Marden Tabet ING.pmd - Revista Brasileira de Cardiologia Invasiva

Tebet MA, et al. Primary Angioplasty Using the Radial Access With High Bolus Dose of Tirofiban: a Safe and Effective Technique.
Rev Bras Cardiol Invas 2007; 15(3).
Figure 1 - Means of access used in elective angioplasties during
the period from January 2006 until May 2007.
the rest. The success in the elective angioplasties was
98.5%, with ballon angioplasties only in only 5 (1.5%)
patients. The 6F caliber introducers were used in 294
patients (97.3%0, in 3 (0.9%) of patients we used 5F
introducers and, in 5 (1.5%), 7F caliber introducers.
When the right radial approach was not possible, we
opted for the left radial artery for the performance of
the procedure. In cases on which a temporary pacemaker
was necessary, we used the radial access associated
to punction of the jugular vein or even to the
punction of the femoral vein.
This routine access, for the performance of primary
angioplasty, was only implanted after a learning curve
period of the operators, in accordance with several
studies that highlight its importance 23-26 .
In our patients group, there was a predominance
of AMI of the lower wall, clinically stable in most
cases. An eventual major clinical instability, would
potencially contribute negatively to the clinical success
and would determine a higher necessity for the use of
intra-aorta balloon use, which might result in a lower
use of the radial access.
In spite of it having become an option over ten
years ago, for the performance of coronary angioplasty,
in our midst, the radial access is still not much used.
Araújo and Mangione 27 assesed 53.777 patients submitted
to coronary intervention enrolled in the CENIC
(Centro Nacional de Intervenciones Vasculares – National
Center of Vascular Intervention). Out of these, 48.455
patients underwent elective coronary angioplasty and
5.322 in the course of infarct. The radial access was
used only in 10.1% of the elective cases and in 4.6%
in the infarct case patients, with the femoral approach
used in 87.7% of the elective cases and in 91.7 of the
emergencies. It was noticed, that in our country, the
radial access is used in selected patients (Male, with
only one lesion and who had not undergone previous
surgical revascularization). Patients with more serious
illness are selected for femoral access.
After its introduction by Kiemeneij and Laarman 28 ,
the benefits of the radial technique have been clearly
demonstrated in several studies 7 . Hemorragic complications
in the access site are virtually eliminated. After
the procedure, walking and hospital discharge are more
precocious 8 . The morbidity of the procedure is lower
4
and the patients deffinitely prefer this approach to the
transfemoral one 8,29 .
Several studies prove the efficacy and safety of the
radial approach in patients submitted to primary angioplasty
4, 30, 31 . Saito et al. 31 , randomized 213 patients
with AMI within the first 12 hours of the beginning of
the symptoms: 77 were treated with the radial approach
(RTI) and 72 with the femoral approach (FTI). The success
rate of reperfusion and the incidence of major cardiac
events (death, non-fatal AMI, repeated revascularization),
during hospitalization, were similar (96.1% and 5.2%
vs. 97.1% and 8.3%) in the TRI and TFI groups respectively
(p = 0.624 and p = 0.444).
Philippe et al. 4 also compared the clinical results
of the transradial intervention (TRI) and transfemoral
intervention (TFI), in primary angioplasty with the use
of abciximab. One hundred and nineteen patients were
prospectively assessed (TRI n = 64 and TFI n = 55). In
that non-randomized study, the free of events overlife was
similar for both techniques (97%0 vs. 94.5%; p = 0.19).
There were no major hemorragic complications in the
TRI group, the opposite to what was found in the TFI
group (5.5%, p = 0.03). The hospital stay was also significantly
longer in the TFI group 5.9 +/- 2.1 vs. 4.5 +/- 1.2
days; p = 0.05).
The glicoprotein inhibitors of the Iib/IIIa are an
adjunct therapy of the utmost importance in the treatment
of AMI, in spite of conflicting results do not show
benefits in the reduction of the mortality rate, when
compared to stent implantation 12 . Abciximab has been
indicated as the class I drug but, due to its high cost
is little used. In comparison to abcximab, tirofiban in
the customary doses (bolus of 10 ug/kg and infusion
of 0.15 ug/kg/min) were less effective, specially in patients
with acute coronary syndrome 14 . The lower event incidence
provided by abciximab in that study is due to
the lower incidence of periprocedure AMI. Differences
were apparent within the next 12 hours, 24 hours at
the most, after the procedure. It was found that the
extension of the inhibition of the agregation was higher
from 15 to 60 minutes from the beginning of the
treatment with abciximab. Schneider et al. 16 assessed
the dose of the bolus of tirofiban cappable of producing
an agregation inhibition higher than 90%, during the
first hour of treatment, in patients with accute coronary
syndrome, that underwent PCI. Two dossages where
tested: bolus of 20 ug/kg and infusion of 0.15 ug/kg/min
during 18 to 24 hs or bolus of 25 ug/kg with the same
infusion. The second dossage showed an agregation
inhibition higher than 90% in the first hour. With the
regime used in the TARGET study, the average extention
(bolus of 10 ug/kg and infusion of 0.15 ug/kg/min) gives
an inhibition of the agregation in response to 20 uM
of ADP was 90-94%, in the period of 15 to 60 minutes
after the beginning of treatment with abciximab, and
60 – 66%, after tirofiban 17,18 . The interval of 15 to 60
minutes after the beginning of the treatment, is a critical