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DM &Coronary Heart Disease(many
controversies)
• The incidence of diabetes mellitus has increased at an
alarming rate over the past 2 decades. Current estimates
of the numbers of people with diabetes include 17.7
million in the U.S. and 171 million worldwide . These
numbers are projected to double by the year 2030.
• The association between diabetes and cardiovascular
disease is well established . Coronary artery disease
(CAD) is the leading cause of death in diabetic patients,
accounting for 75% of the deaths .
• Coronary artery disease is also more often silent in
patients with diabetes .
Epidemiology
• Given the elevated risk of cardiovascular events and the higher
prevalence of silent coronary artery disease (CAD) in diabetic
versus non-diabetic patients, screening asymptomatic diabetic
patients for CAD is an appealing concept.
• However, many factors argue against implementing a broad-
based screening program at the present time.
• Foremost is the lack of any published data demonstrating that a
prospectively applied screening program improves outcome in
asymptomatic diabetic patients.
Screening for CAD in asymptomatic diabetic patients
•Consensus documents recommend more aggressive
treatment of hypertension and hyperlipidemia solely on
the basis of diabetes status, without differentiation
based on the presence or absence of identifiable CAD.
There is no evidence that use of anti-ischemic
medication can alter the natural history of CAD in these
patients.
• However, the DIAD (Detection of Ischemia in Asymptomatic
Diabetics) study, reported a much lower percentage of abnormal
SPECT images (16%) and images with a very large (10% of the
left ventricle) defect (1%).
• The financial implications of screening all asymptomatic diabetic
patients determined to be at intermediate and high risk by
clinical scoring systems is enormous. Clearly more data are
needed to address this issue. Future studies should consider
possible methods to enrich the patient subset that might benefit
from screening and should include carefully performed cost-
effective analyses.
J Am Coll Cardiol 2006
• The screening test must accurately characterize low- and
high-risk patients.
• Stress SPECT is well-established for its risk stratifying
properties . According to ACC/AHA guidelines , patients
characterized as low risk should have an annual cardiac
death rate 1%.
• The annual risk of cardiac death or nonfatal myocardial
infarction in general patient populations with normal SPECT
images is 0.6% . The ability of stress SPECT to identify low-
risk diabetic patients might not be as accurate.
• In the Cedars-Sinai study , the annual rate of cardiac death or
nonfatal myocardial infarction in asymptomatic diabetic
patients with normal images was 1.6%. In the Mayo Clinic study
, annual mortality in patients categorized as low risk by SPECT
was 3.6%.
• Identification of individuals afflicted with the disease should
lead to a treatment that improves outcome.
• However, A common argument for identifying CAD in
asymptomatic patients in general is to intensify treatment of
risk factors. This rationale might not apply to treatment of risk
factors in diabetic patients.
The National Cholesterol Education Program (NCEP) and Joint
committee of hypertension
• recommend more aggressive treatment of lipids and
hypertension, respectively, simply on the basis of diabetes
status. As noted in the AHA Prevention Conference the
results of a screening test in diabetic patients do not alter risk
factor management, because these patients are consid- ered
higher risk on the basis of diabetes alone. .
• In clinical practice, beta-blockers are often prescribed to
patients with silent ischemia but without evidence that they
alter the natural history of chronic CAD.
-
• The goal of screening might be to identify individuals with
severe CAD who are candidates for revascularization.
• The BARI (Bypass and Angioplasty Revascularization
Intervention) trial compared outcomes in symptomatic patients
(two-thirds unstable angina) with multivessel CAD randomized
to coronary artery bypass grafting (CABG) or balloon
angioplasty. In the diabetic subset of patients, those assigned to
CABG had better survival (21). There are no randomized data
comparing treatment strategies in asymptomatic diabetic
patients.
• The process should be cost-effective.
• Bax et al. (5) recommend using clinical risk scores and
proceeding with stress SPECT in diabetic patients categorized as
intermediate or high risk.
• These scores are determined by age, gender, and the presence
and severity of risk factors. all diabetic men and women who are
60 years old are at intermediate risk, regardless of the presence
of any other risk factors.
• The proposal by Bax et al. would result in screening all diabetic
patients 60 years old and many younger patients with additional
risk factors.
• Of the 17 to 18 million patients with diabetes in the U.S.,
approximately 20% have recognized CAD . The number of the
remaining approximately 14 million who are intermediate or high
risk by clinical assessment is not known but is likely to be
substantial.
• Stress SPECT imaging is expensive, especially as currently
performed, with add-on costs for gated left ventricular ejection
fraction and wall motion measurements and additional
pharmaceutical charges for the radioisotope and adenosine).
