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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 6, November/December 2016
346
AFRICA
Methods
Forty-one consecutive patients who underwent CTO
revascularisation with one or two BVSs between January 2013
and December 2014 were analysed in the present study. A total
of 52 BVSs were implanted. All patients were over 18 years old
and had a diagnosis of stable angina pectoris. Lesions with a
reference vessel diameter (RVD) of between 2.5 and 4 mm were
included. Patients who had suffered from a myocardial infarction
(MI) within one month of the procedure and patients who had
left main coronary artery (LMCA) lesions or bifurcation lesions
consisting of a side branch of over 2.5 mm were excluded. An
informed consent for the procedure was obtained from each
patient.
All CTO lesions were recanalised with dedicated CTO guide
wires. After a mandatory pre-dilatation with an appropriate
balloon, one or two BVS were implanted in the lesion. We did
not use a strategy of hybrid stenting and no metallic stent was
implanted in the lesions. Post-dilatation was performed with a
compliant or non-compliant balloon after BVS implantation at
the physician’s discretion if it was necessary.
Procedural features [target vessel, Japanese CTO score
(J-CTO score), BVS diameter, BVS length, post-dilatation rate,
type of post-dilatation balloon, procedure time, fluoroscopy
time, contrast volume, post-procedure reference vessel diameter
(RVD), post-procedure minimal lesion diameter (MLD),
CTO technique and rate of microcatheter use] were analysed.
Quantitative coronary angiography (QCA) measurements were
used to assess RVD and MLD.
One-, three- and six-month, and one-year follow-up visits
were made after each intervention. During routine visits,
cardiovascular stress tests (treadmill exercise test or myocardial
perfusion imaging test) were performed to diagnose the ischaemic
situation associated with the intervention. Re-intervention and
revascularisation were performed as needed. Rates of death,
myocardial infarction (MI), angina, coronary artery bypass graft
(CABG), target lesion revascularisation (TLR) and target-vessel
revascularisation (TVR) were analysed.
Statistical analysis
Measurement data were described as mean and standard
deviation. Descriptive and frequency statistics were used for
statistical analysis. The level of statistical significance accepted
was 0.05. Data were analysed with the use of SPSS 17.0 software
(SPSS, IBM, Chicago, USA).
Results
Baseline patient characteristics and therapy at discharge are
shown in Table 1. Thirty patients were treated by single BVS, and
11 patients were treated with two BVSs. Mean age was 61.9
±
9.7
years, and 85.4% of the patients were male. Among our patient
group, 51.2% had diabetes mellitus, 80.5% had hypertension and
46.3% had hyperlipidaemia. Renal function was within normal
limits in all patients, 65.9% had prior MI, 56.1% had prior
percutaneous coronary intervention (PCI) and 17.1% had prior
CABG surgery; 24.3% of the procedures were performed by the
radial route.
Nearly half of the BVSs were implanted in the right coronary
artery (RCA). Fourteen patients had lesions on the left anterior
descending (LAD) artery and seven had lesions on the circumflex
(CX) artery. Six patients had easy lesion complexity, 23 had
intermediate complexity, eight had difficult, and four had very
difficult complexity, according to the J-CTO score. Procedural
success rate was 100%. Case examples are shown in Fig. 1.
All patients were treated with acetylsalicylic acid after
the intervention. Additionally, 35 patients were treated with
clopidogrel, three with ticagrelor and three with prasugrel. The
rate of statin use was 97.5% among our patient group and beta-
blocker use was 85.3%.
Mean BVS diameter and BVS length were 2.8
±
0.29
and 25.6
±
4.2 mm, respectively. Our post-dilatation rate was
97.5%, mainly by non-compliant balloon (NCB) (92.6%). Post-
procedure RVD was 2.8
±
0.25 mm and post-procedure MLD
was 2.5
±
0.25 mm. We performed CTO procedures mainly by
the antegrade approach (87.8%). We used a microcatheter in 13
patients (31.7%).
Six patients had side branch occlusion and four had side
branch narrowing. All of these patients were treated successfully
by provisional stenting and final kissing balloon dilatation. Our
procedure time was 92
±
35.6 min, fluoro time was 20.2
±
4.8
min and the mean value of contrast volume was 146.6
±
26.7 ml
(Table 2).
At the end of one year, no death was observed. One patient
had lesion-related MI and needed revascularisation because of
early cessation of dual anti-platelet therapy. Eleven patients had
angina and five of them needed TVR. Our TLR rate was 2.4%
and TVR rate was 12.2% (Table 3).
Table 1. Patient characteristics and therapy at discharge
Patient characteristics
n
= 41 patients (%)
Age (years)
61.9
±
9.7
Male gender
35 (85.4)
Diabetes
21 (51.2)
Hypertension
33 (80.5)
Hyperlipidaemia
19 (46.3)
Smoking
14 (34.1)
Chronic renal failure
–
Prior MI
27 (65.9)
Prior PCI
23 (56.1)
Prior CABG
7 (17.1)
Radial intervention
10 (24.3)
Lesion complexity (J-CTO score)
Easy (J -CTO score of 0)
6 (14.6)
Intermediate (J-CTO score of 1)
23 (56)
Difficult ( J-CTO score of 2)
8 (19.5)
Very difficult (J-CTO score of ≥ 3)
4 (9.7)
Target vessel
LAD
14 (34.1)
CX
7 (17)
RCA
20 (48.7)
Procedural success
41 (100)
Therapy at discharge
ASA
41 (100)
Clopidogrel
35 (85.3)
Prasugrel
3 (7.3)
Ticagrelor
3 (7.3)
Statin
40 (97.5)
Beta-blocker
35 (85.3)
CABG: coronary artery bypass graft, CX: circumflex artery, J-CTO: Japanese
CTO, LAD: left anterior descending artery, MI: myocardial infarction, PCI:
percutaneous coronary intervention, RCA: right coronary artery.