Edifoligide and long-term outcomes after coronary artery bypass grafting: PRoject of Ex-vivo Vein graft ENgineering via Transfection IV (PREVENT IV) 5-year results

Radial artery versus saphenous vein versus right internal thoracic artery for coronary artery bypass grafting

OBJECTIVES

We used individual patient data from 4 of the largest contemporary coronary bypass surgery trials to evaluate differences in long-term outcomes when radial artery (RA), right internal thoracic artery (RITA) or saphenous vein graft (SVG) are used to complement the left internal thoracic artery-to-left anterior descending graft.

METHODS

Primary outcome was all-cause mortality. Secondary outcome was a composite of major adverse cardiac and cerebrovascular events (all-cause mortality, myocardial infarction and stroke). Propensity score matching and Cox regression were used to reduce the effect of treatment selection bias and confounders.

RESULTS

A total of 10 256 patients (1510 RITA; 1385 RA; 7361 SVG) were included. The matched population consisted of 1776 propensity score-matched triplets. The mean follow-up was 7.9 ± 0.1, 7.8 ± 0.1 and 7.8 ± 0.1 years in the RITA, RA and SVG cohorts respectively. All-cause mortality was significantly lower in the RA versus the SVG [hazard ratio (HR) 0.62, 95% confidence interval (CI): 0.51-0.76, P = 0.003] and the RITA group (HR 0.59, 95% CI 0.48-0.71, P = 0.001). Major adverse cardiac and cerebrovascular event rate was also lower in the RA group versus the SVG (HR 0.78, 95% CI 0.67-0.90, P = 0.04) and the RITA group (HR 0.75, 95% CI 0.65-0.86, P = 0.02). Results were consistent in the Cox-adjusted analysis and solid to hidden confounders.

CONCLUSIONS

In this pooled analysis of 4 large coronary bypass surgery trials, the use of the RA was associated with better clinical outcomes when compared to SVG and RITA.

Adenoviral vectors for cardiovascular gene therapy applications: a clinical and industry perspective

Abstract

Despite the development of novel pharmacological treatments, cardiovascular disease morbidity and mortality remain high indicating an unmet clinical need. Viral gene therapy enables targeted delivery of therapeutic transgenes and represents an attractive platform for tackling acquired and inherited cardiovascular diseases in the future. Current cardiovascular gene therapy trials in humans mainly focus on improving cardiac angiogenesis and function. Encouragingly, local delivery of therapeutic transgenes utilising first-generation human adenovirus serotype (HAd)-5 is safe in the short term and has shown some efficacy in drug refractory angina pectoris and heart failure with reduced ejection fraction. Despite this success, systemic delivery of therapeutic HAd-5 vectors targeting cardiovascular tissues and internal organs is limited by negligible gene transfer to target cells, elimination by the immune system, liver sequestration, off-target effects, and episomal degradation. To circumvent these barriers, cardiovascular gene therapy research has focused on determining the safety and efficacy of rare alternative serotypes and/or genetically engineered adenoviral capsid protein-modified vectors following local or systemic delivery. Pre-clinical studies have identified several vectors including HAd-11, HAd-35, and HAd-20–42-42 as promising platforms for local and systemic targeting of vascular endothelial and smooth muscle cells. In the past, clinical gene therapy trials were often restricted by limited scale-up capabilities of gene therapy medicinal products (GTMPs) and lack of regulatory guidance. However, significant improvement of industrial GTMP scale-up and purification, development of novel producer cell lines, and issuing of GTMP regulatory guidance by national regulatory health agencies have addressed many of these challenges, creating a more robust framework for future adenoviral-based cardiovascular gene therapy. In addition, this has enabled the mass roll out of adenovirus vector-based COVID-19 vaccines.

Key messages

First-generation HAd-5 vectors are widely used in cardiovascular gene therapy.

HAd-5-based gene therapy was shown to lead to cardiac angiogenesis and improved function.

Novel HAd vectors may represent promising transgene carriers for systemic delivery.

Novel methods allow industrial scale-up of rare/genetically altered Ad serotypes.

National regulatory health agencies have issued guidance on GMP for GTMPs.

Storage solutions to improve grafts preservation and longevity in coronary artery bypass grafting surgery: hype or hope?

PURPOSE OF REVIEW

Saphenous vein grafts (SVGs) remain the most-commonly used conduits for coronary artery bypass grafting (CABG).Significant rates of vein graft failure (VGF) remain a limitation of their use as this diminishes the long-term benefits of CABG. The choice of intraoperative SVGs preservation solution is believed to have an impact on graft patency; however, the superiority of one solution over the others remains in question.

RECENT FINDINGS

In the present review, we describe the pathophysiological mechanisms underlying the different phases of VGF. We also reviewed the most recent literature comparing and evaluating the efficacy of various storage solutions. These include heparinized saline, autologous heparinized blood, buffered solutions, and crystalloid cardioplegia.

SUMMARY

It is clear that the composition of the SVGs storage solution has an impact on vessel wall structure and function. There is a lack of translational and clinical research on the topic; thus, conclusions cannot be drawn regarding the superiority of one solution over the others in terms of VGF. Future research needs to be conducted to address this gap in the literature in order to make meaningful evidence-based recommendations on intraoperative graft storage.

