Complete versus culprit-only revascularisation in ST elevation myocardial infarction with multi-vessel disease

BACKGROUND

Multi-vessel coronary disease in people with ST elevation myocardial infarction (STEMI) is common and is associated with worse prognosis after STEMI. Based on limited evidence, international guidelines recommend intervention on only the culprit vessel during STEMI. This, in turn, leaves other significantly stenosed coronary arteries for medical therapy or revascularisation based on inducible ischaemia on provocative testing. Newer data suggest that intervention on both the culprit and non-culprit stenotic coronary arteries (complete intervention) may yield better results compared with culprit-only intervention.

OBJECTIVES

To assess the effects of early complete revascularisation compared with culprit vessel only intervention strategy in people with STEMI and multi-vessel coronary disease.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, World Health Organization International Clinical Trials Registry Platform Search Portal, and ClinicalTrials.gov. The date of the last search was 4 January 2017. We applied no language restrictions. We handsearched conference proceedings to December 2016, and contacted authors and companies related to the field.

SELECTION CRITERIA

We included only randomised controlled trials (RCTs), wherein complete revascularisation strategy was compared with a culprit-only percutaneous coronary intervention (PCI) for the treatment of people with STEMI and multi-vessel coronary disease.

DATA COLLECTION AND ANALYSIS

We assessed the methodological quality of each trial using the Cochrane 'Risk of bias' tool. We resolved the disagreements by discussion among review authors. We followed standard methodological approaches recommended by Cochrane. The primary outcomes were long-term (one year or greater after the index intervention) all-cause mortality, long-term cardiovascular mortality, long-term non-fatal myocardial infarction, and adverse events. The secondary outcomes were short-term (within the first 30 days after the index intervention) all-cause mortality, short-term cardiovascular mortality, short-term non-fatal myocardial infarction, revascularisation, health-related quality of life, and cost. We analysed data using fixed-effect models, and expressed results as risk ratios (RR) with 95% confidence intervals (CI). We used GRADE criteria to assess the quality of evidence and we conducted Trial Sequential Analysis (TSA) to control risks of random errors.

MAIN RESULTS

We included nine RCTs, that involved 2633 people with STEMI and multi-vessel coronary disease randomly assigned to either a complete (n = 1381) versus culprit-only (n = 1252) revascularisation strategy. The complete and the culprit-only revascularisation strategies did not differ for long-term all-cause mortality (65/1274 (5.1%) in complete group versus 72/1143 (6.3%) in culprit-only group; RR 0.80, 95% CI 0.58 to 1.11; participants = 2417; studies = 8; I2 = 0%; very low quality evidence). Compared with culprit-only intervention, the complete revascularisation strategy was associated with a lower proportion of long-term cardiovascular mortality (28/1143 (2.4%) in complete group versus 51/1086 (4.7%) in culprit-only group; RR 0.50, 95% CI 0.32 to 0.79; participants = 2229; studies = 6; I2 = 0%; very low quality evidence) and long-term non-fatal myocardial infarction (47/1095 (4.3%) in complete group versus 70/1004 (7.0%) in culprit-only group; RR 0.62, 95% CI 0.44 to 0.89; participants = 2099; studies = 6; I2 = 0%; very low quality evidence). The complete and the culprit-only revascularisation strategies did not differ in combined adverse events (51/2096 (2.4%) in complete group versus 57/1990 (2.9%) in culprit-only group; RR 0.84, 95% CI 0.58 to 1.21; participants = 4086; I2 = 0%; very low quality evidence). Complete revascularisation was associated with lower proportion of long-term revascularisation (145/1374 (10.6%) in complete group versus 258/1242 (20.8%) in culprit-only group; RR 0.47, 95% CI 0.39 to 0.57; participants = 2616; studies = 9; I2 = 31%; very low quality evidence). TSA of long-term all-cause mortality, long-term cardiovascular mortality, and long-term non-fatal myocardial infarction showed that more RCTs are needed to reach more conclusive results on these outcomes. Regarding long-term repeat revascularisation more RCTs may not change our present result. The quality of the evidence was judged to be very low for all primary and the majority of the secondary outcomes mainly due to risk of bias, imprecision, and indirectness.

