Chronic stable angina revascularization

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Overview

The goals of treatment of stable angina are to reduce symptoms, delay the progression of atherosclerosis, and prevent cardiovascular events. This is usually established with medical therapy with revascularization used only in selected patients. The main indications for revascularization therapy (PCI or CABG) in stable angina are:

• Patients with symptoms uncontrolled with optimal medical therapy (see above).

The definition of an inadequate response to medical therapy is fairly wide and depends on the patient’s lifestyle, occupation, and expectations. At one extreme are patients who are limited by angina pectoris despite optimal drug treatment and lifestyle modifications, including achievement of optimal weight and cessation of smoking. At the other end of the range are patients who consider medical therapy to have failed if control of angina pectoris requires higher doses of anti-anginal medications that cause side effects.

• Patients who would have a survival benefit from revascularization (PCI or CABG).

This depends on the location, severity, and number of lesions; the presence or absence of left ventricular dysfunction is an important factor as well.

There is evidence and/or general agreement that coronary angiography should be performed to risk stratify patients with chronic stable angina in the following settings:

• Disabling anginal symptoms (Canadian Cardiovascular Society [CCS] classes III and IV) despite medical therapy.
• High-risk criteria on noninvasive testing independent of the severity of angina (The amount and distribution of viable but jeopardized left ventricular myocardium and the percentage of irreversibly scarred myocardium).
• Survivors of sudden cardiac death or serious ventricular arrhythmia.
• Symptoms and signs of heart failure.
• Clinical features that suggest that the patient has a high likelihood of severe coronary artery disease.

On the other hand, angiography is not recommended for patients with CCS class I or II angina that responds to medical therapy and, on noninvasive testing, shows no evidence of ischemia.

There are currently two well-established revascularization approaches for the treatment of chronic stable angina caused by coronary atherosclerosis. Since the introduction of bypass surgery in 1967 and percutaneous transluminal coronary angioplasty [PTCA] in 1977, it has become clear that both strategies can contribute to the effective treatment of patients with chronic stable angina and both have weaknesses. The choice between PCI and CABG is based upon anatomy and other factors such as left ventricular function and the presence or absence of diabetes. In general, PTCA is reserved for single or some cases of two vessel disease, while CABG is reserved for patients with two or three vessel disease or left main disease. With the availability of drug-eluting stents, PCI is increasingly being performed for many lesions including more complex ones.

Percutaneous Coronary Intervention(PCI)

Percutaneous coronary intervention began in 1977 as PTCA, a strategy in which a catheter-borne balloon was inflated at the point of coronary stenosis. The advantages of PCI for the treatment of CAD are many and include a low level of procedure-related morbidity, a low procedure-related mortality rate in properly selected patients, a short hospital stay, early return to activity, and the feasibility of multiple procedures. The disadvantages of PCI are that it is not feasible for many patients, there is a significant incidence of restenosis in lesions that are successfully treated, and there is a risk of acute coronary occlusion during PCI.

Ideal candidates for PTCA/PCI have stable angina, are under 75 years of age, with single-vessel, single-lesion CAD, without a history of diabetes. Lesions that are best for these procedures are short (<10 mm), concentric, discrete, and readily accessible. The risk of morbidity and mortality from the procedure is increased, particularly in patients with long (>20 mm), tortuous, irregular, angulated, calcified, severely stenotic (>90% stenosis) lesions and when more than one such lesion is present in an artery. Other important factors include operator volume and the presence or absence of on site cardiovascular surgeon. The 2005 ACC/AHA/SCAI guidelines for percutaneous coronary intervention made recommendations about hospital and operator volume and the importance of onsite cardiac surgery for both elective and primary PCI.

Primary success of coronary interventions is generally defined as an absolute increase of 20 percentage points in luminal diameter and a final diameter obstruction less than 30%. Such angiographic success can be anticipated in more than 90% of properly selected patients.

Complications of percutaneous coronary intervention

The improvements in devices, the use of stents, and aggressive antiplatelet therapy have significantly reduced the incidence of major procedural complications of PCI over the past 2 decades despite the increasing complexity of cases. However, as with any invasive procedure, complications can occur. The major complications of PTCA/PCI include coronary artery dissection and acute closure, intramural hematoma, coronary artery perforation, and occlusion of branch vessels: Dissections are found in up to 50 percent of patients immediately after PTCA. Intimal tears or dissections following PTCA have been arbitrarily divided into types A to F.

