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Rassegna della Letteratura
Effect of Intracoronary Gamma-Radiation Therapy on In-Stent Restenosis
An Intravascular Ultrasound Analysis from the Gamma-1 Study
Gary S. Mintz, MD; Neil J. Weissman, MD; Paul S. Teirstein, MD; Steven G. Ellis, MD; Ron Waksman, MD; Robert J. Russo, MD; Issam Moussa, MD; Prabhaker Tripuraneni, MD; Shrish Jani, MD; Yoshio Kobayashi, MD; Joseph A. Giorgianni, BA; Chrysoula Pappas, MD; Richard A. Kuntz, MD; Jeffrey Moses, MD; Martin B. Leon, MD
(Circulation. 2000; 102: 2915)
Background
- The aim of this study was to use serial volumetric intravascular ultrasound to evaluate
the effect of Y-radiation on recurrent in-stent restenosis.
Methods and Results - After successful reintervention, patients were randomized to receive
either 192Ir or placebo. Intravascular ultrasound studies with motorized pullback (0.5
mm/s) were performed immediately after irradiation and at 8-month follow-up in 70
patients. Paired volumetric analysis of the stented segment and of 5-mm proximal and
distal reference segments was performed; this included measurements of the external
elastic membrane, lumen, plaque and media (external elastic membrane minus lumen), stent,
and intimal hyperplasia (stent minus lumen). Baseline proximal reference, stent, and
distal reference measurements were similar in both groups. The changes in proximal and
distal reference measurements of the external elastic membrane, plaque and media, and
lumen areas were similar in both groups. However, the decrease in stented segment lumen
volume was less in the 192Ir patients than the placebo patients (-25±34 mm3 versus
-48±42 mm3; P=0.0225), and the increase in the volume of intimal hyperplasia in the
stented segment was less in the 192Ir patients than in the placebo patients (28±37 mm3
versus 50±40 mm3; P=0.0352). When averaged over the length of the stented segment (32±13
mm versus 33±14 mm; P=0.9), the increase in mean area of intimal hyperplasia was 0.8±1.0
mm2 in the 192Ir group and 1.6±1.2 mm2 in the control group (P=0.0065). Late stent-vessel
wall malapposition was noted in one placebo patient and no 192Ir patients.
Conclusions -Y-Radiation therapy can effectively prevent recurrent in-stent restenosis by
inhibiting neointimal formation within the stent. At the stent edge, there were no
significant differences between 192Ir and placebo patients.
Randomized Comparison of Elective Stent Implantation and Coronary Balloon Angioplasty Guided by Online Quantitative Angiography and Intracoronary Doppler
Carlo Di Mario, MD, PhD; Jeffrey W. Moses, MD; Todd J. Anderson, MD, MRCP; Raoul Bonan, MD; Toshiya Muramatsu, MD; Abnash Chander Jain, MD; Josè Suarez de Lezo, MD; Seung Yun Cho, MD; Morton Kern, MD; Ian T. Meredith, MBBS, PhD; David Cohen, MD, MSc; Issam Moussa, MD; Antonio Colombo, MD;
(Circulation. 2000;102:2938)
Background
- The purpose of this study was to compare long-term outcomes of coronary stenting in all
lesions (elective stenting) or only in lesions with inadequate morphological and
functional results after balloon angioplasty (guided PTCA).
Methods and Results - Treatment of multivessel disease, with any lesion length and vessel
size, was allowed provided that all lesions were suitable for stent implantation. Patients
were randomized to elective stent implantation (n=370) or guided PTCA (n=365). An optimal
PTCA result (residual diameter stenosis <35%, coronary flow reserve measured with a
Doppler guidewire>2.0, absence of threatening dissections) was achieved in 166 lesions
(43%). The remaining 218 lesions underwent stent implantation (provisional stenting).
Final residual diameter stenosis was lower in the elective and provisional stent groups
(9.3% and 10.2%) than in the optimal PTCA group (24.8%, P<0.00001). On an
intention-to-treat analysis, the probability of>1 major adverse cardiac event at 12
months was 17.8% in the elective stenting group and 18.9% in the guided PTCA group (20.1%
for optimal PTCA and 18.0% for the provisional stenting subgroup, P=NS). The incidence of
repeat target lesion revascularization at 1 year was 14.9% in the elective stent group and
15.6% in the guided PTCA group (17.6% for optimal PTCA and 14.1% for the provisional
stenting subgroup, P=NS).
Conclusions - When balloon angioplasty is guided by online quantitative angiography and
Doppler-derived coronary flow reserve, with provisional stenting reserved for suboptimal
results, early and late clinical outcomes are comparable to those achieved by elective
stenting of all patients.
