Version May 2024
INTRODUCTION — Coronary artery bypass graft surgery (CABG) is performed in patients with stable angina and acute coronary syndromes to prolong life or to treat angina refractory to medical or percutaneous revascularization therapies.
Angina may return after apparently successful CABG. The cause varies with the time when symptoms are first noted after surgery:
●Recurrent angina during the early postoperative period is usually due to a technical problem with a graft or with early graft closure. This is indication for prompt coronary angiography with percutaneous coronary intervention (PCI), if feasible.
●Recurrent angina after the first few months, called late recurrent angina, can occur with the development of stenosis in a bypass graft (either saphenous vein or arterial) or with progression of atherosclerosis in non-bypassed vessels.
This topic will review the management of patients with late recurrent angina after CABG. Early ischemia due to graft occlusion, the technical aspects of percutaneous coronary intervention to treat saphenous vein graft stenosis, and determinants of long-term outcome after CABG are discussed separately. (See "Early noncardiac complications of coronary artery bypass graft surgery" and "Coronary artery bypass graft surgery: Prevention and management of vein graft stenosis" and "Coronary artery bypass graft surgery: Graft choices".)
INCIDENCE OF LATE EVENTS BY TYPE OF CONDUIT — The frequency of the development of late recurrent angina is not well studied; most series report on rates of repeat revascularization (either coronary artery bypass graft surgery [CABG] or percutaneous coronary intervention [PCI]) rather than anginal rates.
Long-term (more than 10 years) follow-up of patients who received CABG with saphenous vein grafts (SVGs) only in the 1970s and early 1980s showed repeat revascularization rates between 25 and 31 percent [1,2]. In more contemporary reports, revascularization rates have come from studies that compare SVG with arterial grafts, CABG to PCI, or graft disease to native vessel disease. For example, in the SYNTAX trial that compared CABG with PCI in patients with three-vessel or left main disease, the rate of repeat revascularization at three years was 11 percent in the CABG group (and 21 percent in the PCI group) [3].
Late recurrent angina can occur with the development of stenotic lesions in either saphenous vein grafts (SVGs) or arterial grafts. The need for repeat revascularization, and presumably the frequency of recurrent angina, is reduced with arterial grafts, since long-term patency is much higher compared to SVGs [4-6]. In a report that compared 2306 patients who underwent CABG with an internal thoracic artery (ITA) graft to the left anterior descending artery (alone or with one or more SVGs) to 3625 patients who received only SVGs, the 10-year rates of freedom from cardiac reoperation were 94.4 and 90.1 percent, respectively [5]. In a meta-analysis of six randomized trials of 1036 patients who received SVGs or arterial grafts, the use of radial artery grafts was associated with a lower incidence of myocardial infarction (hazard ratio [HR] 0.72; 95% CI 0.53-0.99) and a lower incidence of repeat revascularization (HR 0.50; 95% CI 0.40-0.63) [7]. However, there was not a lower incidence of death from any cause (HR 0.90; 95% CI 0.59-1.41). (See "Coronary artery bypass graft surgery: Graft choices", section on 'Vein grafts'.)
Late recurrent angina after CABG can result from progressive atherosclerosis in a native vessel as well. Two studies performed before the routine use of arterial grafting found that SVG disease, as opposed to new native artery disease, was the cause of late recurrent angina in 54 and 80 percent of the cases [8,9]. In contrast, progression of native disease is most often the cause of late recurrent angina in patients who had received an ITA graft. This was illustrated in an analysis from the BARI trial of CABG versus PCI in patients with stable angina [10]. On repeat coronary angiography at five years, 82 patients who underwent CABG showed evidence of increased jeopardized myocardium; progression of disease in previously untreated vessels accounted for two-thirds of this increase in myocardium at risk.
RISK FACTORS — The development of late recurrent angina correlates with male sex, increasing age, and risk factors for atherosclerotic cardiovascular disease such as hyperlipidemia, hypertension, cigarette smoking, and diabetes [11-14]. (See "Overview of established risk factors for cardiovascular disease", section on 'Established risk factors for atherosclerotic CVD'.)
Other risk factors for the development of symptoms due to bypass graft failure are presented separately. (See "Coronary artery bypass graft surgery: Graft choices", section on 'Late occlusion'.)
