Coronary endarterectomy: The current state of knowledge

New strategy of using double-network hydrogel extravascular stent for preventing venous graft restenosis after coronary artery bypass grafting

OBJECTIVE

Effective therapies for the prevention of vein graft failure, which frequently occurs in coronary artery bypass grafting (CABG) due to intimal hyperplasia (IH), are still lacking. Here, we investigated the effects of the perivenous application of double-network hydrogel on vein grafts in carotid artery bypass grafting in a rabbit model.

METHODS

Healthy New Zealand white rabbits were randomized into the following groups: no graft, graft, or graft + Double-network hydrogel external stent (DNHES). The rabbits' carotid artery was bypassed via the jugular vein. Double-network hydrogel external stent was wrapped around the jugular graft after the anastomoses were completed. Blood flow parameters and tissue histology of the vein grafts were evaluated.

RESULTS

Compared with the untreated vein grafts at 12 weeks after the surgery, the DNHES significantly improved graft flow, attenuated intimal and medial thickening, reduced the anti-proliferating cell nuclear antigen proliferation index of the vein grafts, decreased the mRNA and protein expression of Mitogen-Activated Protein Kinase (MAPK) and Transforming Growth Factor-β (TGF-β), and increased the mRNA and protein expression of endothelial Nitric Oxide Synthase (eNOS).

CONCLUSION

The perivenous application of DNHES exerts beneficial effects on vein grafts, reduces the inflammatory response in carotid artery bypass grafting in a rabbit model, and appears to be a safe and promising strategy to prevent vein graft failure.

Coronary plaque burden predicts perioperative cardiovascular events after coronary endarterectomy

Background and aims

The risk factors of perioperative and long-term cardiovascular events in patients undergoing coronary artery bypass grafting (CABG) with adjunctive coronary endarterectomy (CE) are not well determined. This study evaluated the clinical value of coronary plaque burden, coronary anatomic stenosis, and serum biomarkers for predicting perioperative cardiovascular events after off-pump CABG + CE.

Methods

This retrospective cohort single-center study enrolled 125 patients undergoing off-pump CABG + CE between February 2018 and September 2021 in China. Coronary plaque burden was reflected by the length of plaque removed by CE. Plaque length-max, which represents the plaque length in patients undergoing single-vessel CE and the maximum plaque length in patients undergoing multivessel CE, was calculated. The primary endpoint was perioperative myocardial infraction (PMI).

Results

Plaque length-max was significantly higher in patients with PMI than in those without PMI (2.4 ± 1.5 vs. 1.6 ± 0.9, p = .001). A threshold plaque length-max of 1.15 cm was an independent predictor of PMI (area under the curve: 0.67; sensitivity 87.9%; specificity 59.8%; p = .005). Patients with plaque length-max ≥1.15 had a > 5-fold increase in PMI after adjusting for confounding factors (odds ratio = 5.89; p = .002). Furthermore, interleukin-6 (Beta = .32: p = .028), CD68 (Beta = .34; p = .045), and osteopontin (Beta = .43; p = .008) were significantly correlated with plaque length-max.

Conclusions

Plaque length-max was superior to clinical cardiovascular risk factors in predicting PMI occurrence after off-pump CABG + CE, which might be associated with systemic and plaque inflammation state.

Noncoding RNAs in Vascular Cell Biology and Restenosis

In-stent restenosis (ISR), characterised by ≥50% re-narrowing of the target vessel, is a common complication following stent implantation and remains a significant challenge to the long-term success of angioplasty procedures. Considering the global burden of cardiovascular diseases, improving angioplasty patient outcomes remains a key priority. Noncoding RNAs (ncRNAs) including microRNA (miRNA), long noncoding RNA (lncRNA) and circular RNA (circRNA) have been extensively implicated in vascular cell biology and ISR through multiple, both distinct and overlapping, mechanisms. Vascular smooth muscle cells, endothelial cells and macrophages constitute the main cell types involved in the multifactorial pathophysiology of ISR. The identification of critical regulators exemplified by ncRNAs in all these cell types and processes makes them an exciting therapeutic target in the field of restenosis. In this review, we will comprehensively explore the potential functions and underlying molecular mechanisms of ncRNAs in vascular cell biology in the context of restenosis, with an in-depth focus on vascular cell dysfunction during restenosis development and progression. We will also discuss the diagnostic biomarker and therapeutic target potential of ncRNAs in ISR. Finally, we will discuss the current shortcomings, challenges, and perspectives toward the clinical application of ncRNAs.

