(Circulation. 1997;96:1482-1487.)
© 1997 American Heart Association, Inc.
Articles |
From Stiftsklinik Augustinum (R. von E., R.O., M.R., W.O.), München; Krankenhaus Siegburg (E.G.); Klinikum Bayreuth (W.M.); Klinikum Lippe-Detmold (U.T.); Universitätsklinikum Essen (R.E.); and Sandoz (J.B., G.W.), Nürnberg, Germany.
Correspondence to Rainer von Essen, MD, Klinik für Innere Medizin, Stiftsklinik Augustinum, Wolkerweg 16, 81375 München, Germany.
| Abstract |
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Methods and Results Patients received either octreotide or
placebo, starting 1 hour before angioplasty and continued for 3 weeks.
The minimal luminal diameters before and after angioplasty and at
6-month follow-up were analyzed with a digital quantitative
algorithm. Of the initial 274 patients recruited, 217 (108 in the
octreotide group and 109 in the placebo group) could be
analyzed after a complete 6-month evaluation: the minimal
luminal diameters were 1.67±0.57 mm in the
oc-treotide-treated group and 1.66±0.64 mm in the placebo
group (two-paired P=.70), and the relative losses were
0.16±0.22 and 0.13±0.21 (two-paired P=.27). The
restenosis rates were also identical in both treatment groups:
final diameter stenosis
50% (34.3% versus 33.9%,
two-paired P=1.0), loss of
50% of the initial gain
(34.3% versus 33.9%, two-paired P=1.0), and absolute
reduction of minimal luminal diameter >0.72 mm (29.6% versus
24.8%, two-paired P=.45). Likewise, there was no
difference with regard to the incidence of clinical events (death,
myocardial infarction, bypass operations, reintervention). Octreotide
was well tolerated, with the exception of gastrointestinal side
effects, which were three times more common than in the placebo
group.
Conclusions Octreotide did not reduce the angiographically determined restenosis rate or the incidence of major clinical events after coronary angioplasty.
Key Words: angioplasty restenosis octreotide
| Introduction |
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The impact of octreotide on restenosis in patients with angioplasty has not been tested; therefore, the purpose of the VERAS trial was to determine whether systemic therapy with octreotide for 3 weeks initiated before coronary angioplasty would decrease the extent or the incidence of restenosis assessed by QCA after 6 months.
| Methods |
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Criteria for Inclusion in the Study
Patients between 21 and 75 years with angiographically proven,
significant coronary artery disease (stenosis
50%
luminal diameter) amenable to PTCA could participate. Patients with
their first restenosis after PTCA could be included. Patients
with severe congestive heart failure (ejection fraction <40%), a
myocardial infarction within the previous 2 weeks, or another major
illness were excluded from the study. Other criteria for exclusion were
the inability to follow the protocol, previous CABG, a history of
gastrointestinal bleeding within the past 3 months, a history of a
cerebrovascular incident, insulin-dependent diabetes mellitus, and
hypersensitivity to octreotide. Women of child-bearing potential and
participants of other trials within the past 8 weeks were also
excluded.
Randomization and Treatment Protocol
Patients were randomly assigned to receive subcutaneous
injections of 500 µg octreotide or placebo every 8 hours for 3 weeks.
The first injection had to be given 1 hour before the PTCA; 274
patients formed the intention-to-treat population. Of these, PTCA was
not possible or not successful (eg, guide wire could not be passed or
bail-out stent implantation) in 15 patients. Nineteen patients
discontinued treatment because of (mainly gastrointestinal) adverse
events, 11 patients withdrew their informed consent, and 4 patients
refused the angiographic follow-up. For 8 patients, evaluation by QCA
was not possible. Therefore, completed clinical and angiographic
follow-up could be obtained in 217 patients.
Concomitant therapy consisted of aspirin, nitrates, ß-blockers, calcium antagonists, ACE inhibitors, and lipid-lowering drugs if indicated. Heparin was not allowed in addition to the dose specified during the PTCA procedure.
Follow-up Protocol
Routine follow-up angiography was performed at 6 months; when
symptoms recurred within the follow-up period, coronary
angiography was carried out earlier (when no definite
restenosis was present and the follow-up time was <5
months, the patient was asked to undergo another coronary
angiogram at 7 months). The compliance was judged by counting the
remaining ampoules, inspection of injection sites, and questioning.
PTCA Procedure
A bolus of 10 000 U heparin was given initially, and an
additional bolus of 5000 U was administered if the procedure took >60
minutes. Choice of balloon type, inflation duration, and pressure was
left to the operator. Nitroglycerin (0.3 mg IC) was
given before imaging. Three coronary angiograms were obtained
and compared immediately before and after PTCA and after the follow-up
procedure at 6 months (including a baseline and follow-up left
ventricular angiogram). PTCA was considered successful if
the reduction in the percentage of vessel diameter stenosis was
20%, the post-PTCA percentage of vessel diameter stenosis
was <50%, and no severe complications related to angioplasty
occurred. The angiographic views of the patients were documented and
kept constant.
