Coronary artery bypass graft surgery: Prevention and management of vein graft stenosis

INTRODUCTION — Most patients who undergo coronary artery bypass graft (CABG) surgery receive at least one saphenous vein graft (SVG) in addition to one or more arterial grafts. Compared to arterial grafts, vein grafts have a relatively high rate of clinically important stenosis at 5 and 10 years (movie 1). (See "Coronary artery bypass graft surgery: Graft choices", section on 'Vein grafts'.)

This topic will discuss issues related to the prevention, clinical presentation, and management of SVG stenosis. The risk factors for and rates of graft failure and long-term outcomes after CABG are discussed separately. (See "Coronary artery bypass graft surgery: Graft choices" and "Late recurrent angina pectoris after coronary artery bypass graft surgery" and "Coronary artery bypass graft surgery: Long-term clinical outcomes".)

STENOSIS VERSUS OCCLUSION — Vein graft stenosis implies there is still flow in the graft and that revascularization is technically possible.

The phrase "vein graft occlusion" implies the graft is 100 percent closed (occluded). Ordinarily, this means there is no option for percutaneous revascularization of the graft itself, particularly if the occlusion is chronic.

When grafts are occluded, the best treatment is often to go after the native coronary vessel rather than try to recanalize an occluded graft. (See 'Indications for repeat revascularization' below.)

PREVENTION — Secondary preventive interventions, such as aspirin and statin, achieving blood pressure goal, avoidance of smoking, and the control of serum glucose in patients with diabetes, are recommended for all patients with coronary heart disease (CHD). (See "Prevention of cardiovascular disease events in those with established disease (secondary prevention) or at very high risk" and "Management of low density lipoprotein cholesterol (LDL-C) in the secondary prevention of cardiovascular disease" and "Goal blood pressure in adults with hypertension".)

Antiplatelet agents and statins are of proven efficacy for the prevention of saphenous vein graft (SVG) stenosis. (See 'Antiplatelet agents' below.)

Antiplatelet agents — We recommend that among patients not treated with aspirin before coronary artery bypass graft surgery (CABG), aspirin with or without a loading dose should be started as soon after surgery as possible. The decision of whether to give a loading dose of aspirin may be influenced by clinical factors such as recent acute coronary syndrome or concern about a risk of early graft failure. Low-dose aspirin should be continued indefinitely.

We do not routinely use dual antiplatelet therapy with aspirin plus a P2Y₁₂ inhibitor in these patients.

For patients who are allergic to aspirin, we suggest aspirin desensitization prior to elective CABG. Clopidogrel (300 mg loading six hours after surgery, followed by a maintenance dose of 75 mg/day) monotherapy is an option for patients who cannot be desensitized. The management of patients allergic to aspirin is discussed elsewhere. (See "Introduction of aspirin to patients with aspirin hypersensitivity requiring cardiovascular interventions", section on 'Indications for urgent aspirin therapy'.)

Platelet activation and vein graft thrombosis are thought to be early steps in the process of stenosis and occlusion and forms the rationale for using antiplatelet therapy for prevention. (See "Coronary artery bypass graft surgery: Graft choices", section on 'Occlusion within the first 12 to 18 months'.)

Aspirin given early in the postoperative period improves cardiovascular outcomes after CABG [1] and reduces the incidence of SVG stenosis [2,3]. In a meta-analysis from the Antiplatelet Trialists' Collaboration, low-dose aspirin was associated with improved graft patency, as assessed by coronary angiography, at an average of one year after surgery [4]. The pooled odds reduction for SVG closure was 41 percent (8 percent absolute risk reduction) with low-dose aspirin (75 to 325 mg/day) compared to placebo or control therapy.

The use of dual antiplatelet therapy with aspirin and a P2Y₁₂ inhibitor (clopidogrel) has been evaluated in older small studies that came to differing conclusions regarding the impact of DAPT:

●In a study of 249 patients who were randomly assigned to aspirin (100 mg/day) and clopidogrel (75 mg/day) or to aspirin alone prior to CABG, the rate of vein graft patency at three months, as assessed by multislice computed tomography angiography, was significantly higher in those treated with dual antiplatelet therapy (92 versus 86 percent) [5].

