Internal Mammary Artery Graft Research Articles

Obscure Rare Cause of Recurrent Angina in Post CABG Patient: Coronary-Subclavian Steal Syndrome

Coronary subclavian steal syndrome (CSSS) is a rare and unrecognized complication of coronary bypass grafting surgery when a left internal mammary artery (LIMA) graft is utilized for left anterior descending (LAD) artery revascularization without knowing left subclavian artery status. We describe a case of a 67-year-old male, with a known history of triple vessel coronary artery disease (CAD) managed with CABGx3 in March 2003. The patient presented after 16 years with complaints of recurrent angina for the past 15 years which aggravates on exertion, especially of left hand. Recurrent hospitalizations and repeated Coronary angiograms (CAG) as well as CT Coronary angiography failed to diagnose the cause of angina. Subclavian angiography and subsequent methodical clinical examination during the present admission revealed left subclavian origin stenosis which was successfully revascularized by deployment of a stent resulting in convincing relief in the patient’s angina.

Outcomes of Single versus Sequential Vein Grafts in Isolated Coronary Artery Bypass Surgery: Insights from a Large Tertiary Care Center

BackgroundSaphenous venous grafts (SVG) remain the most widely used conduits in coronary artery bypass graft surgery (CABG). Data comparing outcomes of single saphenous venous grafting (SinCABG) versus sequential venous grafting (SeqCABG), however, are limited. MethodsBetween 2002 and 2012, 2,375 patients with 3-vessel coronary artery disease underwent isolated elective CABG at the Leipzig Heart Center with a left internal mammary artery graft to left anterior descending artery and ≥2 distal SVG anastomoses. Of these, 1,278 received ≥2 singular saphenous venous grafts (SinCABG) and 563 received ≥1 sequential saphenous vein grafts with >1 distal anastomoses (SeqCABG). The primary end point was long term survival. Secondary outcomes included short-term survival, early postoperative outcomes as well as early and late graft patency. ResultsAt 30-days, mortality was 1.3% following SinCABG as compared to 2.3% after SeqCABG (p=0.13). The postoperative complications rate did not differ between groups. Early postoperative coronary angiographies were performed in 127 patients (7%), while clinically indicated follow-up coronary angiographies were performed in 372 patients (20%) over a median follow up of 5 years (IQR 1.7-8.9). No differences in early or late patency rates were found between both grafting techniques (p=0.79 and p=0.39, respectively). The median duration of long-term clinical follow-up was 8.4 years (IQR 5.6-11.4). Long-term survival rates at 1, 5, 10 and 15 years in SinCABG versus SeqCABG were 95% versus 94%, 83% versus 82%, 63% versus 62%, and 47% versus 41%, respectively (p=0.22). ConclusionsShort and long-term mortality as well as early and late graft patency rates did not differ in patients undergoing SinCABG as compared to patients undergoing SeqCABG.

Robot-Assisted Minimally Invasive Coronary Artery Bypass Grafting: Total Arterial Revascularization Using the Double-Docking Technique.

The right internal mammary artery is considered to be the second choice for arterial conduits for coronary artery bypass grafting (CABG). However, the widespread use of bilateral internal mammary artery (BIMA) grafting is limited owing to increased technical demands, lengthy procedure, and high incidence of sternal wound complications. We compared the early clinical outcomes of a novel robot-assisted double-docking technique (DDT) with an open sternotomy technique for total arterial revascularization using BIMA. Between June 2019 and June 2023, 445 patients with multivessel coronary artery disease underwent open sternotomy CABG using BIMA grafting and 145 patients underwent robot-assisted BIMA grafting using DDT. Comparative analysis of 104 pairs of matched patients obtained using propensity score matching was performed. Procedural characteristics, postoperative 30-day mortality, and composite outcome (major adverse cardiac and cerebrovascular events) at a median follow-up of 1.5 years were evaluated. Preprocedural characteristics were well balanced between the groups after propensity matching. The number of distal anastomoses performed in the conventional group was statistically higher than that performed using DDT (P < 0.001). The durations of postsurgical ventilation, intensive care unit stay, and in-hospital stay were significantly lower with the DDT than with conventional CABG (P < 0.001). There was no significant difference in all-cause mortality or major adverse cardiac events between the DDT and conventional CABG groups at a median follow-up of 1.5 years. The DDT is feasible and efficacious for revascularization of multiple coronary targets in select individuals. It is equivalent to open sternotomy in terms of early clinical outcomes and superior to open sternotomy with regard to rates of sternal infection and intensive care unit and in-hospital stay.