Angiographic Analysis and Predefined Criteria for
Restenosis
Stenosis was measured in two (right coronary
artery) or six (left coronary artery) near-orthogonal views
after intracoronary administration of nitrates. Whenever
possible, end-diastolic frames were analyzed, and
the views were chosen that showed the stenosis best. The
clinically most relevant lesion was defined as the "target
lesion" after the initial diagnostic angiography and
before randomization at the discretion of the investigator; only the
target lesion was considered in the analysis described
below.
Angiographic analysis was performed in the QCA core laboratory in a blinded fashion by means of a digital quantitative algorithm (QANSAD). This centerline method is described in detail elsewhere.20 After the original calibration, the x-ray tube patient distance was used for standardization. The edge contour of the segment of interest was automatically detected and measurements of the most stenotic diameter (MLD) were made; then, the prestenotic and poststenotic segments were defined and measured, and percent stenosis was calculated for each view.
Restenosis was defined as1 21 final percentage of
vessel diameter stenosis
50%, loss of
50% of the gain in
the percentage of vessel diameter stenosis achieved at PTCA,
and absolute loss of >0.72 mm of MLD.
The morphology of the stenosis was classified according to American College of Cardiology/American Heart Association classification of lesion type.
End Points
The primary end point of this study was the within-patient
change in MLD related to the interpolated reference diameter as
determined by QCA after PTCA and at follow-up. The following
calculations were performed: relative gain, MLDpost-PTCA
minus MLDpre-PTCA/reference diameter; net gain index,
MLDfollow-up minus MLDpre-PTCA/reference
diameter; and relative loss, MLDpost-PTCA minus
MLDfollow-up/reference diameter.
Secondary end points were the restenosis rate according to the three definitions mentioned above as well as the incidence of clinical events such as death, myocardial infarction, CABG, or repeat PTCA.
Statistical Analysis
The required sample size was calculated to achieve a statistical
significant difference with respect to the reduction of relative loss
values from 0.11±0.15 (mean±SD) in the control group to 0.05±0.15
(mean±SD) with octreotide medication (two-sided test with
=0.05 and
ß=0.20). For safety/tolerability analysis, all randomized
patients were included who received at least one dose of medication and
had at least one post-baseline safety evaluation. For efficacy
analysis, intention-to-treat and per-protocol populations were
defined: the intention-to-treat population comprised randomized
patients who received at least one dose of medication, and the
per-protocol population consisted of all randomized patients who
completed the planned duration of treatment; had valid baseline,
post-PTCA, and repeat angiographies; and did not violate the protocol
in any way liable to influence efficacy outcome. Continuous
variables were compared by the U test
(Wilcoxon-Mann-Whitney), qualitative variables were
analyzed by the
2 test; and Fisher's
exact test was used to compare restenosis rates between both
treatment groups.
| Results |
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Before angioplasty, the percentage of stenosis of the vessel to
be dilated was 67.8±11.6% (MLD, 1.01±0.48 mm) for patients
treated with octreotide (n=108 patients with angiographic follow-up)
and 68.1±13.2% (MLD, 0.94±0.41 mm) for patients in the placebo
group (n=109). Immediately after PTCA, the percentages were
30.4±11.9% (MLD, 2.15±0.54 mm) and 31.6±12.1% (MLD,
2.04±0.51 mm), respectively. At 6-month follow-up, the percentage
of residual stenosis was 44.0±16.1% (MLD, 1.68±0.58 mm)
in the octreotide-treated group and 42.5±18.6% (MLD, 1.66±0.64
mm) in the placebo-treated group
(Figure
). Therefore, no difference in
vessel stenosis between the two groups was demonstrated. The
interpolated reference diameters were 3.06±0.66 mm before PTCA
and 3.12±0.67 mm after PTCA for patients in the octreotide group
and 2.97±0.67 and 2.98±0.58 mm, respectively, for patients in
the placebo group. At follow-up, the interpolated reference diameters
shifted slightly to 2.99±0.68 and 2.88±0.66 mm,
respectively.
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Relative gain, relative loss, and net gain index are presented
in Table 3
; there were no statistically
significant differences between the octreotide and the placebo group.
