Non-invasive assessment of saphenous vein graft patency in asymptomatic patients

Symptomatic late saphenous vein graft failure in coronary artery bypass surgery

OBJECTIVES

Coronary artery bypass grafting for advanced coronary artery disease is a well-established procedure with excellent long-term results. The issue of saphenous vein graft (SVG) performance and its relation to clinical symptoms and thereby the potential for improvement by using superior grafts are still not fully understood. We aim to estimate the contribution of late SVG failure to the long-term outcome.

METHODS

A study population operated between 1997 and 2020, with an internal thoracic artery with a single distal anastomosis and 1, 2 or 3 distal SVG anastomoses, was isolated from the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies registry. Data regarding postoperative clinically driven coronary angiography and status of bypass grafts were collected.

RESULTS

The study population consisted of 44 951 patients. Clinically driven angiography occurred in 10.1% (9.5-10.8), 7.9% (7.6-8.3) and 7.1% (6.7-7.5), respectively, of patients within 3 years and 23.6% (22.6-24.5), 20.0% (19.5-20.6) and 17.5% (16.9-18.2), respectively, of patients within 10 years after surgery. Excluding the first 3 postoperative years, no failed SVGs were found in >75%, 60% and 45%, respectively, of cases when an angiography was performed in the first 10 years after surgery.

CONCLUSIONS

The results suggest that the risk of symptomatic graft failure due to vein graft disease during the first 10 years after surgery is in the range of 1-2% for every grafted coronary vessel and provide an estimate for the upper limit of the improvements in results that could be achieved by replacing SVGs with superior grafts.

Drug-Eluting Stent Restenosis: Modern Approach to a Classic Challenge

In-stent restenosis (ISR) is a recognized complication following percutaneous coronary intervention in which the luminal diameter is narrowed through neointimal hyperplasia and vessel remodeling. Although rates of ISR have decreased in most recent years owing to newer generation drug-eluting stents, thinner struts, and better intravascular imaging modalities, ISR remains a prevalent dilemma that proves to be challenging to manage. Several factors have been proposed to contribute to ISR formation, including mechanical stent characteristics, technical factors during the coronary intervention, and biological aspects of drug-eluting stents. Presentation of ISR can range from asymptomatic to late myocardial infarction and could be difficult to differentiate from acute thrombus formation. No definite guidelines are present on the management of ISR. In this review, we will discuss the mechanisms underlying ISR and provide insight into patient-related and procedural risk factors contributing to ISR, in addition to highlighting common treatment approaches utilized in the management of ISR.

Trends and Outcomes of Myocardial Infarction in Patients With Previous Coronary Artery Bypass Surgery

Data on myocardial infarction (MI) treatment in patients with previous coronary artery bypass grafting (CABG) is limited. We queried the Nationwide Readmissions Database to identify hospitalizations of patients with MI from 2016 to 2019. Among hospitalized patients presenting with MI, 10.3% had previous CABG. Patients with MI who had previous CABG were less likely to be revascularized than those without previous CABG for both ST-segment elevation MI (STEMI) (46.4% vs 68.4%) and non-ST-segment elevation MI (NSTEMI) (30.8% vs 36.7%). CABG was associated with a lower risk of death in NSTEMI patients (odds ratio [OR] 0.84, 95% confidence interval [CI] 0.82 to 0.86), but a higher risk in STEMI patients (OR 1.06, 95% CI 1.01 to 1.13). Revascularization was associated with a lower risk of in-hospital death in patients with previous CABG presenting with STEMI (OR 0.30, 95% CI 0.26 to 0.35) and NSTEMI (OR 0.21, 95% CI 0.19 to 0.23).

Contemporary coronary artery bypass graft surgery and subsequent percutaneous revascularization

Patients who have undergone coronary artery bypass graft (CABG) surgery are susceptible to bypass graft failure and progression of native coronary artery disease. Although the saphenous vein graft (SVG) was traditionally the most-used conduit, arterial grafts (including the left and right internal thoracic arteries and the radial artery) have improved patency rates. However, the need for secondary revascularization remains common, and percutaneous coronary intervention (PCI) has become the most common modality of secondary revascularization after CABG surgery. Procedural characteristics and clinical outcomes differ considerably from those associated with PCI in patients without previous CABG surgery, owing to altered coronary anatomy and differences in conduit pathophysiology. In particular, SVG PCI carries an increased risk of complications, and operators are shifting their focus towards embolic protection strategies and complex native-vessel interventions, increasingly using SVGs as conduits to facilitate native-vessel PCI rather than pursuing SVG PCI. In this Review, we discuss the differences in conduit pathophysiology, changes in CABG surgery techniques, and the latest evidence in terms of PCI in patients with previous CABG surgery, with a particular emphasis on safety and long-term efficacy. We explore the subject of contemporary CABG surgery and subsequent percutaneous revascularization in this complex patient population.