• Type A — Luminal haziness

• Type B — Linear dissection

• Type C — Extraluminal contrast staining

• Type D — Spiral dissection

• Type E — Dissection with reduced flow

• Type F — Dissection with total occlusion

These problems are now much less frequent since stent placement is performed in most percutaneous coronary procedures. Abrupt closure is most often due to arterial dissection and is manifested as acute ischemic chest pain and ECG changes. The incidence of abrupt closure with conventional balloon angioplasty (PTCA) is approximately 5% and is associated with a 10-fold increase in mortality to about 1 percent and nonfatal MI. The frequency of this complication, however, has now been greatly reduced by pretreatment with the platelet glycoprotein IIb/IIIa receptor blockers and by the insertion of an intracoronary stent. If stenting does not restore adequate flow, emergency CABG can be performed.

Coronary artery intramural hematoma is defined as an accumulation of blood within the medial space displacing the internal elastic membrane inward and the external elastic membrane outward, with or without identifiable entry and exit points. It is identified in 6.7 percent of procedures by intravascular ultrasound (IVUS).

Coronary artery perforation in the stent era is a rare but potentially disastrous complication.

Downstream embolization of thrombus or plaque contents with microvascular obstruction is common after PCI and occlusion of side branches has been reported in up to 19 percent of cases in which a stent was placed across a major side branch.

Stent thrombosis is catastrophic complication that usually leads to death or ST segment elevation MI. It is therefore a medical emergency. Stent thrombosis can occur acutely (during or soon after the PCI), subacutely (within 30 days after stent placement), or as a complication. Late stent thrombosis is associated with the cessation of aspirin or clopidogrel therapy. On the other hand, very late stent thrombosis, occurring after one year, is associated with drug-eluting stents.

Restenosis is the result of arterial damage with subsequent neointimal tissue proliferation. It is usually defined as a greater than 50% diameter stenosis. The incidence of angiographic restenosis is approximately 30% to 40% after PTCA. Intracoronary stents reduce the rate of angiographic and clinical restenosis and post-procedural myocardial infarction compared to percutaneous transluminal coronary angioplasty (PTCA) alone. Trials have demonstrated that the sirolimus and paclitaxel drug-eluting stents markedly reduced the incidence of in-stent restenosis and the rate of target lesion revascularization compared to bare metal stents. As a result, stents are currently utilized in nearly all percutaneous coronary interventions. However, the benefits of drug-eluting stents on restenosis must be weighed against rates of stent thrombosis, which often leads to death or MI, if dual antiplatelet therapy is prematurely discontinued. Restenosis occurs more frequently in diabetics, smaller arteries, among total occlusions, and in left anterior descending arteries, particularly proximal lesions. Since not all angiographic restenosis results in recurrent symptoms, the rates of clinical restenosis are lower than these angiographic estimates. Recurrent sever angina occurs in approximately half of the patients who develop angiographic restenosis and usually responds to stenting. In symptomatic patients with BMS restenosis, a repeat stenting using a DES is usually recommended. In symptomatic patients with intracoronary DES restenosis, there are insufficient data to suggest any specific treatment.

Clinical trials: PTCA/PCI versus medical treatment in the management of stable angina pectoris:

There are important limitations concerning the applicability of the results of older trials and even newer trials to the current clinical practice.

In early trials of percutaneous intervention versus medical therapy, the majority of patients underwent coronary angioplasty alone without stenting. For example, the benefits of PTCA have been compared to medical therapy in single vessel disease in the randomized Veterans Affairs Angioplasty Compared to Medicine (ACME) trial. PTCA resulted in a reduction in anginal symptoms compared to medical therapy (50% angina free versus 24% at one month), however, while the benefit of PTCA was still significant at 6 months, the magnitude of this benefit was reduced (64% angina free versus 45%). Patients treated with PTCA also had an improvement of 2.1  3.1 minutes in exercise duration which was significantly greater than the 0.5  2.2 minutes experienced in the medical therapy group.