Restenosis per patient was defined according to the three
different criteria listed above. Restenosis at follow-up
defined as final percent stenosis
50% occurred in 34.3% in
the octreotide group and 33.9% in the placebo group. Likewise, on the
basis of the second definition (loss of
50% of initial gain), the
restenosis rates were 34.3% versus 33.9%, respectively. On
the basis of the third definition (absolute loss of >0.72 mm),
the restenosis rates were 29.6% versus 24.8% (Table 4
). All differences were not significant,
and there was a good correlation among all three criteria used.
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Table 5
summarizes the incidence of major
clinical events during the follow-up period of 6 months. Primary
clinical end points were death, myocardial infarction, CABG, and repeat
intervention. Reinterventions were considered only when their need was
based on clinical symptoms and premature angiographic evaluation; the
necessity for reintervention obtained as a result of routine
angiography at 6 months was not considered. The distribution of these
events was nearly identical between the two groups. As expected, repeat
PTCA was the most frequent event. One patient died because of an
allergic reaction to contrast media application during repeat
angiography, so there was no relation to drug administration.
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Side effects (Table 6
) were mainly
gastroenterological, as expected: 57 patients in the octreotide group
complained of diarrhea (compared with 19 in the placebo group), 15
versus 10 of nausea, 8 versus 2 of vomiting, 8 versus 6 of bloating,
and 16 versus 10 of pain (especially abdominal pain); steatorrhea was
noticed in 9 patients versus 0. Interestingly, only three infections
occurred in the octreotide-treated group versus nine in the
placebo-treated group. Other signs and symptoms were equally
distributed and rare. Angina pectoris complaints are also listed in the
table, reflecting the major clinical events mentioned above.
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| Discussion |
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At the start of the VERAS study, SMC proliferation as the response to injury was considered the main culprit for the narrowing of the vessel lumen, and it was hypothesized that octreotide prevents myointimal thickening after vessel injury by systemic and local inhibition of growth factor effects. In in vitro experiments, oc-treotide inhibited IGF-1 and bFGF-induced proliferation of human coronary artery SMCs in a dose-dependent manner; PDGF-stimulated cultures were only minimally affected by octreotide. No effect on SMC migration was observed.17 Additionally, octreotide reduced neointimal thickening after balloon injury of femoral arteries in rats. This effect of octreotide correlated with a decrease in local IGF-1 mRNA levels as well as decreased activation of transcription factors.18 19
First clinical approaches with a somatostatin analogue were reported for angiopeptin.23 24 25 However, due to the inconsistent results of three clinical trials, it was the purpose of the VERAS trial to determine the effect of high-dose octreotide to prevent or reduce restenosis in a large clinical trial. With respect to adverse events, gastrointestinal side effects occurred predominantly as expected.26 These side effects (especially diarrhea) could be treated effectively with pancreatic enzyme preparations.
Discrepancy Between Experimental Data and Angiographic and
Clinical Outcome
VERAS does not show any effect of octreotide on the
angiographically determined restenosis rate or the incidence of
clinical events. Several explanations may account for this apparent
failure. With respect to the method of QCA, differences between the
individual centers were eliminated by central evaluation of the cine
films using state-of-the-art QCA equipment. Additionally, the
angiographic characteristics before angioplasty were identical between
both treatment groups. The high dosage of octreotide might still have
been too low, and it may be possible that a second study with local
application of octreotide via a catheter would be successful. On the
other hand, the pretreatment period might have been too short to
effectively reduce the IGF-1 level; however, the application regimen
was sufficient to inhibit the growth factorinduced proliferation
of SMCs on the level of signal transduction. Species differences in the
biological response to vascular injury and in animal models of
restenosis and different protocol designs for experimental and
clinical studies may well explain the different outcomes in the
treatment of restenosis.
The strategies aimed at blocking selectively biological mediators by octreotide could be limited by the multiplicity of mediators and their mutual interference, the plurality of cell surface receptors, and intracellular signaling mechanisms. Furthermore, it was recently discussed that restenosis is related not only to the formation of new intimal mass but also to remodeling processes.27 28 Even beneficial effects of vascular SMC proliferation and reendothelialization as part of an essential reparative process are hypothesized.29 30 Therefore, the inhibition of growth factors via stimulation of tyrosine phosphatase activity by octreotide seems insufficient for the prevention of restenosis in patients after PTCA.
A major and perhaps successful approach to prevent the development of restenosis is by blocking the platelet glycoprotein IIb/IIIa inhibiting platelet aggregation. The monoclonal antibody c7E3 has been shown to reduce major ischemic complications in high-risk patients after angioplasty by 23%.31 Furthermore, the EPILOG trial was prematurely stopped because of positive findings at the first interim analysis.32 This study also included low-risk patients; the incidence of bleeding events was the same in the treatment and placebo groups because of weight-adjusted heparin administration. An angiographic analysis of restenosis is pending. Trapidil, a PDGF antagonist, has also been shown to be effective in reducing the restenosis rate after angioplasty (24.2% in the trapidil group versus 39.7% in the aspirin group); however, clinical events were similar in both groups.33 Whether trapidil or glycoprotein IIb/IIIa receptor blockers maintain the very promising first findings remain to be seen.