AUTHORS' CONCLUSIONS

Compared with culprit-only intervention, the complete revascularisation strategy may be superior due to lower proportions of long-term cardiovascular mortality, long-term revascularisation, and long-term non-fatal myocardial infarction, but these findings are based on evidence of very low quality. TSA also supports the need for more RCTs in order to draw stronger conclusions regarding the effects of complete revascularisation on long-term all-cause mortality, long-term cardiovascular mortality, and long-term non-fatal myocardial infarction.

Free internal mammary artery graft reimplantation on the same vessel in repeat coronary revascularization

We describe the case of a 62-year-old man who needed a 3-vessel coronary artery bypass reoperation and mitral valve replacement. The patient's existing free left internal mammary artery graft was not functioning because of a critical stenosis in the native vessel just after the distal anastomosis. The free graft itself was in perfect condition, and we decided to reuse it. Because the course of the graft was so tortuous, we concluded that skeletonization would yield the extra length needed for reimplantation. After reimplanting the graft, we performed venous grafting and mitral valve replacement. The patient was well and had no signs of ischemia at 29 months postoperatively. There have been few reports on recycling internal mammary artery grafts in repeat coronary artery bypass grafting. To our knowledge, ours is the first report of the reimplantation of a free internal mammary artery graft on the same vessel. We describe the procedure and our decision-making process.

Effect of revascularization of chronic total occlusion on tandem stenoses in a "donor" artery

The presence, severity, and extent of ischemia predict the outcome of coronary artery disease. Indeed the extent of myocardial ischemia and viability determines the value of revascularization in coronary stenosis after acute myocardial infarction. In multivessel coronary artery disease, noninvasive methods for the evaluation of ischemia are often inadequate to guide percutaneous coronary intervention. It is a common misperception that revascularization might not benefit a myocardial segment in the chronic total occlusion distribution when that segment is supplied by well-developed collateral vessels, because severe ischemia is unlikely to be present under these circumstances. An 82-year-old man presented with acute coronary syndrome, tandem stenoses in a "donor" artery, and a chronic total occlusion of the right coronary artery. We present a rationale for using fractional flow reserve to determine the existence of ischemia and to aid in deciding the best approach to the treatment of that ischemia.

Novel single-stage operation and inflow source: for thoracic aortic aneurysm and limb ischemia

Patients with thoracic aortic aneurysms sometimes also have peripheral vascular disease. In such cases, staged operations are usually performed in order to avoid additional morbidity. We have achieved good long-term outcomes in 2 patients with use of a single-stage surgical technique. Our novel procedure uses a pre-sewn side branch with a Dacron graft as the inflow source for the aortofemoral bypass during thoracic aortic aneurysm repair. As of 25 and 52 months' follow-up, these grafts were patent in our 2 patients. We believe that this procedure is a safe and easy single-stage operation that achieves favorable patency. To our knowledge, this is the first report to document the use of a pre-sewn perfusion branch of a Dacron graft as an inflow source for aortofemoral bypass.

Scoring system for predicting saphenous vein graft patency in coronary artery bypass grafting

The initial and long-term benefits of coronary artery bypass grafting depend upon maintaining the coronary blood flow supplied by the graft. In order to devise a scoring system for predicting graft patency, we evaluated presumptive correlations between saphenous vein graft patency and the characteristics of saphenous veins that were used as conduits in coronary revascularization.We prospectively evaluated 1,000 saphenous vein segments that were implanted in 403 consecutive patients who underwent on-pump coronary artery bypass grafting at our hospital from January 2006 through February 2009. Branches, varicosity, diameter, and wall thickness were evaluated, and a scoring system was created in order to obtain a value for each characteristic. The patients were postoperatively monitored for 1 year, and graft patency was then evaluated with the use of 64-slice multidetector computed tomography.Lesions were found in 12.3% of the grafts. All of the evaluated characteristics of the grafts had a significant correlation with saphenous vein graft flow (P <0.0001). Using the venous characteristics in our statistical analysis, we devised a formula to obtain a score (range, 4-12) to predict the patency of each graft. A cutoff score of 7 yielded 87.8% sensitivity and 82.8% specificity.Our scoring system has good prognostic value. We believe that it can assist surgeons in choosing the most appropriate conduit and target vessel for coronary artery bypass grafting, especially in high-risk patients who are particularly dependent on blood flow through saphenous vein grafts.

