Determinants of embolic protection device use: Case study in the acceptance of a new medical technology

Comparison of procedural success and long-term outcomes of stent thrombosis in coronary bypass grafts versus native coronary arteries

Percutaneous coronary intervention within bypass grafts accounts for a significant percentage of total interventions. Bypass graft interventions are associated with an increased risk for stent thrombosis (ST), a condition that leads to significant morbidity and mortality. Despite this, the procedural characteristics and long-term outcomes of patients with bypass-graft ST have not been reported. The aim of the present study was to evaluate the procedural success and long-term outcomes of patients presenting with ST of coronary bypass grafts. Clinical and procedural characteristics of 205 ST cases at 5 academic hospitals were reviewed. Long-term mortality and major adverse cardiovascular events (stroke, reinfarction, and revascularization) were ascertained through review of medical records and the Social Security Death Index. Kaplan-Meier analysis was used to determine the association between ST in a bypass graft and long-term outcomes. Thirteen patients (6%) in the cohort presented with ST of a coronary bypass graft. Patients with bypass-graft ST had less severe presentations with a lower proportion of ST-segment elevation myocardial infarction (23% vs 69%, p <0.001). Despite this, ST of a bypass graft was associated with a trend toward reduced postprocedural Thrombolysis In Myocardial Infarction (TIMI) flow grade (p = 0.09), leading to lower angiographic (58% vs 92%, p <0.001) and procedural (62% vs 92%, p <0.001) success. After multivariate adjustment, bypass-graft ST was associated with increased long-term mortality (hazard ratio 3.3, 95% confidence interval 1.0 to 10.7) and major adverse cardiovascular events (hazard ratio 2.7, 95% confidence interval 1.1 to 6.9). In conclusion, ST in coronary bypass grafts is associated with reduced angiographic and procedural success as well as increased long-term major adverse cardiovascular events compared to ST in native coronary vessels.

Selective use of embolic protection devices during saphenous vein grafts interventions: a single-center experience

OBJECTIVES

To report on outcomes with selective use of embolic protection devices (EPD) during percutaneous coronary intervention (PCI) to saphenous vein grafts (SVG).

BACKGROUND

PCI to SVG is associated with increased risk and the use of EPD is recommended in this setting.

METHODS

Angiographic and clinical outcomes were prospectively obtained from 534 consecutive patients who underwent PCI to SVG with or without EPD at a tertiary cardiac centre. Long-term outcomes were obtained by linkage to a provincial registry.

RESULTS

EPD, deployed in 198 of 373 SVGs (53%) suitable for deployment of a distal EPD, were used more often in ectatic (33% vs. 19%, P = 0.003), ulcerated (17% vs. 9%, P = 0.03), thrombotic (26% vs. 10%, P < 0.0001) vein grafts, with longer degenerated segments (P = 0.002), and in lesions involving the body of the graft (85% vs. 66%, P < 0.0001), and less with lesions involving the graft ostium (29% vs. 44%, P = 0.003). Patients suitable for but not receiving EPD tended to be more likely to have a periprocedural myocardial infarction. During 3 years of follow-up, 49% of the patients had a cardiovascular event. Cumulative mortality was 8.4%, 18.8% and 14.7% in patients unsuitable for distal EPD, suitable but without EPD, and with EPD (p = 0.11). Nonuse of EPD was an independent predictor of MACE at 3 years. (P = 0.02).

CONCLUSIONS

Selective use of EPD is associated with low in-hospital cardiovascular event rates. Long-term outcomes are manifested by a high rate of events, especially in patients with SVG's suitable for but not receiving EPD. This suggests that routine use of distal EPD may be warranted in unselected patients with suitable SVG anatomy.

Proximal protection in recanalization of totally occluded saphenous vein grafts in acute coronary syndrome

Percutaneous treatment of old, degenerated saphenous vein grafts (SVG) is associated with a high likelihood of major adverse cardiac events. When an acute coronary syndrome (ACS) develops in a patient with old SVG, fresh thrombus may superimpose on an old, degenerative atheroma: a sudden increase in the athero-thrombotic burden ensues with consequent, frequent total occlusion of the lumen. In this scenario, transluminal recanalization of the graft is usually associated with the highest chance of distal embolization and no-reflow and positioning of an embolic protection device (EPD) is almost mandatory. However, distal EPD are difficult to place when the vessel is totally occluded and do not completely avoid distal embolization. We report two cases of totally occluded SVG in patients admitted for ACS that were recanalized with the aid of a proximal EPD system with angiographic and clinical success.

