Elective Stenting versus Balloon

Angioplasty with Bail-out Stenting for

Small Vessel Coronary Artery Disease:

Evidence from a Meta-analysis of

Randomized Trials

TCT, Washington, 30 September 2004

There are no conflicts of interest nor funding to declare

Pierfrancesco Agostoni

on behalf of all co-authors

INTRODUCTION

Bare-metal stents have been shown to reduce angiographic restenosis and repeat revascularization in discrete lesions in large vessels.1,2

1.Serruys PW, et al. BENESTENT Trial. NEJM,19942. Fishman DL, et al. STRESS Trial. NEJM,1994

The use of stents has increased radically also for “non-STRESS/BENESTENT” lesions, despite the lack of evidence of benefit.

INTRODUCTION

Small vessels (with RVD < 3 mm) account for 40-50% of all coronary stenoses.3

3. Wong P, et al. Catheter Cardiovasc Interv, 2000

Several recent randomized trials have compared bare-metal stenting vs. PTCA in small vessels, with conflicting and overall inconclusive results.

INTRODUCTION

As systematic overviews and meta-analytic techniques may provide more precise effect estimates with greater statistical power, leading to more robust and generalized conclusions...

AIM OF OUR REVIEW* Research

* Retrieve

* Evaluate

* Combine

in a systematic way

all the randomized trials comparing bare-metal stenting vs. PTCA for the treatment of atherosclerotic lesions in small coronary vessels.

METHODS

Systematic Research MEDLINE, CENTRAL

AHA, ACC, ESC, TCT 2000-2004 abstracts

Inclusion criteria Prospective comparison

Randomized allocation

Intention-to-treat

Follow-up 6 months Exclusion criteria

Non-mandatory angiographic follow-up Use of DES or other devices stents

Antithrombotic drugs ASA and thienopyridines

METHODS

Death

Myocardial infarction

Repeat revascularization (TVR/TLR)

MACE

Secondary end-points Restenosis, RVD, MLD pre-, post-PCI and at follow-up,

DS pre-, post-PCI and at follow-up, acute gain, late loss

Primary End-points

METHODS

Binary outcomes

Odds Ratios (95% Confidence Intervals)

Random effect model

Heterogeneity

Cochran Q 2 test

METHODS

Trials with mean DS post-PTCA < 20% (optimal)

and

Trials with mean DS post-PTCA > 20% (sub-optimal)

1. ACC Expert consensus Document JACC, 19982. Kastrati et al. JACC, 2001

Pre-specified sub-group analysis1,2

Included Studies

Death

Heterogeneity: p = 0.76Overall effect: p = 0.42

Myocardial Infarction

Heterogeneity: p = 0.92Overall effect: p = 0.18

Repeat Revascularization

Heterogeneity: p = 0.04Overall effect: p = 0.02

Heterogeneity: p = 0.62Overall effect: p = 0.54

MACE

Heterogeneity: p = 0.01Overall effect: p = 0.004

Heterogeneity: p = 0.27Overall effect: p = 0.24

CONCLUSIONS

Bare-metal stenting is clinically superior to PTCA for the treatment of small vessels, in particular when compared to a sub-optimal PTCA result.

The finding of significant heterogeneity casts a light of caution on the comprehensive pooled effect estimates.

A strategy based on “optimal” PTCA with provisional stenting may be a valid alternative to systematic stenting.

CONCLUSIONS

In any case, the rates of MACE (17%) and repeat revascularization (15%) remain high after stenting, unfavorably comparing with the MACE and revascularization rates in vessels with RVD > 3 mm ( 10%).4,5

4. Weaver WD, et al. OPUS-1 Trial. Lancet, 20015. Serruys PW, et al. JACC, 1999

Future Strategies

As drug-eluting stents have been proved to be effective both in randomized trials6-8 and in observational registries8…

6. Schofer J, et al. E-SIRIUS Trial. Lancet, 2003 7. Schampaert E, et al. C-SIRIUS Trial. JACC, 20048. Ardissino D. SES-SMART Trial. ACC meeting, 20038. Lemos PA, et al. RESEARCH Registry. AJC, 2004

The use of DES should be considered the

first-line therapy

for the treatment of vessels with RVD < 3 mm.

Angiographic Restenosis

Heterogeneity: p = 0.002Overall effect: p < 0.001

Heterogeneity: p = 0.11Overall effect: p = 0.25

High quality trials: Park et al., ISAR-SMART, SISCA

Quality AssessmentJadad’s Score (0-5 points)

• Study defined as randomized(1 point)– if randomization was correct 1 point more

– if not correct 1 point less

– if not mentioned no points

• Study defined as blinded(1 point)– it is impossible in “interventional” trials! Stent is visible!

• Clear description of drop-outs and withdrawals (1 point)

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