●In a trial of 113 CABG patients who were randomly assigned to either aspirin 162 mg plus clopidogrel 75 mg daily or aspirin 162 mg daily, there was no significant difference in the rate of SVG hyperplasia as determined by intravascular ultrasound at one year [6].

A potential benefit from the addition of the more potent P2Y₁₂ receptor blocker ticagrelor to aspirin has been evaluated in two more recent, moderate-sized, randomized trials that evaluated vein graft patency at one year:

●The DACAB trial randomly assigned 500 patients undergoing elective CABG to ticagrelor plus aspirin, ticagrelor alone, or aspirin alone within 24 hours [7]. The primary outcome of SVG patency at one year, as determined by multislice computed tomographic angiography or coronary angiography, occurred in 88.7, 82.8, and 76.5 percent of vein grafts in the three groups, respectively. The difference in rate in the ticagrelor plus aspirin and aspirin groups was significant (12.2 percent, 95% CI 5.2-19.2 percent; p<0.001). The rate of SVG occlusion in the aspirin arm of almost 24 percent is much higher than expected and may be due to chance.

●The POPular CABG trial randomly assigned 499 aspirin-treated patients with chronic (68 percent) and acute coronary syndromes to ticagrelor or placebo [8]. The primary outcome of 100 percent SVG occlusion as assessed with CCTA occurred in 10.5 and 9.1 percent of the two groups, respectively (odds ratio 1.29, 95% CI 0.73-2.30).

The cause(s) of the differing findings in these two trials of ticagrelor are speculative. In the absence of additional evidence to support dual antiplatelet therapy to reduce the risk of the development of SVG stenosis, we do not recommend this therapy.

A third trial that was stopped prematurely randomly assigned 1859 CABG patients to ticagrelor 90 mg twice daily or aspirin 100 mg once daily [9]. At 12 months, there was no difference in the rate of a composite outcome of cardiovascular death, MI, repeat revascularization, and stroke (9.7 versus 8.2, respectively; p = 0.89).

Issues related to the preoperative use of aspirin and platelet P2Y₁₂ receptor blocker therapy are discussed elsewhere. (See "Coronary artery bypass surgery: Perioperative medical management", section on 'Preoperative aspirin' and "Coronary artery bypass surgery: Perioperative medical management", section on 'Platelet P2Y12 receptor blocker therapy'.)

Anticoagulant therapy — There is no evidence that long-term anticoagulant therapy, with or without antiplatelet therapy, prevents early graft failure. In the COMPASS-CABG study, a prespecified substudy of the Cardiovascular OutcoMes for People Using Anticoagulation StrategieS (COMPASS) trial of patients with stable disease, 1448 patients were randomly assigned at 4 to 14 days after CABG to rivaroxaban 2.5 mg twice daily plus aspirin 100 mg once daily, rivaroxaban 5 mg twice daily, or aspirin 100 mg once daily [10]. Patients underwent computed tomographic angiography at a mean follow-up of 1.13 years to assess graft patency. Neither the combination of rivaroxaban plus aspirin nor rivaroxaban alone, compared with aspirin alone, reduced the risk of graft failure (odds ratio 1.13, 95% CI 0.82-1.57 and 0.95, 95% CI 0.67-1.33, respectively). A lower-than-expected rate of graft failure is an important limitation of this trial. It should be kept in mind that the full COMPASS trial found that anticoagulant therapy lowers the risk of cardiovascular death, myocardial infarction, or stroke in patients with stable coronary artery disease and is discussed separately. (See "Prevention of cardiovascular disease events in those with established disease (secondary prevention) or at very high risk", section on 'Anticoagulant therapy'.)

