In coronary artery disease (CAD) whose symptoms are not significantly relieved with drug therapy alone, revascularization therapy (revascularization, revascularization; removal of an obstacle to passage in occluded blood vessels) should be performed. The following surgical procedures are available for this purpose:
- Percutaneous coronary intervention (PCI).
- Aortocoronary vein bypass (ACVBV; coronary artery bypass graft, CABG/coronary artery bypass surgery).
Revascularization recommendations for multivessel disease
| Extent of CHD | Bypass surgery | PCI |
| 1- or 2-vessel disease (2-GE) without proximal RIVA stenosis. | ↑ | ↑↑ |
| 2-GE with proximal RIVA stenosis* , SYNTAX score* * (SyS) ≤ 22. | ↑↑ | ↑↑ |
| 2-GE with proximal RIVA stenosis, SyS ≥ 23 | ↑↑ | ↑ |
| 3-GE, SyS ≤ 22 | ↑↑ | ↑ |
| 3-GE, SyS ≥ 23 | ↑↑ | not recommended (n .e.) |
| 2 or 3-GE and diabetes mellitus. | ↑↑ | n. e. |
| Main stem stenosis (HSS)* * * (proximal or medial) and SyS ≤ 22. | ↑↑ | ↑↑ |
| HSS (bifurcation) or HSS and SyS 23-32 | ↑ | ↑ |
| HSS SyS ≥ 33 | ↑ | n. e. |
* Ramus interventricularis anterior * * SYNTAX score based on coronary anatomy and complexity of coronary lesions* * * See below “Further notes”.
Percutaneous coronary intervention (PCI)
This is a procedure to dilate (widen) narrowed coronary arteries. A catheter with a balloon is inserted through the femoral or radial artery to the heart. At the stenosis of the coronary vessel, the balloon is dilated so that the stenosis is lifted and blood flow is again possible. In most cases, a stent (“vascular stent”) is inserted, which is designed to keep the blood vessel open. Post-interventional anticoagulation (inhibition of blood clotting) is usually required. Indications
- For less complex stenoses (narrowing) of one or two coronary vessels.
- Coronary single-vessel disease with proximal RIVA stenosis (high-grade proximal stenoses (>70 percent) of the ramus interventricularis anterior): PCI or bypass surgery
Further notes
- According to the 15-year results of a randomized trial, invasive intervention by cardiac catheterization has no prognostic or symptomatic benefit in intermediate coronary stenosis that does not cause ischemia.
- In the COURAGE trial, there was no difference between drug therapy and stenting in early PCI in patients with stable CHD at 12 years.
For details on the procedure, see “percutaneous coronary intervention (PCI).”
Aortocoronary vein bypass (ACVB; coronary artery bypass graft, CABG)
In a bypass operation, a vessel graft is performed to bypass a vessel that has become stenotic or even occluded due to atherosclerosis (arteriosclerosis, hardening of the arteries). Both an endogenous vessel – usually the saphenous vein – and an artificial vessel can be used. In an aortocoronary bypass, a connection is made between the aorta (main artery) and one of the coronary arteries (arteries that surround the heart in a circle and supply the heart muscle with blood). Indications
- In complex disease patterns (with multiple and complexly narrowed coronary vessels/coronary arteries); this form of intervention has an advantage over PTCA in these cases.
- Coronary single-vessel disease with proximal RIVA stenosis (high-grade proximal stenosis (>70 percent) of the ramus interventricularis anterior): PCI or bypass surgery; with respect to the need for reintervention, bypass surgery is superior to PCI
- Patients with proximal or medial main stem stenosis and a SYN-TAX score ≤ 22 should be offered PCI or bypass surgery equally.
- Multivessel coronary artery disease in diabetes mellitus Note: Stents for coronary revascularization are at higher risk than bypass surgery
The European Society of Cardiology (ESC) and European Association for Cardiothoracic Surgery (EACTS) guideline on bypass surgery for coronary artery disease (CAD) [see guideline below: 3] advocates coronary bypass surgery for:
- Three-vessel disease in which calcification of the arteries is very pronounced
- Main stem stenosis (narrowing in the area of origin of the left coronary artery/coronary artery).
- Concomitant diseases
- Diabetes mellitus
- Reduced left ventricular function (< 35%)
- Contraindications
- Dual antiplatelet therapy (DAPT).
- Recurrent stent stenosis
For details on the procedure, see “Cardiac bypass surgery”. Further notes
- In the PRECOMBAT trial, for stenoses (vasoconstrictions) in unprotected main stems (main stem stenosis), outcomes for PCI and bypass were equivalent at 5 years. After 5 years of follow-up, analysis for the MACE end point (major adverse cardiovascular events: death, myocardial infarction (heart attack), apoplexy (stroke), repeat revascularization) showed no significant difference between PCI and bypass (17.5 vs. 14.4)
- In the STICH trial, the superiority of bypass surgery over medical therapy was evident at 56 months: this was evident when considering the combined end point of all-cause mortality and hospitalization (58% vs. 68%, HR 0.74, p < 0.001). After 10 years, the outcome of bypass patients showed statistical significance; this was mainly due to lower cardiovascular mortality; surgically revascularized patients lived 1.4 years longer than patients in the MED group (patients with optimal drug therapy).
- At long-term follow-up (mean 5.5 years), patients with coronary artery disease, diabetes mellitus, and left heart failure, (left ventricular failure) treated with aortocoronary venous bypass (ACVB) had a significantly lower incidence of serious adverse cardiac and cerebrovascular events and better long-term survival compared with PCI, without a higher risk of apoplexy (stroke).
- Patients who report recurrence of chest pain (chest pain) after previous coronary artery bypass grafting should receive repeat coronary artery bypass grafting instead of PCI (which is currently considered first-line therapy), according to data from a cohort study, because this provides a clear overall survival benefit: 30-day mortality (death rate) was increased in the bypass group, but long-term mortality risk was reduced by 28% compared with PCI patients.
- ISCHEMIA trial: after a median observation period of 3, 3 years, it has not (yet) been demonstrated that patients with stable angina can be protected from subsequent cardiac events by stenting or bypass surgery. A final evaluation is still pending.
- EXCEL study: 5-year data show that stenting and bypass surgery are equally effective in the patients studied. The primary end point of the study was a composite of death from any cause, myocardial infarction (heart attack), and apoplexy (stroke): the end point outcome at 5 years was 22% versus 19, 2%, although this was not statistically significant. However, the hard endpoint all-cause mortality (all-cause death rate) at 5 years was 13.0% (PCI) versus 9.9% (surgery).
- In patients with complex coronary artery disease/coronary artery disease (RIVA or main stem stenoses or multivessel coronary artery disease without RIVA involvement) and systolic heart failure, mortality (death rate) was relatively 60% higher after percutaneous coronary intervention than after coronary artery bypass graft surgery after a follow-up period of approximately 5 years.
- Percutaneous coronary intervention (PCI) or bypass surgery for left main stem stenosis: for this purpose, the following three randomized trials, SYNTAX, NOBLE, and PRECOMBAT, were subjected to a new statistical analysis, a so-called Bayes analysis or Bayes interpretation:
- Regarding the primary end point of the EXCEL trial (death from any cause, stroke, and myocardial infarction): single patient with low-risk left main stem stenosis undergoing PCI instead of bypass: 95% probability of worse outcome.
- Mortality (death rate) evaluated alone: Probability of worse performance at 99%.
- Pooled studies incl. EXCEL study: probability of higher mortality 85 %.
CONCLUSION: PCI for low-risk left main stem stenosis should be downgraded in the guidelines.