"Pulmonary slit" procedure for preventing tension on the left internal thoracic artery graft

The gold-standard bypass graft to the left anterior descending coronary artery is the left internal thoracic artery harvested with its pedicle. At times, however, the length of the internal thoracic artery is insufficient for distal anastomosis. Different methods of lengthening the internal thoracic artery or of reducing the distance to the anastomosis site have been described, but at times even these may be inadequate. In order to extend the benefits of the left internal thoracic artery graft to more patients, we perform the "pulmonary slit" procedure as described here.

Right coronary revascularization by coronary-coronary bypass with a segment of internal thoracic artery

In certain coronary artery bypass grafting operations, the internal thoracic artery is not by itself adequate for complete arterial revascularization. Which graft should be used for revascularization of the right coronary artery is still a matter of debate. From August 2000 through July 2005, we performed coronary-coronary bypass grafting on 48 patients (77.1% men, 22.9% women), whose mean age was 57.2 years (range, 40-75 yr). After completion of the internal thoracic artery anastomoses, we performed coronary-coronary bypass grafting with a remaining (distal) segment of the left (or, rarely, the full length of the free right) internal thoracic artery. The proximal and distal anastomoses of the internal thoracic artery to the right coronary artery were end-to-side. We preferred to use the right coronary ostium as the proximal anastomosis site where possible; otherwise, we used a disease-free segment of the right coronary artery. A total of 192 anastomoses were performed (mean, 4.15 per patient); all used the bilateral internal thoracic arteries as conduits. There were no in-hospital deaths or perioperative myocardial infarctions. The duration of follow-up ranged from 1 to 46 months (mean, 9.6 mo). Follow-up angiography was performed in 24 patients (50%). The mean time to coronary angiography was 16.5 months (range, 7 days-2 years). The patency rate was 100%. We conclude that coronary-coronary anastomosis by means of a distal segment of the internal thoracic artery can help to achieve complete arterial revascularization in selected patients.

Unprotected left main coronary artery intervention for acute myocardial infarction and cardiogenic shock

Medical therapy alone often insufficiently alters the clinical course of patients who have experienced acute myocardial infarction and concomitant cardiogenic shock, and in whom the left main coronary artery is the culprit vessel. Emergency coronary artery bypass grafting is an effective yet time-consuming approach that entails the risk of extensive, irreversible myocardial damage. Percutaneous coronary intervention in the unprotected left main coronary artery can enable initial revascularization and rapid stabilization even in high-risk patients, but outcomes from the procedure since the recent advent of drug-eluting stents are still being determined. Herein, we report the successful deployment of a sirolimus-eluting stent in a 65-year-old man who had experienced acute myocardial infarction and cardiogenic shock consequent to an occluded left main coronary artery. The patient recovered rapidly and completely. We review the medical literature and compare percutaneous coronary intervention with other methods of treatment.

Immunohistochemical comparison of traditional and modified harvesting of the left internal mammary artery

The left internal mammary artery is the conduit of choice for coronary artery bypass grafting. In the traditional ("clipped-artery") harvesting technique, this artery is prepared as a pedicle; the distal part is clipped, cut, and covered with a papaverine-soaked cloth until anastomosis is performed. In modified ("nonclipped-artery") harvesting, the prepared artery is kept in situ and left connected to the systemic circulation until anastomosis. Better outcomes from use of the nonclip technique have been reported. In order to determine comparative endothelial integrity and endothelial nitric oxide synthase activity, we performed an immunohistochemical study of arterial graft segments that were procured by each technique. This cross-sectional study involved 40 patients who underwent elective coronary artery bypass grafting. The patients were randomized into 2 groups of 20. One group underwent traditional clipped-artery harvesting; the other group, modified nonclipped-artery harvesting. By immunohistochemical methods, we examined redundant segments taken from bifurcation levels of the arteries. The tunica media was thinner in the clipped arterial segments, a phenomenon that we attribute to high luminal pressure. Endothelial nitric oxide synthase immunostaining was absent in regions of denudation in the luminal endothelia of the clipped arteries; in contrast, pronounced immunostaining occurred in the endothelia of the nonclipped segments. We found that traditional harvesting disrupted the integrity of the luminal endothelia of the clipped arteries. In addition, the traditional procedure decreased nitric oxide production, as was revealed by immunostaining.

