Myocardial Revascularization Surgery: JACC Historical Breakthroughs in Perspective

Rationale and design of a single-center randomized trial to compare the graft patency between the radial artery and the no-touch saphenous vein in coronary artery bypass grafting surgery (GRAFT-CAB Study)

BACKGROUND

Previous studies suggested only the radial artery and the No-touch (NT) technique were effective in reducing graft occlusion after coronary artery bypass grafting (CABG) surgery. However, there is no randomized trial comparing these 2 graft conduits. The optimum second conduit for CABG remains undetermined.

MATERIALS AND METHODS

This study is a prospective, single-center randomized clinical trial, aiming to compare the graft patency between the radial artery and the NT vein graft. All patients undergoing isolated CABG with left internal mammary artery (LIMA) plus at least 2 additional grafts will be considered eligible. About 774 cases (516 in the radial artery group and 258 in the NT vein group) will be enrolled in over 1 to 2 years. Participants will be randomized and allocated to two bypass strategies: the LIMA plus 1 radial artery and 1 conventional vein graft, or the LIMA plus 2 NT vein grafts. The primary outcome is graft occlusion at 1 year after CABG evaluated by CT angiography. The secondary outcomes include graft occlusion at 3 and 5 years and major adverse cardiac or cerebrovascular events at 1, 3, and 5 years follow-ups.

DISCUSSION

This study will define whether or not the NT vein has a lower graft occlusion rate than the radial artery in short and mid-term follow-ups, and provide new evidence for the second conduit choice in CABG surgery.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06014047. Registered on October 15th, 2023.

Skeletonized Versus Pedicled Harvesting of the Internal Thoracic Artery and Long-Term Clinical Outcomes in Coronary Artery Bypass Surgery

BACKGROUND

The internal thoracic artery (ITA) is the most important conduit for coronary artery bypass grafting. Recent evidence suggests that skeletonized ITA harvesting yields long-term outcomes inferior to those of pedicled harvesting. The aim was to investigate the impact of the ITA harvesting method on 10-year mortality and major adverse cardiovascular events.

METHODS AND RESULTS

In this observational cohort study, we identified all patients from the SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) register who underwent isolated coronary artery bypass grafting using at least 1 ITA at Karolinska University Hospital from 2012 to 2021. The main outcome was all-cause mortality, and the secondary outcomes were a combination of myocardial infarction, repeat revascularization, heart failure, and stroke. Outcomes were ascertained using national health data registers and compared between the skeletonized and pedicled groups using weighted flexible parametric survival models. Among 3267 patients, 1657 (51%) underwent pedicled ITA harvesting and 1610 (49%) underwent skeletonized ITA harvesting. The patients' mean age was 66 years, and 15% were women. The weighted all-cause mortality incidence rate in the pedicled versus skeletonized ITA group was 2.6% (95CI, 2.2%-3.0%) versus 2.6% (95% CI, 2.2%-3.1%), respectively (hazard ratio (HR), 1.01 [95% CI, 0.81-1.27]). The weighted major adverse cardiovascular events incidence rate was 7.8% (95% CI, 7.1%-8.6%) versus 7.5% (95% CI, 6.7%-8.4%), respectively (HR, 0.94 [95% CI, 0.82-1.08]).

CONCLUSIONS

We found no significant differences in all-cause mortality or major adverse cardiovascular events rates between the 2 ITA harvesting methods.

Comparison of clinical effects of coronary artery bypass grafting between left anterior small thoracotomy approach and lower-end sternal splitting approach

OBJECTIVE

To compare the clinical effects of coronary artery bypass grafting (CABG) between the left anterior small thoracotomy (LAST) and lower-end sternal splitting (LESS) approaches for coronary artery disease.

METHODS

In total, 110 patients who underwent LAST from October 2015 to December 2020 in Tianjin Chest Hospital were selected as the observation group. Patients who underwent the LESS approach during the same period were analyzed. The propensity score was calculated by a logistic regression model, and nearest-neighbor matching was used for 1:1 matching.

RESULTS

The length of hospital stay and ventilator support time were significantly shorter in the LAST than LESS group. The target vessels in the obtuse marginal branch and posterior left ventricular artery branch grafts were significantly more numerous in the LAST than LESS group, but those in the right coronary artery graft were significantly less numerous in the LAST group.