Clinical Characteristics, Management Strategies, and Outcomes of Non-ST-Segment-Elevation Myocardial Infarction Patients With and Without Prior Coronary Artery Bypass Grafting

Background

There are limited data on the management strategies, temporal trends and clinical outcomes of patients who present with non–ST‐segment–elevation myocardial infarction and have a prior history of CABG.

Methods and Results

We identified 287 658 patients with non–ST‐segment–elevation myocardial infarction between 2010 and 2017 in the United Kingdom Myocardial Infarction National Audit Project database. Clinical and outcome data were analyzed by dividing into 2 groups by prior history of coronary artery bypass grafting (CABG): group 1, no prior CABG (n=262 362); and group 2, prior CABG (n=25 296). Patients in group 2 were older, had higher GRACE (Global Registry of Acute Coronary Events) risk scores and burden of comorbid illnesses. More patients underwent coronary angiography (69% versus 63%) and revascularization (53% versus 40%) in group 1 compared with group 2. Adjusted odds of receiving inpatient coronary angiogram (odds ratio [OR], 0.91; 95% CI, 0.88–0.95; P<0.001) and revascularization (OR, 0.73; 95% CI, 0.70–0.76; P<0.001) were lower in group 2 compared with group 1. Following multivariable logistic regression analyses, the OR of in‐hospital major adverse cardiovascular events (composite of inpatient death and reinfarction; OR, 0.97; 95% CI, 0.90–1.04; P=0.44), all‐cause mortality (OR, 0.96; 95% CI, 0.88–1.04; P=0.31), reinfarction (OR, 1.02; 95% CI, 0.89–1.17; P=0.78), and major bleeding (OR, 1.01; 95% CI, 0.90–1.11; P=0.98) were similar across groups. Lower adjusted risk of inpatient mortality (OR, 0.67; 95% CI, 0.46–0.98; P=0.04) but similar risk of bleeding (OR,1.07; CI, 0.79–1.44; P=0.68) and reinfarction (OR, 1.13; 95% CI, 0.81–1.57; P=0.47) were observed in group 2 patients who underwent percutaneous coronary intervention compared with those managed medically.

Conclusions

In this national cohort, patients with non–ST‐segment–elevation myocardial infarction with prior CABG had a higher risk profile, but similar risk‐adjusted in‐hospital adverse outcomes compared with patients without prior CABG. Patients with prior CABG who received percutaneous coronary intervention had lower in‐hospital mortality compared with those who received medical management.

Development of a risk score for early saphenous vein graft failure: An individual patient data meta-analysis

OBJECTIVES

Early saphenous vein graft (SVG) occlusion is typically attributed to technical factors. We aimed at exploring clinical, anatomical, and operative factors associated with the risk of early SVG occlusion (within 12 months postsurgery).

METHODS

Published literature in MEDLINE was searched for studies reporting the incidence of early SVG occlusion. Individual patient data (IPD) on early SVG occlusion were used from the SAFINOUS-CABG Consortium. A derivation (n = 1492 patients) and validation (n = 372 patients) cohort were used for model training (with 10-fold cross-validation) and external validation respectively.

RESULTS

In aggregate data meta-analysis (48 studies, 41,530 SVGs) the pooled estimate for early SVG occlusion was 11%. The developed IPD model for early SVG occlusion, which included clinical, anatomical, and operative characteristics (age, sex, dyslipidemia, diabetes mellitus, smoking, serum creatinine, endoscopic vein harvesting, use of complex grafts, grafted target vessel, and number of SVGs), had good performance in the derivation (c-index = 0.744; 95% confidence interval [CI], 0.701-0.774) and validation cohort (c-index = 0.734; 95% CI, 0.659-0.809). Based on this model. we constructed a simplified 12-variable risk score system (SAFINOUS score) with good performance for early SVG occlusion (c-index = 0.700, 95% CI, 0.684-0.716).

CONCLUSIONS

From a large international IPD collaboration, we developed a novel risk score to assess the individualized risk for early SVG occlusion. The SAFINOUS risk score could be used to identify patients that are more likely to benefit from aggressive treatment strategies.