Spontaneous avulsion of left internal mammary artery graft a complication of coronary artery bypass surgery: case report and review of the literature

BackgroundCoronary artery bypass grafting (CABG) surgery is a common procedure for managing multi-vessel coronary artery disease to revascularize the myocardium. Among the various conduits used, the left internal mammary artery (LIMA) is preferred due to its better long-term patency rate. However, CABG procedures involving LIMA may result in rare but serious complications, such as avulsion of the LIMA post-CABG, which leads to disruption of blood flow to the myocardium and the development of fatal cardiac tamponade.Case presentationWe hereby present a unique case of spontaneous avulsion of a LIMA graft to the left anterior descending artery (LAD) away from the site of anastomosis, twenty-four hours following CABG surgery in a 67-year-old male patient. Emergency re-exploration and repair of the LIMA with interposition vein graft were performed and resulted in successful stabilization of the patient’s critical condition. However, this was followed by a complicated recovery period involving atrial fibrillation, acute kidney injury, and wound infection.ConclusionAvulsion of LIMA graft following CABG is rare, yet a fatal complication that requires high clinical suspicion and prompt management. Avulsion has been reported a few times in literature following both minimal invasive and conventional CABG. Understanding the etiology, clinical presentation, and management of this complication is crucial to avoid catastrophic outcomes.

Unlocking vascular vitality: Exploring the impact of LIMA harvesting technique on endothelial health

BackgroundThis study investigates the impact of different harvesting techniques on the morphology and endothelial function of the left internal mammary artery (LIMA) grafts in coronary artery bypass grafting (CABG). MethodsFifty-three patients undergoing elective CABG were randomly assigned to two groups based on the harvesting technique: traditional clipping and nonclipping. Histological analyses revealed that arteries in the nonclipped group exhibited greater dilation and preserved endothelial integrity compared to the control group. ResultsThe nonclipped group exhibited greater arterial dilation and preserved endothelial integrity compared to the clipped group. Immunostaining for endothelial nitric oxide synthase (eNOS) showed significantly higher expression in the nonclipped group, conversly COX-2 staining showed fewer expression in the nonclipped group indicating better endothelial function preservation. ConclusionThese findings suggest that maintaining perfusion during LIMA harvesting may improve endothelial function and potentially enhance graft patency in the long term. Further research is warranted to validate these results and optimize harvesting techniques for CABG procedures.

Unraveling the Mystery: How High Density Lipoprotein ‘Good’ Cholesterol Goes ‘Bad’?

Background: In recent years, research has highlighted the importance of Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in the progression of atherosclerosis, particularly its interaction with high-density lipoprotein (HDL). Our study aimed to explore the role of dysfunctional High-Density Lipoprotein (HDL) in binding to Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) among patients with Coronary Artery Disease (CAD) and its implications for the advancement of atherosclerosis. Methods: We enrolled twenty-one patients who underwent multivessel CABG using internal mammary artery (IMA), radial artery (RA), and saphenous vein (SV) grafts between November 2019 and April 2020. Using CD31 to identify endothelial cells, we evaluated LOX-1 expression in all cultured cells. Results: Our study comprised 21 patients, including 17 (80.9%) males and 4 (19.04%) females. We observed a significant positive correlation between HDL and LOX-1+ expression in specimens extracted from all types of grafts (SV, r=0.60; RA, r=0.48; IMA, r=0.53). Approximately 28% of the variation in LOX-1+ expression for IMA (F=7.03; p

A Single-Surgeon Experience Transitioning to Total Arterial Revascularization.

