Long-term histological and immunohistochemical findings in human venous aorto-coronary bypass grafts

Chronic Total Occlusion Percutaneous Coronary Intervention in Patients With Prior Coronary Artery Bypass Graft: Current Evidence and Future Perspectives

Coronary chronic total occlusion (CTO), which occurs in 18. 4–52% of all patients referred for coronary angiography, represents one of the last barriers in coronary intervention. Approximately half of all patients with prior coronary artery bypass graft (CABG), who undergo coronary angiography, are diagnosed with coronary CTO. In fact, these patients often develop recurrent symptoms and events, necessitating revascularization. Currently, there is neither a consensus nor developed guidelines for the treatment of CTO patients with prior CABG, and the prognosis of these patients remains unknown. In this review, we discuss current evidence and future perspectives on CTO revascularization in patients with prior CABG, with special emphasis on clinical and lesion characteristics, procedural success rates, periprocedural complications, and long-term outcomes.

Periprocedural and In-Hospital Outcomes Among Percutaneous Coronary Intervention in Saphenous Vein Graft: A Retrospective Observational Study at a Tertiary Care Hospital in South Asian Country

Background

Saphenous vein graft (SVG) may occlude either early or several months to years after coronary artery bypass graft (CABG) surgery. Doing re-do CABG surgery is associated with higher complication and mortality rate as compared to percutaneous coronary intervention (PCI) in SVG. However, PCI of SVG is associated with more periprocedural and in-hospital complications as compared to PCI of native coronary arteries. Due to the scarcity of local data in this regard, this study was designed to estimate the periprocedural and in-hospital outcomes among PCI in SVG.

Objectives

We aim to study the periprocedural and in-hospital outcomes among patients who underwent PCI in SVG.

Methods

It is a retrospective observational study. We reviewed hospital record files of 167 consecutive patients, admitted to Aga Khan University Hospital, Karachi, from January 2010 to December 2019, who underwent PCI in SVG.

Results

Out of 167 patients, 145 (86.8%) were male with a mean age of 72.26 (±8.46) years. Hypertension was the most common comorbid condition. Majority of 141(84.4%) patients presented within 6-10 years since the last CABG done. Seventy-eight (46.7%) patients presented with non-ST elevation myocardial infarction (NSTEMI). Patients who presented with acute coronary syndrome (ACS), 51 (36.9%), and 21 (15.2%) had congestive heart failure and cardiogenic shock on presentation respectively. Coronary angiography was performed in the majority of 155 (92.8%) patients through the femoral artery. The body of the SVG was the most common site affected by the disease. In 88 (52.7%) patients stents were deployed in SVG to obtuse marginal (OM). Drug-eluting stents (DES) were used in 124 (74.3%) patients. 22 (13.2%) of patients developed periprocedural complications, predominantly slow flow and 7 (4.2)% patients had in-hospital complications.

Conclusions

PCI of SVG is associated with a high procedural success rate and acceptable risk for periprocedural and in-hospital complications. PCI of SVG may be considered as a safe and efficacious option for the percutaneous intervention of SVG lesions.

Intravascular lithotripsy in saphenous vein grafts and graft stent failure: A case series

The long-term patency of saphenous vein grafts (SVGs) is poor compared to arterial bypass grafts. Re-do coronary artery bypass graft surgery (CABG) is high risk, thus graft failure often requires revascularization with percutaneous coronary intervention (PCI). While PCI to the native vessels is preferable, PCI to SVGs is sometimes necessary despite being associated with a high incidence of stent failure. While early SVG degeneration is associated with friable disease, calcification becomes an increasing problem in older grafts. Intravascular Lithotripsy (IVL) has been demonstrated to be safe and effective in the treatment of calcified native coronary artery disease (CAD). We present the first case series of five patients undergoing PCI to de novo SVG disease or SVG stent failure utilizing IVL for calcium modification.

Long-Term Outcome of Consecutive Patients With Previous Coronary Bypass Surgery, Treated With Newer-Generation Drug-Eluting Stents

Background

Percutaneous coronary intervention (PCI) in patients with previous coronary artery bypass grafting (CABG) is associated with adverse clinical events. Although newer generation drug‐eluting stents showed favorable short‐term safety profiles, there is a lack of long‐term outcome data. We evaluated the impact of previous CABG on 5‐year clinical outcomes of patients treated with PCI using newer‐generation drug‐eluting stents.