Decoy Technology as a Promising Therapeutic Tool for Atherosclerosis

Cardiovascular diseases (CVDs) have been classified into several types of disease, of which atherosclerosis is the most prevalent. Atherosclerosis is characterized as an inflammatory chronic disease which is caused by the formation of lesions in the arterial wall. Subsequently, lesion progression and disruption ultimately lead to heart disease and stroke. The development of atherosclerosis is the underlying cause of approximately 50% of all deaths in westernized societies. Countless studies have aimed to improve therapeutic approaches for atherosclerosis treatment; however, it remains high on the global list of challenges toward healthy and long lives. Some patients with familial hypercholesterolemia could not get intended LDL-C goals even with high doses of traditional therapies such as statins, with many of them being unable to tolerate statins because of the harsh side effects. Furthermore, even in patients achieving target LDL-C levels, the residual risk of traditional therapies is still significant thus highlighting the necessity of ongoing research for more effective therapeutic approaches with minimal side effects. Decoy-based drug candidates represent an opportunity to inhibit regulatory pathways that promote atherosclerosis. In this review, the potential roles of decoys in the treatment of atherosclerosis were described based on the in vitro and in vivo findings.

Preventing treatment failures in coronary artery disease: what can we learn from the biology of in-stent restenosis, vein graft failure, and internal thoracic arteries?

Coronary artery disease (CAD) remains one of the most important causes of morbidity and mortality worldwide, and the availability of percutaneous or surgical revascularization procedures significantly improves survival. However, both strategies are daunted by complications which limit long-term effectiveness. In-stent restenosis (ISR) is a major drawback for intracoronary stenting, while graft failure is the limiting factor for coronary artery bypass graft surgery (CABG), especially using veins. Conversely, internal thoracic artery (ITA) is known to maintain long-term patency in CABG. Understanding the biology and pathophysiology of ISR and vein graft failure (VGF) and mechanisms behind ITA resistance to failure is crucial to combat these complications in CAD treatment. This review intends to provide an overview of the biological mechanisms underlying stent and VGF and of the potential therapeutic strategy to prevent these complications. Interestingly, despite being different modalities of revascularization, mechanisms of failure of stent and saphenous vein grafts are very similar from the biological standpoint.

Harnessing nucleic acid-based therapeutics for atherosclerotic cardiovascular disease: state of the art

Dyslipidemia is one of the major but modifiable risk factors for atherosclerotic cardiovascular disease (ACVD). Despite the accessibility of statins and other lipid-lowering drugs, the burden of ACVD is still high globally, highlighting the need for new therapeutic approaches. Nucleic acid-based technologies, including antisense oligonucleotides (ASOs), small interfering (si)RNAs, miRNAs, and decoys, are emerging therapeutic modalities for the treatment of ACVD. These technologies aim to degrade gene mRNA transcripts to decrease the levels of atherogenic lipoproteins. Using gene-silencing approaches, the levels of atherogenic lipoproteins can be decreased by targeting proteins that have key roles in lipoprotein metabolism. Here, we highlight preclinical and clinical findings using these approaches for the development of novel therapies against ACVD.

Biochemical Properties of a Decoy Oligodeoxynucleotide Inhibitor of STAT3 Transcription Factor

Cyclic STAT3 decoy (CS3D) is a second-generation, double-stranded oligodeoxynucleotide (ODN) that mimics a genomic response element for signal transducer and activator of transcription 3 (STAT3), an oncogenic transcription factor. CS3D competitively inhibits STAT3 binding to target gene promoters, resulting in decreased expression of proteins that promote cellular proliferation and survival. Previous studies have demonstrated antitumor activity of CS3D in preclinical models of solid tumors. However, prior to entering human clinical trials, the efficiency of generating the CS3D molecule and its stability in biological fluids should be determined. CS3D is synthesized as a single-stranded ODN and must have its free ends ligated to generate the final cyclic form. In this study, we report a ligation efficiency of nearly 95 percent. The ligated CS3D demonstrated a half-life of 7.9 h in human serum, indicating adequate stability for intravenous delivery. These results provide requisite biochemical characterization of CS3D that will inform upcoming clinical trials.

Nonsteroidal Anti-Inflammatory Drugs and Clinical Outcomes in Patients Undergoing Coronary Artery Bypass Surgery

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in perioperative pain management of patients undergoing coronary artery bypass graft surgery. However, the association of periprocedural use of NSAIDs and clinical outcomes after coronary artery bypass graft is understudied.

METHODS

We conducted a retrospective analysis using pooled data from 2 multicenter randomized controlled trials (PREVENT IV [n = 3014] and MEND-CABG II [n = 3023]). Rates of death, death or myocardial infarction, and death, myocardial infarction, or stroke in the 30 days following coronary artery bypass graft surgery were compared in patients using or not using perioperative NSAIDs. Inverse probability of treatment weighting and Cox proportional hazards regression models were used to adjust for confounding.

RESULTS

A total of 5887 patients were studied. Median age was 65 years, 78% were male, and 91% were White. NSAIDs were used in 2368 (40.2%) patients. The majority of patients (1822 [30.9%]) received NSAIDs after coronary artery bypass graft surgery; 289 (4.9%) used them prior to and after the surgery; and 257 (4.4) received NSAIDs prior to the surgery only. Adjusted 30-day outcomes were similar in patients receiving and not receiving NSAIDs (death: hazard ratio [HR] 1.18; 95% confidence interval [CI], 0.48-2.92; death or myocardial infarction: HR 0.87; 95% CI, 0.42-1.79; death, myocardial infarction, or stroke: HR 0.87; 95% CI, 0.46-1.65).

