treated medically. These medically treated patients were more likely to die or have a nonfatal myocardial infarction (composite outcome; HR 4.08; 95% CI: 2.82–5.93). There was also a graded relation between the appropriateness score and clinical outcome of revascularization over the entire scale of appropriateness (p for linear trend < 0.01). Thus, underuse of revascularization was found to be significantly and powerfully associated with adverse clinical outcomes.
Based on these types of analyses, the predominant and most valuable role of AUC was clear cut: diminish underuse of revascularization and thus improved clinical outcomes. To this effect, the AUC noted that "these criteria provide a framework for discussion and are intended to assist patients and clinicians, but are not to diminish the difficulty or uncertainty of clinical decision making" and "it is not anticipated that all physicians or facilities will have 100% of their revascularization procedures deemed appropriate". Given the limited nature of this evaluation, only 180 revascularization scenarios were evaluated by the AUC technical panel; anatomic scenarios such as ostial lesions, bifurcation lesions and diffuse disease, and the amount of myocardium supplied were excluded. And if the true purpose of AUC were to guide proper use of revascularization, given that underuse is associated with poor clinical outcomes, some focus would be given to that end of the spectrum.
The Origins of Appropriate Use Criteria
In the 2009 publication of the 'Appropriateness Criteria for Coronary Revascularization,' (hereafter referred to as Appropriate Use Criteria or AUC), Patel et al. noted that the "appropriateness criteria are designed to examine the use of diagnostic and therapeutic procedures to support efficient use of medical resources during the pursuit of quality medical care". Thus, the intent of such criteria is to establish best practice standards, thereby improving quality of care, reducing its variability and possibly reducing its costs. These criteria were specifically designed to extend beyond the guidelines to delineate management of the more common scenarios encountered in clinical practice.
This effort was driven by limitations of practice guidelines that were potently underscored by Tricoci et al. in a study evaluating the evolution of recommendations in the American College of Cardiology (ACC)/American Heart Association (AHA) practice guidelines based on level of evidence. The preponderance of guidelines was found to be supported by level of evidence C, formulated by expert opinion and not trial-based evidence.
This role for AUC, as a valuable supplement to guideline-derived heuristics, was derived from studies of the application of RAND-University of California at Los Angeles necessity criteria for revascularization. A retrospective study of 671 patients performed by Kravitz et al. studied these clinical criteria adjudicating necessity of revascularization (coronary artery bypass grafting [CABG] or percutaneous transluminal coronary angioplasty [PTCA]) based on the opinions of nine panelists representing internal medicine, cardiology, and cardiothoracic surgery. A variety of clinical scenarios were assessed that scored appropriateness of revascularization from 1 (designated as inappropriate) to 9 (designated as most appropriate) after a two-round modified Delphi process These panelists were "chosen from a list of nationally recognized leaders nominated by medical specialty societies." Validation for these published criteria was derived from the fact that patients who received necessary revascularization within 1 year of angiography had lower mortality than those who did not (8.7 vs 15.8%, p = 0.01). Thus, performing appropriate intervention based on these criteria manifested in positive results, and supported the validity of the RAND-University of California at Los Angeles criteria for detecting underuse of appropriate intervention.
In a prospective study of clinical outcomes, enrolling over 2500 patients followed for a median of 30 months after angiography, Hemingway et al. furthered the notion that implementation of AUC would lead to less underuse of coronary revascularization, and improved clinical outcomes. In 908 patients with indications for PTCA graded as appropriate (score 7–9), over a third were treated medically. These medically treated patients were more likely to have angina at follow-up than those who underwent PTCA (OR 1.97; 95% CI: 1.29–3.00). In 1353 patients within indications for CABG graded as appropriate, over a quarter were treated medically. These medically treated patients were more likely to die or have a nonfatal myocardial infarction (composite outcome; HR 4.08; 95% CI: 2.82–5.93). There was also a graded relation between the appropriateness score and clinical outcome of revascularization over the entire scale of appropriateness (p for linear trend < 0.01). Thus, underuse of revascularization was found to be significantly and powerfully associated with adverse clinical outcomes.
Based on these types of analyses, the predominant and most valuable role of AUC was clear cut: diminish underuse of revascularization and thus improved clinical outcomes. To this effect, the AUC noted that "these criteria provide a framework for discussion and are intended to assist patients and clinicians, but are not to diminish the difficulty or uncertainty of clinical decision making" and "it is not anticipated that all physicians or facilities will have 100% of their revascularization procedures deemed appropriate". Given the limited nature of this evaluation, only 180 revascularization scenarios were evaluated by the AUC technical panel; anatomic scenarios such as ostial lesions, bifurcation lesions and diffuse disease, and the amount of myocardium supplied were excluded. And if the true purpose of AUC were to guide proper use of revascularization, given that underuse is associated with poor clinical outcomes, some focus would be given to that end of the spectrum.