Stone GW Rogers C Hermiller J et al Reference

Circulation 2003; 108: 548-553 Abstract

BACKGROUND: The high rate of periprocedural complications resulting from atherothrombotic embolization after percutaneous intervention in diseased saphenous vein grafts is reduced by distal microcirculatory protection using a balloon occlusion and aspiration system. Whether filter-based catheters, which offer the inherent advantages of maintained perfusion and ease of use, are as effective for this purpose has not been established. METHODS AND RESULTS: A total of 651 patients undergoing percutaneous intervention of 682 saphenous vein graft lesions were prospectively randomized to distal protection with the filter-based Boston Scientific FilterWire EX versus the Medtronic GuardWire balloon occlusion and aspiration system. Device success was 95.5% and 97.2% with the FilterWire EX and GuardWire, respectively (p = 0.25). Postprocedural measures of epicardial flow and angiographic complications were similar between the 2 groups, although bailout Ilb/IIIa inhibitors were required slightly less frequently in the FilterWire EX group (0% versus 1.5%, p = 0.03). The primary end point, the composite incidence of death, myocardial infarction, or target vessel revascularization at 30 days, occurred in 9.9% of FilterWire EX patients and 11.6% of GuardWire patients (difference [95% CI] = -1.7% [-6.4%, 3.1%]; p for superiority = 0.53, p for noninferiority = 0.0008). CONCLUSIONS: Distal protection with the FilterWire EX may be safely used as an adjunct to percutaneous intervention of diseased saphe-nous vein grafts and, compared with distal protection with the GuardWire balloon occlusion and aspiration system, results in similar rates of major adverse cardiac events at 30 days.

Summary

Due to the fact that percutaneous coronary intervention (PCI) of diseased saphenous vein grafts (SVG) results in the distal embolization of atherosclerotic debris, a need arose for a device or devices that could protect the distal vessel during PCI from being showered with debris and resulting in periprocedural myocardial infarction (MI). A balloon occlusion and aspiration device, the Medtronic GuardWire, was developed and tested in a multicentre, randomized trial vs. no protection. The result was that the use of the GuardWire led to less periprocedural events and a higher angiographical and clinical success rate. Use of the GuardWire necessitates complete occlusion of the SVG, which has resulted in transient hypotension, angina, and left ventricular dysfunction. A new filter device, the Boston Scientific FilterWire EX, was developed to protect the microcirculation without having the SVG completely occluded.

The primary end point was the 30-day composite incidence of major adverse cardiac events (MACE), including death, MI, or target vessel revascularization. A total of 332 patients with

CK-MB

Figure 1 Cumulative frequency distribution curves of peak postprocedural CK-MB for patients randomized to FilterWire EX vs. the GuardWire. Each curve represents the percentage of patients whose CK-MB elevation exceeds the value on the xaxis.

CK-MB

Figure 1 Cumulative frequency distribution curves of peak postprocedural CK-MB for patients randomized to FilterWire EX vs. the GuardWire. Each curve represents the percentage of patients whose CK-MB elevation exceeds the value on the xaxis.

348 grafts were randomized to the FilterWire EX compared to 319 patients with 334 grafts in the GuardWire group. All patients received 325 mg of aspirin and were loaded with either 300 mg of clopidogrel or 500 mg of ticlodipine within 4 h after the procedure. The use of glycoprotein Ilb/IIIa inhibitors was left to the individual operator's discretion. Device success rates for the devices were 95% for the FilterWire and 97% for the GuardWire. There was no statistically significant difference in the end point between the two devices (Figure 1). Postprocedural measures of epicardial coronary blood flow, procedural complications, and postprocedural creatine kinase myocardial band (CK-MB) release were similar between the two groups; however, the use of glycoprotein IIb/IIIa inhibitors for "bailout" was slightly higher in the GuardWire group.

Citation Count 30

Strengths

This was a well-designed randomized, controlled trial that demonstrated the benefit of using a new distal protection device for PCI of SVGs. This trial showed that the newer filter device was not inferior to the established balloon occlusion and aspiration device.

Weaknesses

The trial could potentially expose weaknesses of the GuardWire system, namely the downsides of left ventricle (LV) dysfunction and angina that accompany total occlusion of a diseased SVG while undergoing PCI; however, the trial is not ambitious enough to prove a difference in terms of MI or LV function assessment postprocedure. Instead, they use a composite end point with the goal of being non-inferior.

Key message

In a population similar to that used in the trial that established the GuardWire as the standard of care for PCI of SVGs, a new filter device was shown to be as safe and effective (p for non-inferiority = 0.0008) as the established balloon occlusion and aspiration system. The benefit of

Table 1 Procedural outcomes and acceleration index (AI). Circulation 2003; 108: 548-553

FilterWire EX GuardWire p

Table 1 Procedural outcomes and acceleration index (AI). Circulation 2003; 108: 548-553

FilterWire EX GuardWire p

Number of patients, Number of lesions

332,

348

319,

334

-

Procedure duration* (min)

59.0

i 30.5

62.1

± 30.3

0.21

Device success (%)

95.5

97.2

0.25

Failure to deliver device

3.9

0.6

0.005

Failure to deploy filter

0.6

-

-

Failure to inflate balloon

-

0.9

-

Failure to maintain occlusion, or rupture

-

1.2

-

Clinical success (%)

85.8

86.2

0.89

GP IIB/GP IIA inhibitors used before intervention(%)

51.5

53.3

0.65

GP IIB/GP IIA inhibitors used during procedure (%)

0

1.5

0.03

Stents implanted (%)

98.4

98.2

0.99

Number of stents implanted per lesion

1.2 i

: 0.5

1.2 ±

: 0.6

0.14

Total length of stents (mm)

23.0

± 12.1

24.4

± 13.3

0.13

Maximal device size (mm)

4.0 i

: 0.6

4.2 ±

: 0.9

0.05

Maximal inflation pressure (atm)

14.9

± 4.6

13.7

± 4.7

0.03

Reference vessel diameter after procedure (mm)

3.38

± 0.72

3.39

± 0.63

0.84

In-stent minimal luminal diameter after

3.23

± 0.61

3.21

± 0.64

0.64

procedure (mm)

In-stent diameter stenosis after procedure (%)

3.3 i

: 12.0

4.6 ±

: 13.6

0.21

In-lesion minimal luminal diameter after

2.96

± 0.63

2.91

± 0.58

0.36

procedure (mm)

In-lesion diameter stenosis after procedure (%)

12.9

± 9.5

13.7

± 10.7

0.05

TIMI flow post (%)

0/1

0.3

0

0.99

2

4.0

2.3

0.26

3

95.7

97.7

0.19

Thrombus (%)

3.1

6.3

0.06

Dissection (%)

0.6

2.3

0.10

Perforation (%)

0.9

1.0

0.99

Distal embolus (%)

2.5

2.0

0.79

* Time from arterial puncture to guide catheter removal.

* Time from arterial puncture to guide catheter removal.

using a distal protection device for PCI of SVG is further proven by this study. For operators concerned with the transient occlusion of a diseased SVG during PCI and the subsequent events that can occur, this trial shows that the non-occlusive filter device can be used with equal efficacy (Table 1).

Title 6

Randomized comparison of angioplasty of complex coronary lesions at a single center: Excimer laser, Rotational atherectomy, and Balloon Angioplasty Comparison (ERBAC) Study

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