CONCLUSION

In this pooled data analysis, perioperative NSAID use was common among patients undergoing coronary artery bypass graft surgery and was not associated with an increased short-term risk for major adverse clinical outcomes.

Improving the Outcome of Vein Grafts: Should Vascular Surgeons Turn Veins into Arteries?

Autogenous vein grafts remain the gold standard conduit for arterial bypass, particularly for the treatment of critical limb ischemia. Vein graft adaptation to the arterial environment, i.e., adequate dilation and wall thickening, contributes to the superior performance of vein grafts. However, abnormal venous wall remodeling with excessive neointimal hyperplasia commonly causes vein graft failure. Since the PREVENT trials failed to improve vein graft outcomes, new strategies focus on the adaptive response of the venous endothelial cells to the post-surgical arterial environment. Eph-B4, the determinant of venous endothelium during embryonic development, remains expressed and functional in adult venous tissue. After surgery, vein grafts lose their venous identity, with loss of Eph-B4 expression; however, arterial identity is not gained, consistent with loss of all vessel identity. In mouse vein grafts, stimulation of venous Eph-B4 signaling promotes retention of venous identity in endothelial cells and is associated with vein graft walls that are not thickened. Eph-B4 regulates downstream signaling pathways of relevance to vascular biology, including caveolin-1, Akt, and endothelial nitric oxide synthase (eNOS). Regulation of the Eph-B4 signaling pathway may be a novel therapeutic target to prevent vein graft failure.

Physiology of in-situ arterial revascularization in coronary artery bypass grafting: Preoperative, intraoperative and postoperative factors and influences

Surgical revascularization with coronary artery bypass grafting (CABG) has become established as the most effective interventional therapy for patients with moderately severe and severe stable ischemic heart disease (SIHD). This recommendation is based on traditional 5-year outcomes of mortality and avoidance of myocardial infarction leading to reintervention and/or cardiac death. However, these results are confounded in that they challenge the traditional CABG surgical tenets of completeness of anatomic revascularization, the impact of arterial revascularization on late survival, and the lesser impact of secondary prevention following CABG on late outcomes. Moreover, the emergence of physiologic-based revascularization with percutaneous cardiovascular intervention as an alternative strategy for revascularization in SIHD raises the question of whether there are similar physiologic effects in CABG. Finally, the ongoing ISCHEMIA trial is specifically addressing the importance of the physiology of moderate or severe ischemia in optimizing therapeutic interventions in SIHD. So it is time to address the role that physiology plays in surgical revascularization. The long-standing anatomic framework for surgical revascularization is no longer sufficient to explain the mechanisms for short-term and long-term outcomes in CABG. Novel intraoperative imaging technologies have generated important new data on the physiologic blood flow and myocardial perfusion responses to revascularization on an individual graft and global basis. Long-standing assumptions about technical issues such as competitive flow are brought into question by real-time visualization of the physiology of revascularization. Our underestimation of the impact of Guideline Directed Medical Therapy, or Optimal Medical Therapy, on the physiology of preoperative SIHD, and the full impact of secondary prevention on post-intervention SIHD, must be better understood. In this review, these issues are addressed through the perspective of multi-arterial revascularization in CABG, which is emerging (after 30 years) as the “standard of care” for CABG. In fact, it is the physiology of these arterial grafts that is the mechanism for their impact on long-term outcomes in CABG. Moreover, a better understanding of all of these preoperative, intraoperative and postoperative components of the physiology of revascularization that will generate the next, more granular body of knowledge about CABG, and enable surgeons to design and execute a better surgical revascularization procedure for patients in the future.

Improving quality and outcomes of coronary artery bypass grafting procedures

The evolution in the approach, clinical care and outcomes of ischemic heart disease, has been dramatic over the past decade. Optimizing medical therapy initially and throughout the care delivery process has been transformative. The addition of new physiologic data to the traditional anatomic framework for diagnosis and therapy of more extensive stable ischemic heart disease (SIHD) enables quality and outcomes improvements in this patient population overall and in the patient subsets of acute coronary syndrome and SIHD. In patients undergoing coronary artery bypass grafting (CABG), these developments have changed the objective goal of surgical revascularization over this time interval. This review discusses the opportunities for quality and outcomes improvement in CABG, in the context of SIHD overall.

Frequency and Predictors of Internal Mammary Artery Graft Failure and Subsequent Clinical Outcomes: Insights From the Project of Ex-vivo Vein Graft Engineering via Transfection (PREVENT) IV Trial

BACKGROUND

The internal mammary artery (IMA) is the preferred conduit for bypassing the left anterior descending (LAD) artery in patients undergoing coronary artery bypass grafting. Systematic evaluation of the frequency and predictors of IMA failure and long-term outcomes is lacking.