A proposed alternative mechanism of action for transmyocardial revascularization prefaced by a review of the accepted explanations

Laser transmyocardial revascularization, a procedure originally intended to simulate the perfusion mechanism of the reptilian heart, has evolved into an effective but poorly understood treatment for angina when traditional revascularization is not an option. Herein, we review the explanations that have been proposed over the years and suggest a new one. We hypothesize that the long-term mechanism of action of transmyocardial revascularization is the redistribution of stresses on the ventricular wall through the creation of fibrous transmyocardial scars, which penetrate the various layers of muscle that surround the left ventricular cavity. The stress redistribution of a load in an otherwise unchanged ventricular wall reduces the wall stress per unit of wall volume, which in turn decreases the workload for the hyperkinetic compensating areas. This reduces both oxygen demand and local metabolite production, lowering the level of angina.

Hybrid coronary revascularization in high-risk patients

From January 2002 through June 2004, 17 patients (2% of all coronary cases) were treated with off-pump coronary artery bypass grafting combined with percutaneous coronary intervention. There were 13 men and 4 women, whose ages ranged from 54 to 78 years (mean, 63.1 +/- 20.9 yr). Preoperative angiography revealed 2-vessel coronary artery disease in 12 patients and 3-vessel disease in the remaining 5 patients. In all patients, extensive lesions (>50%) in the circumflex and right coronary arteries were treated first with a percutaneous intervention, followed by beating-heart coronary artery bypass grafting within 3 hours to treat the remaining obstructed vessels. Coronary angiography was performed 12 months after the operation to evaluate the effectiveness of the procedure. Procedure-related complications did not occur, and there was no in-hospital death. All patients underwent a successful left internal mammary artery-left anterior descending artery anastomosis with the exception of 1 patient, in whom we used a saphenous vein because of previous chest radiotherapy. The postoperative courses were uneventful, and no deterioration of preoperative organ dysfunction was noticed in any patient. There was no cardiac-related death or myocardial infarction. In follow-up angiography, all left internal mammary artery-left anterior descending artery anastomoses were patent. Three patients with restenosis were treated medically, which resulted in substantial reduction of angina. Hybrid coronary revascularization enables complete revascularization and may be an alternative method of treating selected patients who have concomitant disease.

Pedicled right internal mammary artery for reoperative off-pump revascularization of left anterior descending coronary artery

In situ right internal mammary artery is the graft of choice in reoperative off-pump coronary artery bypass grafting, as well as in primary on-pump coronary artery bypass grafting, unless the vessel has been used previously. However, there are not enough data about postoperative angiographic findings of the in situ right internal mammary artery in reoperative coronary artery bypass grafting with the off-pump technique. From September 1993 through January 2004, we reviewed the postoperative course and the graft patency of 12 selected patients who underwent off-pump coronary artery bypass grafting reoperation only for revascularization of the left anterior descending artery, by means of a pedicled right internal mammary artery graft. All patients were evaluated clinically and by postoperative coronary angiography. There were no early or late deaths during the mean follow-up period of 33.08 +/- 30.05 months (range, 1-77 months). The mean interval from the 1st operation to the 2nd operation was 74.1 +/- 57.01 months (range, 4.5-171 months). Postoperative coronary angiograms of all patients showed a 100% patency rate for both in situ grafts and composite grafts. We suggest that use of the in situ right internal mammary artery in off-pump coronary artery bypass grafting is a safe and reliable option for revascularizing the left anterior descending artery, especially in reoperation.