Statins — − In addition to improvements lowering the risk of death and myocardial infarction, lipid-lowering also may protect against SVG stenosis (see "Management of low density lipoprotein cholesterol (LDL-C) in the secondary prevention of cardiovascular disease"). This was illustrated in the Post Coronary Artery Bypass Graft Trial, which evaluated 1351 patients with serum LDL cholesterol concentrations between 130 and 175 mg/dL (3.4 to 4.5 mmol/L) and at least one patent vein graft documented on angiography performed one to 11 years after CABG [11-13]. Patients were randomly assigned to receive aggressive therapy with lovastatin and, if needed, cholestyramine to reduce low density lipoprotein cholesterol to less than 100 mg/dL (2.6 mmol/L) or to moderate therapy, which resulted in levels of approximately 134 mg/dL (3.5 mmol/L). After about four years, aggressive therapy was associated with a lower percentage of grafts showing progression of atherosclerosis (27 versus 39 percent).

CLINICAL PRESENTATION — Most patients with saphenous vein graft (SVG) stenosis present with recurrent angina. (See "Late recurrent angina pectoris after coronary artery bypass graft surgery", section on 'Clinical manifestations'.)

Less often, patients with SVG stenosis present with an acute myocardial infarction [14,15]. (See "Approach to the patient with suspected angina pectoris".)

DIAGNOSIS — Saphenous vein graft (SVG) stenosis may be silent or may present as stable angina or an acute coronary syndrome. (See "Late recurrent angina pectoris after coronary artery bypass graft surgery", section on 'Diagnosis'.)

While stress testing with or without imaging may confirm the diagnosis of stable angina, these are not sufficiently reliable to discriminate between ischemia due to native or vein graft disease. The diagnosis of SVG stenosis is usually made at the time of coronary arteriography. However, coronary arteriography is indicated only in those patients who are likely to benefit from repeat revascularization. We uncommonly use intravascular ultrasound (IVUS) or measurement of fractional flow reserve in diseased vein grafts. IVUS is occasionally used to size the vessel.

INDICATIONS FOR REPEAT REVASCULARIZATION — The broad discussion of the indications for revascularization in patients with angina after coronary artery bypass graft surgery (CABG) is found elsewhere. For patients with saphenous vein graft (SVG) stenosis, revascularization is indicated to improve survival or to improve the quality of life. (See "Late recurrent angina pectoris after coronary artery bypass graft surgery", section on 'Indications for revascularization'.)

Impairment of flow in a SVG early (up to 30 days) after surgery is usually attributable to technical failure, a relatively small conduit, or extrinsic factors as the explanation. There is a high likelihood that angina will persist or that acute thrombosis will complicate the stenosis. Such patients should undergo immediate coronary arteriography and percutaneous coronary intervention (PCI) if possible. (See "Coronary artery bypass graft surgery: Graft choices", section on 'Early occlusion' and "Early cardiac complications of coronary artery bypass graft surgery", section on 'Early graft occlusion'.)

Although most patients with recurrent angina due to SVG stenosis after 30 days can have marked improvement in symptoms with antianginal medical therapy, catheterization should be performed at the earliest signs of recurrent ischemia in most patients to detect critical graft lesions that can be treated before irreversible loss of graft function. Stenoses in these vessels can progress rapidly to total thrombotic occlusion [16]. A heavy thrombus burden in an SVG markedly increases the difficulty in obtaining a satisfactory result using a catheter technique.

We suggest repeat revascularization for the following groups of stable patients:

●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 to the proximal left anterior descending artery (LAD) territory and demonstrable extensive anterior ischemia on noninvasive testing or significant disease in multiple other vessels. (See "Management of significant proximal left anterior descending coronary artery disease", section on 'Indications for revascularization'.)

The lack of mortality benefit of revascularization in patients without significant proximal LAD obstruction was demonstrated 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 [17].

●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. Our threshold for recommending revascularization is somewhat lower in these patients compared to those with native disease, as saphenous vein graft lesions may be at higher risk for acute occlusion with progression.

We do not perform PCI of chronic totally occluded vein grafts due to a lower success rate and a high rate of complication.