Other older trials compared PTCA to both limited (AVERT trial) and optimal medical interventions (RITA-2 and MASS II). The findings of these trials were that patients undergoing PTCA had similar rates of death and myocardial infarction as those on medical therapy and were less likely to have angina during the first few years.

More recent literature provides comparison between the use of stents and medical management, however, there is few data examining the extensive use of drug eluting stents and current extensive antithrombotic regimens (clopidogrel and GP IIb/IIIa inhibitors). In the most recent trial, COURAGE, drug-eluting stents were used in only 15 percent of patients. However, the COURAGE trial has the data most applicable to current practice. In this study 2287 patients were randomized to either aggressive medical therapy alone or aggressive medical therapy plus PCI with bare metal stenting. Patients were required to have both objective evidence of ischemia and significant CHD in a least one vessel; 87 percent were symptomatic and 58 percent had Canadian Cardiovascular Society CCS class II or III angina. Patients were excluded if they had CCS class IV angina, ≥50 percent left main disease, a markedly positive treadmill test (significant ST segment depressions and/or a hypotensive response during stage I of the Bruce protocol), an LVEF less than 30 percent, or coronary lesions deemed unsuitable for PCI. All patients received optimal medical therapy with beta blockers, calcium channel blockers, nitrates, antiplatelet therapy (either aspirin or clopidogrel), and aggressive lipid-lowering therapy with statin (attained median LDL-cholesterol was 72 mg/dL at five years). Exercise was recommended to achieve further improvements in the lipid profile when necessary. The results were published at a median follow-up of 4.6 years. There was no significant difference between the two treatment strategies for the primary end point of death from any cause and non-fatal MI. There was no significant difference in the rates of hospitalization for ACS. Patients in the PCI group underwent significantly fewer subsequent revascularization procedures (21 versus 33 percent, HR 0.60, 95% CI 0.51-71).

The issue of whether patients who receive PCI plus optimal medical therapy have a better quality of life and less angina than those who receive optimal medical therapy was addressed in COURAGE as well:

At baseline, 22 percent of patients were free of angina. At three months, significantly more patients who received PCI were angina free (53 versus 42 percent), but at 36 months there was no significant difference (59 versus 56 percent). Patients in both groups showed significant improvements from baseline values in various measures of quality of life. The percent of patients with clinically significant improvement in parameters such as physical limitation, angina stability, angina frequency, and overall quality of life was significantly higher in the PCI group by the sixth months. However, there was no significant difference in these rates at 36 months.

The results of COURAGE demonstrate that PCI with bare metal stents plus optimal medical therapy and initial, optimal medical therapy with revascularization as necessary are comparable strategies.

Coronary Artery Bypass Grafting(CABG)

CABG is carried out to prolong life or improve its quality (see above). Prolongation of life has been shown in patients with more than 50% luminal diameter stenosis of the left main coronary artery and in those with impaired left ventricular function (left ventricular ejection fraction <40%) and critical, >70% stenosis in all three major coronary arteries or in two arteries, one of which is the proximal left anterior descending artery. The presence of a high-risk result on a noninvasive test also increases the benefit of surgery. Patients with severe left ventricular dysfunction obtain a survival benefit from CABG if the myocardium with impaired contractile function is viable (hibernating myocardium) rather than necrotic. The stenotic arteries are bypassed with an internal mammary (arterial) or saphenous vein graft. Arterial grafts have excellent long-term patency rates (90% at 10 years), whereas saphenous vein grafts show accelerated atherosclerosis with approximately 50% patency at 10 years. The use of internal mammary artery grafts is associated with a 27% reduction in 15-year mortality compared with saphenous vein grafts. The left internal mammary artery is most favorable to a graft to the left anterior descending coronary artery and the right internal mammary artery is most applicable to graft to the right coronary artery. Patients who require more than two grafts generally receive a combination of arterial and venous grafts. Minimally invasive CABG via a smaller thoractomy incision or a thorascopic approach reduces the morbidity and hospital length-of-stay. The operative mortality of CABG is about 2%. The steady improvements in perioperative care have been offset by the progressively sicker patients who are referred for this procedure. Angina pectoris is relieved in more than 90% of patients who undergo CABG. The recurrence of angina is due to graft stenosis or progression of disease in nongrafted vessels.