CONCLUSIONS

CABG using either the LAST or LESS approach is safe and effective, especially in low-risk patients. The LAST approach can achieve complete revascularization for multivessel lesions and has the advantages of less trauma and an aesthetic outcome. However, it requires a certain learning curve to master the surgical techniques and has specific surgical indications.

When to Consider Coronary Revascularization for Stable Coronary Artery Disease

Revascularization is an effective adjunct to medical therapy for some patients with chronic coronary disease. Despite numerous randomized trials, there remains significant uncertainty regarding if and how to revascularize many patients. Coronary artery bypass grafting is a class I indication for patients with significant left main stenosis or multivessel disease with ejection fraction ≤ 35%. For other patients, clinicians must carefully consider the potential benefits of symptom improvement and reduction of future myocardial infarction or CV death against the risk and cost of revascularization. Although guidelines provide a framework for these decisions, each individual patient will have distinct coronary anatomy, clinical factors, and preferences.

Intimal hyperplasia, saphenous vein graft disease, and clinical outcomes: Insights from the CTSN VEST randomized trial

BACKGROUND

Diffuse intimal hyperplasia and graft irregularity adversely affect the long-term patency of saphenous vein grafts (SVGs) and clinical outcomes of patients undergoing coronary artery bypass grafting (CABG). The VEST trial evaluated the efficacy of external graft support in limiting the development of intimal hyperplasia (IH) at 1 year postsurgery. In the present secondary analysis, we explored the associations between graft disease and IH and clinical events. We also examined risk factors for early graft occlusion.

METHODS

VEST is a within-patient randomized, multicenter trial that enrolled 224 patients with multivessel coronary disease undergoing CABG surgery, of whom 203 were evaluated by 1 year postsurgery. Intimal hyperplasia, lumen uniformity, graft stenosis, and graft perfusion were measured by intravascular ultrasound and angiography. Major cardiac and cerebrovascular events (MACCE; including death, myocardial infarction, stroke, and revascularization) were recorded over a median follow-up of 3 years.

RESULTS

Worse lumen uniformity, greater stenosis, and worse graft perfusion were associated with higher IH values and an increased incidence of clinical events. Consistent with previous findings, we identified endoscopic vein harvesting, female sex, and transit time flow measurement of pulsatility index and flow as risk factors for SVG occlusion during the first year postsurgery.

CONCLUSIONS

In this secondary analysis of the VEST trial, we observed an association between intimal hyperplasia area and clinical measures of SVG disease at 1 year postsurgery. More severe SVG disease and larger areas of IH were associated with a higher incidence of 3-year MACCE. Ongoing follow-up to 5 years will further elucidate the impact of SVG disease on long-term clinical outcomes of CABG.

Regional and temporal differences in the associations between cardiovascular disease and its classic risk factors: An analysis of 49 cohorts from 11 European countries

AIMS

The regional and temporal differences in the associations between cardiovascular disease (CVD) and its classic risk factors are unknown. The current study examined these associations in different European regions over a 30-year period.

METHODS

The study sample comprised 553818 individuals from 49 cohorts in 11 European countries (baseline: 1982-2012) who were followed up for a maximum of 10 years. Risk factors (sex, smoking, diabetes, non-HDL [high-density lipoprotein] cholesterol, systolic blood pressure [BP], and body mass index [BMI]) and CVD events (coronary heart disease or stroke) were harmonized across cohorts. Risk factor-outcome associations were analysed using multivariable-adjusted Cox regression models, and differences in associations were assessed using meta-regression.

RESULTS

The differences in the risk factor-CVD associations between central Europe, northern Europe, southern Europe, and the United Kingdom were generally small. Men had a slightly higher hazard ratio (HR) in southern Europe (p = 0.043 for overall difference) and those with diabetes had a slightly lower HR in central Europe (p = 0.022 for overall difference) compared with the other regions. Of the six CVD risk factors, minor HR decreases per decade were observed for non-HDL cholesterol (7% per mmol/L; 95% confidence interval [CI], 3-10%) and systolic BP (4% per 20 mmHg; 95% CI, 1-8%), while a minor HR increase per decade was observed for BMI (7% per 10 kg/m2; 95% CI, 1-13%).