CLINICAL MANIFESTATIONS — Late recurrent angina may occur at any time after the first few months from coronary artery bypass graft surgery (CABG) and may present as stable or unstable angina. These patients often have symptoms similar to those present before CABG. However, a different presentation (including differing characteristics of pain or symptoms of exercise intolerance or dyspnea instead of pain) may occur, and clinicians should have a relatively low threshold for considering recurrent myocardial ischemia in a patient with prior CABG. (See "Approach to the patient with suspected angina pectoris", section on 'History'.)
While a physical examination directed at the cardiovascular system should be performed in any patient with a suspicion of recurrent angina, it cannot confirm the diagnosis of recurrent angina. Alternative causes of chest pain, such as chest wall tenderness or a herpes zoster rash can be found. A broader discussion of use of the physical examination in adults with chest pain is found elsewhere. (See "Outpatient evaluation of the adult with chest pain", section on 'Differential Diagnosis'.)
DIAGNOSIS — Late recurrent angina after coronary artery bypass graft surgery (CABG) is diagnosed when a patient with symptoms consistent with angina is found to have evidence of myocardial ischemia on stress testing with imaging, significant obstructive coronary artery lesions on coronary arteriography, or evidence of an acute coronary syndrome. (See "Diagnosis of acute myocardial infarction", section on 'Definitions'.)
Although the history may be strongly suspicious for recurrent angina, many physicians try to confirm the suspicion with diagnostic testing. Because these patients have a high pretest probability of obstructive coronary artery disease, a positive test will support the diagnosis. Such testing will also provide prognostic information about exercise tolerance, which should be used to help formulate a management strategy.
We recommend obtaining a 12-lead electrocardiogram (ECG) in all patients as soon as recurrent angina is suspected; it should be compared to prior ECGs. New findings of ST-segment or T wave changes representing ischemia, Q waves, bundle branch block, or arrhythmias should raise the possibility of an acute coronary syndrome (ACS). (See "ECG tutorial: ST and T wave changes" and "ECG tutorial: Myocardial ischemia and infarction".) ACS should be suspected in patients with symptoms of myocardial ischemia and one or more of these ECG abnormalities. For patients with possible ACS, including unstable angina, we recommend urgent coronary arteriography, as they may require urgent revascularization [8]. (See 'Indications for revascularization' below.)
For patients who have a stable presentation, including a stable ECG, many physicians perform stress testing with imaging (either nuclear or echocardiographic). (See "Stress testing for the diagnosis of obstructive coronary heart disease", section on 'Our approach to diagnostic stress testing' and "Role of stress testing after coronary artery revascularization", section on 'Evaluation of symptomatic patients'.)
Similar to patients without prior revascularization, any patient whose stress test results suggest a large area of myocardium at risk, or other high risk features, should be considered for diagnostic coronary angiography. The rationale for this recommendation is that the presence of a high grade lesion in a bypass graft(s) or in an unbypassed vessel(s), particularly the left anterior descending artery, supplying a large area of myocardium may be an indication for revascularization [15]. (See "Chronic coronary syndrome: Indications for revascularization", section on 'Summary and recommendations'.)
MANAGEMENT — It should be confirmed that patients with prior coronary artery bypass graft surgery (CABG) are receiving appropriate secondary prevention therapies, including the prescription of antiplatelet and statin therapy, routine exercise (and referral to cardiac rehabilitation programs in some patients), glycemic and blood pressure control, and counseling for smoking cessation. (See "Prevention of cardiovascular disease events in those with established disease (secondary prevention) or at very high risk".)
For patients in whom repeat revascularization is not felt to be necessary, many can have their symptoms controlled with use of these preventative strategies as well as with the use of antianginal medication. In general, we suggest starting with an antianginal regimen that was previously effective for the patient. (See "Chronic coronary syndrome: Overview of care".)
The following discussion will present the indications for revascularization and outcomes with either percutaneous coronary intervention (PCI) or repeat CABG.
Indications for revascularization — In patients with prior CABG, revascularization with either CABG or PCI is indicated to either improve survival or symptoms, similar to the broad population of patients with coronary artery disease. The following discussion applies to patients with new lesions in either native vessels or bypass grafts, unless otherwise specified.
We suggest repeat revascularization for the following groups of stable patients:
●Left main coronary disease – Those for whom revascularization is likely to improve survival. Similar to patients who have not previously undergone CABG, this benefit is likely limited to patients with obstruction of blood flow in the left main coronary artery.