Clinical trials: coronary artery bypass surgery versus medical treatment in the management of stable angina pectoris:

It is well established that CABG provides more symptoms relief and survival benefits in some patients with chronic stable angina. However, the long term benefit of CABG is limited by the progression of atherosclerosis in other unbypassed vessels and stenosis of the graft itself. The CASS Trial (Coronary Artery Surgery Study) showed that more patients remained symptom-free after CABG compared to medical therapy at one year (66 versus 30 percent) and five years (63 versus 38 percent). However, by 10 years, this difference had disappeared (47 versus 42 percent). Trials from the 1970's showed that CABG offered no significant overall mortality benefits compared to medical therapy. However, several trials established the survival benefits in selected patients:

• Left main coronary artery stenosis or left main equivalent disease (defined as severe (≥70 percent) proximal left anterior descending and proximal left circumflex disease):

The Veterans Administration Cooperative Study compared a strategy of initial CABG versus deferred CABG: there was a substantial survival advantage patients assigned to initial CABG at two years (93 versus 71 percent) and at 11 years, but not at 18 years. The benefit was greatest in high-risk patients with >75 percent left main stenosis and/or left ventricular dysfunction. The CASS registry demonstrated similar results. Yusuf S et al published an overview of 10-year results from randomized trials by the Coronary Artery Bypass Graft Surgery Trialists Collaboration. They found that the relative risk reduction for death provided by CABG over medical therapy alone was greater at five years for left main disease than for three vessel or one or two vessel disease (odds ratio 0.32 versus 0.58 and 0.77); the absolute survival benefit from CABG among those with left main disease was 19.3 months.

PCI for left main coronary artery stenosis: PCI has been performed in patients with angina and left main disease who are considered inoperable, at high risk for CABG, or with prior CABG and one patent graft to either the left anterior descending or circumflex artery ("protected" left main).

• Multivessel coronary disease and left ventricular dysfunction:

Reduced left ventricular function is an important determinant of prognosis in patients with stable angina and is an indication for revascularization. CABG may improve survival in patients with left ventricular dysfunction and hibernating myocardium; therefore, myocardial viability should be assessed prior to recommending CABG in patients with multivessel coronary disease and left ventricular dysfunction. CASS registry showed that survival at seven years was improved with CABG compared to medical treatment (88 versus 65 percent) in patients with an LVEF between 35 and 49 percent and had three vessel disease. No benefit from CABG could be identified in patients with one or two vessel disease.

Clinical trials: Bypass surgery versus percutaneous intervention in the management of stable angina pectoris:

Limitations of the clinical trials

Multiple trials have compared the strategy of initial PTCA with initial CABG for treatment of CAD. These large randomized trials were published in the mid-1990s. The findings from these studies constitute the primary source of data upon which clinical decision making has been made.

1. The patients entered into these trials are poorly reflective of the general population (numerous patients were excluded and most included patients had preserved left ventricular function and focal atherosclerotic coronary disease).
2. The initial trials are probably not relevant to current practice because of the lack of use of stents (especially drug eluting stents or DES) during PCI or of internal mammary artery rather than saphenous vein grafts during CABG. In addition, current antithrombotic regimens (eg, clopidogrel and glycoprotein IIb/IIIa inhibitors) were not employed during PCI.

Percutaneous intervention versus CABG for isolated LAD disease

There is great evidence that CABG of the LAD using an arterial conduit is associated with improved survival compared to medical therapy, especially if the LAD lesion is severe or associated with multi-vessel disease and/or left ventricular dysfunction. The internal mammary artery grafts are preferred because of the increases in long-term patency and survival compared to venous grafts. On the other hand, medical therapy can be considered for patients with isolated LAD disease with minimal evidence of ischemia on stress testing. In regards to percutaneous interventions on the LAD (usually PTCA with stent), this can be performed with a great success and low risk of complications in proximal LAD disease. However, surgical revascularization should be considered in more complex lesions such as ostial location, particularly with involvement of the distal left main, adjacent circumflex ostial disease, or complex bifurcation lesions involving a dominant first diagonal branch. Despite this low incidence of major complications with stenting of the proximal lesion, the need for revascularization is still lower with CABG than with stenting. This was illustrated in the SIMA trial (Stent versus Internal Mammary Artery grafting):

• SIMA trial: The SIMA trial involved 123 patients with a proximal, isolated LAD stenosis, and compared stenting using bare-metal stent (BMS) to CABG using an internal mammary artery. At 10 years, the incidence of death and myocardial infarction was identical; only the need for additional revascularization was significantly higher in the stent group. It is remarkable that no patients randomized to CABG required a second revascularization of the LAD.