Background: Coronary artery bypass grafting remains the standard of care for advanced and multifocal coronary artery disease; however, for patients that are surgical candidates, total arterial revascularization (TAR) remains underutilized due to concerns such as sternal wound infections and the learning curve. We present the results of a large cohort of mid-career surgeons transitioning to TAR, focusing on short-term outcomes and the learning curve. Methods: The surgeons transitioned to using TAR as the preferred revascularization technique in August of 2017. The Society of Thoracic Surgeons database was reviewed to identify all patients who underwent isolated non-emergent CABG performed by a single surgeon from January 2014 through January 2022. Patients were divided into two groups-those who had TAR and those who had traditional CABG using one internal mammary artery and vein grafts (IMA-SVG). Results: Eight hundred ninety-eight patients meet inclusion criteria (458 IMA-SVG and 440 TAR). The TAR group had slightly longer cardiopulmonary bypass time, cross clamp times, and operative times (all p < 0.05); however, ICU stay was shorter and 30-day readmission rate was lower for TAR compared to IMA-SVG (all p < 0.05). The TAR group also required fewer postoperative transfusions (p = 0.005). There was no difference in prolonged intubation, stroke, length of stay, mortality, or sternal wound complications between groups (all p > 0.05). The average TAR was 30 min longer; however, learning curves, stratified by number of grafts placed, showed no significant learning curve associated with TAR. Conclusions: An experienced surgeon transitioning from IMA-SVG to TAR slightly increases operative time, but decreases ICU stay, readmissions, and postoperative transfusions with no significant difference in rates of immediate post-operative complications or 30-day mortality, with a minimal learning curve.

Coronary angiography was used to assess the effect of diabetes on off-pump coronary artery bypass graft patency.

This study aimed to examine the influence of diabetes on the left internal mammary artery (LIMA) and saphenous vein (SV) graft failure for 5-year follow-up. We enrolled 202 patients who underwent isolated off-pump coronary artery bypass grafting (CABG) surgery in 2014, angiographic follow-up occurred at 5 years after surgery. Angiographic outcomes in patients with or without diabetes were analyzed. Multivariate logistic regression analysis was used to identify independent predictors of graft dysfunction. A total of 66 (32.7%) patients had diabetes. Five-year rates of LIMA and SV graft failure were similar in patients with and without diabetes. In addition, in diabetics, the proportion of complete graft failure was significantly lower in the LIMA grafts (12/66, 18.2%) than in the SV grafts (57/133, 42.9%) (P = .001). In nondiabetic, the proportion of complete graft failure was also significantly lower in the LIMA grafts (28/136, 20.6%) than in the SV grafts (105/275, 38.2%) (P < .001). Multivariate logistic regression analysis showed that mean graft flow (MGF) was an independent predictor factor for LIMA (odds ratio = 1.186, 95% CI = 1.114-1.263, P < .001) and SV (odds ratio = 1.056, 95% CI = 1.035-1.077, P < .001) graft failure. Diabetes did not influence the patency of LIMA or SV grafts over a 5-year follow-up. LIMA grafts should be maximized in patients undergoing off-pump CABG surgery. Diabetes does not affect the patency of grafts CABG. Using angiography, our study proved that diabetes does not affect the patency of grafted vessels after CABG for 5 years.

Hybrid coronary revascularization: position paper of the European Society of Cardiology Working Group on Cardiovascular Surgery and European Association of Percutaneous Cardiovascular Interventions.

