Claudia presented her poster "Treating Coronary Heart Disease in Diabetic Patients: a systematic review of systematic reviews" at the CUTEHeart Poster session of CPC2016.

1. TREATING CORONARY HEART DISEASE IN DIABETIC PATIENTS:
A SYSTEMATIC REVIEW OF SYSTEMATIC REVIEWS
Claudia Nisa PhD1, Luis Filipe Azevedo MD PhD1,2, Frederic Resnic MD PhD,3,4, Mariana F Lobo
MSc1, Alberto Freitas PhD1,4, Vanessa Azzone PhD5, Leonor Bacelar Nicolau MSc6, Armando
Teixeira‐Pinto PhD7, Sharon‐Lise Normand PhD5,8, Altamiro Costa‐Pereira MD PhD1,4
1Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Portugal; 2Department of Health Information and Decision
Sciences, Faculty of Medicine, University of Porto, Portugal ; 3Tufts University School of Medicine, Boston, Massachusetts, United States; 4Department of
Cardiovascular Medicine and Comparative Research Institute, Lahey Hospital and Medical Center, Burlington, Massachusetts, United States; 5Department of
Health Care Policy, Harvard Medical School, Boston, Massachusetts, United States; 6Institute of Preventive Medicine and Public Health and ISAMB – Institute
of Environmental Health, Faculty of Medicine, University of Lisbon; 8Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston,
Massachusetts, United States; 7School of Public Health and Faculty of Medicine, the University of Sidney, Sidney, Australia

2. MOTIVATION

3. INITIAL OBJECTIVE
Review of Systematic Reviews comparing revascularization strategies
REVIEW Included Studies
Follow‐
up
Mortality MI Repeat revascularization Stroke
Potential sources of bias
RE (95%CI) Favors RE (95%CI) Favors RE (95%CI) Favors RE (95%CI) Favors
Tu et a
2014
FREEDOM, CARDia,
VA CARDS, ARTS I &
ARTS II, ERACI II &
III, SYNTAX,
PRECOMBAT
Min 30
days
max 5
years
OR 1.63 (1.31‐
2.02)
CABG OR 1.28 (0.68‐2.40) n.s.
OR 2.53
(1.75‐3.64)
CABG NR
ARTS II and ERACI III not
RCTs Mixing pre‐specified
with post‐hoc diabetic
subgroup analysis
Fanari et
al 2014
SYNTAX,
FREEDOM, CARDia
Min 1y
max 5 y
1y OR 0.97 (0.68‐
1.38); 5y OR 1.36
(1.11‐1.66)
1y n.s.;
5y CABG
1y OR 1.27 (0.75‐
2.15); 5y OR 2.01
(1.54‐2.62)
1y n.s.;
5y CABG
NR
1y OR 0.40
(0.19‐0.81); 5y
OR 0.59 (0.39‐
0.89)
DES
Incomplete search;
Mixing pre‐specified with
post‐hoc diabetic
subgroup analysis
Wu et al
2015
ARTS II, ASAN‐MV,
Briguori et al, Dohi
et al, CARDia, Lee
et al, Dominguez‐
Franco et al,
FREEDOM, Luo et
al, MAIN‐COMPARE,
Ohno et al , Qiao et
al, SYNTAX, VA
CARDS, Yamagata et
al, Zhao et al
Min 1y
max 5 y
30days OR 2.03
(1.11‐3.73); 1y OR
0.97 (0.70‐1.33);
max HR 0.74
(0.59‐0.92)
30days
CABG; 1y
and 5y
n.s.
30days OR 1.41
(0.77‐2.57); 1y OR
0.72 (0.43‐1.20);
max Or 0.56 (0.43‐
0.74)
30 days
and 1y
n.s.; 5y
CABG
30days OR
0.76 (0.19‐
3.02); 1y OR
0.28 (0.19‐
0.42); max
OR 0.36
(0.23‐0.55)
30 days
n.s.; 1y
and 5y
CABG
30days OR 6.02
(2.43‐14.87); 1y
OR 2.75 (1.48‐
5.10); max OR
2.02 (1.33‐3.06)
DES
Estimates using data from
RCTs and non‐RCTs;
Mixing pre‐specified with
post‐hoc diabetic
subgroup analysis

4. REVISED OBJECTIVE
Meta‐Analysis of primary trials
To reassess the clinical evidence based on primary RCTs
comparing CABG with PCI controlling for:
Follow‐up differences
Pre‐defined versus post‐hoc diabetics comparison
Primary endpoint: all‐cause mortality;
Secondary endpoints: myocardial infarction, repeated
revascularization, and stroke;
No specific follow‐up period defined to evaluate the range
of follow‐up endpoints available

5. RESULTS
13 RCTs included (4372 patients)
Only 6 RCTs with pre‐specified subgroup
analysis (46%) for diabetics
Trials with post‐hoc analyses reporting mostly
mortality
Substantial difference between trials with ex‐
ante versus ex‐post analyses in the
distribution of risk factors namely proportion
of patients with multi‐vessel disease and
insulin dependence

6. Up to 1 year 2 to 3 years 4 to 5 years 6 to 10 years Longest follow‐up
Results overall favoring CABG at 5 years only;
Identified only in trials with a pre‐specified
subgroup comparison;
Meta‐regression model with dummy for pre‐
specification (0=post‐hoc; 1=pre‐specified) not
significant but funnel plot suggests that larger
studies with lower variance favor CABG.
RESULTS

7. DISCUSSION
The large amount of existing reviews examining the effectiveness of CABG versus
PCI did not return more consensus in results;
Many potential sources of bias identified, in particular combining very distinct
follow‐up duration and data from ex‐ante versus ex‐post subgroup analysis;
In particular for all‐cause mortality, there are conflicting results depending on
whether the diabetic subgroup analysis was pre‐specified; CABG best option in
the long‐term only in trials pre‐specifying diabetes;
Future Research should address:
The implications of this result to other high‐risk patients and risk factors (e.g., kidney disease)
If this difference is identified in trials comparing stents versus stents
Possible consequences for the estimation of relative cost‐effectiveness between revascularization strategies