2987
`
`AHA Medical/Scientific Statement
`
`Special Report
`
`Guidelines for Percutaneous
`Transluminal Coronary Angioplasty
`A Report of the American Heart Association/American
`College of Cardiology Task Force on Assessment of
`Diagnostic and Therapeutic Cardiovascular Procedures
`(Committee on Percutaneous
`Transluminal Coronary Angioplasty)
`
`Thomas J. Ryan, MD, Chair; William B. Bauman, MD; J. Ward Kennedy, MD;
`Dean J. Kereiakes, MD; Spencer B. King III, MD; Ben D. McCallister, MD;
`Sidney C. Smith, Jr, MD; Daniel J. Ullyot, MD
`
`Preamble
`t is becoming more apparent each day that despite
`a strong national commitment to excellence in
`health care, the resources and personnel are finite.
`It is therefore appropriate that the medical profession
`examine the impact of developing technology and new
`therapeutic modalities on the practice of cardiology.
`Such analyses, carefully conducted, could potentially
`have an impact on the cost of medical care without
`diminishing the effectiveness of that care.
`To this end, in 1980 the American College of Cardi-
`ology and the American Heart Association established
`the Task Force on Assessment of Diagnostic and Ther-
`apeutic Cardiovascular Procedures with the following
`charge:
`The task force of the American College of Cardiology
`and the American Heart Association shall develop
`guidelines relating to the role of new therapeutic ap-
`proaches and of specific noninvasive and invasive pro-
`cedures in the diagnosis and management of cardiovas-
`cular disease.
`The task force shall address, when appropriate, the
`contribution, uniqueness, sensitivity, specificity, indica-
`tions, contraindications, and cost-effectiveness of such
`diagnostic procedures and therapeutic modalities.
`The task force shall emphasize the role and values of
`the guidelines as an educational resource.
`The task force shall include a chair and six members,
`three representatives from the American Heart Associa-
`tion and three representatives from the American College
`
`"Guidelines for Percutaneous Transluminal Coronary Angio-
`plasty" was approved by the American Heart Association Steering
`Committee on June 16, 1993, and by the American College of
`Cardiology Board of Trustees on June 30, 1993.
`Requests for reprints should be sent to the Office of Scientific
`Affairs, American Heart Association, 7272 Greenville Avenue,
`Dallas, TX 75231-4596.
`© American Heart Association and American College of Cardi-
`ology, 1993.
`
`of Cardiology. The task force may select ad hoc members
`as needed upon the approval of the presidents of both
`organizations. Recommendations of the task force are
`forwarded to the president of each organization.
`The members of the task force are George A. Beller,
`MD; Robert A. O'Rourke, MD; J. Ward Kennedy, MD;
`Robert C. Schlant, MD; Sylvan Lee Weinberg, MD;
`William L. Winters, Jr, MD; and Charles Fisch, MD,
`chair.
`This document was reviewed by the officers and other
`responsible individuals of the two organizations and
`received final approval in June 1993. It is being pub-
`lished simultaneously in Circulation and the Journal of
`the American College of Cardiology. The potential effect
`of this document on the practice of cardiology and some
`of its unavoidable shortcomings are clearly set out in the
`introduction.
`
`Charles Fisch, MD
`
`Introduction
`The American College of Cardiology/American
`Heart Association Task Force on Assessment of Diag-
`nostic and Therapeutic Cardiovascular Procedures was
`formed to gather information and make recommenda-
`tions about appropriate use of technology in the diag-
`nosis and treatment of patients with cardiovascular
`disease. Coronary angioplasty is one such important
`technique. We are currently witnessing an extraordinary
`expansion of the use of coronary angioplasty as an
`alternative means of achieving myocardial revascular-
`ization. An estimated 300 000 angioplasty procedures
`were performed in the United States in 1990, a more
`than tenfold increase over the past decade.1 Such
`growth is attributable not only to demonstrated clinical
`benefit but also to continuing technical advances that
`have led to improved techniques and higher success
`rates over time. There was some concomitant broaden-
`ing of the indications for both coronary angiography
`and angioplasty, which led the task force to promulgate
`
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`2988
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`Circulation
`
`Vol 88, No 6 December 1993
`
`guidelines for coronary angiography in 19872 and guide-
`lines for percutaneous transluminal coronary angio-
`plasty (PTCA) in 1988.3 In view of the continuing
`advances and expanding role of interventional cardiol-
`ogy in clinical practice today, it was recommended that
`this committee review current indications and proce-
`dures governing the performance of angioplasty in the
`United States and determine whether any alterations in
`the previously published guidelines are warranted. Such
`a review was anticipated and recommended in the
`original committee report.3 This document presents the
`summary opinion of the reconvened committee with its
`newly constituted membership.