CONCLUSION

The results demonstrate that all classic CVD risk factors are still relevant in Europe, irrespective of regional area. Preventive strategies should focus on risk factors with the greatest population attributable risk.

External stenting for saphenous vein grafts in coronary artery bypass grafting: A meta-analysis

OBJECTIVES

Autologous saphenous vein grafts (SVGs) are the most commonly used bypass conduits in coronary artery bypass grafting (CABG) with multivessel coronary artery disease. Although external support devices for SVGs have shown promising outcomes, the overall efficacy and safety remains controversial. We aimed to evaluate external stenting for SVGs in CABG versus non-stented SVGs.

METHODS

MEDLINE, EMBASE, Cochrane Library and clinicaltrails.gov were searched for randomized controlled trials (RCTs) to evaluate external-stented SVGs versus non-stented SVGs in CABG up to 31 August 2022. The risk ratio and mean difference with 95% confidence interval were analysed. The primary efficacy outcomes included intimal hyperplasia area and thickness. The secondary efficacy outcomes were graft failure (≥50% stenosis) and lumen diameter uniformity.

RESULTS

We pooled 438 patients from three RCTs. The external stented SVGs group showed significant reductions in intimal hyperplasia area (MD: -0.78, p < 0.001, I2  = 0%) and thickness (MD: -0.06, p < 0.001, I2  = 0%) compared to the non-stented SVGs group. Meanwhile, external support devices improved lumen uniformity with Fitzgibbon I classification (risk ratio (RR):1.1595, p = 0.05, I2  = 0%). SVG failure rates were not increased in the external stented SVGs group during the short follow-up period (RR: 1.14, p = 0.38, I2  = 0%). Furthermore, the incidences of mortality and major cardiac and cerebrovascular events were consistent with previous reports.

CONCLUSIONS

External support devices for SVGs significantly reduced the intimal hyperplasia area and thickness, and improved the lumen uniformity, assessed with the Fitzgibbon I classification. Meanwhile, they did not increase the overall SVG failure rate.

Combining Minimally Invasive Direct Coronary Artery Bypass Grafting with Transapical Aortic Valve Implantation-The Next Level Heart Team Approach

We present the results of a combined approach for transapical aortic valve replacement and minimally invasive coronary artery bypass grafting (taTAVI-MIDCAB) in patients with combined aortic stenosis and coronary artery disease.

BACKGROUND

For patients presenting with aortic stenosis and coronary artery disease, a simultaneous procedure addressing both diseases is recommended to reduce operative risk. In high-risk patients with hostile femoral or coronary axis, taTAVI-MIDCAB can be an alternative minimally invasive approach, offering the benefits of left interior mammary artery to left anterior descending coronary artery (LIMA-LAD) grafting.

METHODS

From 2014 to 2022, 10 patients underwent taTAVI-MIDCAB for combined coronary and severe aortic stenosis in the hybrid operation theater at our institution. We assessed perioperative outcomes and follow-up outcomes.

RESULTS

The median age was 83 years (81 to 86). The procedure was successfully performed in all patients without conversion to sternotomy. The median length of hospital and intensive care unit stay was 9 days (7 to 16) and 2.5 days (1 to 5), respectively. The median flow over the coronary artery bypass was 31 (22 to 44) mL/min, with a pulsatility index (PI) of 2.4 (2.1 to 3.2). Mild paravalvular leak occurred in 2 patients (10%). There were no neurological events nor acute kidney injury. Pacemaker implantation was required in 1 patient (10%).

CONCLUSIONS

Simultaneous surgical coronary revascularization and interventional valve implantation in the setting of a hostile femoral and coronary axis appears to be safe and beneficial.

Percutaneous Coronary Intervention vs Coronary Artery Bypass Graft Surgery for Left Main Disease in Patients With and Without Acute Coronary Syndromes: A Pooled Analysis of 4 Randomized Clinical Trials

Importance

Patients with left main coronary artery disease presenting with an acute coronary syndrome (ACS) represent a high-risk and understudied subgroup of patients with atherosclerosis.