Coronary endarterectomy in patients with diffuse coronary artery disease: assessment of graft patency with computed tomography angiography

Background:

With a growing population of patients with advanced coronary artery disease (CAD), many of whom have undergone prior percutaneous coronary interventions, coronary endarterectomy (CE) allows for the extension of revascularization in patients with otherwise limited options. Whether adjunctive CE associated with standard surgery, combined with contemporary antiplatelet therapy, improves outcomes remains largely unknown.

Methods:

We studied 147 consecutive patients who underwent 154 adjunctive CE procedures for advanced CAD between January 2015 and January 2018. We used computed tomography angiography (CTA) in a subgroup of 32 consecutive patients who underwent CE during coronary artery bypass grafting after June 2016 to assess graft and coronary patency.

Results:

Patients (mean age 67 ± SD 10 yr) underwent CE of the right (102 patients), the left anterior descending (LAD, 22 patients) and the circumflex (17 patients) coronary arteries. Seven patients (5%) experienced a procedural myocardial infarction and there were no perioperative deaths. Among the 32 patients who underwent CTA 3 months after surgery, the mean patency of the endarterectomized coronary arteries and bypass grafts was 90% and 88%, respectively. All 6 arterial grafts on the LAD artery were patent. The mean survival rate and the mean rate of freedom from major adverse cardiovascular events was 95% ± 2% and 95% ± 6%, respectively. The patency rate was 100 % for patients evaluated at 3-year follow up.

Conclusion:

Coronary endarterectomy offers a surgical option for patients with diffuse CAD who may be unsuitable for coronary bypass alone. Grafts and endarterectomized coronary artery patency remain adequate and explain the excellent patient survival and the freedom rate from major adverse cardiovascular events.

Distal anastomosis support for bypass grafting with coronary endarterectomy for the severe diseased posterior descending artery

BACKGROUND

The posterior descending artery is the most common vessel chosen for an endarterectomy, while endarterectomy to the posterior descending artery is associated with decreased graft patency. The purpose of this study was to describe a distal anastomosis support (DAS) technique and retrospectively investigate the effect of DAS on the mid-term graft patency.

METHODS

Between January 2016 and December 2018, 200 patients with a PDA severe lesion who underwent off-pump coronary artery bypass (OPCAB) with CE (OPCAB + CE group, n = 95) and OPCAB + CE with DAS for anastomosis of PDA grafted by saphenous vein (SVG) (OPCAB + CE + DAS group, n = 105) were evaluated retrospectively. All patients came back to follow-up visit 6th, 12th, 24th, and 36th postoperative month. The primary endpoint is the graft failure (FitzGibbon B or O) of SVG-PDA on the follow-up CTA or CAG.

RESULTS

There was no significant difference in perioperative outcomes. We found significantly improved cumulative graft patency in OPCAB + CE + DAS group at 36 months after operation (84.6% vs 76.5%, p = 0.02). In multivariate Cox regression analysis, plaque length larger than 2 cm (hazard ratio [HR], 13.108, 95% confidence interval [CI], 2.842-60.457, p = 0.001), and peak TNI ⩾70× ULN within 48 hours of surgery (HR, 3.778, 95% CI, 1.453-9.823, p = 0.006) were independent predictors of graft failure, whereas PDA diameter greater than 1.5 mm (HR, 0.231, 95% CI, 0.081-0.654, p = 0.006), and DAS use (HR, 0.336, 95% CI, 0.139-0.812, p = 0.015) were significant protective factors.

CONCLUSIONS

Concomitant DAS conferred superior mid-term patency of SVG-PDA. Adding the DAS procedure to OPCAB + CE may be a promising surgical option for patients with a PDA severe lesion, especially when PDA diameter less than 1.5 mm and plaque length greater than 2 cm.