Percutaneous coronary intervention versus repeat coronary artery bypass graft surgery — Most patients in whom there is an indication for repeat revascularization undergo PCI with stenting. Repeat CABG is not optimal since many patients who develop graft disease are poor candidates for surgery because they are older, more likely to have comorbid illnesses, and are at risk for increased morbidity compared to their first bypass surgery. Furthermore, reoperation is generally associated with less complete revascularization and control of symptoms when compared to the first procedure. In addition, repeat CABG is associated with an increase in in-hospital mortality compared to PCI (6 to 9 versus ≤0.5 percent overall and 11.2 versus 1.6 percent in diabetics). On the other hand, the requirement for subsequent revascularization is greater with PCI and no difference has been detected in long-term survival with the two approaches. This issue is discussed in detail elsewhere. (See "Late recurrent angina pectoris after coronary artery bypass graft surgery", section on 'Indications for revascularization'.)

Recommendations of others — Our approach to revascularization in patients with prior CABG is similar to that found in the 2011 American College of Cardiology Foundation/American Heart Association/Society for Cardiovascular Angiography and Interventions guideline for PCI [18].

OUTCOMES WITH PCI — Since saphenous vein grafts (SVGs) lack side branches, distal occlusion results in stasis and thrombus formation throughout the graft, which makes percutaneous coronary intervention (PCI) more difficult [19]. Thus, as with bypass surgery, outcomes after PCI for SVG stenosis are worse than in native vessels [19]. This was illustrated in a pooled analysis of five randomized glycoprotein (GP) IIb/IIIa inhibitor trials in which PCI for SVG stenosis was associated with significant increases in mortality at both 30 days (2.1 versus 1.0 percent compared to PCI in native vessels) and six months (4.7 versus 2.0 percent) [20].

In a large observational series evaluating the outcomes with these procedures, the in-hospital incidence of and risk factors for a major cardiac event after any PCI were evaluated in 1062 patients with SVG stenosis who were followed for three years [21]. The patients were treated with percutaneous transluminal coronary angioplasty (PTCA) alone (42 percent), laser or atherectomy (16 percent), or stenting (42 percent). The following findings were noted:

●The incidence of in-hospital major adverse cardiac events was 13 percent; death occurred in 8 percent, myocardial infarction (MI) in 2 percent, and bypass surgery was performed in 3 percent. Predictors of an in-hospital event were a restenotic lesion, unstable angina, and heart failure.

●Late major coronary events occurred in 54 percent of patients and included death in 9 percent, MI in 9 percent, and target vessel revascularization (TVR) in 36 percent.

●Angiographic restenosis occurred significantly less often in stented grafts (29 versus 43 percent in nonstented grafts). However, there was no event-free or survival benefit with stenting, due at least in part to progressive disease at nonstented sites.

Because of the increase in risk with PCI of a totally occluded SVG, it has been suggested that attention be paid to the risk/benefit ratio in such patients and that, if possible, an attempt should be made to recanalize the underlying native coronary artery rather than the vein graft [19]. If this is not possible, medical therapy rather than PCI should initially be tried unless the patient has symptoms that interfere with the quality of life or a large amount of myocardium at risk.

Elective stent placement for vein graft disease may reduce the long-term incidence of restenosis, as it does in native coronary arteries. (See "Percutaneous coronary intervention with intracoronary stents: Overview".)

Similar to the native circulation, stenting has replaced balloon angioplasty in the setting, due in large part to lower rates of restenosis [21-24].

Adverse events and durability after PCI for SVG stenosis are worse than in native vessels. A pooled analysis of five randomized GP IIb/IIIa inhibitor trials found that PCI for SVG stenosis was associated with significantly higher mortality compared with PCI for native disease at both 30 days (2.1 versus 1.0 percent) and six months (4.7 versus 2.0 percent) [20]. In an observational study of 175 patients, poorer overall and event-free survival persisted in patients with SVG disease at five years [25]. The increased need for repeat revascularization was primarily due to progression of disease at other sites.

Restenosis requiring repeat revascularization remains an important problem. It is less frequent with stenting compared with angioplasty. There have been conflicting reports of benefit of DES versus BMS, although we use DES in most cases. (See "Percutaneous coronary intervention with intracoronary stents: Overview" and 'Outcome by stent type' below.)