Myocardial revascularization in coronary artery disease via percutaneous coronary intervention or coronary artery bypass graft (CABG) surgery effectively relieves symptoms, significantly improves prognosis and quality of life when combined with guideline-directed medical therapy. Hybrid coronary revascularization is a promising alternative to percutaneous coronary intervention or CABG in selected patients and is defined as a planned and/or intended combination of consecutive CABG surgery using at least 1 internal mammary artery to the left anterior descending (LAD), and catheter-based coronary intervention to the non-LAD vessels for the treatment of multivessel disease. The main indications for hybrid coronary revascularization are (i) to achieve complete revascularization in patients who cannot undergo conventional CABG, (ii) to treat patients with acute coronary syndromes and multivessel disease with a non-LAD vessel as the culprit lesion that needs revascularization and (iii) in highly select patients with multivessel disease with complex LAD lesions and simple percutaneous coronary intervention targets for all other vessels. Hybrid coronary revascularization patients receive a left internal mammary artery graft to the LAD artery through a minimal incision along with percutaneous coronary intervention to the remaining diseased coronary vessels using latest generation drug-eluting stents. A collaborative environment with a dedicated heart team is the optimal platform to perform such interventions, which aim to improve the quality and outcome of myocardial revascularization. This position paper analyses the rationale of hybrid coronary revascularization and the currently available evidence on the various techniques and delves into the sequence of the interventions and pharmacological management during and after the procedure.

Comparative effectiveness of antiplatelet therapies for saphenous venous graft occlusion and cardiovascular outcomes: a network meta-analysis.

The ideal antiplatelet therapy to maintain graft patency after coronary artery bypass graft surgery (CABG) remains controversial. This review of randomized controlled trials (RCTs) aims to compare aspirin monotherapy, ticagrelor monotherapy, dual antiplatelet therapy (DAPT) with aspirin and ticagrelor (Asp+Tica) or with aspirin and clopidogrel (Asp+Clopi) to evaluate differences in post-CABG saphenous vein graft (SVG) occlusion, internal mammary artery (IMA) occlusion, myocardial infarction (MI), bleeding, and all-cause mortality (ACM) rates. The literature review was conducted on several electronic databases, including Medline, Embase, and Cochrane Central, from inception to August 10, 2022. Data was extracted using a predefined proforma. A Bayesian random-effects model was used for calculating point effect estimates (odds ratio and standard deviation). Quality assessment was done using the Cochrane RoB-2 tool. Ten RCTs comprising 2139 patients taking anti-platelets post-CABG were included. For preventing SVG occlusion, Asp+Tica showed the lowest mean AR of 0.144±0.068. Asp+Tica also showed a trend toward lesser postoperative MI risk and lower ACM rates, with a mean AR of 0.040±0.053 and 0.018±0.029, respectively. For maintaining IMA graft patency, Asp+Clopi showed the lowest mean AR of 0.092±0.053. Ticagrelor had the lowest mean AR of 0.049±0.075, with Asp+Tica showing a similar mean AR of 0.049±0.045 for postoperative major bleeding risk. Our analysis demonstrates that Asp+Tica can be the ideal therapy for patients undergoing CABG using SVG as it decreases the risk of post-CABG SVG occlusion and is not associated with a significantly higher risk for major bleeding.

Effect of Type-2 Diabetes Mellitus on the Expression and Function of Smooth Muscle ATP-Sensitive Potassium Channels in Human Internal Mammary Artery Grafts.

Here we have shown for the first time altered expression of the vascular smooth muscle (VSM) KATP channel subunits in segments of the human internal mammary artery (HIMA) in patients with type-2 diabetes mellitus (T2DM). Functional properties of vascular KATP channels in the presence of T2DM, and the interaction between its subunits and endogenous ligands known to relax this vessel, were tested using the potassium (K) channels opener, pinacidil. HIMA is the most commonly used vascular graft in cardiac surgery. Previously it was shown that pinacidil relaxes HIMA segments through interaction with KATP (SUR2B/Kir6.1) vascular channels, but it is unknown whether pinacidil sensitivity is changed in the presence of T2DM, considering diabetes-induced vascular complications commonly seen in patients undergoing coronary artery bypass graft surgery (CABG). KATP subunits were detected in HIMA segments using Western blot and immunohistochemistry analyses. An organ bath system was used to interrogate endothelium-independent vasorelaxation caused by pinacidil. In pharmacological experiments, pinacidil was able to relax HIMA from patients with T2DM, with sensitivity comparable to our previous results. All three KATP subunits (SUR2B, Kir6.1 and Kir6.2) were observed in HIMA from patients with and without T2DM. There were no differences in the expression of the SUR2B subunit. The expression of the Kir6.1 subunit was lower in HIMA from T2DM patients. In the same group, the expression of the Kir6.2 subunit was higher. Therefore, KATP channels might not be the only method of pinacidil-induced dilatation of T2DM HIMA. T2DM may decrease the level of Kir6.1, a dominant subunit in VSM of HIMA, altering the interaction between pinacidil and those channels.

