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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 1, January/February 2019
46
AFRICA
IC abciximab delivery resulted in a modest but statistically
significant reduction in infarct size compared with aspiration
thrombectomy. However, in this trial, there was no control group
of patients receiving IV abciximab.
18
Therefore, whether IC or
IV abciximab delivery would be more effective after removal of
IC thrombotic and atherosclerotic materials has not been tested.
This study was intended to compare the effects of IC versus IV
administration of abciximab in patients with STEMI undergoing
primary PCI with aspiration thrombectomy. Intracoronary
abciximab was administered through the distal part of the same
catheter (Export catheter) after aspiration thrombectomy was
completed.
Methods
This was a two-centre, open-label, controlled, single-blind,
randomised study. The study was performed at the Department
of Cardiology of the Military Hospital (Hôpital Central de
l’Armée) and at the Department of Cardiology A2 of the
Mustapha Pacha University Hospital, in collaboration with the
Cardiology Oncology Collaborative Research Group (COCRG).
Patients were recruited in this prospective, randomised, blind
study from 1 October 2013 to 31 October 2015.
Inclusion criteria were a chest pain suggestive of acute
myocardial infarction (AMI) evolving for
≥
30 minutes and less
than 12 hours, resistant to nitroglycerin administration, and
ST-segment elevation recorded
≥
1 mm from standard and
≥
2
mm from precordial leads.
Exclusion criteria were cardiogenic shock, high blood
pressure, not controlled by treatment, after measuring twice
(systolic BP
≥
240 mmHg, diastolic BP
≥
120 mmHg, or both),
left bundle branch block, pregnancy, thrombocytopaenia, severe
kidney or liver failure, major surgery lasting for less than
one month, gastrointestinal haemorrhage in the past year,
coagulation disorders, including coagulation factors and platelet
disorders, ischaemic stroke lasting for less than one month,
current staging or treatment of cancer, oral anticoagulant
therapy, administration of a thrombolytic treatment during the
seven days preceding the study, and allergy/hypersensitivity to
aspirin, heparin or abciximab.
During the study period, 160 patients were consecutively
included. The study was approved by the ethics committee of
the institution and patients gave informed consent at admission
to the catheterisation laboratory.
Patients were randomly assigned on a 1:1 basis to either
an IV or IC abciximab bolus (ReoPro 10 mg/5 ml, Eli Lilly,
Indianapolis, IN), delivered over one minute through the
aspiration thrombectomy catheter at the site of coronary
occlusion, after anterograde flow had recovered. Intracoronary
or IV bolus administration was followed by a 12-hour IV
infusion of abciximab at 0.125 µg/kg/min. Coronary angiography
was performed after introduction of a 6F catheter though the
femoral or radial artery.
Two-orthogonal-axis coronary artery imaging was performed
to assess baseline and post-procedural TIMI flow grade and
myocardial blush grade (MBG). TIMI flow grade was defined
according to the TIMI study group.
19
In brief, TIMI 0 denotes no
perfusion (no anterograde flow beyond the point of occlusion);
TIMI 1: penetration without perfusion (faint anterograde
coronary flow beyond the occlusion with incomplete filling of
the distal coronary bed); TIMI 2: partial perfusion (delayed
or sluggish anterograde flow with complete filling of the distal
territory); TIMI 3: complete perfusion (normal flow with
complete filling of the distal territory).
19
Myocardial blush grade 0 denotes no contrast density or
persistent blush or staining in the territory supplied by the infarct
artery; MBG 1: minimal contrast density; MBG 2: moderate
contrast density but less than that obtained during angiography
of a contralateral or ipsilateral non-infarct-related coronary
artery; and MBG 3: normal contrast density, comparable with
that obtained during angiography of a contralateral or ipsilateral
non-infarct-related coronary artery.
20
Before PCI, patients were treated with aspirin (bolus of 250
mg), intravenous heparin (60-IU/kg bolus) and clopidogrel
(loading dose of 600 mg). Adjunctive therapy included 1 mg
IC nitroglycerin during the procedure. After completion of
primary PCI, patients received 150 mg clopidogrel daily p.o. for
one month, then 75 mg p.o. daily for one year, together with a
statin, beta-blocker, angiotensin converting enzyme inhibitor or
angiotensin receptor antagonist, and 75 mg aspirin.
Aspiration thrombectomy was performed using an Export
catheter (Medtronic, Minneapolis, Minnesota). IC abciximab
was administered through the distal part of the same catheter
after aspiration thrombectomy was completed. Additional or
post-balloon predilatation as well as stenting remained at the
discretion of the interventional cardiologist.
The primary efficacy endpoint was assessed by ST-segment
resolution. ST-segment elevation was measured to the nearest
0.1 mV, 40 ms after the end of the QRS using the TP segment as
baseline. According to previous reports,
5-6
ST-segment resolution
was defined as successful if
≥
70% of the sum of ST-elevation
present on the baseline ECG had resolved by 60 minutes
after primary PCI (complete ST-segment resolution). Partial
ST-segment resolution was defined if
≥
50% but
<
70% of the
sum of ST-elevation present on the baseline ECG had resolved
by 60 minutes after primary PCI.
5,6,21,22
Secondary efficacy endpoints consisted of (1) major adverse
cardiovascular events (MACE), including cardiovascular death,
stent thrombosis, target-vessel revascularisation, and recurrent
myocardial infarction at 30 days and six months; and (2)
achievement of MBG 2 to 3 after completion of primary PCI.
Recurrent AMI was defined as recurrent symptoms or
ST-elevation or increase in troponin levels.
23
Target vessel
revascularisation was defined as any repeat revascularisation
procedure on the infarct-related coronary artery.
Safety endpoints consisted of major and minor bleeding
during hospital stay. Major haemorrhage was defined as
retroperitoneal or intracranial bleeding, bleeding resulting in
a
≥
15% absolute decrease in haematocrit or a decrease in
haemoglobin level
>
5 g/dl.
20
Minor haemorrhage consisted of
clinical or echo/CT scan-documented bleeding associated with
a decrease in blood haemoglobin level
>
3 g/dl and
<
5 g/dl or a
decrease in haematocrit
>
9% and
<
15%.
24
Statistical analysis
This study was powered for a ST-segment resolution rate of
56% at 60 minutes.
7
Evaluating two groups of 72 patients would
provide 90% power to demonstrate a relative 25% difference
in ST-segment resolution rate between the IC and IV groups.