METHODS AND RESULTS

The Project of Ex-vivo Vein Graft Engineering via Transfection (PREVENT) IV trial participants who underwent IMA-LAD revascularization and had 12- to 18-month angiographic follow-up (n=1539) were included. Logistic regression with fast false selection rate methods was used to identify characteristics associated with IMA failure (≥75% stenosis). The relationship between IMA failure and long-term outcomes, including death, myocardial infarction, and repeat revascularization, was assessed with Cox regression. IMA failure occurred in 132 participants (8.6%). Predictors of IMA graft failure were LAD stenosis <75% (odds ratio, 1.76; 95% confidence interval, 1.19-2.59), additional bypass graft to diagonal branch (odds ratio, 1.92; 95% confidence interval, 1.33-2.76), and not having diabetes mellitus (odds ratio, 1.82; 95% confidence interval, 1.20-2.78). LAD stenosis and additional diagonal graft remained predictive of IMA failure in an alternative model that included angiographic failure or death before angiography as the outcome. IMA failure was associated with a significantly higher incidence of subsequent acute (<14 days of angiography) clinical events, mostly as a result of a higher rate of repeat revascularization.

CONCLUSIONS

IMA failure was common and associated with higher rates of repeat revascularization, and patients with intermediate LAD stenosis or with an additional bypass graft to the diagonal branch had increased risk for IMA failure. These findings raise concerns about competitive flow and the benefit of coronary artery bypass grafting in intermediate LAD stenosis without functional evidence of ischemia.

CLINICAL TRIAL REGISTRATION

URL: http:/www.clinicaltrials.gov. Unique identifier: NCT00042081.

Symptomatic graft failure and impact on clinical outcome after coronary artery bypass grafting surgery: Results from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease registry

BACKGROUND

In contemporary coronary artery bypass graft (CABG) surgery, the association between symptomatic graft failure (GF) and long-term clinical outcome remains unclear. We sought to identify the clinical characteristics and outcomes of GF in symptomatic patients requiring cardiac catheterization within 1 year of CABG surgery.

METHODS

Using the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease registry, 5,276 patients undergoing CABG surgery from September 2002 to August 2011 were identified. Clinical outcomes in patients with symptomatic GF were observed. Predictors of GF were analyzed at a graft level, whereas long-term survival was assessed at a patient level. A propensity score matching technique was used to adjust for baseline characteristics.

RESULTS

Of our CABG cohort, 5.3% (281 patients [285 arterial and 653 vein grafts]) required symptom based coronary angiography within 1 year of CABG surgery. Acute coronary syndrome was the most common presentation (64.4%). At angiography, 27.0% (77/285) of arterial and 34.5% (225/653) of vein grafts were occluded. Respectively, arterial and vein GFs were treated as follows: percutaneous coronary intervention 61.0% versus 41.8%, re-do CABG 9.1% versus 0%, and medically without intervention 29.9% versus 58.2%. A strong trend toward reduced patient survival was noted with "arterial graft failure" (arterial ± vein GF) compared to "vein graft failure only" (no arterial GF) (adjusted hazard ratio 2.2, 95% CI 0.98-5.0, P = .056).

CONCLUSION

Although the rate of cardiac catheterization within 1 year of CABG is infrequent, these patients exhibit high GF rates and commonly present with an acute coronary syndrome. In addition, "arterial graft failure" compared to "vein graft failure only" confers a higher risk of adverse long-term survival.

Preservation solution impacts physiologic function and cellular viability of human saphenous vein graft

INTRODUCTION

Recent clinical data suggest intraoperative preservation of human saphenous vein (HSV) in normal saline is associated with vein graft failure. We evaluated the influence of several preservation media on acute physiologic function and cellular viability of HSV conduit.

METHODS

Unprepared (UP) HSV obtained from coronary artery bypass graft patients was characterized on a muscle bath after 2-hour storage in 6 solutions: Plasma-Lyte A, 0.9% NaCl (normal saline), University of Wisconsin solution, Celsior solution, autologous whole blood, or glutathione-ascorbic acid L-arginine (GALA) solution. Vascular smooth muscle contractility was assessed after exposure to depolarizing KCl and phenylephrine. The relaxation of phenylephrine-precontracted HSV to sodium nitroprusside and carbachol (endothelial-independent and -dependent relaxation, respectively) was also assessed. Cellular viability was determined via the methyl thiazolyl tetrazolium (MTT) assay. Rat aortae were used to assess the effect of pH during graft preservation on endothelial-dependent relaxation.

RESULTS

Preservation of HSV in normal saline and autologous whole blood impaired contractile responses to KCl relative to UP tissues, whereas preservation in University of Wisconsin solution and Celsior solution enhanced contractile responses (P < .05). Relative to UP tissues, responses to phenylephrine were decreased with preservation in normal saline, whereas preservation in University of Wisconsin solution, Celsior solution, and GALA all potentiated these responses (P < .05). Only preservation in normal saline impaired endothelial-independent relaxation (P = .005). Preservation in Plasma-Lyte A (P = .02), normal saline (P = .002), and University of Wisconsin solution (P = .02) impaired endothelial-dependent relaxation. Normal saline preservation decreased MTT viability index relative to UP tissues (0.02 ± 0.002 mg(-1)0.5 mL(-1) vs 0.033 ± 0.005 mg(-1)0.5 mL(-1); P = .03). Endothelial function was impaired by acidic pH in rat aorta.