Successful treatment of saphenous venous graft thrombus by tirofiban infusion

A 60-year old man with a history of coronary-artery bypass grafting presented with symptoms of acute coronary syndrome. Coronary angiography revealed a huge intraluminal thrombus in the saphenous vein graft to the second obtuse marginal branch of the left circumflex artery. A glycoprotein IIb/IIIa inhibitor (tirofiban) was administered intravenously. Two days later, thrombus dissolution and Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow were evident on repeat coronary angiography. Glycoprotein IIb/IIIa inhibitors may be useful in a thrombus-laden saphenous-vein graft.

Saphenous Vein Graft Stenting and Major Adverse Cardiac Events

Background— Treatment of saphenous vein graft (SVG) stenosis with percutaneous coronary intervention has a 15% to 20% incidence of major adverse cardiac events (MACE) within 30 days. Although MACE rates are reduced significantly by the use of embolic protection devices (EPDs), neither the level of baseline risk nor the benefit provided by EPDs has been well characterized.

Methods and Results— Data from 5 randomized controlled trials and 1 registry evaluating EPDs in SVG percutaneous coronary intervention (n=3958 patients) were pooled for analysis. MACE was defined as a composite of death, myocardial infarction, and target vessel revascularization. Baseline variables and 2 summary angiographic variables (an SVG degeneration score and an estimate of lesion plaque volume) were included in a multivariable logistic regression model to predict 30-day MACE, with adjustment for the type of device used and inter-study variation. The angiographic variables were potent predictors of MACE (increasing SVG degeneration score, P <0.0001; larger estimated plaque volume, P <0.0001), with significant contributions from the presence of thrombus ( P <0.01), increasing patient age ( P <0.01), glycoprotein IIb/IIIa inhibitor use ( P =0.02), and current tobacco abuse ( P =0.03). The treatment benefit of EPDs was preserved across all categories of risk as categorized by SVG degeneration or plaque volume.

Conclusions— The strongest predictors of 30-day MACE in SVG percutaneous coronary intervention are angiographic estimates of plaque volume and SVG degeneration. Identification of these predictors of 30-day MACE allows reliable prediction of patient outcomes and confirms consistent treatment benefit with the use of EPDs across the range of patients tested in randomized trials.

Thrombus predicts ischemic complications during percutaneous coronary intervention in saphenous vein grafts: Results from TARGET (do tirofiban and reopro give similar efficacy trial?)

BACKGROUND

Saphenous vein graft (SVG) percutaneous coronary intervention (PCI) carries a high risk of ischemic complications. However, there are scant recent data to identify which SVG lesions carry particularly high risk in recent years. We studied demographic and angiographic factors associated with ischemic complications after SVG PCI without distal protection in the TARGET (do tirofiban and reopro give similar efficacy trial?) study.

METHODS

TARGET was a multicenter double-dummy, double-blinded study randomizing 4,809 PCI patients to tirofiban or abciximab. Of these, 254 patients underwent PCI involving an SVG lesion. The primary endpoint of this analysis was major adverse cardiac events (MACEs) at 30 days, including death, nonfatal myocardial infarction (MI), and urgent target vessel revascularization.

RESULTS

No demographic characteristic was associated with 30-day MACE. Lesion length > 20 mm (odds ratio [OR] = 2.7, P = 0.03), thrombus (OR = 3.9, P = 0.003), eccentricity (P = 0.001), thrombolysis in myocardial infarction flow < 3 post-procedure (OR = 5.6, P = 0.037), and >1 target lesion (OR = 2.5, P = 0.035) were univariate variables associated with 30-day MACE. Multivariate analysis associated only thrombus (OR = 3.8, P = 0.015) with 30-day MACE. No difference in outcomes was noted between patients receiving abciximab and tirofiban. SVG patients had lesser angiographic success (95.6% vs. 98%, P = 0.04) and increased 30-day Q-wave MI (2.5% vs. 0.9%, P = 0.039) compared with non-SVG patients, but a similar incidence of death (0% vs. 0.4%), non-Q-MI (5.9% vs. 4.5%), and target vessel revascularization (0.5% vs. 1%).

CONCLUSION

In the era of routine stenting and GpIIb/IIIa inhibitors, thrombus is the angiographic characteristic most closely associated with adverse outcomes of SVG PCI.