Circulation. 1998;98:1824-1827
(Circulation. 1998;98:1824-1827.)
© 1998 American Heart Association, Inc.
Angiographic Restenosis Rates of Patients After Multilesion Coronary Interventions
Peter Mazeika, MD;
Paulo Caramori, MD;
; Neeraj Prasad, MD
Interventional Cardiology Fellows,
Toronto General Hospital,
Toronto, Canada
To the Editor:
Moussa and colleagues report restenosis in 43 (22%) of
201 lesions and 31 (37%) of 84 patients undergoing multivessel
coronary stenting at angiographic follow-up at a mean of 5.2
months.1
Confirmation of the lesion-to-lesion independence of
restenosis after balloon angioplasty or stenting has validated
lesion-based restenosis analysis in patients with
multivessel disease.2 Restenosis rates
for patients with multiple treated lesions can therefore be calculated
and equal the sum of the independent probabilities of
restenosis.
Given a lesion restenosis rate of 22% after stenting,
the proportion of patients with restenosis at 
1 site for 2,
3, 4, or 5 treated lesions would be 39%, 53%, 63%, and 71%,
respectively. Moussa et al treated 2 lesions in 66 patients, 3 lesions
in 24 patients, 4 lesions in 5 patients, and 5 lesions in 3 patients,
which gives a predicted restenosis rate by patient of 45%,
slightly higher than the observed 37%. This difference may be due to
chance or to clustering of restenosis in particular patients.
Clustering is supported by the observation that 20 (47%) of 43
restenotic lesions occurred in 8 (10%) of 84
patients1 (P<0.05 by comparison of
proportions). Further information on these 8 patients, including
diabetic status, postprocedure lumen diameter, number of lesions
treated, and number of stents used per lesion, should be provided. The
existence of distinct lesion populations with differing propensities
for restenosis may be of particular relevance to case
selection.
Patients with multivessel disease may have lesions requiring
dilation that are amenable to balloon angioplasty but not to stenting.
Furthermore, restenosis rates are higher after vein graft
interventions. The disproportionate impact of lesion restenosis
rate and the number of lesions treated on the patient's overall risk
of restenosis should be underscored. On the basis of lesion
restenosis rates from the STRESS,3
BENESTENT,4 and SAVED5
trials, a hypothetical patient who had 1 coronary
stenosis stented, a second ballooned, and stent placement for a
third vein graft lesion would have a predicted overall
restenosis rate of 71%. In the study by Moussa et
al,1 two thirds of the patients had only 2
lesions stented, which partly explains their good results.
What do the authors believe are the implications of these
observations for case selection, including the issue of left
ventricular dysfunction for which completeness of
revascularization may be prognostically important?
Should there be a limit to the number of lesions treated? Is a more
complete follow-up, including coronary angiography, advisable
in these patients?
References
-
Moussa I, Reimers B, Moses J, Di Mario C, Di
Francesco L, Ferraro M, Colombo A. Long-term angiographic and clinical
outcome of patients undergoing multivessel coronary stenting.
Circulation. 1997;96:3873–3879.
-
Gibson CM, Kuntz RE, Nobuyoshi M, Rosner B, Baim DS.
Lesion-to-lesion independence of restenosis after treatment by
conventional angioplasty, stenting, or directional atherectomy:
validation of lesion-based restenosis analysis.
Circulation. 1993;87:1123–1129.
-
Fischman DL, Leon MB, Baim DS, Schatz RA, Savage
MP, Penn I, Detre K, Veltri L, Ricci D, Nobuyoshi M, Cleman M, Heuser
R, Almond D, Teirstein PS, Fish D, Colombo A, Brinker J, Moses J,
Shaknovich A, Hirschfeld J, Bailey S, Ellis S, Rake R, Goldberg S, for
the STRESS Investigators. A randomized comparison of
coronary-stent placement and balloon angioplasty in the
treatment of coronary artery disease. N Engl J
Med. 1994;331:496–501.