`These recommendations were shaped over the course
`of 9 months' deliberation and reflect much thoughtful
`discussion and broad consultation, as well as a detailed
`review of the world literature. The committee pro-
`ceeded on the premise that angioplasty is an effective
`means of achieving myocardial revascularization and its
`appropriate use is to be broadly encouraged. At the
`same time, the committee is mindful of the many forces
`that can affect the performance of any specific proce-
`dure and recognizes the potential for a variety of
`inappropriate and expedient considerations to influence
`the performance of angioplasty in this country. Accord-
`ingly, the committee offers these recommendations with
`a heightened awareness of the need for the cardiology
`community at large, and institutional programs specifi-
`cally, to police themselves in the use of coronary
`angioplasty.
`The technique of angioplasty is in evolution and the
`long-term results are not yet fully elucidated; therefore,
`even these revised recommendations are likely to
`change over subsequent years. Because multiple vari-
`ables must be weighed in selecting balloon angioplasty
`treatment this report is not intended to provide strict
`indications or contraindications for the procedure. Rel-
`evant considerations include occupational needs, the
`family setting, associated illnesses, and lifestyle prefer-
`ences. Rather, the report is intended to provide a
`statement of general consensus that may be helpful to
`the practitioner as well as to health care administrators
`and other professionals interested in the delivery of
`medical care. The American College of Cardiology and
`the American Heart Association recognize that the
`ultimate judgment regarding the appropriateness of any
`specific procedure is the responsibility of the physician
`caring for the patient. The guidelines should not be
`considered all-inclusive or exclusive of other methods
`that may be available for the care of the individual
`patient. The committee will not offer detailed recom-
`mendations about the specific resources required to
`perform coronary angioplasty or to train those perform-
`ing the procedure. It is essential that physicians per-
`forming angioplasty and related procedures are ade-
`quately trained, that facilities and equipment used are
`capable of obtaining the necessary radiographic infor-
`mation, and that the safety record of the laboratory is
`acceptable.
`This report includes some general considerations that
`provide a brief review of the growth and development of
`the procedure, identification of contraindications to its
`use, and a statement acknowledging general risks asso-
`ciated with angioplasty. A brief discussion of consider-
`ations unique to angioplasty follows with an enumera-
`
`tion of those factors currently recognized as influencing
`the outcome, the requirement for surgical backup,
`performance of angioplasty at the time of initial cathe-
`terization, management of the patient after angioplasty,
`the problems of restenosis and incomplete revascular-
`ization, the need for periodic institutional credentialing,
`and institutional mortality and morbidity review. Lastly,
`specific guidelines for the application of coronary an-
`gioplasty are presented; these were developed accord-
`ing to anatomic (single versus multivessel disease),
`clinical (asymptomatic versus symptomatic patients),
`and physiological (presence or absence of inducible
`ischemia) considerations. The indications derived from
`consensus for angioplasty are judged to be either Class
`I, II, or III (defined in "Indications for Angioplasty"),
`based primarily on multifactorial risk assessment
`weighed against expected outcome, judgments of feasi-
`bility, appropriateness to the clinical setting, and overall
`efficacy viewed in the light of current knowledge and
`technology.
`
`General Considerations
`
`Background
`Symptomatic coronary artery disease is present in
`more than 6 million people in the United States.