CONCLUSION

Preservation of HSV in normal saline causes graft injury leading to impaired physiologic function and decreased viability of the HSV. This harm is mitigated by the use of buffered salt solutions as preservation media.

Psoriasis drug development and GWAS interpretation through in silico analysis of transcription factor binding sites

Background

Psoriasis is a cytokine-mediated skin disease that can be treated effectively with immunosuppressive biologic agents. These medications, however, are not equally effective in all patients and are poorly suited for treating mild psoriasis. To develop more targeted therapies, interfering with transcription factor (TF) activity is a promising strategy.

Methods

Meta-analysis was used to identify differentially expressed genes (DEGs) in the lesional skin from psoriasis patients (n = 237). We compiled a dictionary of 2935 binding sites representing empirically-determined binding affinities of TFs and unconventional DNA-binding proteins (uDBPs). This dictionary was screened to identify “psoriasis response elements” (PREs) overrepresented in sequences upstream of psoriasis DEGs.

Results

PREs are recognized by IRF1, ISGF3, NF-kappaB and multiple TFs with helix-turn-helix (homeo) or other all-alpha-helical (high-mobility group) DNA-binding domains. We identified a limited set of DEGs that encode proteins interacting with PRE motifs, including TFs (GATA3, EHF, FOXM1, SOX5) and uDBPs (AVEN, RBM8A, GPAM, WISP2). PREs were prominent within enhancer regions near cytokine-encoding DEGs (IL17A, IL19 and IL1B), suggesting that PREs might be incorporated into complex decoy oligonucleotides (cdODNs). To illustrate this idea, we designed a cdODN to concomitantly target psoriasis-activated TFs (i.e., FOXM1, ISGF3, IRF1 and NF-kappaB). Finally, we screened psoriasis-associated SNPs to identify risk alleles that disrupt or engender PRE motifs. This identified possible sites of allele-specific TF/uDBP binding and showed that PREs are disproportionately disrupted by psoriasis risk alleles.

Conclusions

We identified new TF/uDBP candidates and developed an approach that (i) connects transcriptome informatics to cdODN drug development and (ii) enhances our ability to interpret GWAS findings. Disruption of PRE motifs by psoriasis risk alleles may contribute to disease susceptibility.

Electronic supplementary material

The online version of this article (doi:10.1186/s40169-015-0054-5) contains supplementary material, which is available to authorized users.

Endoscopic harvesting device type and outcomes in patients undergoing coronary artery bypass surgery

OBJECTIVE

To evaluate angiographic and clinical outcomes associated with open and closed dissection tunnel endoscopic vein harvesting (EVH) devices.

BACKGROUND

A previous PREVENT-IV (PRoject of Ex-vivo Vein graft ENgineering via Transfection IV) analysis reported that EVH for coronary artery bypass graft surgery was associated with worse outcomes than with traditional vein harvesting; however, outcomes by EVH device type were not available.

METHODS

Using data from the PREVENT-IV trial, we compared 1549 patients from 75 surgical sites who underwent EVH with open (n = 390) or closed (n = 1159) harvest tunnel devices. Outcomes included the incidence of vein graft failure at 12 to 18 months and a composite of death, myocardial infarction, and revascularization through 5 years.

RESULTS

Among patients undergoing open and closed tunnel EVH, no difference in the per-patient incidence of vein graft failure (43.8% vs 47.1%; adjusted odds ratio, 0.91; 95% confidence interval, 0.53-1.55; P = 0.724) or per-graft incidence of vein graft failure (25.5% vs 25.9%; adjusted odds ratio, 0.96; 95% confidence interval, 0.59-1.55; P = 0.847) was observed. At 5 years, no difference was observed in the primary composite clinical outcome between patients who underwent open and closed system EVH (21.5% vs 23.9%; adjusted hazard ratio, 0.85; 95% confidence interval, 0.66-1.10; P = 0.221).

CONCLUSIONS

No differences in angiographic or clinical outcomes were observed among patients who underwent open versus closed tunnel endoscopic harvesting for coronary bypass surgery. These findings suggest that the risks associated with EVH that were reported in a previous PREVENT-IV analysis are not related to a specific EVH device.

Long-term clinical and angiographic outcomes in patients with diabetes undergoing coronary artery bypass graft surgery: results from the Project of Ex-vivo Vein Graft Engineering via Transfection IV trial

BACKGROUND

There is limited information about the association between diabetes, its treatment, and long-term angiographic and clinical outcomes in patients undergoing coronary artery bypass graft surgery (CABG). We evaluated the association of diabetes and its treatment with 1-year angiographic graft failure and 5-year clinical outcomes in patients undergoing CABG.

METHODS

Using data from 3,014 patients in PREVENT IV, we analyzed angiographic and clinical outcomes in patients with and without diabetes and among those who did and did not receive insulin before CABG. Logistic regression and Cox proportional hazards models were used to adjust for differences in baseline variables.

RESULTS

Overall, 1,139 (37.8%) patients had diabetes. Of these, 305 (26.8%) received insulin. One-year rates of vein graft failure were similar in patients with and without diabetes but, among diabetics, tended to be higher in patients who received insulin compared with those who did not. At 5 years, rates of death, myocardial infarction, or revascularization were higher among patients with compared with those without diabetes (adjusted hazard ratio 1.57; 95% CI 1.26-1.96; P < .001) and, among diabetics, higher among those who received insulin (adjusted hazard ratio 1.15; 95% CI 1.02-1.30; P = .02).