Predominant Use of Bilateral Internal Mammary Arteries in Off-Pump Coronary Artery Bypass Surgery

Bilateral internal mammary artery (BIMA) in coronary artery bypass grafting (CABG) has been shown to provide long-term clinical benefits over single internal mammary artery (SIMA) grafting. Nevertheless, the perceived technical complexity of the procedure and concerns about potential early postoperative complications, particularly sternal wound infections have led to a utilization rate of BIMA grafting of less than 5% in the United States. We systematically compared early (30-day) post-operative outcomes between the BIMA and SIMA cohorts in patients with similar baseline characteristics. A retrospective single center study was conducted on matched patients, using stabilized inverse probability treatment weighting to mitigate bias between the two study cohorts. From 546 off-pump CABG patients initially identified, we examined 328 BIMA and 213 SIMA grafts from the matched samples. Despite utilizing 60.4% BIMA grafts, we observed similar rates of 30-day overall and cardiac mortality between the BIMA and SIMA groups. Rates of 30-day postoperative complications, including superficial and deep sternal wound infections, stroke, sepsis, acute kidney injury, and cardiac arrest, were similar between the two groups. Rates of 30-day overall and cardiac readmission were also similar. Additionally, median length of hospital stays, intensive care unit stay, and ventilation times were similar between the two groups. In conclusion, our data suggest that a BIMA utilization rate of 60.4% in off-pump CABG procedure is achievable without causing any significant increment in early post-operative complications, including deep sternal wound infection.

Preoperative Quantitative Flow Ratio, Intraoperative Transit Time Flow Measurement Parameters, and Their Predictive Value for Short-Term Graft Failure After Coronary Artery Bypass Grafting.

Studies on the relationship between the preoperative quantitative flow ratio (QFR) and parameters of intraoperative transit time flow measurement (TTFM) are extremely rare. In addition, the predictive value of QFR and TTFM parameters for early internal mammary artery (IMA) failure after coronary artery bypass grafting still needs to be validated.Methods and Results: We retrospectively collected data from 510 patients who underwent in situ IMA grafting to the left anterior descending (LAD) artery at Fuwai Hospital. Spearman correlation coefficients between preoperative QFR of the LAD artery and intraoperative TTFM parameters of the IMA were -0.13 (P=0.004) for mean graft flow (Qm) and 0.14 (P=0.002) for the pulsatility index (PI). QFR and TTFM exhibited similar and good predictive value for early IMA failure (5.7% at 1 year), and they were better than percentage diameter stenosis (area under the curve 0.749 for QFR, 0.733 for Qm, 0.688 for PI, and 0.524 for percentage diameter stenosis). The optimal cut-off value of QFR was 0.765. Both univariate and multivariable regression analyses revealed that QFR >0.765, Qm ≤15 mL/min, and PI >3.0 independently contributed to early IMA failure. There were statistically significant correlations between preoperative QFR of the LAD artery and intraoperative TTFM parameters (Qm, PI) of the IMA. Preoperative QFR and intraoperative Qm and PI exhibited excellent predictive value for early IMA failure.

Male-female differences following concomitant coronary artery bypass grafting and aortic valve replacement surgery.