`Despite the availability of effective medical therapy, a
`significant proportion of patients are candidates for a
`revascularization procedure because of unacceptable
`symptoms or potentially life-threatening lesions. An
`estimated 300 000 coronary artery bypass operations
`and 300 000 coronary angioplasty procedures were per-
`formed in 1990.1 Although coronary angioplasty is still
`performed most often in patients with single-vessel
`coronary disease, increasing numbers of patients with
`multivessel disease and those who have undergone
`surgical bypass are also being treated. Coronary bypass
`surgery is used most often to treat multivessel coronary
`disease, with a majority of patients receiving three or
`more bypass grafts. Use of the internal mammary artery
`as a conduit has risen dramatically in recent years, from
`less than 4% of the total number of procedures (an
`estimated 6000) in 1983 to more than 60% of all
`operations in 1990.1 The leading indication for surgery
`continues to be relief of angina, an approach supported
`by findings of randomized trials that have shown that,
`compared with medical therapy, surgical revasculariza-
`tion significantly reduces symptoms and improves qual-
`ity of life.4 At the same time there has been an
`expansion of the patients for whom it is recognized that
`bypass surgery improves survival.5-12 This improvement
`in survival has been established in patients with left
`main coronary disease,5 certain patients with three-
`vessel disease,6-8 some patients with two-vessel disease
`when the proximal anterior descending coronary artery
`is involved,7'9 as well as in subsets of patients with severe
`symptoms10 or with a positive exercise test."1 Although
`PTCA has been effective in alleviating angina in many
`classes of patients, there have not yet been trials com-
`paring angioplasty with medical therapy in the subsets
`shown to have improved survival with surgery.
`Immediate and Long-Term Results
`Coronary angioplasty was first introduced by Andreas
`Gruentzig in A7713 as an alternative form of revascu-
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`Guidelines for Percutaneous Transluminal Coronary Angioplasty
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`2989
`
`larization. During the early years of its application
`Gruentzig and others used angioplasty predominantly
`to treat patients with discrete proximal noncalcified
`subtotal occlusive lesions in a single coronary artery. In
`subsequent years the technique has been used success-
`fully in patients with multivessel disease, multiple sub-
`total stenoses in the same vessel, certain complete
`occlusions, partial occlusion of saphenous vein or inter-
`nal mammary artery grafts, or recent total thrombotic
`occlusions associated with acute myocardial infarction.
`By 1980 Gruentzig had performed the procedure on
`169 symptomatic patients, 40% of whom had multivessel
`disease. The 10-year follow-up of those patients showed
`persistent long-term benefit, with 89.5% of the patients
`surviving and 75% remaining asymptomatic. Ten-year
`survival in patients with single-vessel disease (95%)
`exceeded that in patients with multivessel disease
`(81%). Repeat angioplasty was required by 31% and
`coronary bypass surgery by 31%.14 Five-year survival in
`patients treated at Emory University in 1981, most of
`whom had single-vessel disease, was 97%15 and at 10
`years was 92%. The National Heart, Lung, and Blood
`Institute established a PTCA registry in 1979 to help
`evaluate the technique. Through 1982 a total of 3079
`patients were entered into the voluntary registry, and
`numerous analyses from this data bank have substanti-
`ated the effectiveness and safety of angioplasty.16 Be-
`cause technical advances resulted in improved success
`rates and expanded application, a new registry was
`opened by the NHLBI in 1985 to evaluate more recent
`trends in angioplasty. Sixteen centers agreed to volun-
`tarily collect data on an additional 2500 patients. The
`primary clinical success rate increased from 61% in the
`initial cohort to 78%.17 Despite a change in complexity,
`with half of the cases in the second registry having
`multivessel disease, the rate of nonfatal myocardial
`infarction decreased from 4.9% to 4.3% and that of
`emergency coronary artery surgery from 5.8% to 3.4%;
`the mortality rate remained unchanged (1.2% and
`1.0%). Five-year follow-up of the data from the second
`registry indicates an overall survival rate of 90%.18
`Investigators in a recently completed trial, Angio-
`plasty Compared to Medical Therapy,19 compared an-
`gioplasty with medical therapy in patients with single-
`vessel disease. Although improved symptoms and a
`modest increase in exercise performance were docu-
`mented among the patients randomly assigned to
`PTCA, there was no demonstrable effect on survival, a
`feature also similar to surgical trials in patients with
`single-vessel disease. This study is also noteworthy for
`the observation that nearly 50% of the patients ran-
`domly assigned to medical therapy became angina-free
`during the 6-month period of observation.