Efficacy — Initial observational studies found a 17 to 30 percent restenosis rate for stented vein grafts [24,26,27]. These values are lower than the 40 to 45 percent seen in historical controls treated by other means such as balloon angioplasty and atherectomy [23,24]. The subacute thrombosis rate is very low (about 1 to 2 percent), a reflection of the usually larger luminal diameters in vein grafts than in native coronary arteries [26,27]. (See "Coronary artery stent thrombosis: Clinical presentation and management".)

Predictors for restenosis include a restenotic lesion, smaller reference vessel size, higher percent post-stent diameter stenosis, use of long or multiple stenoses, and stenosis at the coronary or aortic anastomosis [27,28]. (See "Intracoronary stent restenosis".)

Although data are limited, the rate of restenosis at this site appears to be lower than those at the aorto-ostial site or the shaft portion of the vein graft. In a review of 182 such patients who underwent either PTCA or stenting, the in-hospital outcome was the same for both procedures, and the procedural success rate was 98 percent with major ischemic complications occurring in 1 percent [29]. After an average follow-up of 17 months, the mortality and ST elevation MI (STEMI) rates were the same with both procedures (12 versus 13 percent and 1 versus 0 percent); however, there was a trend toward a higher rate of target lesion revascularization with PTCA (25 versus 14 percent).

The outcome of SVG stenting is also worse in patients with diabetes, who have higher rates of in-hospital mortality and target lesion revascularization at one year, and a lower rate of overall cardiac event-free survival at one year [30]. (See "Coronary artery revascularization in stable patients with diabetes mellitus".)

If PCI is performed, stenting is preferred to balloon angioplasty (without stenting), as the latter is associated with high rates of restenosis [21,22].

Complications — Coronary embolization of atherothrombotic debris, resulting in elevated cardiac enzymes and an STEMI or non-ST elevation MI (NSTEMI) during catheter intervention, is a more common problem after PCI in SVGs [19]. A possible explanation is that atherosclerotic plaques in SVGs are softer, and more friable, and more commonly associated with thrombus and platelet activation compared to plaques in native coronary arteries [31]. Plaque debris can be retrieved and distal embolization minimized after PCI with an embolic protection device, leading to a reduction in both MI and no-reflow (microvascular dysfunction). (See 'Embolic protection devices' below.)

Patients with ST-elevation myocardial infarction — Primary PCI is usually the preferred therapy in patients with an STEMI. There are limited data on the efficacy of this modality in patients with SVG lesions. In one study of 370 patients who underwent primary or rescue PTCA, 21 (5.7 percent) were performed on SVGs, with a stent implanted in 14 [15]. Flow was established in 86 percent of patients, but TIMI grade 3 was restored in only 48 percent. Distal embolization and no-reflow occurred in 57 and 71 percent, respectively. The in-hospital mortality was 19 percent and, at six months, the rate of survival free of death, repeat target vessel revascularization, or MI was 55 percent. These results were worse when compared to a parallel group of patients undergoing primary PCI of a native coronary artery. (See "Acute ST-elevation myocardial infarction: Selecting a reperfusion strategy".)

Outcome by stent type — Drug-eluting stents (DES) are preferred to bare metal stents (BMS) in native coronary arterial lesions because their use is associated with a marked reduction in the incidence of restenosis and target vessel revascularization. However, the optimal stent choice for SVG stenosis is not known. (See "Percutaneous coronary intervention with intracoronary stents: Overview".)

Evidence suggests that current generation DES and BMS perform comparably in SVG. In the DIVA trial, 599 patients (predominantly men) were randomly assigned to everolimus- or zotarolimus-eluting stents or BMS [32]. At 12 months, the rate of the primary outcome of target vessel failure, a composite of cardiac death, target vessel MI, or target vessel revascularization, was similar in the two groups (17 versus 19 percent; adjusted hazard ratio 0.92, 95% CI 0.63-1.34). However, the study has limitations, including early termination, male predominance, and absence of double-blind randomization.

Considering the outcomes, as well as the limitations of DIVA, we prefer DES to BMS for SVG stenosis. The lack of difference may be related to disease progression rather than absence of restenosis benefit.