CONCLUSIONS

Patients with diabetes had similar rates of vein graft failure but worse clinical outcomes than patients without diabetes. Patients who received insulin had significantly worse clinical outcomes than patients who did not receive insulin. Further studies to better understand the mechanism behind these findings and to improve the outcomes of patients with insulin-requiring diabetes undergoing CABG surgery are warranted.

Vein graft preservation solutions, patency, and outcomes after coronary artery bypass graft surgery: follow-up from the PREVENT IV randomized clinical trial

IMPORTANCE

In vitro and animal model data suggest that intraoperative preservation solutions may influence endothelial function and vein graft failure (VGF) after coronary artery bypass graft (CABG) surgery. Clinical studies to validate these findings are lacking.

OBJECTIVE

To evaluate the effect of vein graft preservation solutions on VGF and clinical outcomes in patients undergoing CABG surgery.

DESIGN, SETTING, AND PARTICIPANTS

Data from the Project of Ex-Vivo Vein Graft Engineering via Transfection IV (PREVENT IV) study, a phase 3, multicenter, randomized, double-blind, placebo-controlled trial that enrolled 3014 patients at 107 US sites from August 1, 2002, through October 22, 2003, were used. Eligibility criteria for the trial included CABG surgery for coronary artery disease with at least 2 planned vein grafts.

INTERVENTIONS

Preservation of vein grafts in saline, blood, or buffered saline solutions.

MAIN OUTCOMES AND MEASURES

One-year angiographic VGF and 5-year rates of death, myocardial infarction, and subsequent revascularization.

RESULTS

Most patients had grafts preserved in saline (1339 [44.4%]), followed by blood (971 [32.2%]) and buffered saline (507 [16.8%]). Baseline characteristics were similar among groups. One-year VGF rates were much lower in the buffered saline group than in the saline group (patient-level odds ratio [OR], 0.59 [95% CI, 0.45-0.78; P < .001]; graft-level OR, 0.63 [95% CI, 0.49-0.79; P < .001]) or the blood group (patient-level OR, 0.62 [95% CI, 0.46-0.83; P = .001]; graft-level OR, 0.63 [95% CI, 0.48-0.81; P < .001]). Use of buffered saline solution also tended to be associated with a lower 5-year risk for death, myocardial infarction, or subsequent revascularization compared with saline (hazard ratio, 0.81 [95% CI, 0.64-1.02; P = .08]) and blood (0.81 [0.63-1.03; P = .09]) solutions.

CONCLUSIONS AND RELEVANCE

Patients undergoing CABG whose vein grafts were preserved in a buffered saline solution had lower VGF rates and trends toward better long-term clinical outcomes compared with patients whose grafts were preserved in saline- or blood-based solutions.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00042081.

Relationship between postoperative clopidogrel use and subsequent angiographic and clinical outcomes following coronary artery bypass grafting

Dual antiplatelet therapy with both aspirin and clopidogrel is increasingly used after coronary artery bypass grafting (CABG); however, little is known about the safety or efficacy. We sought to determine the relationship between postoperative clopidogrel and clinical and angiographic outcomes following CABG. We evaluated 3,014 patients from PREVENT IV who underwent CABG at 107 US sites. Postoperative antiplatelet therapy was left to physician discretion. Risk-adjusted angiographic and clinical outcomes were compared in patients taking and not taking clopidogrel 30 days post-CABG. At 30 days, 633 (21%) patients were taking clopidogrel. Clopidogrel users were more likely to have peripheral vascular (15 vs. 11%) and cerebrovascular disease (17 vs. 11%), prior myocardial infarction (MI) (46 vs. 41%), and off-pump surgery (33 vs. 18%). Clopidogrel use was associated with statistically insignificant higher graft failure (adjusted odds ratio 1.3; 95% confidence interval [CI] [1.0, 1.7]; P = 0.05). At 5-year follow-up, clopidogrel use was associated with similar composite rates of death, MI, or revascularization (27 vs. 24%; adjusted hazard ratio 1.1; 95% CI [0.9, 1.4]; P = 0.38) compared with those not using clopidogrel. There was an interaction between use of cardiopulmonary bypass and clopidogrel with a trend toward lower 5-year clinical events with clopidogrel in patients undergoing off-pump CABG. In this observational analysis, clopidogrel use was not associated with better 5-year outcomes following CABG. There may be better outcomes with clopidogrel among patients having off-pump surgery. Adequately powered randomized clinical trials are needed to determine the role of dual antiplatelet therapy after CABG.

Central venous pressure after coronary artery bypass surgery: does it predict postoperative mortality or renal failure?

OBJECTIVE

Although hemodynamic monitoring is often performed after coronary artery bypass grafting (CABG), the role of monitoring postoperative central venous pressure (CVP) measurement as a predictor of clinical outcomes is unknown. As such, this study tests the hypothesis that postoperative CVP is predictive of operative mortality or renal failure.