Invasive Versus Medical Management in Patients With Prior Coronary Artery Bypass Surgery With a Non-ST Segment Elevation Acute Coronary Syndrome

Supplemental Digital Content is available in the text.

The benefits of routine invasive management in patients with prior coronary artery bypass grafts presenting with non-ST elevation acute coronary syndromes are uncertain because these patients were excluded from pivotal trials.

The effect on survival from the use of a saphenous vein graft during coronary bypass surgery: a large cohort study

OBJECTIVES

Saphenous vein graft (SVG) remains the predominant conduit used in coronary surgery. The internal mammary artery has higher later term patency and confers superior survival. Current debate focuses on the increased use of arterial conduits rather than eradication of venous conduits.

METHODS

Patient data extracted from the Australian and New Zealand Society of Cardiothoracic Surgeons database from 2001-2013 were linked to the national death registry held by the Australian Institute of Health and Welfare for all-cause mortality with censor date 7 October 2014. The dataset was divided according to use of SVG rather than the arterial conduit. Analyses of SVG ≥ 1 or SVG = 1 were compared to SVG = 0. Additionally, groups of 3, 4 or 5 grafts were subjected to multiple analyses testing the mortality hazard with increasing use of SVG. Propensity score matched analyses were conducted using 24 variables.

RESULTS

Of 51 113 primary coronary surgery patients, unmatched survival at up to 12.5 years was significantly lower for SVG ≥ 1, n = 33 359, mortality hazard ratio (HR) 1.24 [95% confidence interval (CI) 1.18-1.30], P < 0.001; and for SVG = 1, mortality HR 1.19 (95% CI 1.12-1.26), P < 0.001. Similar results were present for the propensity score matched groups; SVG ≥ 1, n = 14 355 pairs, HR 1.22 (95% CI 1.15-1.30), P < 0.001; and for SVG = 1, n = 12 316 pairs, HR 1.22 (95% CI 1.14-1.30), P < 0.001. All matched analyses within restricted graft groups had increasing HR with increased number of SVG used.

CONCLUSIONS

Any use of SVGs is independently associated with reduced survival after coronary artery bypass surgery.

Application of indocyanine green fluorescence endoscopic system in transsphenoidal surgery for pituitary tumors

BACKGROUND

For the precise removal of pituitary tumors, preserving the surrounding normal structures, we need real-time intraoperative information on tumor location, margins, and surrounding structures. The aim of this study was to evaluate the benefits of a new intraoperative real-time imaging modality using indocyanine green (ICG) fluorescence through an endoscopic system during transsphenoidal surgery (TSS) for pituitary tumors.

METHODS

Between August 2013 and October 2014, 20 patients with pituitary and parasellar region tumors underwent TSS using the ICG fluorescence endoscopic system. We used a peripheral vein bolus dose of 6.25 mg/injection of ICG, started with a time counter, and examined how each tissue type increased and decreased in fluorescence through time.

RESULTS

A total of 33 investigations were performed for 20 patients: 9 had growth hormone secreting adenomas, 6 non-functioning pituitary adenomas, 3 Rathke's cleft cysts, 1 meningioma, and 1 pituicytoma. After the injection of ICG, the intensity of fluorescence of tumor and normal tissues under near-infrared light showed clear differences. We could differentiate tumor margins from adjacent normal tissues and define clearly the surrounding normal structures using the different fluorescent intensities time changes and tissue-specific fluorescence patterns.

CONCLUSIONS

The ICG endoscopic system is simple, user-friendly, quick, cost-effective, and reliable. The method offered real-time information during TSS to delimit pituitary and parasellar region tumor tissue from surrounding normal structures. This method can contribute to the improvement of total removal rates of tumors, reduction of complications after TSS, saving surgical time, and preserving endocrinological functions.

Choice of Stent for Percutaneous Coronary Intervention of Saphenous Vein Grafts

Background—

There are limited data on comparison of contemporary drug-eluting stent (DES) platforms, previous generation DES, and bare-metal stents (BMS) for percutaneous coronary intervention in saphenous vein grafts (SVG). We aimed to assess clinical outcomes following percutaneous coronary intervention to SVG in patients receiving bare-metal stents (BMS), first-generation DES, and newer generation DES in a large unselected national data set from the BCIS (British Cardiovascular Intervention Society).