Coronary Endarterectomy: a Case Control Study and Evaluation of Early Patency Rate of Endarterectomized Arteries

OBJECTIVE

To compare two groups of patients - the coronary endarterectomy group, with patients undergoing coronary artery bypass grafting (CABG) with coronary endarterectomy (CE), and the control group, with patients undergoing CABG without CE. We analyzed the rate of major outcomes (perioperative acute myocardial infarction [AMI], stroke, and mortality) and minor outcomes (time of cardiopulmonary bypass [CPB], time of aortic clamp, and postoperative length of hospital stay). We also determined the rates of early graft patency in patients undergoing CE.

METHODS

We reviewed a database of patients submitted to CABG, with or without associated CE, between January 2011 and June 2017. Twenty-five patients submitted to CE were compared with 201 patients submitted only to conventional surgery; the two groups presented similar preoperative characteristics and all the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II variables did not presented statistically significant difference. We considered statistically significant values of P< 0.05.

RESULTS

There was no statistically significant difference in relation to time of post-surgical hospitalization (P=0.8139), incidence of perioperative AMI (P=0.2976), stroke (P=0,2976), and mortality rate (P=1.0000), but endarterectomy was associated with longer aortic clamping time (P=0.0004) and CPB time (P=0.0030). The rate of patency evaluated in patients submitted to endarterectomy (78,95%) was compatible with that described in the literature.

CONCLUSION

In this sample, coronary endarterectomy was associated with the rate of early graft patency similar to that of the literature, with morbidity and mortality rates similar to those of conventional surgery.

Coronary endarterectomy: an old tool for patients currently operated on with coronary artery bypass grafting. Long-term results, risk factor analysis

Aim

Coronary endarterectomy (CE) may provide a useful adjunctive technique to coronary artery bypass grafting (CABG) in patients with diffuse coronary artery disease. Nevertheless, the incidence of complications still remains high, long-term results remain unclear, and no risk factors for late mortality have been completely described yet.

Material and methods

We retrospectively reviewed 90 consecutive patients (67 ±8.2 years) undergoing isolated CABG in association with CE between 2006 and 2013. Mean follow-up was 75.1 ±36.2 months (median: 84 months) and it was 100% complete (6755/6755 patient-months).

Results

Operative mortality was 4.4%, the incidence of perioperative myocardial infarction was 11%. Ten-year survival was 83.3 ±4.1%, freedom from cardiac death 92.7 ±2.9%, and freedom from major adverse cardiac and cerebrovascular events 58.2 ±10.2%. Independent predictors of late mortality were age older than 70 years at time of the surgery (p = 0.018) and chronic obstructive pulmonary disease (p = 0.036). Ten-year freedom from cardiac death was better after CE on the left descending coronary artery (LAD) (93.2 ±3.3%) in comparison to CE not on the LAD (74.6 ±10.2%), although this difference did not reach statistical significance (p = 0.102).

Conclusions

Although the incidence of perioperative myocardial infarction continues to be not negligible, in the presence of diffusely diseased coronary artery vessels CE associated with CABG appears to be a feasible adjunctive surgical tool, conferring satisfactory early and long-term outcomes. Coronary endarterectomy on the LAD confers a high probability of freedom from late cardiac death. Patients older than 70 years and those affected by a primary respiratory disease represent a new challenge on which to focus attention due to the increased risk of late death.

Frequency of Coronary Endarterectomy in Patients Undergoing Coronary Artery Bypass Grafting at a Single Tertiary Texas Hospital 2010 to 2016 With Morphologic Studies of the Operatively Excised Specimens

This study examines the frequency of coronary endarterectomy (CE) procedures during coronary artery bypass grafting (CABG), and determines the quantity of plaque in the specimens. Of the 2,268 CABG operations performed from January 2010 to June 2016, 35 patients had CE during CABG. The specimens were incised into 5-mm cross sections, stained by the Movat method, and examined. The number of CEs performed ranged from 0.21% to 4.01%. A total of 140 cm of specimens were examined, and all 140 cm contained considerable quantities of atherosclerotic plaque and narrowed lumens. The quantity of plaque present was similar to or greater than that observed in previously studied patients with fatal coronary artery disease. The frequency of CE during CABG varies greatly in surgeons. The quantity of plaque is enormous, and the lumens are severely narrowed.