The survival benefit of CABG in patient in whom the LAD was never bypassed remains uncertain. (See "Management of significant proximal left anterior descending coronary artery disease", section on 'Indications for revascularization'.)
The lack of a survival benefit of revascularization in patients without significant proximal LAD obstruction was reported in an observational study of over 4600 patients with prior CABG who had a patent left internal thoracic artery (LITA) bypass graft to the LAD but significant disease in another territory [15]. There was no significant difference in mortality during 20-year follow-up between those who continued with medical therapy and those who received either CABG or PCI.
●Significant angina – Patients with bothersome angina after a trial of medical therapy. Revascularization may be undertaken if there is a reasonable likelihood of procedural success and the patient understands the possibility of recurrent angina.
●Other patients – Patients with stable angina but certain anatomic configurations in the previously bypassed graft(s). In general, we prefer elective stenting even for stable patients who have vein graft stenosis >70 percent due to the increased risk for progression to occlusion over time and the poor outcomes for intervention after total occlusion.
Patients with saphenous vein grafts containing large amounts of particulate debris may need to be considered for reoperation CABG if the use of rheolytic thrombectomy, aspiration thrombectomy, or distal protection is unlikely to lead to a good outcome.
Other patients with early, recurrent in-stent restenosis in bypassed grafts may elect to have repeat bypass surgery after evaluation by a cardiac surgeon and an interventional cardiologist.
Similar to the broad group of patients with an acute coronary syndrome (ACS), most patients with an ACS after CABG should be referred for diagnostic coronary arteriography with a view toward early revascularization. Patients with an unstable presentation after CABG are at increased risk for significant coronary events, including death or myocardial infarction, compared to those without prior CABG. In an analysis of the PURSUIT trial (glycoprotein IIb/IIIa inhibitor versus placebo), patients with prior CABG had significantly higher 30-day mortality rates [16].
Repeat percutaneous coronary intervention versus coronary artery bypass graft surgery — In patients with prior CABG, we prefer PCI to repeat CABG in:
●Patients with limited areas of ischemia-causing symptoms and in whom there are suitable targets.
●Patients with a patent LITA graft to the LAD artery.
●Patients with poor CABG targets.
●Patients with comorbid conditions for whom repeat CABG will not prolong life and in whom the benefit to risk ratio is not favorable.
Given the approximately three- to fourfold increase in mortality after repeat CABG (see 'Repeat coronary artery bypass graft surgery' below), this procedure should be reserved for patients who cannot undergo PCI for technical reasons or for patients who will be able to undergo LITA grafting to the LAD. For patients who are good surgical candidates and have significant LAD stenosis, we tend to prefer CABG with a LITA graft to the LAD as opposed to PCI. If repeat CABG cannot be performed, for example, due to a high risk of reoperation, PCI of the LAD is a reasonable option.
There is no high quality evidence that can be used to support a choice of CABG or PCI in patients for whom either procedure is reasonable and technically feasible. Early comparative studies are not particularly helpful, as balloon angioplasty was performed without stenting in most patients [17-20].
More studies suggest comparable long-term mortality between PCI and CABG, but the potential for bias in the choice of procedure limits our ability to draw strong conclusions from these studies:
●A retrospective study of 2191 patients with prior CABG who underwent multivessel revascularization between 1995 and 2000 evaluated outcomes in the 1487 who had repeat CABG and the 704 who underwent PCI (77 percent with at least one stent) [21]. The most important factors involved in the choice of repeat CABG were more diseased or occluded grafts, absence of a prior myocardial infarction (MI), lower left ventricular ejection fraction, longer interval from first CABG (15 versus 6 years), more total occlusions in native coronary arteries, and the absence of a patent thoracic artery graft. There was no difference in 30-day mortality with CABG compared to PCI (2.8 versus 1.7 percent, respectively). At five years, unadjusted cumulative survival was similar with CABG and PCI (79.5 versus 75.3 percent). After adjustment, PCI was associated with a nonsignificant increase in mortality risk (hazard ratio 1.47, 95% CI 0.94-2.28).
●The AWESOME trial randomly assigned 454 patients with angina refractory to medical therapy and one of five high risk features including prior CABG to either CABG or PCI [19,20]. Among the 142 patients with refractory post-CABG ischemia (a high risk feature), there was no significant difference in the three-year survival rates (73 and 76 percent, respectively). Interpretation of these results is limited by the small number of patients and the fact that stents were used in only 54 percent of PCIs.