Combined coronary artery bypass grafting (CABG) and aortic valve replacement (AVR), and female sex are associated with increased perioperative mortality in clinical risk scores. This study investigated male-female differences in short-term outcome stratified by age groups. All patients undergoing AVR and CABG between January 2001 and June 2021 at our institution were included. 1963 patients were grouped by decades into: 59years and younger (n=127), 60-69 (n=471), 70-79 (n=1070), and 80years and older (n=295). The primary end points of this study were 30 and 180days mortality. Secondary end points were influence of preoperative risk factors and impact of sex on survival and postoperative major adverse events. Female patients showed higher 30 and 180days mortality after combined CABG and AVR surgery (8.3% vs. 4.2%, P<0.01; 15.8% vs. 9.4%, P<0.01). Stratified by age groups, 30 and 180days mortality remained significantly higher in septuagenarians (9.6% vs. 2.5%, P<0.01; 16.3% vs. 7.7%, P<0.01). Females were significantly older, had better preserved left ventricular function, and higher incidence of diabetes mellitus compared with male patients in this subgroup (P<0.01; P=0.01; P<0.01). Additionally, females received significantly less internal mammary artery (IMA) conduits (P<0.01). Female sex (OR: 3.33, 95% CI: [1.76-6.31]; 1.93, [1.22-3.06]), higher age (1.28, [1.13-1.45]; 1.16, [1.06-1.26]), diabetes mellitus (1.93, [1.03-3.60]; 1.70, [1.08-2.67]) and LVEF <30% (3.26, [1.48-7.17]; 2.23, [1.24-4.02]) were correlated with 30 and 180days mortality, respectively. Upon multivariable testing, sex (1.77, [1.21-2.58]) and LVEF <30% (3.71, [2.39-5.76]) remained independent predictors for major adverse postoperative events. Infrequent use of IMA grafts was associated with increased 30 and 180days mortality as well as adverse events (0.47, [0.25-0.87]; 0.46, [0.29-0.72]; 0.61, [0.42-0.88]). Sex disparities in baseline characteristics may delay operative intervention in female patients. The inherent risk profiles might be responsible for outcome differences in septuagenarians.

Pre-Coronary Artery Bypass Grafting Computed Tomography-Based Fractional Flow Reserve Predicts Graft Failure: Implications for Planning Invasive Treatment of Coronary Artery Disease.

The aim of the study is to evaluate whether a pre-coronary artery bypass grafting (CABG) coronary computed tomography-based fractional flow reserve (FFR-CT) result at the site of a future anastomosis would predict the graft failure in patients undergoing CABG. In 43 patients who had coronary computed tomography angiography (CCTA) prior to the CABG, follow-up CCTA were acquired >12 months post-CABG procedure. The FFR-CT values were simulated on the basis of the pre-CABG CCTA. Based on follow-up CCTA, the anastomosis sites and the graft patency were determined. The graft failure was defined as either its stenosis >50% or occlusion. Ninety eight (44 saphenous, 54 left or right internal mammary artery) grafts were assessed. Eighteen grafts from 16 patients were dysfunctional on follow-up CCTA. The FFR-CT values at the location of future anastomosis were higher in dysfunctional than in normal grafts (0.77 [0.71-0.81] vs 0.60 [0.56-0.66], respectively, P = 0.0007). Pre-CABG FFR-CT (hazard ratio = 1.1; 95% CI: 1.012-1.1, P = 0.0230), and bypass graft to right coronary artery (hazard ratio = 3.7; 95% CI: 1.4-9.3 vs left anterior descending artery) were independent predictors of graft dysfunction during follow-up. The optimal threshold of FFR-CT to predict graft failure was >0.68 (sensitivity 88.9% (95% CI: 65.3-98.6), specificity 63.7% (95% CI: 52.2-74.2), positive predictive value 35.6% (95% CI: 28.3%-43.5%), negative predictive value 96.2% (95% CI: 87.2%-99.0%)). Pre-CABG functional FFR-CT predicts future coronary bypass graft failure. This shows utility of FFR-CT for guiding coronary revascularization and also suggests significance of physiological assessment prior to CABG.

