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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 5, September/October 2014
AFRICA
249
Letter to the Editor
Efficacy and safety of sirolimus-eluting stents versus
bare-metal stents in coronary artery disease patients
with diabetes
Dear Sir
I read with great interest the recent article titled ‘Efficacy
and safety of sirolimus-eluting stents versus bare-metal stents
in coronary artery disease patients with diabetes: a meta-
analysis’ by Qiao
et al
., published online in the
Cardiovascular
Journal of Africa
.
1
I believe this is a well-conducted meta-
analysis that compared the major cardiac events, target-lesion
revascularisation, myocardial infarction and mortality rate in
coronary arterial disease (CAD) patients with diabetes who were
treated with sirolimus-eluting stents (SES) or bare-metal stent
(BMS). However, there are some issues I would like to point out.
The electronic databases (PubMed, MEDLINE, EMBASE,
Springer, Elsevier Science Direct, Cochrane Library and Google
scholar) were systematically searched by the authors. However,
they did not describe the search strategy for databases in detail,
which plays an important role in systematic reviews. The manual
searches were not clearly described. The lack of a manual search
protocol may be considered a weakness of the meta-analysis.
The publication language in this meta-analysis was limited
to English but the authors did not mention it in the discussion.
Therefore, there may have been a language bias in their meta-
analysis. I suggest that there be no language limitation for the
included studies to reduce the bias.
The inclusion and exclusion criteria were not adequately
described in this meta-analysis. I suggest that explicit inclusion
and exclusion criteria be introduced in detail.
The publication bias in this meta-analysis was evaluated with
Egger’s test and funnel plots. However, the number of studies
was less than 10, and as far as I know, a funnel plot should be
inspected visually to assess for publication bias in meta-analyses
with at least 10 studies. Therefore, it was inappropriate.
Under the statistical analysis heading, the authors wrote
‘Pooled ORs were obtained using the Mantel-Haenszel method
in a fixed-effect model, and the DerSimonian-Laid method in a
random-effects model’. However, it is not appropriate to use the
Mantel-Haenszel method in a random-effects model to pool the
data for all forest plots, regardless of heterogeneity.
Itisveryimportantinmeta-analysestoevaluatemethodological
quality of included studies. However, the authors did not provide
any methodological quality assessment or detailed scores for
each trial in this article.
In conclusion, I agree with the results of this meta-analysis.
SES are safer and more effective than BMS in CAD patients with
diabetes, as far as major cardiac events are concerned. To reach
a definitive conclusion, however, more high-quality studies with
larger sample sizes are needed.
Juehua Jing, MD,
jingjuehuapaper@163.comDepartment of Orthopaedics, Second Hospital of Anhui
Medical University, Hefei,Anhui Province, People’s Republic
of China
Reference
1.
Qiao Y, Bian Y, Yan X, Liu Z, Chen Y. Efficacy and safety of sirolimus-
eluting stents versus bare-metal stents in coronary artery disease patients
with diabetes: a meta-analysis.
Cardiovasc J Afr
2013;
24
(7): 274–279.