Repeat coronary artery bypass graft surgery — Patients for whom repeat CABG is being considered need to be informed of the higher perioperative mortality and morbidity with a second procedure. Multiple observational studies have shown an approximate three- to fourfold increase in the risk of death with repeat CABG, with rates of 4.8 and 1.8 found in a 2009 report [9,22-24]. For patients who undergo repeat CABG, the principles guiding the choice of arterial or venous graft are similar to initial CABG. If the LAD territory is being revascularized, an arterial conduit should be used. (See "Coronary artery bypass graft surgery: Graft choices", section on 'Summary and recommendations'.)
Given the increased early mortality with repeat CABG, it has been proposed that there may be an advantage to minimally invasive CABG in this setting, particularly in patients with a patent left internal thoracic artery graft in whom the occluded vessels are inaccessible to PCI. Data are limited on this issue. (See "Off-pump and minimally invasive direct coronary artery bypass graft surgery: Clinical use", section on 'MIDCAB'.)
Percutaneous coronary intervention — For patients with recurrent angina after CABG undergoing PCI, decisions need to be made regarding whether to intervene on the native coronary circulation, a saphenous vein graft(s), an arterial graft(s), or some combination. PCI of the bypassed native artery has been preferred to PCI of a bypass graft (when technically feasible) because of the higher risk of distal embolization during bypass graft PCI than during native-vessel PCI [25]. In patients with previous CABG who require PCI, two-thirds of patients undergo PCI on the native artery, and one-third undergo PCI of a bypass graft [26]. The use of embolic protection devices has significantly lowered the risk of bypass graft intervention [27-29], but PCI of a native artery is associated with better outcomes. In a large prospective registry, patients with prior CABG who underwent PCI of a native vessel had lower rates of cardiac death, stent thrombosis, ischemia-driven target-vessel revascularization, and overall adverse events at two years than those who underwent PCI of an SVG [30]. A detailed discussion of the periprocedural aspects of PCI for SVG stenosis is presented separately. (See "Coronary artery bypass graft surgery: Prevention and management of vein graft stenosis", section on 'Outcomes with PCI'.)
Left main PCI in the setting of an occluded bypass conduit to either the left circumflex or left anterior descending arteries is a reasonable option if the bypass to the opposite vessel is patent. (See "Left main coronary artery disease", section on 'Other considerations'.)
Internal thoracic artery grafts are less prone than saphenous vein grafts to develop atherosclerosis, but may develop a proliferative lesion, most frequently at the distal anastomosis site and less commonly at the ostium or within the shaft [31,32]. Some of these are thought to represent a technical complication of the operation, such as a reaction to suturing. These lesions can be treated by PCI [31,33-35]. The efficacy of this approach was illustrated in a review of 174 patients with 202 lesions: Anastomotic (distal) lesions were mostly treated with balloon angioplasty, while ostial lesions were more frequently treated with stents [31]. The procedural success was 97 percent, there were no cases of MI, in-hospital mortality was 0.6 percent, and the rate of urgent CABG was 0.6 percent. At one year, mortality was 4.4 percent, MI occurred in 2.9 percent, and target vessel revascularization was performed in 7.4 percent. (See "Percutaneous coronary intervention of specific coronary lesions", section on 'Ostial lesions' and "Coronary artery bypass graft surgery: Graft choices", section on 'Arterial grafts'.)
Unstable patients — For patients with an acute coronary syndrome, we recommend early angiography and urgent revascularization as opposed to a conservative strategy. While there are no studies that directly compare these approaches in patients with prior CABG and an ACS, we believe the benefits to this approach are similar to those in patients without prior CABG. (See "Non-ST-elevation acute coronary syndromes: Selecting an approach to revascularization", section on 'Signs of ongoing myocardial dysfunction or infarction'.)
In most cases we prefer PCI, if technically feasible, to CABG. This is based on the relative delay to revascularization if CABG is carried out and the increased mortality associated with repeat CABG. (See 'Repeat coronary artery bypass graft surgery' above.)
Heart team — Despite the paucity of trial evidence, many experts suggest that a heart team (at a minimum comprised of a cardiac surgeon and an interventional cardiologist) can review the feasibility of revascularization, area at risk, comorbidities, and clinical status to facilitate the decision between reoperation bypass surgery or PCI in patients with prior bypass surgery [36].