`In recent years, angioplasty in multivessel disease has
`been associated with a mortality risk of approximately
`1% to 2%,20-23 although it is recognized that the proce-
`dure can have a higher risk in patients with more severe
`disease. In the NHLBI registry, double-vessel disease
`angioplasty was associated with a 0.9% in-hospital
`mortality rate, while triple-vessel disease was associated
`with a 2.8% mortality rate. The 5-year survival for
`patients with single-vessel disease was 93.2%, for those
`with double-vessel disease, 88.8%, and for those with
`triple-vessel disease, 86%.18 In one report from a single
`institution, involving 700 patients with multivessel dis-
`
`ease (53% having double-vessel disease and 47% having
`triple-vessel disease), the 5-year overall survival rate
`was 88%. Event-free survival, defined as freedom from
`death, Q-wave infarction, and coronary bypass surgery,
`was 74%.23
`Influence of New Devices
`Two aspects of balloon angioplasty have motivated
`cardiologists to seek alternative methods of improving
`flow through obstructed arteries: the acute complica-
`tions resulting from the angioplasty procedure itself and
`the occurrence of late restenosis following the proce-
`dure. Although atherectomy, laser angioplasty, and
`stenting have improved initial results in certain ana-
`tomic situations, the overall rates of acute complication
`and restenosis with use of these devices have not
`differed from those with balloon angioplasty.24,25 Al-
`though in certain situations an operator may use an
`approved new interventional device, it is to be noted
`that these devices have been approved only for specific
`indications that are more restrictive than those for
`balloon angioplasty. These guidelines are based princi-
`pally on experience with balloon angioplasty, and
`throughout this document the term "angioplasty" will
`be used to describe the procedure of endovascular
`enlargement of the coronary lumen by a balloon or
`other device.
`Comparison With Bypass Surgery
`Coronary angioplasty and coronary bypass grafting
`are both intended to improve myocardial blood flow.
`Both are palliative rather than curative and should be
`seen as complementary rather than competitive proce-
`dures. Both are associated with potential risks, includ-
`ing stroke, myocardial injury, and death.
`The major advantage of coronary angioplasty is its
`relative ease of use, avoiding general anesthesia, thora-
`cotomy, extracorporeal circulation, mechanical ventila-
`tion, and prolonged convalescence. Repeat angioplasty
`can be performed more easily than repeat bypass sur-
`gery and revascularization can be achieved more quickly
`in emergency situations. The disadvantages of angio-
`plasty are high early restenosis rates and the inability to
`relieve many stenoses because of the nature and extent
`of the coronary lesion.
`Coronary bypass surgery has the advantages of
`greater durability (graft patency rates exceeding 90% at
`10 years with arterial conduits) and more complete
`revascularization irrespective of the morphology of the
`obstructing atherosclerotic lesion.
`Generally speaking, the greater the extent of coro-
`nary atherosclerosis and its diffuseness through the
`vessel wall, the more compelling the choice of coronary
`artery bypass surgery, particularly if left ventricular
`function is depressed. Patients with lesser extent of
`disease and localized lesions are good candidates for
`endovascular approaches. The use of either technique
`assumes the presence of clinical indications such as
`failure of medical treatment to control symptoms or a
`potential survival benefit.
`The use of the two technologies in terms of patient
`selection and comparisons of outcome await the comple-
`tion of several ongoing randomized clinical trials26 (the
`Bypass Angioplasty Revascularization Investigation, the
`Coronary Angioplasty Versus Bypass Revascularization
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`Circulation
`
`Vol 88, No 6 December 1993
`
`Investigation, the Emory Angioplasty Surgery Trial, the
`German Angioplasty Bypass Investigation, and Random-
`ized Intervention Treatment ofAngina27) in which the two
`treatments are compared in patients eligible for both
`techniques. Changing technology, institutional and oper-
`ator experience, and patient preference will continue to
`influence choice of treatment.