Methods and Results—

Patients undergoing percutaneous coronary intervention to SVG in the United Kingdom from January 2006 to December 2013 were divided into 3 groups according to stent use: BMS, first-generation DES, and newer generation DES group. Study outcomes included in-hospital major adverse cardiovascular events, 30-day mortality, and 1-year mortality. Patients (n=15 003) underwent percutaneous coronary intervention to SVG in England and Wales during the study period. Of these, 38% received BMS, 15% received first-generation DES, and 47% received second-generation DES. The rates of in-hospital major adverse cardiovascular events were significantly lower in patients treated with second-generation DES (odds ratio, 0.51; 95% confidence interval, 0.38–0.68; P <0.001), but not with first-generation DES, compared with BMS-treated patients. Similarly, 30-day mortality (odds ratio, 0.43; 95% confidence interval, 0.32–0.59; P <0.001) and 1-year mortality (odds ratio, 0.60; 95% confidence interval, 0.51–0.71; P <0.001) were lower in patients treated with second-generation DES, but not with first-generation DES, compared with the patients treated with BMS.

Conclusions—

Patients receiving second-generation DES for the treatment SVG disease have lower rates of in-hospital major adverse cardiovascular events, 30-day mortality, and 1-year mortality, compared with those receiving BMS.

Non-invasive versus invasive management in patients with prior coronary artery bypass surgery with a non-ST segment elevation acute coronary syndrome: study design of the pilot randomised controlled trial and registry (CABG-ACS)

Introduction

There is an evidence gap about how to best treat patients with prior coronary artery bypass grafts (CABGs) presenting with non-ST segment elevation acute coronary syndromes (NSTE-ACS) because historically, these patients were excluded from pivotal randomised trials. We aim to undertake a pilot trial of routine non-invasive management versus routine invasive management in patients with NSTE-ACS with prior CABG and optimal medical therapy during routine clinical care. Our trial is a proof-of-concept study for feasibility, safety, potential efficacy and health economic modelling. We hypothesise that a routine invasive approach in patients with NSTE-ACS with prior CABG is not superior to a non-invasive approach with optimal medical therapy.

Methods and analysis

60 patients will be enrolled in a randomised clinical trial in 4 hospitals. A screening log will be prospectively completed. Patients not randomised due to lack of eligibility criteria and/or patient or physician preference and who give consent will be included in a registry. We will gather information about screening, enrolment, eligibility, randomisation, patient characteristics and adverse events (including post-discharge). The primary efficacy outcome is the composite of all-cause mortality, rehospitalisation for refractory ischaemia/angina, myocardial infarction and hospitalisation for heart failure. The primary safety outcome is the composite of bleeding, stroke, procedure-related myocardial infarction and worsening renal function. Health status will be assessed using EuroQol 5 Dimensions (EQ-5D) assessed at baseline and 6 monthly intervals, for at least 18 months.

Trial registration number

NCT01895751 (ClinicalTrials.gov).

Mid-term outcomes for Endoscopic versus Open Vein Harvest: a case control study

Background

Saphenous vein remains the most common conduit for coronary artery bypass grafting with increasing uptake of minimally invasive harvesting techniques. While Endoscopic Vein Harvest (EVH) has been demonstrated to improve early morbidity compared to Open Vein Harvest (OVH), recent literature suggests that this may be at the expense of graft patency at one year and survival at three years.

Methods

We undertook a retrospective single-centre, single-surgeon, case-control study of EVH (n = 89) and OVH (n = 182). The primary endpoint was death with secondary endpoints including acute coronary syndrome, revascularisation or other major adverse cardiac events. Freedom from angina, wound complications and self-rated health status were also assessed. Where repeat angiography had been performed, this was reviewed.

Results

Both groups were well matched demographically and for peri-operative characteristics. All cause mortality was 2/89 (2%) and 11/182 (6%) in the EVH and OVH groups respectively. This was shown by Cox Log-Rank analysis to be non-significant (p = 0.65), even if adjusting for inpatient mortality (p = 0.74). There was no difference in the rates of freedom from angina (p = 1.00), re-admission (p = 0.78) or need for further anti-anginals (p = 1.00). There was a significant reduction in the incidence of leg wound infections and complications in the endoscopic group (EVH: 7%; OVH: 28%; p = 0.0008) and the skew of high patient self-rated health scores in the EVH group (61% compared to 52% in the open group) approached statistical significance (p = 0.06).

Conclusions

While aware of the limitations of this small retrospective study, we are heartened by the preliminary results and consider our data to be justification for continuing to provide patients the opportunity to have minimally invasive conduit harvest in our centre. More robust evidence is still required to elucidate the implications of endoscopic techniques on conduit patency and patient outcome, but until the results of a large, prospective and randomised trial are available, we believe we can confidently offer our patients the option and benefits of EVH.