In prior, generally small studies that also had methodologic limitations, comparing DES with BMS provided conflicting information regarding clinical outcomes. Observational studies suggested that DES have a similar benefit compared with BMS in diseased SVGs [33-35]. Small randomized trials come to differing conclusions with most showing benefit (lower rates of angiographic in-stent restenosis) [36-38] from early generation DES and one not [39].

In addition, there is some evidence that newer generation DES perform well when used to treat vein graft lesions [40-43].

ADJUNCTIVE THERAPIES FOR PERCUTANEOUS CORONARY INTERVENTION

Glycoprotein IIb/IIIa inhibitors — A thrombus is present in up to 70 percent of occluded saphenous vein grafts (SVGs), and is associated with an increased rate of failure and complications such as abrupt closure, distal embolization, and no reflow. The potential role of platelets in mediating distal embolization and myocardial infarction (MI) has led to interest in the role of antiplatelet agents for preventing these complications.

A pooled analysis of five randomized trials evaluated the efficacy of intravenous glycoprotein (GP) IIb/IIIa inhibitors during percutaneous coronary intervention (PCI) included 627 patients who underwent PCI for SVG stenosis [20]. There was no evidence of benefit, GP IIb/IIIa inhibitor therapy was associated with nonsignificant trends toward an increase in the triple end point of death, MI, or revascularization at 30 days (16.5 versus 12.6 percent) and at six months (39.4 versus 32.7 percent). As with native coronary lesions, we do not routinely use GP IIb/IIIa in treatment of SVG lesions undergoing PCI.

Atherectomy — It has been thought that rotational, directional, or extraction atherectomy might be beneficial in some patients with SVG stenosis, especially when the lesions are densely calcified, aorto-ostial, or at the distal anastomosis site. However, removing graft atheroma using catheter-based techniques has not demonstrated durable value and these procedures are rarely used [44-48]. (See "Specialized revascularization devices in the management of coronary heart disease".)

Thrombolysis and thrombectomy — As atheromas in SVGs are often associated with thrombus, thrombolysis and thrombectomy have been studied as adjunctive therapy for SVG stenosis or occlusion. We do not recommend using thrombolytic therapy to treat SVG thrombus [49]. Catheter-based thrombectomy is an alternative to pharmacologic thrombolysis. None of the devices that can mechanically aspirate thrombus have been shown to improve clinically important outcomes [48-53]. These devices should rarely be used in this setting. For example, we occasionally use the AngioJet device for cases with extremely large clot burden.

Embolic protection devices — Our current practice is to use embolic protection devices (EPDs) routinely for all SVG lesions that are (technically) amenable to a protection device. EPDs trap blood and suspended debris in the body of the SVG during stenting, allowing their evacuation before normal flow is restored [54]. Studies with these devices have shown that large quantities of atheroembolic debris are liberated during PCI [54-57]. The aspirate also contains vasoactive substances that can contribute to impaired microvascular perfusion [58].

A review of early results with the FilterWire EX system highlighted the importance of anatomic, device-specific, and operator-related factors (eg, lack of optimal filter apposition against the SVG wall and an excessively distal lesion resulting in incomplete filter opening or unprotected native side branches) in the attainment of maximal efficacy. Operator attention to these factors reduced the 30-day incidence of adverse events, primarily periprocedural MI, from 21.3 to 11.3 percent [59].

The FIRE trial compared the PercuSurge GuardWire and the FilterWire EX system in 651 patients undergoing SVG stenting. Initial procedural success was excellent for both devices (97 and 96 percent, respectively). At 30 days, the composite end point of death, MI, or target vessel revascularization was comparable for the GuardWire and the FilterWire (11.6 and 9.9 percent) [60]. The outcomes in terms of the composite end point remained comparable at six months but an additional 10 percent of patients had a new event (21.9 versus 19.3 percent overall) [61]. Target vessel revascularization was required in 9.1 percent.

The GuardWire is no longer commercially available. Other filter devices have demonstrated similar outcomes as the FilterWire EX and are commercially available.