The restenosis rate after PCI is likely to decrease with the increased use of drug-eluting stents(DES). In fact, clinical trials of sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) have demonstrated a marked reduction in the incidence of restenosis in trials evaluating patients with both single and multivessel coronary disease:

• The RAVEL trial (A Randomized Comparison of a Sirolimus-Eluting Stent With a Standard Stent for Coronary Revascularization) is the first controlled trial of a coronary drug-eluting stent. The The 5-year rate of target lesion revascularization (TLR) associated with SES was significantly lower than that with BMS.

• The role of drug-eluting stents in patients with LAD disease was evaluated in a post hoc analysis of data from the SIRIUS trial. Of 1101 patients enrolled in the original study, 459 had an LAD stenosis. All patients were randomly assigned to either a sirolimus-eluting stent or a bare metal stent. At eight months, the incidence of angiographic LAD restenosis was significantly lower among patients treated with a sirolimus-eluting stent (2 versus 42 percent). At one year, the incidence of major adverse events (death, MI, or target lesion revascularization) was also significantly reduced (10 versus 25 percent).

• Paclitaxel stent (PES): In 536 randomized patients with an LAD lesion in the TAXUS IV trial, at one year, the Paclitaxel stent was associated with significant reductions in target vessel revascularization (7.9 versus 18.6 percent) and the need for CABG (2.6 versus 6.3 percent).

• TAXi trial compared both types of drug-eluting stents: These stents were associated with very low rates of target lesion revascularization (1 and 3 percent at seven months). The three-year follow-up study, the TAXi-LATE trial , showed no difference in mortality of all causes in the PES and the SES groups (3% vs. 7%, P=0.98) or in major adverse cardiac event free survival (89% vs. 83%, P=0.28). Four stent thromboses were observed, two in the PES group (205 and 788 days) and two in the SES group (210 and 772 days).

Drug-eluting stents also appear to improve outcomes in patients with lesions at the origins of the LAD. This was illustrated in a study comparing sirolimus stents in 68 consecutive patients with such lesions to 77 patients treated with bare metal stents during the preceding two years. Positioning of the sirolimus stent into the distal left main trunk was required in one-third of patients for complete lesion coverage. The sirolimus stent was associated with significant reductions in angiographic restenosis at six months (5 versus 32 percent with bare metal stents) and target vessel revascularization at one year (0 versus 17 percent).

Percutaneous intervention (PTCA/PCI) versus CABG for multivessel disease

The two U.S. trials of PTCA versus CABG are the multicenter Bypass Angioplasty Revascularization Investigation (BARI) trial and the single-center Emory Angioplasty Surgery Trial (EAST).

In both trials, a majority of patients had two- rather than three-vessel disease and normal LV function. In the BARI trial, 37% of patients had a proximal LAD lesion. In the EAST trial, more than 70% of patients had proximal LAD lesions. The results of both these trials at an approximately seven to eight-year follow-up interval have shown that early and late survival rates have been equivalent for the PTCA and CABG groups. In the BARI trial, the subgroup of patients with treated diabetes had a significantly better survival rate with CABG. That survival advantage for CABG was focused in the group of diabetic patients with multiple severe lesions. In the EAST trial, persons with diabetes had an equivalent survival rate with CABG or PTCA at five years, after which the curves began to diverge but failed to reach a statistically significant difference at eight years (surgical survival 75.5%, PTCA 60.1%; p = 0.23). In both trials, the biggest differences in late outcomes were the need for repeat revascularization procedures and symptom status. In both BARI and EAST, 54% of PTCA patients underwent subsequent revascularization procedures during the five-year follow-up versus 8% of the BARI CABG group and 13% of the EAST CABG group. In addition, the rate of freedom from angina was better in the CABG group in both EAST and BARI, and fewer patients in the CABG groups needed to take anti-anginal medications.