Objective

To assess clinical outcomes after PCI vs CABG in patients with left main disease with vs without ACS.

Design, Setting, and Participants

Data were pooled from 4 trials comparing PCI with drug-eluting stents vs CABG in patients with left main disease who were considered equally suitable candidates for either strategy (SYNTAX, PRECOMBAT, NOBLE, and EXCEL). Patients were categorized as presenting with or without ACS. Kaplan-Meier event rates through 5 years and Cox model hazard ratios were generated, and interactions were tested. Patients were enrolled in the individual trials from 2004 through 2015. Individual patient data from the trials were pooled and reconciled from 2020 to 2021, and the analyses pertaining to the ACS subgroup were performed from March 2022 through February 2023.

Main Outcomes and Measures

The primary outcome was death through 5 years. Secondary outcomes included cardiovascular death, spontaneous myocardial infarction (MI), procedural MI, stroke, and repeat revascularization.

Results

Among 4394 patients (median [IQR] age, 66 [59-73] years; 3371 [76.7%] male and 1022 [23.3%] female) randomized to receive PCI or CABG, 1466 (33%) had ACS. Patients with ACS were more likely to have diabetes, prior MI, left ventricular ejection fraction less than 50%, and higher SYNTAX scores. At 30 days, patients with ACS had higher all-cause death (hazard ratio [HR], 3.40; 95% CI, 1.81-6.37; P < .001) and cardiovascular death (HR, 3.21; 95% CI, 1.69-6.08; P < .001) compared with those without ACS. Patients with ACS also had higher rates of spontaneous MI (HR, 1.70; 95% CI, 1.25-2.31; P < .001) through 5 years. The rates of all-cause mortality through 5 years with PCI vs CABG were 10.9% vs 11.5% (HR, 0.93; 95% CI, 0.68-1.27) in patients with ACS and 11.3% vs 9.6% (HR, 1.19; 95% CI, 0.95-1.50) in patients without ACS (P = .22 for interaction). The risk of early stroke was lower with PCI vs CABG (ACS: HR, 0.39; 95% CI, 0.12-1.25; no ACS: HR, 0.35; 95% CI, 0.16-0.75), whereas the 5-year risks of spontaneous MI and repeat revascularization were higher with PCI vs CABG (spontaneous MI: ACS: HR, 1.74; 95% CI, 1.09-2.77; no ACS: HR, 3.03; 95% CI, 1.94-4.72; repeat revascularization: ACS: HR, 1.57; 95% CI, 1.19-2.09; no ACS: HR, 1.90; 95% CI, 1.54-2.33), regardless of ACS status.

Conclusion and Relevance

Among largely stable patients undergoing left main revascularization and with predominantly low to intermediate coronary anatomical complexity, those with ACS had higher rates of early death. Nonetheless, rates of all-cause mortality through 5 years were similar with PCI vs CABG in this high-risk subgroup. The relative advantages and disadvantages of PCI vs CABG in terms of early stroke and long-term spontaneous MI and repeat revascularization were consistent regardless of ACS status.

Trial Registration

ClinicalTrials.gov Identifiers: NCT00114972, NCT00422968, NCT01496651, NCT01205776.

Venous External Support in Coronary Artery Bypass Surgery: A Systematic Review and Meta-Analysis

OBJECTIVES

Neointimal hyperplasia and lumen irregularities are major contributors to vein graft failure and the use of VEST^(R) should prevent this. In this review, we aim to evaluate the angiographic outcomes of externally supported vein grafts.

METHODS

Medline, Embase and Cochrane Library were systematically reviewed for randomized clinical trials published by August 2022. The primary outcome was graft failure. Secondary outcomes included graft ectasia, intimal hyperplasia area and thickness, and graft non-uniformity. Odds ratios (OR) for dichotomous variables and mean difference (MD) for continuous variables with 95% confidence intervals (CI) were pooled using a fixed-effects model.