Randomized Comparison of Primary Stenting and Provisional Balloon Angioplasty Guided by Flow Velocity Measurement
Patrick W. Serruys, MD; Bernard de Bruyne, MD; Stéphane Carlier, MD; José Eduardo Sousa, MD; Jan Piek, MD; Toshiya Muramatsu, MD; Chris Vrints, MD; Peter Probst, MD; Ricardo Seabra-Gomes, MD; Ian Simpson, MD; Vasilis Voudris, MD; Olivier Gurné, MD; Nico Pijls, MD; Jorge Belardi, MD; Gerrit-Anne van Es, PhD; Eric Boersma, PhD; Marie-Angèle Morel, MS; Ben van Hout, PhD;
(Circulation. 2000; 102: 2930)
Background
- Coronary stenting improves outcomes compared with balloon angioplasty, but it is costly
and may have other disadvantages. Limiting stent use to patients with a suboptimal result
after angioplasty (provisional angioplasty) may be as effective and less expensive.
Methods and Results - To analyze the cost-effectiveness of provisional angioplasty,
patients scheduled for single-vessel angioplasty were first randomized to receive primary
stenting (97 patients) or balloon angioplasty guided by Doppler flow velocity and
angiography (523 patients). Patients in the latter group were further randomized after
optimization to either additional stenting or termination of the procedure to further
investigate what is "optimal." An optimal result was defined as a flow reserve
>2.5 and a diameter stenosis <36%. Bailout stenting was needed in 129 patients (25%)
who were randomized to balloon angioplasty, and an optimal result was obtained in 184 of
the 523 patients (35%). There was no significant difference in event-free survival at 1
year between primary stenting (86.6%) and provisional angioplasty (85.6%). Costs after 1
year were significantly higher for provisional angioplasty (EUR 6573 versus EUR 5885;
P="0.014)." Results after the second randomization showed that stenting was also
more effective after optimal balloon angioplasty (1-year event free survival, 93.5% versus
84.1%; P="0.066).
Conclusions - After 1 year of follow-up, provisional angioplasty was more expensive and
without clinical benefit. The beneficial value of stenting is not limited to patients with
a suboptimal result after balloon angioplasty.
Beta-Radiation to INHIBIT Recurrence of In-Stent Restenosis: Clinical and Angiographic Results of the Multicenter, Randomized, Double-Blind Study
Ron Waksman, MD
(Circulation. 2000;102:e9046.)
Background: Clinical trials utilizing gamma
radiation therapy have demonstrated a reduction in the recurrence of restenosis for
patients with in-stent restenosis (ISR). INHIBIT (Intimal Hyperplasia Inhibition with Beta
In-stent Trial) is a multicenter randomized double blind study designed to evaluate the
safety and efficacy of 32P (a pure beta emitter) delivered into a centering balloon
catheter via an automatic afterloader for the prevention of recurrent ISR.
Methods: Three hundred and thirty two patients with in-stent restenosis in native
coronaries with lesion <47 mm in length underwent intervention with balloon,
atherectomy, or stent placement (new stenting was placed in 25% of lesions). Following
intervention, a helical centering balloon catheter 2.5-3.5 mm positioned at the treated
segment and automatically loaded with a 32P source 0.018 wire, 27 mm in length to deliver
a randomized dose of either 0 or 20 Gy prescribed at 1.0 mm from the lumen diameter.
Manual stepping of the radiation catheter was performed in 42% of lesions (those >22 mm
in length) with an overlap of up to 2 mm at the stented segment.
Results: There was a 56% reduction in the safety endpoint (composite of death, Q MI, TSR).
The event rate was 14% radiated vs. 31% control, p=0.0002. There was a 50% reduction in
the efficacy endpoint (angiographic binary restenosis rate). The restenosis rate was 26%
radiated vs. 52% control, p=0.0003. There were no adverse effects related to the
radiation. Conclusion: The INHIBIT Trial results have supported the hypotheses for
reduction in MACE and binary angiographic restenosis.
A Randomized Trial Comparing Stenting With Balloon Angioplasty in Small Vessels in Patients With Symptomatic Coronary Artery Disease
Adnan Kastrati, MD; Albert Schömig, MD; Josef Dirschinger, MD; Julinda Mehilli, MD; Franz Dotzer, MD; Nicola von Welser, MD; Franz-Josef Neumann, MD
(Circulation. 2000; 102: 2593)
Background - More than 30% of the lesions
currently treated with interventional approaches are situated in vessels smaller in size
than those representing an established indication for stenting. The objective of this
randomized trial was to assess whether compared with PTCA, stenting of small coronary
vessels is associated with a reduction of restenosis.