ST-elevation myocardial infarction — For patients with ST-elevation myocardial infarction after CABG, we and others recommend culprit-vessel only PCI in the presence [37] or absence of cardiogenic shock [38]. The decision regarding the need for revascularization of other significant lesions can be deferred until the patient is stable. In patients with non-ST elevation acute coronary syndromes, we prefer culprit-vessel only PCI if a single culprit lesion can be identified. We are concerned about large contrast volumes or high radiation doses with multivessel PCI in this setting [38]. PCI is preferred to CABG in most cases due to the rapidity with which revascularization with PCI can be achieved, and the increased mortality seen with repeat CABG. (See 'Repeat coronary artery bypass graft surgery' above.)
Chronically occluded saphenous vein grafts — PCI of chronic total saphenous vein graft occlusions is associated with low success rates, high complication rates, and poor long-term patency rates [39,40]. We do not recommend PCI of these lesions [36].
Post-coronary artery bypass graft surgery angina in patients with diabetes — The discussion of post-CABG angina in patients with diabetes is found elsewhere. (See "Coronary artery revascularization in stable patients with diabetes mellitus", section on 'Previous coronary artery bypass graft surgery'.)
Recommendations of others — Our recommendations are generally in agreement with those made in the 2021 American College of Cardiology Foundation/American Heart Association CABG guideline and the 2011 American College of Cardiology Foundation/American Heart Association/Society for Cardiovascular Angiography and Interventions PCI guideline [36].
The former document suggests that the decision to treat medically refractory ischemia with repeat CABG should consider the following variables: those with vessels unsuitable for PCI, number of diseased bypass grafts, availability of the internal thoracic artery for grafting, chronically occluded coronary arteries, and good distal targets for bypass graft placement.
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Percutaneous coronary intervention" and "Society guideline links: Coronary artery bypass graft surgery".)
INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, “The Basics” and “Beyond the Basics.” The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on “patient info” and the keyword(s) of interest.)
●Basics topics (see "Patient education: Recovery after coronary artery bypass graft surgery (The Basics)")
●Beyond the Basics topics (see "Patient education: Recovery after coronary artery bypass graft surgery (CABG) (Beyond the Basics)")
SUMMARY AND RECOMMENDATIONS
●Role of stress testing – For stable patients in whom there is a suspicion of late recurrent angina, many physicians perform diagnostic testing using stress testing with imaging. Such testing allows confirmation of the diagnosis and provides prognostic information that may be useful for management. Patients with a high pretest likelihood of obstructive disease and patients for whom this testing is not diagnostic may need to proceed to coronary angiography.
●Importance of secondary prevention – All patients should have optimal management of their cardiovascular disease, including the use of antiplatelet therapy, statin, routine exercise (and referral to cardiac rehabilitation programs in some patients), glycemic and blood pressure control, and smoking cessation. (See "Prevention of cardiovascular disease events in those with established disease (secondary prevention) or at very high risk".)
●Acute coronary syndrome (ACS)- ACS after coronary artery bypass graft surgery (CABG) is associated with significantly worse outcome compared with patients without prior CABG. For patients with ACS, we recommend urgent revascularization of the culprit lesion or lesions as opposed to a conservative approach (Grade 1B). (See 'Indications for revascularization' above.)
In patients with ACS, we recommend percutaneous coronary intervention (PCI), if technically feasible, instead of CABG (Grade 1B).
If PCI is performed, we prefer to revascularize only the culprit lesion at the time of the initial procedure. (See 'Unstable patients' above.)
●Chronic coronary syndrome – For patients with a stable presentation, the management strategy will depend on the findings of diagnostic testing (see 'Indications for revascularization' above):
•For patients with obstruction of blood flow to the proximal left anterior descending artery (LAD) and who demonstrable extensive anterior ischemia or significant disease in other vessels, we select patients for revascularization on the basis of symptoms and other considerations, as there is no clear survival advantage with revascularization.
•For patients with obstructive disease but without extensive anterior ischemia, we suggest medical therapy rather than initial revascularization (Grade 2B). For patients who are not satisfied with the quality of their lives after a trial of medical therapy, we suggest PCI if it is technically feasible rather than CABG (Grade 2B).
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