METHODS

This is an observational cohort study of detailed clinical data from 2390 randomly selected patients undergoing high-risk CABG or CABG/valve at 55 hospitals participating in the Society of Thoracic Surgeons' National Cardiac Surgery Database 2004-2005. Eligible patients underwent elective/urgent CABG with an ejection fraction less than 40% or elective/urgent CABG at 65 years or older with diabetes or a glomerular filtration rate less than 60 mL/min per 1.73 m2. The exposure of interest is CVP monitoring in the intensive care unit after adult cardiac surgery. The primary outcome measure was correlation between postoperative CVP and inhospital/30-day mortality and renal failure, assessed as a continuous variable, both unadjusted and after adjusting for important clinical factors using logistic regression modeling.

RESULTS

Mean age was 72 years, 54% of patients had diabetes mellitus, 49% were urgent procedures, and mean cardiopulmonary bypass time was 105 minutes. Patients' CVP 6 hours postoperation was strongly associated with inhospital and 30-day mortality: odds ratio (OR) of 1.5 (95% confidence interval [CI], 1.23-1.87) for every 5-mm Hg increase in CVP; P<.0001. This association remained significant after risk adjustment: adjusted OR of 1.44 (95% CI, 1.10-1.89); P<.01. A model adjusting for cardiac index also revealed increased incidence of mortality or renal failure: adjusted OR of 1.5 (95% CI, 1.28-1.86) for every 5-mm Hg increase in CVP; P<.0001.

CONCLUSIONS

Patients' CVP at 6 hours after CABG surgery was highly predictive of operative mortality or renal failure, independent of cardiac index and other important clinical variables. Future studies will need to assess whether interventions guided by postoperative CVP can improve patient outcomes.

Fractional flow reserve-guided coronary bypass surgery: should surgeons use it?

PURPOSE OF REVIEW

Physiology-based evaluation in stable ischemic heart disease is transforming percutaneous cardiovascular intervention (PCI). Fractional flow reserve (FFR)-guided PCI is associated with more appropriate and beneficial outcomes at lower costs. The surgical community can no longer ignore this development. We review evidence for the rationale, practicality and appropriateness of FFR-guided coronary artery bypass grafting (CABG), as compared with the current conventional, anatomy-based strategy for surgical revascularization.

RECENT FINDINGS

Physiologic evaluation links the nature (anatomic or functional) of coronary stenoses to the perfused myocardium supplied by the target vessel and challenges the use of anatomy as the sole criterion for revascularization intervention. In CABG, a functional perfusion deficit/ischemia identifies myocardial territories that would physiologically benefit from revascularization by grafting beyond the functional stenosis. Conversely, deliberately not grafting beyond an anatomic stenosis would dramatically change the procedure of CABG. Recent studies of functionally guided revascularization (PCI or CABG) support this approach, while recent trials of PCI vs. CABG demonstrated a late survival advantage with anatomy-based CABG. Finally, new intraoperative imaging technologies are elucidating the physiologic consequences of surgical revascularization in real time, yielding insights into resolving this dilemma.

SUMMARY

Physiologic-based revascularization is challenging our thinking about the historic strategy for CABG. Understanding better the physiologic consequences of revascularization will drive the evolution of CABG in the future.

Cardiovascular gene therapy for myocardial infarction

INTRODUCTION

Cardiovascular gene therapy is the third most popular application for gene therapy, representing 8.4% of all gene therapy trials as reported in 2012 estimates. Gene therapy in cardiovascular disease is aiming to treat heart failure from ischemic and non-ischemic causes, peripheral artery disease, venous ulcer, pulmonary hypertension, atherosclerosis and monogenic diseases, such as Fabry disease.

AREAS COVERED

In this review, we will focus on elucidating current molecular targets for the treatment of ventricular dysfunction following myocardial infarction (MI). In particular, we will focus on the treatment of i) the clinical consequences of it, such as heart failure and residual myocardial ischemia and ii) etiological causes of MI (coronary vessels atherosclerosis, bypass venous graft disease, in-stent restenosis).

EXPERT OPINION

We summarise the scheme of the review and the molecular targets either already at the gene therapy clinical trial phase or in the pipeline. These targets will be discussed below. Following this, we will focus on what we believe are the 4 prerequisites of success of any gene target therapy: safety, expression, specificity and efficacy (SESE).

FREEDOM, SYNTAX, FAME and FUNCTIONALITY: the future of surgical revascularization in stable ischemic heart disease

ABSTRACT: At the age of nearly 50 years, the procedure of coronary artery bypass grafting (CABG) now has the most solid evidence supporting its role in revascularization for stable ischemic heart disease in its history. In what is a relatively infrequent occurrence in medicine, the results from large-scale observational database analyses are now aligned with and supported by data from recent randomized trials, providing important contemporary evidence in support of CABG. However, even with strong evidence, the changing landscape of revascularization for stable ischemic heart disease threatens to make this evidence irrelevant in deciding which patients should be referred for CABG in the future. How the procedure of CABG could be modified and optimized for incorporation into this new landscape is discussed in this article.

Impact of extracardiac vascular disease on vein graft failure and outcomes after coronary artery bypass surgery

BACKGROUND

While extracardiac vascular disease (ECVD), defined as a history of peripheral vascular disease (PVD) or cerebrovascular disease (CBVD), is common in patients undergoing coronary artery bypass graft (CABG) surgery, there are limited data available on the association between ECVD, vein graft failure (VGF), and clinical outcomes.

