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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 29, No 6, November/December 2018
AFRICA
375
Recent large, randomised trials have demonstrated that TRI
reduced mortality rates in patients with ST-segment elevation
myocardial infarction (STEMI).
5,7
By contrast, for treatment of
non-ST-segment elevation acute coronary syndrome (NSTE-
ACS), the clinical benefits of TRI remain less well defined.
Although there have been a few studies comparing results
between TRI and TFI in patients with NSTE-ACS, the only
available data were derived from a subgroup analysis or
post hoc
analysis of those studies.
5,8,9
Therefore our main objective was to
compare one-year clinical outcomes and bleeding complications
of TRI with those of TFI in patients with NSTE-ACS, using
data from the Korean TRI registry (KOTRI registry).
Methods
The KOTRI registry was an observational cohort over six
months (February to July 2014) in 20 centres in Korea. However,
due to different processing times for institutional review board
(IRB) approval at the participating centres, the entire study
population was enrolled from May 2012 to January 2015.
10
All patients were included if they had NSTE-ACS, non-ST-
segment elevation myocardial infarction (NSTEMI) or
unstable angina, an invasive approach was proposed, and the
interventional cardiologist was willing to proceed with radial
access. Patients were required to have intact dual circulation of
the hand, as assessed by an Allen’s test, and radial and femoral
artery access were based on the reported final access site.
At the time of admission, patients gave written consent
for the storing of their information in the hospital’s medical
records. This study was approved by the IRB of Soonchunhyang
University Hospital, Seoul, Korea, as well as by all participating
centres, and was conducted according to the principals of the
Declaration of Helsinki.
The primary efficacy endpoint of this study was major adverse
cardiovascular events (MACE), defined as a composite of CD,
non-fatal MI and repeat revascularisation (RR). The secondary
efficacy endpoints included individual components of MACE.
All deaths were considered to have a cardiac cause unless a
non-cardiac origin was definitively documented. MI was defined
according to the recommendations of the ESC/ACCF/AHA/
WHF task force.
11
RR was defined as any repeat percutaneous
intervention or surgical bypass of any segment of the target vessel.
Bleeding complications were recorded during admission
and defined according to the Bleeding Academic Research
Consortium (BARC) criteria.
12
Major bleeding was defined
as BARC type 2 or above (any overt, actionable sign of
haemorrhage that meets at least one of the following criteria:
(1) requiring non-surgical, medical intervention by a healthcare
professional, (2) leading to hospitalisation or increased level of
care, or (3) prompting evaluation). Minor bleeding was defined
as BARC type 1 (bleeding that is not actionable and does not
cause the patient to seek unscheduled performance of studies,
hospitalisation or treatment by a healthcare professional).
All patients were pre-treated with aspirin and a platelet P2Y12
inhibitor. The selection of angioplasty equipment, including the
choice of drug-eluting stents (DES) and the use of glycoprotein
IIb/IIIa inhibitors during the procedure were left to the operator’s
discretion, as was the use of vascular closure devices. After the
procedure, all patients received aspirin indefinitely and a P2Y12
inhibitor for at least 12 months.
After the index PCI, one-, six-, nine- and 12-month follow
ups were recommended. Clinical, angiographic, procedural
and outcome data were collected by independent nurses and
researchers who were unaware of the purpose of the study.
Patient data were reviewed via electronic medical records.
Statistical analysis
The analysis was performed in two parts. First, analyses were
conducted in the crude population. Data are presented as
numbers and frequencies for categorical variables and as mean
±
SD for continuous variables. For between-group comparisons,
the chi-squared test or Fisher’s exact test were used for categorical
variables, and the independent samples
t
-test was used for
continuous variables. A Kaplan–Meier analysis was performed
to calculate the cumulative incidence of clinical outcomes, and
differences were assessed using the log-rank test. A multivariate
Cox proportional hazards regression model was used to identify
independent predictors of MACE. Factors entered into the
multivariate model included those with
p
-values
<
0.10 in the
univariate analysis, and variables with known prognostic value.
In the second part of the analysis, a propensity-score matched
population was selected to adjust for the uneven distribution of
baseline characteristics and a 3:1matched analysiswas performed.
In brief, propensity scores representing the probabilities of TRI
were calculated using a multiple logistic regression model, based
on the 11 measured baseline covariates. The adjusted variables
were as follows: age, gender, hypertension, diabetes mellitus,
dyslipidaemia, chronic kidney disease (CKD), current smoker,
history of ischaemic heart disease (IHD), history of peripheral
artery disease (PAD), initial diagnosis, and extent of disease.
SPSS version 18.0 (SPSS Inc, Chicago, Illinois) and the R
programming language, version 2.8.0 (R Foundation for Statistical
Computing) were used for all statistical analyses. Two-sided
p
-values
<
0.05 were considered to be statistically significant.
Results
The KOTRI registry included 1 319 consecutive patients with
NSTE-ACS from 20 centres who were successfully revascularised
using DES from May 2012 to January 2015. Of these patients,
1 285 were eligible for the study and 34 were excluded due to lack
of follow-up data. Among them, 983 patients were divided into
the TRI group and 302 into the TFI group, according to final
vascular access site.
Baseline clinical and angiographic characteristics are shown in
Table 1. Compared with the TFI group, the TRI group had more
favourable baseline characteristics, such as lower frequency of diabetes
mellitus and CKD, and history of IHD and PAD, except for
dyslipidaemia, which was more common in the TRI group. In addition,
the TRI group was less likely to initially present with NSTEMI and
multi-vessel disease (MVD). Other baseline clinical and angiographic
characteristics were not different between the two groups.
The cumulative clinical outcomes in the crude population at
one year are presented in Table 2 and Fig. 1. The rate of MACE
was significantly lower in the TRI group than in the TFI group
(4.2 vs 7.0%,
p
=
0.045), which was mainly driven by the lower
rate of CD in the TRI group (0.9 vs 2.3%,
p
=
0.050). However,
there were no differences in rates of MI (0.5 vs 0.0%,
p
=
0.207)
and RR (3.3 vs 4.6%,
p
=
0.247) between two groups at one year.