Flow analysis of left internal thoracic artery in myocardial revascularization surgery using y graft

In order to evaluate the left internal thoracic artery flow pattern, when the vessel is used as a graft to supply the left coronary artery system, we evaluated flow by Doppler measurement, both at rest and under dobutamine stress. There were 2 groups of 20 patients each: group A patients received only a left internal thoracic artery graft to the left anterior descending artery, and group B patients received a pedicled left internal thoracic artery graft associated with a vein graft, which together supplied the left anterior descending artery and another branch of the left coronary artery. Angiography showed patent grafts in all patients from both groups. The following characteristics were evaluated: systolic flow, diastolic flow, total flow, total flow under stress/total flow at rest ratio, systolic peak velocity, diastolic peak velocity, and systolic peak velocity/diastolic peak velocity ratio. In group A, the total flow was 45.5 +/- 21.6 mL/min at rest and 68.3 +/- 32.9 mL/min under stress. In group B, the total flow was 98.2 +/- 50.4 mL/min at rest and 175.7 +/- 79.2 mL/min under stress. Comparison between groups showed a total flow increase in group B of 115.8% (P=0.0002) at rest and 157.2% (P <0.0001) under stress. The other characteristics were also statistically significant, except systolic flow, total flow under stress/total flow at rest ratio, and systolic peak velocity. Our results showed that the left internal thoracic artery sufficiently supplies regional myocardium at rest and during exercise (stress), demonstrating its great adaptability in response to demand.

Total arterial coronary bypass: long-term results

Three groups of consecutive patients who had undergone primary elective coronary artery bypass operations were compared at 10 to 20 years of follow-up (mean, 13.6 years), in order to test the supposition that arterial conduits provide better long-term outcome than do the "standard" left internal mammary-to-left anterior descending coronary artery plus saphenous vein bypasses. The arterial group was split into groups A (all arterial) and B (2 or more arterial grafts, plus saphenous vein grafts). Control group C comprised the standard operations. The absence of saphenous vein conduit in group A was associated with fewer angiograms for symptoms, fewer reinterventions, and fewer cardiac deaths than those experienced in groups B and C. We conclude that the survival and cardiac quality-of-life advantage found in group A is attributable to the exclusive use of arterial conduits.

19-year patency of a coronary-coronary venous bypass graft

No data are available on the long-term outcome of coronary-coronary venous bypass grafting. We describe a case in which we successfully stented a discrete, critical stenosis of a coronary-coronary venous graft that had been placed 19 years earlier to minimize manipulation of a severely calcified ascending aorta. Coronary-coronary bypass grafting should be considered in cases involving severe aortic calcification, in situ grafts of inadequate length, and stenosed or occluded subclavian arteries. Such a bypass can be performed with either saphenous vein or arterial conduits, and it provides a flow rate similar to that of aortocoronary bypass. This option could be borne in mind as a 2nd-choice technique for the durable restoration of coronary blood flow in selected cases.

Posttransplant off-pump coronary bypass and laser revascularization in a Jehovah's Witness

A 57-year-old man, who had received a heart transplant 14 years earlier, underwent coronary artery bypass grafting and transmyocardial laser revascularization for left main, left anterior descending, and circumflex coronary artery disease. The procedures were performed through a left thoracotomy incision without cardiopulmonary bypass. Because the patient was of the Jehovah's Witness faith, no blood or blood products were transfused.

Arterial conduits should be evaluated preoperatively in coronary artery bypass patients with pseudoxanthoma elasticum

A 74-year-old man who had pseudoxanthoma elasticum presented with unstable angina and underwent urgent coronary artery bypass grafting. Preoperative angiography did not include the internal mammary arteries. Intraoperatively, the left internal mammary artery was found to be diseased and could not be used. This case lends support to the need for thorough preoperative evaluation, including angiography, of potential arterial conduits in patients with pseudoxanthoma elasticum.

Off-pump bypass surgery: the early experience, 1969-1985

This is a review of 733 patients who underwent off-pump bypass surgery of the right coronary artery and left anterior descending coronary artery between 1969 and 1985. Two hundred sixty-four patients underwent single bypass of the left anterior descending coronary artery, and 79 patients underwent single bypass of the right coronary artery. Both the left anterior descending and right coronary arteries were bypassed in 390 patients. In contrast to the present-day use of mechanical devices to stabilize the target vessel, a 4-suture surgical technique was used for this purpose. This technique, which we illustrate, proved less cumbersome and made the graft anastomosis easy to perform. Our early experience (1969 through 1972) in operating on 199 patients resulted in an operative mortality rate of 4.5% (9/199). From 1973 through 1985, improved patient selection and use of the left internal thoracic artery as the conduit of choice for bypass of the left anterior descending coronary artery reduced the operative mortality rate for 534 patients to 1.3% (7/534). Routine postoperative angiograms were not performed; therefore, the graft patency rate is not available. However, an ongoing 34-year follow-up study of the 264 patients who underwent a single left anterior descending bypass showed the saphenous vein graft to be open in 64.3% (18/28) patients and the left internal thoracic graft in 92.2% (59/64) of patients studied. Seventy-four of the 264 patients in this study were still alive in 2003.