As a matter of fact, therapy with antiproliferative agents otherwise has been disappointing insofar as agents that are effective in vitro and in animal models did not have impressive clinical success. Again, in vivo veritas was proved by the VERAS trial (J. Madri).
| Selected Abbreviations and Acronyms |
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| Appendix 1 |
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Angiographic Core Laboratory
W. Oel, MD; and M. Hanke-Dubois, RN, Stiftsklinik Augustinum,
München.
Participating Clinics and Investigators
The following institutions and investigators participated
in VERAS. The number of patients enrolled at each center is given in
parentheses: Stiftsklinik Augustinum, München (76): R.
von Essen, MD (principal investigator); M. Roth, MD; R. Ostermaier, MD;
R. von der Ropp; MD; F. Saathoff, MD; K. Unger, MD; J.-E. Kasulke, MD;
Krankenhaus Siegburg (76): E. Grube, MD (main investigator);
U. Hausen, RN; N. Cattelaens, MD; U. Gerckens, MD; D. Schiftah, RN;
Klinikum Bayreuth (44): W. Mäurer, MD (main
investigator); K. Hofmann, RN; J. Hornig, MD; B. Bender, MD;
Klinikum Lippe-Detmold (32): U. Tebbe, MD (main
investigator); J. Carlsson, MD; S. Miketic, MD; L. Obergassel, MD;
A. Kuhn, MD; Universitätsklinikum Essen (25): R.
Erbel, MD (main investigator); J. Ge, MD; D. Baumgart, MD; M. Haude,
MD; Elisabeth-Krankenhaus Essen (9): G. Sabin, MD (main
investigator); G. Szurawitzki, MD; M. Tekiyeh, MD; A. Treeger, MD;
Franz-Volhard-Klinik, Freie Universität Berlin,
Berlin-Buch (7): D. Gulba, MD (main investigator), H. Kleiner, MD.
Rudolf-Virchow-Klinik; and Freie Universität Berlin
(5): W. Rutsch, MD (main investigator).
Data Coordinating and Analysis
H. Kaiser, PhD; and H. Bachmann, PhD (Sandoz,
Nürnberg).
Project Coordination
J. Brom, PhD; G. Weidinger, PhD; and R. Ross, Head Monitoring
Group (Sandoz, Nürnberg).
| Acknowledgments |
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Received December 10, 1996; revision received March 24, 1997; accepted March 30, 1997.
| References |
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B
activation and cell proliferation after balloon injury.
J Invest Med. 1996;44(suppl 1):101A. Abstract.This article has been cited by other articles:
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P. Delafontaine, Y.-H. Song, and Y. Li Expression, Regulation, and Function of IGF-1, IGF-1R, and IGF-1 Binding Proteins in Blood Vessels Arterioscler. Thromb. Vasc. Biol., March 1, 2004; 24(3): 435 - 444. [Abstract] [Full Text] |
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J. Frystyk, T. Ledet, N. Moller, A. Flyvbjerg, and H. Orskov Cardiovascular Disease and Insulin-Like Growth Factor I Circulation, August 20, 2002; 106(8): 893 - 895. [Full Text] [PDF] |
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W. R. P. Agema, J. W. Jukema, S. N. Pimstone, and J. J. P. Kastelein Genetic aspects of restenosis after percutaneous coronary interventions;towards more tailored therapy Eur. Heart J., November 2, 2001; 22(22): 2058 - 2074. [PDF] |
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A. Bayes-Genis, C. A. Conover, and R. S. Schwartz The Insulin-Like Growth Factor Axis : A Review of Atherosclerosis and Restenosis Circ. Res., February 4, 2000; 86(2): 125 - 130. [Abstract] [Full Text] [PDF] |
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A. Tiran, R. A. Tio, J. M. Ossewaarde, B. Tiran, P. den Heijer, T. H. The, and M. M. Wilders-Truschnig Coronary Angioplasty Induces Rise in Chlamydia pneumoniae-Specific Antibodies J. Clin. Microbiol., April 1, 1999; 37(4): 1013 - 1017. [Abstract] [Full Text] |
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S. KHARE, U. KUMAR, R. SASI, L. PUEBLA, L. CALDERON, K. LEMSTROM, P. HAYRY, and A. Y. C. PATEL Differential regulation of somatostatin receptor types 1-5 in rat aorta after angioplasty FASEB J, February 1, 1999; 13(2): 387 - 394. [Abstract] [Full Text] |
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