RESULTS

Three randomized controlled trials with a total of 437 patients were included with follow-up ranging from 1 to 2 years. The odds of graft failure were similar in the two groups (OR 1.22; 95%CI 0.88 to 1.71; I²=0%). Intimal hyperplasia area [MD -0.77 mm²; 95%CI -1.10 to -0.45; I²=0%] and thickness [MD -0.06 mm; 95%CI -0.08 to -0.04; I²=0%] were significantly lower in the VEST group. Fitzgibbon Patency Scale of II or III (representing angiographic conduit non-uniformity; OR 0.67; 95%CI 0.48 to 0.94; I²=0%) and graft ectasia (OR 0.53; 95%CI 0.32 to 0.88; I²=33%) were also significantly lower in the VEST group.

CONCLUSIONS

At short-term follow-up, VEST does not seem to reduce the incidence of graft failure, although it is associated with attenuation of intimal hyperplasia and non-uniformity. Longer angiographic follow-up is warranted to determine whether these positive effects might translate into a positive effect in graft failure and in long-term clinical outcomes.

Coronary Anastomosis In Stent-Useful to Do When No Other Alternative Is Given?

Background  Many patients being referred for coronary artery bypass grafting have a history of percutaneous coronary intervention (PCI). Case Description  In a patient after multiple PCI of the left anterior descending artery (LAD), repeated in-stent stenosis was diagnosed. The LAD being covered with stents to the periphery, no meaningful anastomosis with stent-free vessel was possible. After thorough discussion with the patient, the referring cardiologist, and our local heart team, an in-stent anastomosis was planned and created, that was found to be angiographically patent 21 months after surgery with the patient free from angina. Conclusion  Without any alternative treatment method given, our approach of in-stent anastomosis confers a good mid-term angiographic result.

1-Year Patency of Biorestorative Polymeric Coronary Artery Bypass Grafts in an Ovine Model

Many attempts have been made to inhibit or counteract saphenous vein graft (SVG) failure modes; however, only external support for SVGs has gained momentum in clinical utility. This study revealed the feasibility of implantation, and showed good patency out to 12 months of the novel biorestorative graft, in a challenging ovine coronary artery bypass graft model. This finding could trigger the first-in-man trial of using the novel material instead of SVG. We believe that, eventually, this novel biorestorative bypass graft can be one of the options for coronary artery bypass graft patients who have difficulty harvesting SVG.

The Treatment of Coronary Artery Disease

BACKGROUND

The first coronary artery bypass operation (CABG) was performed on May 2, 1960. The first percutaneous coro - nary intervention (PCI) was performed almost 20 years later. Since then, the invasive treatment of coronary artery disease (CAD) has moved into the spotlight of cardiac medical care.

METHODS

We summarize the current status of medical and invasive CAD treatment through a selective review of the literature.

RESULTS

More than 800 000 patients currently undergo invasive diagnostic and therapeutic procedures for CAD in Germany each year. The number of coronary artery bypass grafting (CABG) procedures rose to 65 000/year by the turn of the millennium and has been declining since then. In contrast, the number of PCIs in Germany rose to approximately 350 000/year by 2017, and a beginning decline is being observed at present. This development occurred even though, for elective patients, a survival advantage from an invasive procedure compared to medical therapy has been shown in direct comparison only for CABG.

CONCLUSION

Conservative treatment is always the baseline treatment and has undergone major advances in the last few decades. Moreover, non-invasive coronary evaluation with computed tomography, as well as non-invasive cardiac stress imaging studies, are increasingly replacing primary invasive coronary evaluations. In this review, we illustrate a mechanistic concept of the appropriate use of CABG and PCI that can improve patient care, while underscoring the importance of interdisciplinary and intersectoral collaboration.

External Support for Saphenous Vein Grafts in Coronary Artery Bypass Surgery: A Randomized Clinical Trial

Importance

Intimal hyperplasia and subsequent saphenous vein graft failure may have significant adverse clinical effects in patients undergoing coronary artery bypass surgery. External support of saphenous vein grafts has the potential to prevent vein graft dilation and hence slow the rate of intimal hyperplasia and increase long-term vein patency.

Objective

To determine efficacy, as measured by intimal hyperplasia, and safety of an external saphenous vein graft support device in patients undergoing a coronary bypass graft procedure.

Design, Setting, and Participants

This within-patient randomized, open-label, multicenter study was conducted at 17 Cardiothoracic Surgical Trials Network centers in North America. Between January 2018 and February 2019, 224 patients with multivessel coronary artery disease undergoing isolated bypass surgery were enrolled. For each patient, 1 of 2 vein grafts was randomized to receive external support or no support.