-
Serruys PW, de Jaegere P, Kiemeneij F, Macaya C,
Rutsch W, Heyndrickx G, Emanuelsson H, Marco J, Legrand V, Materne P,
Belardi J, Sigwart U, Colombo A, Goy JJ, van den Heuvel P, Delcan J,
Morel M, for the BENESTENT Study Group. A comparison of
balloon-expandable-stent implantation with balloon angioplasty in
patients with coronary artery disease. N Engl
J Med. 1994;331:489–495.
-
Savage MP, Douglas JS, Fischman DL, Pepine CJ, King
SB, Werner JA, Bailey SR, Overlie PA, Fenton SH, Brinker JA, Leon MB,
Goldberg S, for the SAVED Trial Investigators. Stent placement compared
with balloon angioplasty for obstructed coronary bypass grafts.
N Engl J Med. 1997;337:740–747.
Response
Issam Moussa, MD;
Antonio Colombo, MD;
Massimo Ferraro, RN;
Lucia Di Francesco, PhD;
Jeffrey Moses, MD;
Bernhard Reimers, MD;
; Carlo Di Mario, MD
Cardiac Catheterization Laboratory,
Centro Cuore Columbus,
Milan, Italy
The line of statistical reasoning used by Dr Mazeika and
colleagues to calculate the theoretical probability of
restenosis in patients with several lesions may be misleading
for 2 reasons: (1) even though lesion characteristics play a major role
in determining the probability of restenosis, genetic
predisposition may still be a factor,1 so the
assumption that there is "total" lesion-to-lesion independence is
not true; (2) the probability of an event is the event's long-run
relative frequency in reported trials under similar conditions. In
other words, for the probability calculations to be valid, the
incidence of the event (restenosis) should be equally likely
among all lesions treated. Clearly, the likelihood of
restenosis depends on many factors that are not equally
distributed among all lesions. The univariate and
multivariate analyses of predictors of
restenosis in our study2 illustrate that
patients with long lesions, small vessels, or smaller final minimum
lumen diameter are at higher risk for restenosis;
genetic predisposition cannot be proved or disproved from our
data.
Population-based studies, whether prospective or retrospective,
can only serve as general guidelines. The profile of an individual
patient in clinical practice may not always fit the profile of patients
in a particular study. A patient with normal ventricular
function and 3 focal lesions in vessels >3.0 mm in diameter may
have a good clinical outcome with multivessel stenting, whereas a
patient with poor ventricular function and 3 lesions in
diffusely diseased vessels is at higher risk for cardiac events. The
fact that the same number of lesions were dilated in both patients is
not sufficient to assume that the probability of restenosis
would be similar. Paradoxically, a higher probability of
restenosis would be expected in a patient with a single long
lesion in a small vessel than in a patient with 3 focal lesions in
vessels 3.0 mm in diameter.
In our practice, we advise all patients, particularly those at
high risk, to return for follow-up angiography. Clinical decision
making based on angiographic evaluation coupled with clinical and
functional assessment may be superior to decisions made only according
to the symptoms of the patient.3
References
-
Ribichini F, Steffenino G, Dellavalle A, Matullo
G, Colajanni E, Camilla T, Vado A, Benetton G, Uslenghi E, Piazza A.
Plasma activity and insertion/deletion polymorphism of
angiotensin 1-converting enzyme: a major risk factor and a
marker of risk for coronary stent restenosis.
Circulation. 1998;97:147–154.
-
Moussa I, Reimers B, Moses J, Di Mario C, Di Francesco
L, Ferraro M, Colombo A. Long-term angiographic and clinical outcome of
patients undergoing multivessel coronary stenting.
Circulation. 1997;96:3873–3879.
-
Rupprecht HJ, Espinola-Klein C, Brennecke R. Should we
perform routinely a 6-month-angiography after successful
coronary angioplasty? Circulation. 1997;96(suppl
I):I-323. Abstract.