Non U.S. trials:

• RITA trial: The Randomized Intervention Treatment of Angina (RITA) trial was the first of the large scale trials to be published, involving 1011 patients from the United Kingdom. The long-term outcome of patients in the RITA trial (median follow up of 6.5 years) showed that the rates of death or nonfatal infarction for PTCA or CABG were the same (17 versus 16 percent). Angina was consistently higher in the PTCA group, 26 percent of whom required CABG, and 19 percent of whom required another PTCA. Repeat revascularization was usually performed within the first year, while the reintervention rate was 4 percent per year after the first three years.
• GABI trial: The German Angioplasty Bypass Surgery Investigation showed that both bypass surgery and angioplasty were equally effective in relieving angina at one year. This was associated with an increased rate of periprocedural morbidity with bypass surgery but more reinterventions with angioplasty.
• CABRI trial: The Europe-based multicenter Coronary Angioplasty versus Bypass Revascularization Investigation (CABRI) compared CABG to PTCA in 1054 patients. There was a similar mortality rate in the two groups at one year. However, patients assigned to PTCA required more repeat procedures and had a higher incidence of clinically significant angina. Restenosis after PTCA only partially accounted for this difference; of greater importance was the higher likelihood of residual disease after PTCA compared with CABG.

Stenting versus CABG for multivessel disease:

The introduction of stents has resulted in a significant reduction of restenosis and of target vessel revascularization. 2 trials address this question: The ARTS and the SoS. However, these 2 trials did use bare metal stents and not the drug-eluting stents that further reduce the risk of restenosis. In addition, only few patients were treated with GP IIb/IIa inhibitors.

Bare metal stents

1205 patients were included in the ARTS 1 trial and were randomized to undergo bare metal stent implantation or bypass surgery. There was no difference in mortality (2.5 versus 2.8 percent at one year, 3.7 versus 4.6 percent at three years, 8.0 versus 7.6 percent at five years) or the rate of the combined end point of death, MI, or stroke for stented patients compared to those undergoing CABG. There was, however, a significant increase in the need for repeat revascularization with stenting (21 versus 4 percent at one year, 27 versus 7 percent at three years, and 30 versus 9 percent at five years). Diabetics and those with incomplete revascularization had the worse outcomes.

The Medicine, Angioplasty, or Surgery Study for Multivessel Coronary Artery Disease (MASS II), the Argentine Randomized Study of Coronary Angioplasty with Stenting versus Coronary Bypass Surgery in Patients with Multiple Vessel Disease (ERACI-II) and the Angina with Extremely Serious Operative Mortality Evaluation (AWESOME) showed similar survival rates but higher revascularization rates among patients with bare-metal stents at 5 years. Others (the Stent or Surgery trial; SoS) have shown a significant long-term survival advantage with surgery.

SoS trial: This trial included 988 patients between 1996 and 1999. At a median follow-up of two years, PCI was associated with a significantly higher rate of repeat revascularization (21 versus 6 percent) with CABG. At six years, mortality was significantly higher in the PCI group (10.9 versus 6.8; hazard ratio 1.66, 95% CI 1.08 to 2.55. Of note, there was a large number of death related to cancer in the stenting group.

Meta-analyses: Three meta-analyses published in 1995, 2007, and 2008 showed no significant difference between the PCI and CABG in all-cause mortality or cardiac death at one to five years, although angioplasty for multivessel disease was associated with a significant increase in mortality compared to CABG at five and eight years in a subgroup analysis.

Drug eluting stents:

Data from randomized, controlled trials of drug-eluting stents as compared with bare-metal stents have shown significant reductions in the rate of repeat intervention, with similar rates of death and myocardial infarction. Studies comparing PCI involving drug-eluting stents with CABG have generally been smaller and nonrandomized.