Selecting conduits for coronary artery bypass grafting: caution regarding the right internal mammary artery

This narrative review summarizes the angiographic and clinical outcome results of the most common coronary artery bypass grafting (CABG) conduits. The left internal mammary artery is the preferred first conduit to bypass the left anterior descending artery due to superior long-term survival and graft patency. Recent studies suggest the radial artery may be the preferred second conduit for the circumflex or right coronary artery territories, challenging the belief that the right internal mammary artery is the best choice. Despite their historical high failure rates, saphenous vein grafts continue to be widely used as secondary conduits. Several recent studies report suboptimal rates of right internal mammary artery graft failure, with clinical outcomes comparable to or worse than saphenous veins. The suboptimal rates of RIMA graft failure may be attributed to several factors such as improvements in vein graft failure rates, the use of in situ and non-left anterior descending artery grafting configurations, and skeletonized harvesting techniques. While observational studies favor multiple over single arterial grafting, randomized studies are needed for confirmation. The ongoing Randomized comparison of the clinical Outcome of single vs. Multiple Arterial grafts (ROMA) trial aims to determine if multiple arterial grafting reduces major adverse cardiovascular events and mortality and how secondary conduit selection influences these outcomes. Greater adoption of arterial grafting strategies is likely to come from high-quality evidence of benefit and safety from ongoing and future large pragmatic trials.

Optimizing Internal Mammary Artery Harvest and Preparation

The left internal mammary artery (LIMA) graft plays a pivotal role in coronary artery bypass surgery, offering unparalleled efficacy in revascularization. This review paper delves into the multifaceted considerations surrounding LIMA utilization, aiming to provide a comprehensive understanding of optimal approaches. The study encompasses the alleviation of spasm, selection of graft harvesting techniques, identification of ideal vasodilators, and exploration of optimal delivery methods. Through an analysis of extensive research spanning the past three decades, this review elucidates critical insights for cardiac surgeons and researchers alike. The review emphasizes the ubiquity of severe spasms in harvested LIMA and examines interventions to mitigate this challenge. Studies highlighting the efficacy of papaverine administration through various routes underscore the need for tailored approaches based on clinical context. The debate between skeletonized and pedicled LIMA harvests is explored, revealing the advantages and complexities associated with each technique. Findings suggest that while skeletonized grafts offer enhanced flow, the decision remains multifaceted due to potential complications. Addressing the quest for the ideal vasodilator, the review juxtaposes papaverine and sodium nitroprusside, presenting both as viable options. Despite ongoing discussions, the cost-effectiveness and accessibility of papaverine have positioned it as the favored choice among clinicians. Optimal delivery methods emerge as a crucial factor in graft success, with perivascular injection showing promise in promoting sustained and improved flow rates. The clinical implications of these findings are substantial. By integrating the evidence presented, cardiac surgeons can make informed decisions, maximizing graft patency and patient outcomes. Further, research avenues are identified, encompassing refined delivery techniques, comprehensive comparisons of vasodilators, and long-term clinical outcome evaluations. In conclusion, this review underscores the intricate considerations essential for successful LIMA utilization. By addressing spasms, selecting graft techniques, choosing vasodilators, and refining delivery methods, practitioners can tailor their strategies to the individual patient, enhancing the efficacy of coronary revascularization.

Internal Mammary Artery Graft Flow Steal by a Large Dialysis Arteriovenous Fistula Characterized by Electrical Storm