Methods and Results

In this patient‐level pooled analysis of the prospective TWENTE (The Real‐World Endeavor Resolute versus Xience V Drug‐Eluting Stent Study in Twente) trial and nonenrolled TWENTE registry, we assessed a consecutive series of patients who underwent PCI with newer‐generation drug‐eluting stents for non–ST‐segment–elevation acute coronary syndromes or stable angina. Of all 1709 patients, 202 (11.8%) had a history of CABG. Patients with previous CABG had significantly higher 5‐year rates of cardiac death (10.4% versus 4.3%; P<0.001) and target vessel revascularization (25.0% versus 8.1%; P<0.001). These differences remained statistically significant after adjustment for differences in baseline characteristics. Landmark analysis revealed that from 1‐ to 5‐year follow‐up, the rates of cardiac death (8.1% versus 3.2%; P<0.001) and target vessel revascularization (17.1% versus 5.9%; P<0.001) were significantly higher in patients with previous CABG. Among patients with a history of CABG, PCI of an obstructed vein graft was associated with a higher rate of 5‐year target vessel revascularization (P=0.003).

Conclusions

At 5‐year follow‐up after PCI with newer‐generation drug‐eluting stents, the risk of cardiac death and target vessel revascularization was significantly higher in patients with previous CABG. The target vessel revascularization rate was highest in patients who underwent PCI of obstructed vein grafts.

Drug-eluting stents appear superior to bare metal stents for vein-graft PCI in vessels up to a stent diameter of 4 mm

Background

Research trials have shown improved short-term outcome with drug-eluting stents (DES) over bare metal stents (BMS) in saphenous vein graft (SVG) percutaneous coronary intervention (PCI), primarily by reducing target vessel revascularization (TVR) for in-stent restenosis. We compared the outcomes in patients undergoing SVG stent implantation treated with DES or BMS. In exploratory analyses we investigated the influence of stent generation and diameter.

Methods

Data were obtained from a prospective database of 657 patients who underwent PCI for SVG lesions between 2003 and 2011. A total of 344 patients had PCI with BMS and 313 with DES. Propensity scores were developed based on 15 observed baseline covariates in a logistic regression model with stent type as the dependent variable. The nearest-neighbour-matching algorithm with Greedy 5-1 Digit Matching was used to produce two patient cohorts of 313 patients each. We assessed major adverse cardiac events (MACE) out to a median of 3.3 years (interquartile range: 2.1-4.1). MACE was defined as all-cause mortality, myocardial infarction (MI), TVR and stroke.

Results

There was a significant difference in MACE between the two groups in favour of DES (17.9% DES vs. 31.2% BMS group; p = 0.0017) over the 5-year follow-up period. MACE was driven by increased TVR in the BMS group. There was no difference in death, MI or stroke. Adjusted Cox analysis confirmed a decreased risk of MACE for DES compared with BMS 0.75 (95% confidence interval (CI) 0.52-0.94), with no difference in the hazard of all-cause mortality (hazard ratio: 1.08; 95% CI: 0.77-1.68). However, when looking at stent diameters greater than 4 mm, no difference was seen in MACE rates between BMS and DES.

Conclusions

Overall in our cohort of patients who had PCI for SVG disease, DES use resulted in lower MACE rates compared with BMS over a 5-year follow-up period; however, for stent diameters over 4 mm no difference in MACE rates was seen.

Repeat revascularization: Percutaneous coronary intervention after coronary artery bypass graft surgery

Repeat myocardial revascularization procedures are markedly different from de novo interventions, with increased procedural risk and technical-demanding complexity. However the number of patients previously treated with coronary artery bypass graft (CABG) that need a repeat revascularization due to graft failure is increasing consistently. Late graft failure, usually caused by saphenous vein grafts (SVG) attrition, is certainly not uncommon. However PCI on degenerated SVG presents higher complication rate and worse clinical outcome compared with native arteries interventions. In acute graft failure setting, PCI represents a valuable option to treat postoperative myocardial infarction.

The impact of diabetes mellitus on long-term clinical outcomes after percutaneous coronary saphenous vein graft interventions in the drug-eluting stent era

OBJECTIVES

We aimed to compare early and late clinical outcomes in diabetic and nondiabetic patients who underwent saphenous vein graft (SVG) percutaneous coronary interventions (PCI) with the use of drug-eluting stents (DES).

BACKGROUND

Patients with diabetes mellitus are shown to have less favorable outcomes after SVG intervention with the use of bare metal stents. In the DES era, the impact of diabetes mellitus on restenosis and clinical outcomes post-SVG intervention is not clearly defined.

METHODS

From our institutional PCI registry database, we retrospectively analyzed 477 consecutive patients with prior coronary artery bypass graft surgery undergoing SVG PCI with the implantation of DES stratified by the presence or absence of diabetes mellitus. The primary end-point was 1-year major adverse cardiac event (MACE) rate, defined as death, Q wave myocardial infarction, and target lesion revascularization.