Methods and Results - Patients with symptomatic coronary artery disease with lesions
situated in native coronary vessels between 2 and 2.8 mm in size were randomly assigned to
be treated with either stenting (n=204) or PTCA (n=200). Adjunct therapy consisted of
abciximab, ticlopidine, and aspirin. Repeat angiography at 6-month follow-up was performed
in 83% of the patients. The primary end point of the study was the incidence of
angiographic (>50% diameter stenosis) at follow-up; adverse clinical events, such as
death, myocardial infarction, stroke, or target vessel revascularization, were assessed as
secondary end points. After 7 months, there were no significant differences in the
infarct-free survival rates between the 2 study groups: 96.6% for stent patients, and
97.0% for PTCA patients (P=0.80). Target vessel revascularization was needed in 20.1% of
the stent patients and 16.5% of the PTCA patients (P=0.35). The primary end point of
angiographic restenosis was found in 35.7% of the stent patients and 37.4% of the PTCA
patients (P=0.74). The net lumen gain observed at follow-up was identical (0.76±0.78 in
the stent group versus 0.76±0.63 mm in the PTCA group, P=0.93).
Conclusions - Stenting and PTCA are associated with equally favorable results when used
for treating lesions in small coronary vessels.
Ultrasound-Guided Thrombin Injection for the Treatment of Postcatheterization Pseudoaneurysms
Lucy La Perna, DO; Jeffrey W. Olin, DO; Debbie Goines, RVT; Mary Beth Childs, RN, MSN; Kenneth Ouriel, MD
(Circulation. 2000; 102: 2391)
Background - This prospective study was
designed to assess the safety and efficacy of using bovine thrombin injection to treat
pseudoaneurysms.
Methods and Results - From April 1998 through December 1999, 70 pseudoaneurysm were
injected with bovine thrombin under the guidance of color duplex ultrasound. The most
superficial pseudoaneurysm chamber was entered with a 1.5-inch, 19- to 22-gauge or spinal
needle. Bovine thrombin, in a 1000 U/cc solution, was injected into the chamber. A total
of 36 women and 34 men underwent ultrasound-guided thrombin injection (UGTI). Their mean
age was 69.5 years. Most pseudoaneurysms were associated with diagnostic cardiac
catheterization or percutaneous coronary intervention (80%). Two pseudoaneurysms arose
from the brachial artery; the remainder were in the groin. Twenty-one patients were being
treated with either heparin or warfarin, and the majority of the others were on
antiplatelet therapy with aspirin or clopidogrel. UGTI was successful in 66 of the 70
patients (94%). The first patient in the series had 2 attempts at thrombin injection and
refused further attempts. Two patients had undergone stent graft placement and had short,
wide tracts. Both of these patients required surgical repair of their pseudoaneurysms. The
fourth patient had a nearly complete pseudoaneurysm thrombosis and was lost to follow-up
on discharge. No arterial thrombotic events occurred. One patient had a soleal vein
thrombosis in the ipsilateral leg.
Conclusions - UGTI was safe and effective in 94% of patients with postcatheterization
pseudoaneurysms. Anticoagulant use did not hinder successful thrombosis. UGTI should be
the initial treatment of choice for patients with postcatheterization pseudoaneurysms.
Coronary Pressure Measurement to Assess the Hemodynamic Significance of Serial Stenoses Within One Coronary Artery
Validation in Humans
Nico H.J. Pijls, MD, PhD; Bernard De Bruyne, MD, PhD; G. Jan Willem Bech, MD; Francesco Liistro, MD; Guy R. Heyndrickx, MD, PhD; Hans J.R.M. Bonnier, MD, PhD; Jacques J. Koolen, MD, PhD
(Circulation. 2000; 102: 2371)
Background - When several stenoses are
present within 1 coronary artery, the hemodynamic significance of each stenosis is
influenced by the presence of the other(s), and the calculation of coronary and fractional
flow reserve (CFR and FFR) for each individual stenosis is confounded. Recently, we
developed and experimentally validated a method to determine the true FFR of each stenosis
as it would be after the removal of the other stenosis; the true FFR can be reliably
predicted by coronary pressures measured before treatment at specific locations within the
coronary artery using equations accounting for stenosis interaction. The aim of the
present study was to test the validity of these equations in humans.
Methods and Results - In this study of 32 patients with 2 serial stenoses in 1 coronary
artery, relevant pressures were measured before the intervention, after the treatment of 1
stenosis, and after the treatment of both stenoses. The true FFR of each stenosis
(FFRtrue) was directly measured after the elimination of the other stenosis and compared
with the value predicted (FFRpred) from the initial pressure measurements before
treatment. Although the hyperemic gradient across 1 stenosis increased significantly (from
10±7 to 19±11 mm Hg after treatment of the other stenosis), FFRpred was close to FFRtrue
in all patients (0.78±0.12 versus 0.78±0.11 mm Hg; r=0.92; D%=4±0%). Without accounting
for stenosis interaction, the value of FFR for each stenosis would have been significantly
overestimated (0.85±0.08; P<0.01).
Conclusions - Coronary pressure measurements made by a pressure wire at maximum hyperemia
provide a simple, practical method for assessing the individual hemodynamic significance
of multiple stenoses within the same artery