Sirolimus-eluting stents (SES):

In ARTS II study, the CABG-control group was a historical group from the ARTS I trial. As a result, conclusions should be made with caution. This trial demonstrated lower rates of revascularization and major adverse cardiac and cerebrovascular events (MACCE) with SES compared with BMS, as well as a higher rate of revascularization with equivalent MACCE to CABG at one year.

Paclitaxel-eluting stents (PES):

The SYNergy between PCI with Taxus and Cardiac Surgery (SYNTAX): The SYNTAX trial is a prospective, clinical trial conducted in 85 sites that randomly assigned 1800 patients with three-vessel or left main coronary artery disease to undergo CABG or PCI (in a 1:1 ratio). A noninferiority comparison of the two groups was performed for the primary end point — a major adverse cardiac or cerebrovascular event (i.e., death from any cause, stroke, myocardial infarction, or repeat revascularization) during the 12-month period after randomization. The trial showed that the rates of major adverse cardiac or cerebrovascular events at 12 months were significantly higher in the PCI group (17.8%, vs. 12.4% for CABG; P=0.002), in large part because of an increased rate of repeat revascularization (13.5% vs. 5.9%, P<0.001); as a result, the criterion for noninferiority was not met. The study concluded that CABG remains the standard of care for patients with three-vessel or left main coronary artery disease.

A randomized trial is under way — the Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease (FREEDOM) study — that specifically compares drug-eluting stents with bypass surgery in patients with diabetes who have multivessel disease.

ACC / AHA Guidelines- Revascularization for Chronic Stable Angina (DO NOT EDIT)

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Class I 1. CABG for patients with significant left main coronary disease. (Level of Evidence: A) 2. CABG for patients with 3-vessel disease. The survival benefit is greater in patients with abnormal LV function (ejection fraction <50%). (Level of Evidence: A) 3. CABG for patients with 2-vessel disease with significant proximal left anterior descending CAD and either abnormal LV function (ejection fraction <50%) or demonstrable ischemia on noninvasive testing. (Level of Evidence: A) 4. PTCA for patients with 2- or 3-vessel disease with significant proximal left anterior descending CAD, who have anatomy suitable for catheter-based therapy, normal LV function, and who do not have treated diabetes. (Level of Evidence: B) 5. PTCA or CABG for patients with 1- or 2-vessel CAD without significant proximal left anterior descending CAD but with a large area of viable myocardium and high-risk criteria on noninvasive testing. (Level of Evidence: B) 6. CABG for patients with 1- or 2-vessel CAD without significant proximal left anterior descending CAD who have survived sudden cardiac death or sustained ventricular tachycardia. (Level of Evidence: C) 7. In patients with prior PTCA, CABG or PTCA for recurrent stenosis associated with a large area of viable myocardium and/or high-risk criteria on noninvasive testing. (Level of Evidence: C) 8. PTCA or CABG for patients who have not been successfully treated by medical therapy and can undergo revascularization with acceptable risk. (Level of Evidence: B) Class IIa 1. Repeat CABG for patients with multiple saphenous vein graft stenoses, especially when there is significant stenosis of a graft supplying the left anterior descending coronary artery. PTCA may be appropriate for focal saphenous vein graft lesions or multiple stenoses in poor candidates for reoperative surgery. (Level of Evidence: C) 2. PTCA or CABG for patients with 1- or 2-vessel CAD without significant proximal left anterior descending CAD but with a moderate area of viable myocardium and demonstrable ischemia on noninvasive testing. (Level of Evidence: B) 3. PTCA or CABG for patients with 1-vessel disease with significant proximal left anterior descending CAD. (Level of Evidence: B) Class IIb 1. Compared with CABG, PTCA for patients with 3- or 2-vessel disease with significant proximal left anterior descending CAD who have anatomy suitable for catheter-based therapy and who have treated diabetes or abnormal LV function. (Level of Evidence: B) 2. PTCA for patients with significant left main coronary disease who are not candidates for CABG. (Level of Evidence: C) 3. PTCA for patients with 1- or 2-vessel CAD without significant proximal left anterior descending CAD who have survived sudden cardiac death or sustained ventricular tachycardia. (Level of Evidence: C) Class III 1. PTCA or CABG for patients with 1- or 2-vessel CAD without significant left anterior descending CAD who a. Have mild symptoms that are unlikely due to myocardial ischemia or have not received an adequate trial of medical therapy and 1) Have only a small area of viable myocardium or 2) Have no demonstrable ischemia on noninvasive testing. (Level of Evidence: C) 2. PTCA or CABG for patients with borderline coronary stenoses (50% to 60% diameter in locations other than the left main) and no demonstrable ischemia on noninvasive testing. (Level of Evidence: C) 3. PTCA or CABG for patients with insignificant coronary stenosis (<50% diameter). (Level of Evidence: C) 4. PTCA in patients with significant left main CAD who are candidates for CABG. (Level of Evidence: B)