RESULTS

Baseline clinical characteristics, including mean graft age (120 ± 77 vs. 131 ± 86 months, P = 0.14), were similar between groups, save for a higher prevalence of systemic hypertension and chronic renal insufficiency, and higher body mass index in the diabetic group. Among the 604 SVG lesions treated with DES, the angiographic and procedural characteristics were well matched between groups except for the higher rate of distal protection device use (32% vs. 29%, P = 0.007) in the diabetic group. The rates of 1-year MACE (21% vs. 15%, P = 0.12) and all-cause mortality (7.6% vs. 6.7%, P = 0.86) were similar between groups. After adjustment for the relevant clinical co-variables, diabetic status was not associated with the composite end-point.

CONCLUSION

In conclusion, DES, when used for the treatment of vein graft lesions, equate the short- and long-term outcomes between diabetic and nondiabetic patients, suggesting that DES should be considered the default stent in diabetic populations undergoing PCI for the treatment of SVG lesions.

Aspirate from human stented native coronary arteries vs. saphenous vein grafts: more endothelin but less particulate debris

Stent implantation into atherosclerotic coronary arteries releases particulate debris and soluble substances that contribute to impaired microvascular perfusion. Here we addressed the potential for microvascular obstruction in patients with stenotic native right coronary arteries (nRCA) compared with saphenous vein grafts on right coronary arteries (SVG-RCA). We enrolled symptomatic, male patients with stable angina pectoris and a flow-limiting stenosis in their nRCA or SVG-RCA ( n = 18/18). Plaque volume and composition were analyzed using intravascular ultrasound before stent implantation. Coronary aspirate was retrieved during stent implantation under protection with a distal occlusion/aspiration device and divided into particulate debris and plasma. The release of catecholamines, endothelin, serotonin, thromboxane B2, and tumor necrosis factor-α was measured. The response of rat mesenteric arteries with intact (+E) and denuded (−E) endothelium to aspirate plasma (without and with selective endothelin receptor blockade) was normalized to that by potassium chloride (KClmax = 100%). Plaque volume and composition were not different between nRCA and SVG-RCA. There was less particulate debris (65 ± 8 vs. 146 ± 23 mg; P < 0.05) and more endothelin release (5.8 ± 0.8 vs. 1.3 ± 0.7 pg/ml; P < 0.05) in nRCA than in SVG-RCA, whereas the release of the other mediators was not different. Aspirate from nRCA induced stronger vasoconstriction than that from SVG-RCA [nRCA, 78 ± 6% (+E)/84 ± 5% (−E); SVG-RCA, 59 ± 6% (+E)/68 ± 3% (−E); P < 0.05 nRCA vs. SVG-RCA], which was attenuated by a nonspecific endothelin and a specific endothelin receptor A antagonist. Thus coronary aspirate from stented nRCA is characterized by less debris but more endothelin and stronger vasoconstrictor response than that from SVG-RCA.

Long-term safety and efficacy of drug-eluting and bare metal stents in saphenous vein grafts

BACKGROUND

Long-term safety and efficacy data of drug-eluting stents (DESs) in saphenous vein grafts (SVGs) are lacking. This study sought to compare the clinical outcomes of DES versus bare metal stents (BMS) in SVGs.

METHODS

We studied all stent implantations in SVGs in Sweden during 74 months between 2005 and 2011 registered in the Swedish Coronary Angiography and Angioplasty Registry. We evaluated outcome in patients who received DES compared with those who received BMS after adjustments for differences in clinical, vessel, and lesion characteristics.

RESULTS

Mean follow-up time was 3 years and 4 months. A total of 4,576 stents, implanted at 3,063 procedures, were included in the analysis of which 2,499 stents (54.6 %) were BMS and 2,077 (45.4%) were DES. The outcome analysis was based on 190 stent thromboses, 898 restenoses, and 523 deaths. The incidence of stent thrombosis did not differ between groups. When adjusted for baseline characteristics, including a propensity score for receiving DES, the incidence of restenosis was significantly lower with DES as compared with BMS (risk ratio 0.83, 95% CI 0.70-0.97, P = .019). There was a difference in mortality in the crude analysis between DES and BMS, and after multivariable adjustment, this difference remained statistically significant (risk ratio 0.80, CI 0.65-0.99, P = .038).

CONCLUSIONS

The use of DES compared with BMS in SVGs was associated with a significantly lower adjusted incidence of restenosis and death in this large, national, all-encompassing propensity adjusted observational study.

Paclitaxel-eluting stents reduce neointimal hyperplasia compared to bare metal stents in saphenous vein grafts: intravascular ultrasonography analysis of the SOS (Stenting of Saphenous Vein Grafts) trial

AIMS

To compare the intravascular ultrasonography (IVUS) findings between saphenous vein grafts (SVG) treated with paclitaxel-eluting stents (PES) vs. bare metal stents (BMS) in the Stenting Of Saphenous Vein Grafts (SOS) trial.