Background: Steal syndrome describes a condition in which a dilated vessel distal to a smaller artery attempts to compensate for decreased blood flow by “stealing” from the smaller artery. Steal syndrome is not uncommon and can be seen in certain physiologic and pathologic states. The classic example is an occluded atherosclerotic coronary artery resulting in a misdirection of blood flow into the open channels that have developed over time resulting in downstream ischemia. Case Report: A 66-year-old male fourteen years post 4-vessel coronary artery bypass grafting using his left internal mammary artery to bypass a stenotic segment of the left anterior descending artery, along with three saphenous venous conduits to the right coronary artery. He also had a stent placement by PCI. He was on dual antiplatelet therapy with aspirin and clopidogrel. An electrophysiology study revealed inducible VF and he underwent implantation of a dual chamber ICD 9 months prior to presentation. He experienced an unprovoked fall at home and a workup revealed the flow volume through the patient’s fistula increased to such a degree that the patient developed a steal syndrome from his left internal mammary artery graft. In addition, went into a state of electrical storm caused by ischemic damage to cardiac tissue distal to the graft. By ligating the fistula, the patient’s steal syndrome resolved and he did not suffer further ventricular arrhythmias. Conclusion: Both coronary bypass grafting and fistula formation are common and necessary interventions and providers should take care to monitor for interactions between these proposed interventions to best serve their patients without causing additional harm. Increased vascular flow through any portion of the body can induce a steal syndrome from an upstream region. Patients who undergo arteriovenous (AV) fistula placement may develop a steal syndrome from ipsilateral bypass grafts.

The Role of Coronary Physiology Assessment in the Diagnosis and Treatment of Stable Angina. Dive Inside Recent Findings of Diffuse Coronary Disease Treatment.

Coronary physiology is widely used to assess epicardial coronary lesions in patients with stable angina. Based on the available evidence, physiology plays a crucial role in diagnosing and treating patients. There have been invasive methods for determining cardiac physiology, such as fractional flow reserve and instantaneous wave-free ratio. Still, new non-invasive approaches provide extra anatomical information, such as fractional flow reserve computed tomography (FFR-CT) based on computed tomography and physiology based on angiography. Even though FFR-guided percutaneous coronary intervention (PCI) is clinically beneficial, one-third of patients retain suboptimal FFR after the procedure, associated with severe adverse events, rendering PCI in diffuse coronary artery disease questionable. Using the pullback pressure gradient (PPG), we can analyze the magnitude and extent of pressure losses; a lower value may indicate diffuse disease, while a high value with an abrupt curve may indicate focal disease. Since PCI is not the best option for treating diffuse coronary disease, current strategies focus on conservatively using medical therapy or bypass surgery. It has been demonstrated that patients with diffuse disease of the left anterior descending (LAD) are at a greater risk of developing occlusion of the left internal mammary artery graft than those with focal disease and that maximal medical therapy may be the most effective treatment for these patients.

Transient internal mammary artery graft stenosis on early angiography: navigating pitfalls in hybrid myocardial revascularization.

Left internal mammary artery (LIMA) graft stenoses detected at early coronary angiography may be reversible and consequently prompt unnecessary graft revision. We aim to investigate the frequency, natural course, and clinical significance of internal mammary artery graft stenosis upon early angiography in patients undergoing hybrid myocardial revascularization. In this retrospective sub-study of the Coronary Hybrid Revascularization Study, we compared graft appearance, ie, stenosis degree and flow, on early (in-hospital) and scheduled follow-up coronary angiography after 1 year. We assessed the change in graft patency using the Fitzgibbon classification (grade A: unimpaired runoff; grade B > 50% stenosis; grade O: occlusion), as well as graft association with adverse events (death, myocardial infarction, stroke, and repeat revascularization) at up to 5-year follow-up. We report clinical follow-up data for all 131 patients included in the Coronary Hybrid Revascularization Study. Change in graft patency was analyzed in 86 patients with satisfactory visualization of the LIMA graft on early and follow-up coronary angiography. All LIMA grafts were patent at discharge and follow-up. Twenty-seven of 37 (73%) grade B graft stenoses at early angiography resolved to grade A during follow-up of median 12 months (range, 8-83 months) after surgery. Angiographically significant graft stenoses at early coronary angiography were not associated with adverse clinical outcome up to 5-year follow-up. Our results suggest that the majority of clinically silent LIMA graft stenoses resolve during follow-up and are not associated with adverse clinical outcomes.