A separate issue is the efficacy of distal embolic protection devices in patients with in-stent restenosis in SVGs. The lesion in this setting primarily consists of neointimal proliferation and might be expected to have a lower embolic potential. Observations in 54 consecutive patients who underwent PCI for in-stent restenosis in SVGs without a distal embolic protection device are consistent with this hypothesis [62]. There were no episodes of no-reflow or slow flow during the procedure and no procedure-related MIs. More data are needed to determine the generalizability of these findings.

Taken together, the above trials have demonstrated the utility of distal embolic protection devices to minimize the adverse effect of downstream debris and thereby improve outcomes in PCI for SVG stenosis. Although these devices have become the standard of care in many laboratories, they are currently underutilized in SVG interventions [57,63].

Limitations of distal protection devices include passage of the device across a stenotic lesion before distal protection is in place, occlusion of distal filters with debris, failure to prevent the movement of toxic soluble mediators into the distal myocardium, and inability to use the device in distal lesions. These limitations and others have led to the development of a variety of other distal embolic protection devices, proximal occlusion devices, and local plaque trapping devices [57,63,64], although most are no longer available for commercial use. In our laboratory, we use the Spider filter distal protection device, which offers the advantage of allowing lesion crossing with a usual guidewire.

Intracoronary vasodilators — Some operators recommend prophylactic use of intracoronary vasodilators as an alternative to EPDs. The evidence to do so is limited. In one study, 83 SVG PCI procedures (average graft age 12 years) were performed in 69 patients who received nicardipine (200 to 300 micrograms) delivered via the SVG immediately prior to direct stenting [65]. MI, defined as creatine kinase MB fraction >3 times normal, occurred in three (4.4 percent) patients. These results have to be interpreted with caution given the small nonrandomized sample size at a single center.

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: 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 5^th to 6^th 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 10^th to 12^th 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 topic (see "Patient education: Recovery after coronary artery bypass graft surgery (The Basics)")

●Beyond the Basics topic (see "Patient education: Recovery after coronary artery bypass graft surgery (CABG) (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

●Prevention – Aggressive secondary preventative interventions, such as aspirin and statin use, achieving blood pressure goal, avoidance of smoking, and the control of serum glucose in patients with diabetes, are recommended in all patients with coronary heart disease, including those who have undergone coronary artery bypass graft (CABG) surgery, to improve cardiovascular outcomes. (See 'Prevention' above.)

●Clinical presentation – Saphenous vein graft (SVG) stenosis often presents with recurrent angina. However, the cause of angina in patients with SVGs depends in part upon the time after surgery when symptoms are first noted. (See 'Clinical presentation' above.)

●Type of procedure – Although most patients with recurrent angina due to SVG stenosis can be managed medically, coronary arteriography should be performed at the earliest symptoms or signs of recurrent ischemia to detect critical graft lesions that can be treated before irreversible loss of the graft. (See 'Percutaneous coronary intervention versus repeat coronary artery bypass graft surgery' above.)

●Outcomes – Percutaneous coronary intervention (PCI) is preferred to repeat CABG in most patients with recurrent angina, in part due to the increased risks associated with the latter. Factors that might allow for consideration of CABG include low anticipated success rate of PCI, quality of the distal vessels, and whether the graft to the proximal left anterior descending coronary artery is involved. (See 'Outcomes with PCI' above.)

●Embolic protection – Use of distal embolic protection devices should be considered to minimize the adverse effect of downstream debris and thereby improve outcomes in PCI for SVG stenosis. (See 'Embolic protection devices' above.)

●Type of stent – Drug-eluting stents should be chosen in preference to bare-metal stents when the risk for restenosis outweighs other risks and the patient is able to be compliant with a longer period of dual antiplatelet therapy. (See "Coronary artery stent thrombosis: Incidence and risk factors" and 'Outcome by stent type' above.)

●Outcomes after percutaneous coronary intervention – When approaching a patient with recurrent ischemia due to disease in a bypass graft for whom PCI is indicated, an attempt should be made to revascularize the native vessels(s) if technically feasible. (See 'Outcomes with PCI' above.)