`The increasing use of angioplasty in suitable pa-
`tients has materially affected the indications for the
`coronary bypass operation. This has resulted in a
`change in the case mix of patients undergoing bypass
`surgery in recent years: they are generally older, have
`diffuse, extensive coronary disease, often with im-
`paired left ventricular function, and are higher-risk
`patients than formerly.28 29 There is also a recognized
`paucity of proper risk-adjusted comparisons between
`coronary artery bypass surgery, PTCA, and medical
`treatment. Based on data available in 1989, Wong et
`a130 constructed a decision analytic model that ad-
`dresses the question of when myocardial revascular-
`ization is indicated for chronic stable angina. The
`model considers angioplasty in addition to bypass
`surgery and medical therapy and supports the recom-
`mendation that revascularization is not indicated un-
`less severe symptoms, other markers of substantial
`ischemia, or severe multivessel disease are present.
`The analysis also suggests that angioplasty may be
`preferable to bypass surgery in patients with one- and
`two-vessel disease. In a recent nonrandomized study
`of consecutive patients treated with PTCA or coronary
`artery bypass graft surgery (CABG) for multivessel
`disease and left ventricular dysfunction, in-hospital
`mortality rates were comparable (5% for CABG and
`3% for PTCA).31 Although stroke was more common
`in CABG patients (7% compared with 0%, P=.01),
`there was a trend toward improved 5-year survival for
`patients who had undergone bypass grafting compared
`with those who had undergone PTCA (75% and 67%,
`P=.09). Age and incomplete revascularization, but not
`method of revascularization, were found upon multi-
`variate analysis to correlate with late mortality. For a
`more detailed comparison of CABG with PTCA, the
`reader is referred to the ACC/AHA guidelines and
`indications for coronary artery bypass surgery.12
`Contraindications to Angioplasty
`In general, the contraindications to angioplasty
`include all of the relative contraindications enumer-
`ated for the performance of coronary angiography as
`outlined in the guidelines of an earlier ACC/AHA
`report.2 Before undergoing angioplasty, it is impera-
`tive that the patient clearly understand the procedure,
`its potential complications, and the alternatives of
`medical therapy or bypass surgery and have a truly
`informed understanding of the risk-benefit ratio. The
`importance of a relative contraindication to angio-
`plasty will vary with the symptomatic state as well as
`the general medical condition of the individual pa-
`tient. Certain risks may be appropriate in severely
`symptomatic individuals who, for example, are not
`candidates for bypass surgery, whereas these risks
`would be inadvisable for an asymptomatic or mildly
`symptomatic individual. The currently accepted con-
`traindications to the performance of elective coronary
`angioplasty are the following.
`
`1. Absolute contraindications
`a. There is no significant obstructing lesion.*
`b. There is a significant obstruction (>50%) in the
`left main coronary artery and this main segment is not
`protected by at least one nonobstructed bypass graft to
`the left anterior descending or left circumflex artery.
`c. There is no formal cardiac surgical program within
`the institution.
`2. Relative contraindications
`a. A coagulopathy is present: conditions associated
`with bleeding abnormalities or hypercoagulable states
`may be associated, respectively, with unacceptable risks
`of serious bleeding or thrombotic occlusion of a recently
`dilated vessel.
`b. The patient has diffusely diseased saphenous vein
`grafts without a focal dilatable lesion.
`c. The patient has diffusely diseased native coronary
`arteries with distal vessels suitable for bypass grafting.
`d. The vessel in question is the sole remaining circu-
`lation to the myocardium.
`e. The patient has chronic total occlusions with
`clinical and anatomic features that result in a very low
`anticipated success rate of dilation.
`f. The lesion under consideration is a borderline
`stenotic lesion (usually <50% stenosis).
`g. The procedure is proposed for a non-infarct-
`related artery in patients with multivessel disease who
`are undergoing direct angioplasty for acute myocardial
`infarction.
`In addition to these generally accepted relative con-
`traindications, there are other risks that cause clinicians
`to have considerable reservations about the risk-benefit
`ratio of angioplasty. These risks include those of abrupt
`vessel closure, those associated with emergency bypass
`surgery compared with elective surgery, as well as those
`of restenosis. These risks are viewed as being on a
`continuum, and their aggregate weight should ulti-
`mately determine whether a specific procedure should
`or should not be undertaken.