Interventions

External vein graft support or no support.

Main Outcomes and Measures

The primary efficacy end point was intimal hyperplasia area assessed by intravascular ultrasound at 12 months postrandomization for each study graft. Secondary confirmatory end points were lumen diameter uniformity assessed by angiography and graft failure (≥50% stenosis) by quantitative coronary angiography. Major cardiac and cerebrovascular events were collected through month 12.

Results

Among 224 patients (mean [SD] age, 65.8 [8.3] years; 178 [79.5%] male), 203 (90.6%) were eligible for intravascular ultrasound, of which 85 (41.9%) had at least 1 study graft occluded or severely diseased at 12 months (55 supported, 56 unsupported). After imputation of data missing because of graft occlusion or severe disease, the estimated mean (SE) intimal hyperplasia area was 5.11 (0.16) mm2 in supported grafts and 5.79 (0.20) mm2 in unsupported grafts (P = .07). In a sensitivity analysis of 113 patients with both grafts imaged, the mean intimal hyperplasia area was 4.58 (0.18) mm2 and 5.12 (0.23) mm2 in supported and unsupported grafts, respectively (P = .04). By 12 months, 5 patients (2.2%) died and 16 patients (7.1%) experienced a major cardiac or cerebrovascular event.

Conclusions and Relevance

The 12-month difference in intimal hyperplasia area between supported and unsupported grafts did not achieve statistical significance. Cumulative mortality and major cardiac or cerebrovascular events rates were similar to those in other randomized coronary artery bypass trials. Further investigation to assess the effect of external graft support devices on long-term graft patency and clinical outcomes is warranted.

Trial Registration

ClinicalTrials.gov Identifier: NCT03209609.

Total arterial coronary artery bypass grafting in patients with preoperative anemia

OBJECTIVES

Blood transfusions after coronary artery bypass grafting (CABG) has been associated to adverse outcomes, especially in anemic patients. However, little is known about the influence of the modality of revascularization. Total arterial revascularization (TAR) was shown to reduce postoperative transfusion when compared to saphenous vein-based (SV)-CABG (LIMA plus one/more SV grafts). We, therefore, aimed to investigate the impact of TAR-CABG versus SV-CABG on blood products use and perioperative outcomes in patients with preoperative anemia, normally at higher risk for postoperative transfusions.

METHODS

From a cohort of 936 patients with mild preoperative anemia undergoing primary elective on-pump CABG, 166 matched pairs of patients undergoing either TAR- or SV-CABG were obtained. Anemia was defined as hemoglobin level <13 g/dl for men and <12 g/dl for women. The primary endpoint was the evaluation of red packed cells (RPC) use over the entire hospital stay.

RESULTS

TAR patients showed significantly reduced RPC usage compared with SV (mean difference 0.45 units). TAR patients had a reduced intubation time (mean difference 7.6 h) and were discharged 1.24 days earlier than SV patients. Pneumonia and acute kidney injury were doubled among SV patients. Adjusted regression showed that TAR technique is a predictor of reduced RPC unit use regardless of age and EuroSCORE II (odds ratio: 0.63, p < .01).

CONCLUSION

Patients with preoperative anemia might benefit from TAR regardless of age or calculated operative risk. TAR-CABG was associated to reduced postoperative use of blood products and postoperative length of stay in comparison with SV-CABG in this subset of patients.

Editor-in-Chief's Top Picks From 2021

Each week, I record audio summaries for every paper in JACC, as well as an issue summary. This process has become a true labor of love due to the time they require, but I am motivated by the sheer number of listeners (16M+), and it has allowed me to familiarize myself with every paper that we publish. Thus, I have selected the top 100 papers (both Original Investigations and Review Articles) from distinct specialties each year. In addition to my personal choices, I have included papers that have been the most accessed or downloaded on our websites, as well as those selected by the JACC Editorial Board members. In order to present the full breadth of this important research in a consumable fashion, we will present these abstracts in this issue of JACC, as well as their Central Illustrations and podcasts. The highlights comprise the following sections: Artificial Intelligence & Machine Learning (NEW section), Basic & Translational Research, Biomarkers (NEW section), Cardiac Failure & Myocarditis, Cardiomyopathies & Genetics, Cardio-Oncology, Cardiovascular Disease in Women, Coronary Disease & Interventions, Congenital Heart Disease, Coronavirus, Hypertension, Imaging, Metabolic & Lipid Disorders, Neurovascular Disease & Dementia, Promoting Health & Prevention, Rhythm Disorders & Thromboembolism, Vascular Medicine, and Valvular Heart Disease.^1-100.