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ACC / AHA Guidelines- Recommendations for Revascularization with PCI and CABG in Asymptomatic Patients(DO NOT EDIT)

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Class I 1. CABG for patients with significant left main coronary disease. (Level of Evidence: B) 2. CABG for patients with three-vessel disease. The survival benefit is greater in patients with abnormal LV function (ejection fraction less than 50%). (Level of Evidence: C) 3. CABG for patients with two-vessel disease with significant proximal left anterior descending CAD and either abnormal LV function (ejection fraction less than 50%) or demonstrable ischemia on noninvasive testing. (Level of Evidence: C) 4. PCI for patients with two- or three-vessel disease with significant proximal Left anterior descending CAD who have anatomy suitable for catheter based therapy and normal LV function and who do not have treated diabetes. (Level of Evidence: C) 5. PCI or CABG for patients with one- or two-vessel CAD without significant proximal left anterior descending CAD but with a large area of viable myocardium and high-risk criteria on non-invasive testing. (Level of Evidence: C) 6. CABG for patients with one- or two-vessel CAD without significant proximal left anterior descending CAD who have survived sudden cardiac death or sustained ventricular tachycardia. (Level of Evidence: C) 7. In patients with prior PCI, CABG or PCI for recurrent stenosis associated with a large area of viable myocardium or high-risk criteria on noninvasive testing. (Level of Evidence: C) Class IIa PCI or CABG for patients with one-vessel disease with significant proximal left anterior descending CAD. (Level of Evidence: C) Class IIb 1. Compared with CABG, PCI for patients with two or three vessel disease with significant proximal left anterior descending CAD who have anatomy suitable for catheter-based therapy and who have treated diabetes or abnormal LV function. (Level of Evidence: B) 2. Use of PCI for patients with significant left main coronary disease who are not candidates for CABG. (Level of Evidence: C) 3. PCI for patients with one or two-vessel CAD without significant proximal left anterior descending CAD who have survived sudden cardiac death or sustained ventricular tachycardia. (Level of Evidence: C) 4. Repeat CABG for patients with multiple saphenous vein graft stenoses, with high-risk criteria on noninvasive testing, especially when there is significant stenosis of a graft supplying the LAD. PCI may be appropriate for focal saphenous vein graft lesions or multiple stenoses in poor candidates for reoperative surgery. (Level of Evidence: C) 5. PCI or CABG for patients with one- or two-vessel CAD without significant proximal left anterior descending CAD but with a moderate area of viable myocardium and demonstrable ischemia on noninvasive testing. (Level of Evidence: C) Class III 1. Use of PCI or CABG for patients with one- or two-vessel CAD without significant proximal left anterior descending CAD and a. only a small area of viable myocardium or b. no demonstrable ischemia on noninvasive testing. (Level of Evidence: C) 2. Use of PCI or CABG for patients with borderline coronary stenoses (50% to 60% diameter in locations other than the left main coronary artery) and no demonstrable ischemia on noninvasive testing. (Level of Evidence: C) 3. Use of PCI or CABG for patients with insignificant coronary stenosis (less than 50% diameter). (Level of Evidence: C) 4. Use of PCI in patients with significant left main CAD who are candidates for CABG. (Level of Evidence: B)

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Sources

• The ACC/AHA/ACP–ASIM Guidelines for the Management of Patients With Chronic Stable Angina

• The ACC/AHA 2002 Guideline Update for the Management of Patients With Chronic Stable Angina

• The 2007 Chronic Angina Focused Update of the ACC/AHA 2002 Guidelines for the Management of Patients With Chronic Stable Angina

References

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