`Patients with chronic renal failure may have in-
`creased morbidity following coronary angioplasty due
`to contrast-induced increased renal failure and subse-
`quent prolonged hospitalization. Although coronary
`angioplasty can be performed successfully in patients on
`dialysis, the restenosis rate has been high (81% in one
`report) and the long-term outcome has been unfavor-
`able.32 Whether the long-term results of patients under-
`going renal transplantation are better if coronary angio-
`plasty is performed before or after the procedure is
`unresolved.
`Risks Associated With Angioplasty
`Because coronary angioplasty requires visualization
`of the coronary anatomy as well as systemic arterial and
`venous access, patients undergoing the procedure are at
`risk for the same complications associated with diagnos-
`tic cardiac catheterization.2
`Despite major improvements in angioplasty equip-
`ment and operator skill, abrupt vessel closure remains
`the major cause of morbidity and mortality, occurring in
`3% to 8% of procedures, depending on the definition
`
`*For the purpose of this report, a significant stenosis is defined
`as one that results in a 5O5% reduction in coronary diameter as
`determined by caliper method.
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`used.33-39 Coronary artery dissection, with or without
`thrombus, is the major cause of abrupt vessel closure.
`Although coronary artery spasm appears occasionally to
`be a contributing factor,40 in a number of studies
`hypotension during or immediately after an angioplasty
`procedure preceded abrupt vessel closure,36,41 with a
`lack of adequate perfusion pressure presumably con-
`tributing to the abrupt closure. Intra-aortic balloon
`pumping42 and vasopressors may restore coronary ar-
`tery perfusion pressure. Although successful resolution
`of abrupt vessel closure has been accomplished with
`percutaneous techniques in as many as two thirds of
`patients,37 the condition is associated with a substantial
`mortality rate (4% to 10%), and 20% to 30% of patients
`require emergency bypass surgery, with 9% experienc-
`ing Q-wave infarction.35,39,41
`In the event of abrupt vessel closure, recrossing the
`occluded segment and repeating balloon inflation, in-
`serting a perfusion catheter, or using thrombolytic or
`vasodilator agents can frequently reestablish coronary
`artery patency and relieve ischemia.37'41'4344 Directional
`coronary atherectomy has been successful in managing
`selected cases with bulky plaque separation that pro-
`duces vessel obstruction.45 The preliminary results of
`intracoronary stents have shown promise in the man-
`agement of the dissected coronary artery.46-50 The
`subsequent management of patients with stents requires
`a careful balance between adequate prolonged antico-
`agulation to prevent thrombosis and avoidance of bleed-
`ing complications. Prolonged maneuvers to reestablish
`coronary patency are discouraged if they delay needed
`surgical intervention and risk further myocardial dam-
`age due to prolonged ischemia.
`Peripheral vascular complications (particularly false
`aneurysms and access site bleeding) may occur and are
`usually associated with large guiding catheters, pro-
`longed procedures, advanced age of the patient, and
`periprocedural use of heparin or fibrinolytic agents.51
`The large doses of contrast material required for com-
`plex angioplasty procedures may also contribute to
`morbidity by causing hemodynamic and renal dysfunc-
`tion in some patients. Other infrequent complications
`unique to coronary angioplasty include intracoronary
`embolization of atherosclerotic or thrombotic material,
`coronary perforation, laceration or rupture of a coro-
`nary artery with subsequent hemopericardium, and
`tamponade.
`Certain high-risk patients who may have contraindi-
`cations to coronary bypass surgery may be candidates
`for coronary angioplasty. Hemodynamic support may be
`necessary in these patients and multiple devices have
`been used.52 The most experience is with intra-aortic
`balloon pump counterpulsation; this technique has been
`used with relatively low rates of morbidity and mortal-
`ity.53 Emergency cardiopulmonary support has been
`used in some centers but has the disadvantage of an
`increased number of associated complications.54'55 In
`addition, although the systemic circulation is supported
`by this method, coronary perfusion is not provided
`during hemodynamic collapse, and cardiopulmonary
`support is not cardioprotective against global and re-
`gional myocardial dysfunction.56 The indications for
`cardiopulmonary support need further clarification, and
`at present the technique should not be used to extend
`the use of coronary angioplasty for higher-risk patients.