Percutaneous coronary intervention with drug-eluting stents versus coronary artery bypass grafting in left main coronary artery disease: an individual patient data meta-analysis

BACKGROUND

The optimal revascularisation strategy for patients with left main coronary artery disease is uncertain. We therefore aimed to evaluate long-term outcomes for patients treated with percutaneous coronary intervention (PCI) with drug-eluting stents versus coronary artery bypass grafting (CABG).

METHODS

In this individual patient data meta-analysis, we searched MEDLINE, Embase, and the Cochrane database using the search terms "left main", "percutaneous coronary intervention" or "stent", and "coronary artery bypass graft*" to identify randomised controlled trials (RCTs) published in English between database inception and Aug 31, 2021, comparing PCI with drug-eluting stents with CABG in patients with left main coronary artery disease that had at least 5 years of patient follow-up for all-cause mortality. Two authors (MSS and BAB) identified studies meeting the criteria. The primary endpoint was 5-year all-cause mortality. Secondary endpoints were cardiovascular death, spontaneous myocardial infarction, procedural myocardial infarction, stroke, and repeat revascularisation. We used a one-stage approach; event rates were calculated by use of the Kaplan-Meier method and treatment group comparisons were made by use of a Cox frailty model, with trial as a random effect. In Bayesian analyses, the probabilities of absolute risk differences in the primary endpoint between PCI and CABG being more than 0·0%, and at least 1·0%, 2·5%, or 5·0%, were calculated.

FINDINGS

Our literature search yielded 1599 results, of which four RCTs-SYNTAX, PRECOMBAT, NOBLE, and EXCEL-meeting our inclusion criteria were included in our meta-analysis. 4394 patients, with a median SYNTAX score of 25·0 (IQR 18·0-31·0), were randomly assigned to PCI (n=2197) or CABG (n=2197). The Kaplan-Meier estimate of 5-year all-cause death was 11·2% (95% CI 9·9-12·6) with PCI and 10·2% (9·0-11·6) with CABG (hazard ratio 1·10, 95% CI 0·91-1·32; p=0·33), resulting in a non-statistically significant absolute risk difference of 0·9% (95% CI -0·9 to 2·8). In Bayesian analyses, there was an 85·7% probability that death at 5 years was greater with PCI than with CABG; this difference was more likely than not less than 1·0% (<0·2% per year). The numerical difference in mortality was comprised more of non-cardiovascular than cardiovascular death. Spontaneous myocardial infarction (6·2%, 95% CI 5·2-7·3 vs 2·6%, 2·0-3·4; hazard ratio [HR] 2·35, 95% CI 1·71-3·23; p<0·0001) and repeat revascularisation (18·3%, 16·7-20·0 vs 10·7%, 9·4-12·1; HR 1·78, 1·51-2·10; p<0·0001) were more common with PCI than with CABG. Differences in procedural myocardial infarction between strategies depended on the definition used. Overall, there was no difference in the risk of stroke between PCI (2·7%, 2·0-3·5) and CABG (3·1%, 2·4-3·9; HR 0·84, 0·59-1·21; p=0·36), but the risk was lower with PCI in the first year after randomisation (HR 0·37, 0·19-0·69).

INTERPRETATION

Among patients with left main coronary artery disease and, largely, low or intermediate coronary anatomical complexity, there was no statistically significant difference in 5-year all-cause death between PCI and CABG, although a Bayesian approach suggested a difference probably exists (more likely than not <0·2% per year) favouring CABG. There were trade-offs in terms of the risk of myocardial infarction, stroke, and revascularisation. A heart team approach to communicate expected outcome differences might be useful to assist patients in reaching a treatment decision.

FUNDING

No external funding.