CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 6, November/December 2010
312
AFRICA
of patients with acute MI within the preceding 48 hours of the
procedure, a total of 52 patients were diagnosed for multiple
overlapping stent implantation in their coronary arteries, using at
least two overlapping stents, including one or more DES.
All angioplasty procedures were done with a 6 or 7 French
guiding catheter and a femoral approach. If judged possible by
the operator, direct stenting was attempted; however, in most
cases pre-dilatation with an undersized balloon was used before
DES implantation. High-pressure (
>
12 atm) inflation was used
in the majority of cases (
n
=
40, 76.9%). Stent overlaps were
always post-dilatated at higher pressure with a non-compliant
balloon or with the balloon of a proximally implanted stent. In
total, 114 stents were used for the coverage of 52 lesions.
Seventy-eight drug-eluting stents were used: 63 sirolimus-
eluting stents (Cypher, Johnson & Johnson Cordis Corp) and
15 paclitaxel-eluting stents (Boston Scientific Corp, Natick,
MA). The bare-metal stents used were diverse: one S670,
one S660 and two S7 (Medtronic AVE, Minneapolis, MN),
seven Biodivysio (Biocompatibles, Galway, Ireland), seven
BX-Sonic (Cordis/Johnson & Johnson, Warren, MI), six Driver
(Medtronic Vascular, Santa Rosa, California), six Express 2
(Boston Scientific, Natick, MA), three Vision, and three Zeta
(Guidant, Santa Clara, CA).
Baseline, clinical, angiographic and procedural characteristics
and in-hospital outcomes were obtained by research physicians
and entered into a computerised database by computer opera-
tors. Finally, clinical outcomes, including major adverse cardiac
events (MACE) were obtained by research physicians in clinics
at one, six and 12 months post surgery, and once a year thereaf-
ter, or by formal telephone interviews, and these were recorded
in datasheets, which were later entered into our computerised
database.
All patients gave individual written informed consent for
participation in this study and for the PCI procedure. The Ethics
Committee in our centre approved this study, according to the
Declaration of Helsinki as revised in 2000.
Coronary procedures
Patients received 300 mg of clopidogrel and 325 mg of aspi-
rin before and 7 500–10 000 IU of heparin at the start of the
procedure. The femoral sheath was removed after normalisation
(
<
40 s) of the partial thromboplastin time. Clopidogrel was
followed at a dose of 75 mg/day for at least three months in
2003, and at least six months since 2004, and aspirin was given
indefinitely to all patients. Beta-blockers, angiotensin converting
enzyme inhibitors and statin drugs were administered as appro-
priate in the absence of a specific contraindication. Abciximab
was not used in any cases. Angiographic findings such as vessel
dimensions, pre- and post-procedural stenoses, lesion length, and
thrombolysis in myocardial infarction (TIMI) flow grade were
determined by visual estimation.
Definitions
Angina symptoms were defined according to the classifica-
tion of the Canadian Cardiovascular Society.
12
Lesion types
were noted according to the American College of Cardiology/
American Heart Association (ACC/AHA) lesion characteristics
classification.
13
Q-wave MI was defined as the presence of new
Q waves in post-procedure electrocardiogram, with a two-fold
increase in MB fraction of creatinine kinase. Non-Q-wave MI
was defined as a two-fold increase in MB fraction of creatinine
kinase without the development of new Q waves.
Angiographic success was defined as residual stenosis
<
20%
plus normal TIMI flow grade 3. Procedural success was defined
as angiographic success without major complications (death,
MI, emergency bypass surgery or PCI) during hospitalisation.
MACE was defined as the presence of cardiac death, non-fatal
MI, or target-vessel revascularisation (TVR) during the follow-
up period. TVR was defined as ischaemia-driven repeat percuta-
neous intervention or bypass surgery of the target vessel. Target
lesion revascularisation (TLR) was defined as ischaemia-driven
repeat percutaneous intervention of the target lesion or bypass
surgery of the target vessel.
Statistical analysis
Numerical variables were presented as mean
±
SD, while catego-
rised variables were shown as numbers (%). Continuous vari-
ables were compared using the Student’s
t
-test or non-parametric
Mann-Whitney
U
-test whenever the data did not appear to have
normal distributions, and categorical variables were compared
using the Chi-square or Fischer’s exact test. The analyses
were conducted with SPSS software version 13 for Windows
(Statistical Package for the Social Sciences, Inc, Chicago, IL).
All
p
-values were two-tailed, with statistical significance taken
as
p
<
0.05.
Results
Baseline and immediate results
During the study period, 22 patients were treated with two
homogenous overlapping DES (in 17 cases, two overlapping
Cypher stents; and in five, two overlapping Taxus stents were
used). Thirty patients were treated with at least one DES
combined with at least one BMS in an overlapping manner (in
25 cases, Cypher stents and in five cases, Taxus stents were used,
combined with a variety of bare-metal stents, as stated in the
methods section). In 23 cases, only one BMS was used. In four
cases, two BMS, and in three cases, three bare-metal stents were
used for the coverage of residual lesions. All the overlapping
stents were placed for very long lesions (mean lesion length in
the total population: 43.36
±
9.93 mm).
The patients’ clinical characteristics are listed in Tables 1 and
2. As shown, the patients in these two groups were similar in
baseline demographic characteristics. Lesions were estimated
to be on average longer and the mean inflation pressure per
lesion was higher in the DES-DES group, compared with the
DES-BMS group (47.95
±
9.25 vs 39.98
±
9.15 mm,
p
=
0.003,
and 16.29
±
2.26 vs 14.52
±
2.22 atm,
p
=
0.01, respectively).
Moreover, a higher percentage of procedures were performed
on the left anterior descending artery in the DES-DES group
(Tables 2, 3).
During hospitalisation, angiographic failure occurred in one
patient in each group. In the DES-BMS group, non-Q-wave
MI occurred in one patient (Table 4). He was treated with two
overlapping Cypher stents (2.75
×
33 mm) and one Express 2
(3.5
×
8 mm). Six months later, he underwent repeat coronary
angiography, which showed patent stents.
All dissections were treated with a combination of drug-