Pedicled or skeletonized? A review of the internal thoracic artery graft

The internal thoracic artery is the gold-standard conduit for coronary artery bypass surgery. Until recently, it was used almost exclusively as a pedicle, with construction of 1 distal anastomosis. Skeletonization of the internal thoracic artery has recently been advocated in order to increase the number of arterial anastomoses and decrease the occurrence of sternal wound infections. When skeletonized, the vessel loses its "milieu" which raises the question of whether this technique sacrifices the superior longevity of the conduit. The current status of research on the effects of skeletonization (depriving the internal thoracic artery of vasa vasorum, innervation, and lymphatic and venous drainage, together with creating an imbalance between vasoconstricting and vasodilating substances) appears to support the superiority of the pedicled graft. Long-term patency studies of the skeletonized ITA, with meticulous follow-up and confirmation by angiography, are not currently available. Theoretically, skeletonization of the ITA might adversely affect its long-term resistance to atherosclerosis. More data are needed before this technique can be universally recommended. If the skeletonized ITA has decreased long-term patency, bypass surgery may be at a disadvantage when compared with the new generation of drug-eluting stents.

Full-sternotomy off-pump versus on-pump coronary artery bypass procedures: in-hospital outcomes and complications during one year in a single center

We prospectively compared, according to their preoperative clinical profiles, the in-hospital outcomes of patients operated on consecutively (but without randomization) for isolated coronary artery disease with on-pump or off-pump techniques. During 2001, 324 patients underwent coronary artery bypass grafting: 216 patients (mean age, 66.7 +/- 8.9 years; range, 41-85 years) underwent on-pump revascularization, and 108 patients (mean age, 676 +/- 10 years; range, 37-90 years) underwent full-sternotomy off-pump revascularization. The 2 groups were homogeneous with regard to female sex (22.6% vs 26.8%), previous cardiac operation (2.8% vs 4.6%), cardiogenic shock (1.3% vs 1.9%), diabetes (30% vs 33%), and chronic renal failure that required hemodialysis (3% vs 3.5%). Postoperative complications, including bleeding, myocardial infarction, acute renal failure, mediastinitis with sternal dehiscence, cerebrovascular events, and prolonged respiratory assistance were more frequent in on-pump patients (P = 0.004). The total number of grafts and the grafts per patient ratio were significantly higher in on-pump patients (P = 0.0001), whereas the total number of full arterial revascularizations was higher in off-pump patients (P = 0.0001). Off-pump patients showed a significantly shorter intensive care unit stay (P = 0.02), and less need for intra-aortic balloon pump insertion (P = 0.04). In-hospital mortality was 2.8% in on-pump patients and 2.7% in off-pump patients (P = NS). Although the hospital mortality rate was comparable for the 2 techniques, the in-hospital comparison between the 2 groups showed how the avoidance of cardiopulmonary bypass can significantly reduce the cumulative postoperative incidence of complications in patients undergoing coronary artery bypass grafting.

Can stent-angioplasty be a valid alternative to surgery when revascularization is indicated for anomalous origination of a coronary artery from the opposite sinus?

When intervention is indicated for anomalous origination of a coronary artery from the opposite sinus, stent-angioplasty may seem more attractive than coronary artery bypass grafting. However, in the case of anomalous origination of a coronary artery from the opposite sinus, the anatomy is quite different from that encountered in atherosclerotic disease, and stent-angioplasty would involve unusual challenges, both in technique and prognostic outcomes. We illustrate these points by presenting the 2 first cases in which intervention was indicated because of severe symptoms. We conclude from this preliminary study that coronary artery bypass grafting should still be considered the preferred (although unproven) method of revascularization in patients who have symptomatic anomalous origination of a coronary artery from the opposite sinus. Until adequate data have been gathered to evaluate the late results of stent-angioplasty in these patients (in comparison with the results of surgical and medical treatment), the procedure should be performed only in selected patients, enrolled in prospective, controlled studies.