METHODS AND RESULTS

Of the 80 SOS trial patients, 38 had both baseline and follow-up IVUS examination and were included in this substudy: 17 patients received 28 BMS in 26 lesions and 21 patients received 30 PES in 28 lesions. Quantitative IVUS analysis was performed to determine the volume of in-stent neointimal hyperplasia (NIH) - defined as the difference between stent volume and lumen volume in the stented segments. Baseline characteristics were similar between patients who did and did not undergo baseline and follow-up IVUS. Patients receiving BMS and PES had similar stent and lumen volumes immediately after stenting. At 12-month follow-up, compared to BMS, PES-treated lesions had significantly less NIH volume (3.4 vs. 21.9 mm³, p<0.001) and neointima hyperplasia progression (1.6 vs. 17.1 mm³, p<0.001). No significant differences were seen in the 5 mm segment proximal and distal to the stent.

CONCLUSIONS

Compared to BMS, use of PES in SVG lesions is associated with significantly lower NIH formation, which may help explain the improved clinical outcomes with PES in these lesions.

Late outcomes of drug eluting and bare metal stents in saphenous vein graft percutaneous coronary intervention

AIMS

PCI with drug eluting stents (DES) has been shown to reduce restenosis and major adverse cardiac event (MACE) rates compared to bare metal stents (BMS) in native coronary vessels, although outcomes in saphenous vein graft (SVG) lesions are less clear. We retrospectively studied 388 consecutive patients admitted to our centre for SVG PCI to assess mortality and MACE outcomes (defined as composite endpoint of all-death, stroke, myocardial infarction, stent thrombosis and target lesion (TLR)/vessel (TVR) revascularisation) associated with BMS and DES use.

METHODS AND RESULTS

Two hundred and nineteen (219) patients had BMS and 169 had DES (total 388 patients). Mean follow up was 41.9±23.5 months. No significant differences were observed in mortality (14.2% vs. 11.8%) or MACE (37.6% vs. 35.8%) between the BMS and DES groups at four years follow-up or at other intervening time points studied. Similarly, no differences in TVR/TLR rates were observed over a similar time period (19.8% vs. 21.6%).

CONCLUSIONS

We have observed that DES and BMS use in SVG PCI have comparable mortality and MACE rates, and that in contrast to PCI in native coronary arteries, DES do not reduce revascularisation rates in our study cohort.

Drug-eluting versus bare-metal stent for treatment of saphenous vein grafts: a meta-analysis

BACKGROUND

Saphenous vein grafts develop an aggressive atherosclerotic process and the efficacy of drug eluting stents (DES) in treating saphenous vein graft (SVG) lesions has not been convincingly demonstrated. The aim of this study was to review and analyze the current literature for controlled studies comparing DES versus bare metal stents (BMS) for treatment of SVG stenoses.

METHODOLOGY/PRINCIPAL FINDINGS

We searched several scientific databases and conference proceedings up to March 15, 2010 for controlled studies comparing target vessel revascularization (TVR) between DES and BMS. Summary odds ratios (OR) for the primary endpoint TVR and secondary endpoints infarction, stent thrombosis and death were calculated using random-effect models. A total of 29 studies (3 randomized controlled trials RCT) involving 7549 (202 in RCT) patients were included. The need for target vessel revascularization in the DES group tended to be lower compared to BMS for the 3 RCT (OR 0.50 [0.24-1.00]; p = 0.051) and for observational studies (0.62 [0.49-0.79]; p<0.001). There was no significant difference in the risk for myocardial infarction in the RCT (OR 1.25 [0.22-6.99]; p = 0.250) but a lower risk for DES based on the observational studies 0.68 [0.49-0.95]; p = 0.023. The risk for stent thrombosis was found to be non-different in the RCT (OR 0.78 [0.03-21.73], p = 0.885) while it was in favor of DES in the observational studies (0.58 [0.38 - 0.84]; p<0.001). The mortality was not significantly different between DES and BMS in the RCT's (OR 2.22 [0.17 - 29.50]; p = 0.546) while the observation studies showed a decreased mortality in the DES group (0.69 [0.55-0.85]; p<0.001).

CONCLUSION

DES may decrease TVR rate in treatment of SVG stenoses. No differences in reinfarction rate, stent thrombosis or mortality was found between the DES and BMS groups in the RCT's while the observational data showed lower risk for myocardial infarction, stent thrombosis and death in the DES group. This may be a result of patient selection bias in the observational studies or represent a true finding that was not the detected in the RCT analysis due to limited statistical power.