`
`Need for Surgical Backup
`Surgical backup, a service that was thought to be
`essential during the developmental stages of angio-
`plasty, is still provided in one form or another in most
`cases of elective PTCA.
`At present, 2% to 5% of patients undergoing PTCA
`will sustain damage (dissection, intimal disruption, per-
`foration, or embolization) to the coronary arteries,
`requiring emergency surgical intervention. Emergency
`coronary artery bypass grafting under these circum-
`stances can be done effectively but with an operative
`mortality higher than that encountered in comparable
`patients managed with primary elective surgery.12'29'57
`Many of these patients have one- or two-vessel disease
`and would be uncomplicated surgical patients under
`elective circumstances. The perioperative myocardial
`infarction rate remains high, however, and the oppor-
`tunity to use arterial conduits is reduced. The mortality
`and myocardial infarction rates following emergency
`surgery for failed PTCA increase with the extent of
`coronary disease, the occurrence of cardiac arrest,
`hemodynamic instability, and the need for cardiopul-
`monary resuscitation, which is often required in these
`circumstances. Also contributing to the increased mor-
`tality and morbidity rates of emergency bypass surgery
`for failed angioplasty are all the factors that prolong the
`time to surgical reperfusion. These factors come into
`play in patients who have had prior heart surgery, those
`in whom conduit material is lacking, and especially in
`those for whom the decision to proceed with emergency
`surgical revascularization is delayed. Although no pro-
`spective studies have been done to indicate which
`patients experiencing failed angioplasty should have
`emergency surgical revascularization, it is assumed that
`most patients will benefit from an attempt at surgically
`restoring myocardial blood flow under these circum-
`stances. The indications for emergency CABG following
`failed PTCA should follow the guidelines outlined in
`the ACC/AHA task force report.12
`Because of the variation in institutional practices of
`cardiology and cardiac surgery, there is no standard
`surgical backup for angioplasty. Surgical backup varies
`from informal arrangements in which emergencies are
`managed without prior planning or preparation to for-
`mal standby in which an operating room is kept open
`and an entire surgical team is immediately available.
`However, there is concern that the universal require-
`ment that angioplasty be done only in hospitals having
`cardiac surgical capability is leading to the proliferation
`in the United States of small-volume cardiac surgical
`programs whose major role is to provide surgical backup
`for angioplasty.
`Data from centers in Canada and Europe, where
`surgical programs are limited in number, suggest that
`elective angioplasty can be performed in hospitals with-
`out cardiac surgical capability with results comparable
`to those of centers having this capability.58-60 It must be
`acknowledged, however, that with more than 900 surgi-
`cal/angioplasty units available in the United States, the
`relative lack of surgical facilities in Canada and abroad
`does not pertain here. This gives rise to the current
`opinion in this country that to do elective angioplasty
`without surgical backup exposes both the patient and
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`Circulation
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`Vol 88, No 6 December 1993
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`physician to unnecessary risk and should not be done
`routinely.61
`Formal surgical standby that necessitates the expen-
`diture of enormous resources to provide an operating
`room, equipment, supplies, and highly trained person-
`nel for a procedure that will be used less than 5% of the
`time is both expensive and inefficient.62 For this reason,
`surgical backup for angioplasty is increasingly provided
`on a more informal basis. Better selection of patients
`and lesions for angioplasty, better catheter systems,
`improved technical competence, more stringent creden-
`tialing, case-load requirements for those who perform
`angioplasty, and various "bail-out" techniques have
`made formal surgical standby less necessary than during
`the developmental phase of coronary angioplasty.6364
`The sine qua non for optimal patient care is good
`communication among cardiologist, cardiac surgeon,
`cardiac anesthesiologist, and support personnel in the
`cardiac catheterization laboratory and operating room.
`The current national standard of accepted medical
`practice for coronary angioplasty requires that an expe-
`rienced cardiovascular surgical team