METHODS

Using data from the Project of Ex-vivo Vein Graft Engineering via Transfection IV (PREVENTIV) trial (n = 3,014), 1-year angiographic follow-up and 5-year clinical outcomes (death, myocardial infarction, and revascularization) were determined in patients with and without ECVD. Logistic regression was used to assess risk of VGF. Generalized estimating equations methods were used to account for correlations in a graft-level analysis. Kaplan-Meier estimates and Cox hazards regression were used to compare clinical outcomes. We similarly explored the association of the individual components CBVD and PVD with both VGF and clinical outcomes in an additive model.

RESULTS

Patients with ECVD (n = 634, 21%) were older, more commonly female, and had more comorbidities, lower use of internal thoracic artery grafting, and overall worse graft quality than patients without ECVD. VGF rates tended to be higher (patient-level: odds ratio [OR]: 1.23, 95% confidence interval [CI] 0.96 to 1.58, p = 0.099; graft-level: OR: 1.23, 95% CI: 1.00 to 1.53, p = 0.053) in patients with ECVD. VGF rates were significantly higher among CBVD patients (OR: 1.42, 95% CI: 1.03 to 1.97, p = 0.035; graft-level: OR: 1.40, 95% CI: 1.06 to 1.85, p = 0.019). Patients with ECVD had a higher risk of death, myocardial infarction, or revascularization 5 years after CABG surgery (hazard ratio [HR]: 2.96, 95% CI: 2.02 to 4.35, p < 0.001). This relationship was driven by the subset of patients with PVD (HR = 3.32, 95% CI: 2.16 to 5.09, p < 0.001) and not by those with CBVD (HR = 1.10, 95% CI: 0.88 to 1.37, p = 0.40).

CONCLUSIONS

ECVD is common among patients undergoing CABG surgery and is associated with similar short-term but increasingly worse long-term clinical outcomes. This higher risk may be partly, but not exclusively, due to higher rates of VGF among these patients.

Assessment of a novel, capsid-modified adenovirus with an improved vascular gene transfer profile

Background

Cardiovascular disorders, including coronary artery bypass graft failure and in-stent restenosis remain significant opportunities for the advancement of novel therapeutics that target neointimal hyperplasia, a characteristic of both pathologies. Gene therapy may provide a successful approach to improve the clinical outcome of these conditions, but would benefit from the development of more efficient vectors for vascular gene delivery. The aim of this study was to assess whether a novel genetically engineered Adenovirus could be utilised to produce enhanced levels of vascular gene expression.

Methods

Vascular transduction capacity was assessed in primary human saphenous vein smooth muscle and endothelial cells using vectors expressing the LacZ reporter gene. The therapeutic capacity of the vectors was compared by measuring smooth muscle cell metabolic activity and migration following infection with vectors that over-express the candidate therapeutic gene tissue inhibitor of matrix metalloproteinase-3 (TIMP-3).

Results

Compared to Adenovirus serotype 5 (Ad5), the novel vector Ad5T*F35++ demonstrated improved binding and transduction of human vascular cells. Ad5T*F35++ mediated expression of TIMP-3 reduced smooth muscle cell metabolic activity and migration in vitro. We also demonstrated that in human serum samples pre-existing neutralising antibodies to Ad5T*F35++ were less prevalent than Ad5 neutralising antibodies.

Conclusions

We have developed a novel vector with improved vascular transduction and improved resistance to human serum neutralisation. This may provide a novel vector platform for human vascular gene transfer.

Fractional flow reserve-guided coronary artery bypass grafting: can intraoperative physiologic imaging guide decision making?

OBJECTIVES

Fractional flow reserve-guided coronary artery bypass grafting is emerging in cardiac surgery, in which the nature (anatomic and functional characteristics) of the target vessel epicardial coronary artery stenosis is important in graft site selection. The nature of the stenosis might determine a different physiologic response to bypass grafting. We report our recent experience using near infrared fluorescence complex angiography and perfusion analysis to identify the nature of stenoses in the target vessel by imaging the physiologic response to grafting.

METHODS

In 167 patients who underwent consecutive multivessel coronary artery bypass grafting cases (63% off-pump coronary artery bypass grafting) with traditional anatomy-based revascularization, we imaged and analyzed 359 grafts (53% arterial). This platform provides angiographic data of both the target vessel epicardial coronary artery and graft simultaneously (to assess the imaged competitive flow); and because a change in fluorescence intensity is proportional to the change in blood flow and perfusion, the quantified change (if any) in regional myocardial perfusion surrounding the grafted target vessel epicardial coronary artery.

RESULTS

The patient outcomes in our series were excellent. All 359 grafts were widely patent by angiography, and 24% of the arterial and 22% of the saphenous vein grafts showed no regional myocardial perfusion change in response to bypass grafting. In 165 in situ internal mammary artery grafts to the left anterior descending artery (>70% stenosis), 40 had no change in regional myocardial perfusion, and 32 of the 40 had competitive flow imaged.

CONCLUSIONS

An important number of angiographically patent bypass grafts demonstrated no change in regional myocardial perfusion, suggesting anatomic, but nonfunctional, stenoses in those target vessel epicardial coronary arteries. In in situ arterial grafts, imaged competitive flow is associated with nonfunctional stenoses in the target vessel epicardial coronary artery. Imaging these physiologic responses to target vessel revascularization might be useful in the emerging fractional flow reserve-guided era.