• Bax et al. (5) suggest that computed tomography for coronary
artery calcium imaging has the potential to refine the screening
process, but published data are limited with mixed results (26,27).
More studies are necessary before recommending this approach.
• A cost- effective analysis of the screening process would need to
encompass not only the costs of noninvasive imaging but also
the costs of coronary angiography and revascularization
procedures that would be performed in patients with abnor mal
SPECT studies and include benefits of these proce- dures in
terms of increased quality-adjusted life-years.
CONCLUSIONS
• The detection of silent CAD in patients with diabetes will assume
even greater importance as a health issue in the future as the
number of people with diabetes increases.
• Clearly more studies are needed. Collection of follow-up data,
which is currently in progress in both the DIAD and BARI-2D
trials, might help clarify whether certain diabetic patients benefit
from screening.
• Although screening on the basis of multiple risk factors seems
intuitive, it is important to note that in both the DIAD and Mayo
Clinic studies, multiple risk factors did not predict which patients
had severely abnormal SPECT images.
• The Mayo Clinic studies demonstrated that there is a subset of
asymptomatic diabetic patients with severe CAD who can be
detected by SPECT and whose outcome might be enhanced by
CABG.
• However, the results from the DIAD study suggest that the yield
of detecting patients with severely abnormal images will be low
when SPECT is applied in a prospective manner as the first and
only test.
• A challenge for future studies will be to discover methods to
“enrich” the screened population to pre-select patients for SPECT
imaging. In the current era of escalating medical costs with an
emphasis on evidence-based medicine, it is difficult to support a
broad recommendation to screen all intermediate- and high-risk
asymptomatic diabetic patients with stress SPECT imaging only.
Until more data become available, clinicians should judiciously
apply screening tests on individual asymptomatic patients on the
basis of clinical judgment.
Management of CAD in Diabetic patients
conclusion
Acute Coronary Syndrome
Understand what you can see and cannot see
Resolution
Penetration
Understand the basic morphology of images that you are
observing and its clinical relevance
Natural history and future event…
3 layers of vessel wall in normal
vesselIntima (I: High signal)Media (M: Low signal)Adventitia (A: high-iso signal)
Fibrous plaqueHigh signal low attenuation
and homogenous
Zoom-in view Normal Sections
Case
Basic Angiographydistal LM and critical ostial LAD and instent
stenosis
Normal LCX ostium
Normal RCA
Acute Coronary Syndrome
Checklist
SCREEN for DM among patients with
ACS
USE anti-platelet therapies, prasugrel
or ticagrelor, instead of clopidogrel in
patients with DM undergoing
percutaneous coronary intervention
(PCI)
AVOID both hyper- and hypoglycemia
2013
Screen for DM Among
Patients with ACS• Diabetes is a strong risk factor for
cardiovascular disease
• A significant proportion of patients with
ACS have undiagnosed DM
• Screening for DM is essential among
patients with ACS
– Can use FPG, A1C or 75g OGTT
–Consider standardized order sets
Radke P W ,et al. Eur Heart J 2010;31:2971-3.
ACS Mortality in Diabetes vs. No Diabetes:
Changes Across the Eras
All patients with DM and ACS should receive
the same treatments as those without DM …
with some differences
Recommendation 1
1. Patients with ACS should be
screened for diabetes with a fasting
plasma glucose, A1C or 75 gram
OGTT prior to discharge from
hospital. [Grade D consensus]
2013
Recommendation 2
.2All patients with diabetes and ACS
should receive the same treatments
that are recommended for patients
with ACS without diabetes since they
benefit equally [Grade D, consensus].
Recommendation 3
.3Patients with diabetes and ACS
undergoing PCI should receive
antiplatelet therapy with prasugrel (if
clopidogrel-naïve, <75 years of age,
weight >65kg and no history of stroke)
[Grade A, Level 1] or ticagrelor [Grade B, Level 1],
rather than clopidogrel, to further
reduce recurrent ischemic events.
Patients with DM and non-STE ACS and higher risk
features, destined for a selective invasive strategy
should receive ticagrelor, rather than clopidogrel [Grade B level 2]
2013
Recommendation 4
.4Patients with diabetes and non-STE
ACS and high risk features should
receive an early invasive strategy
rather than a selective invasive
approach to revascularization to
reduce recurrent coronary events,
unless contraindicated [Grade B Level 2].
2013
Recommendation 5
.5In patients with diabetes and STE-ACS,
the presence of retinopathy should not
be a contraindication to fibrinolysis [Grade
B, Level 2].
Recommendation 6
.6In-hospital management of diabetes
in ACS should include strategies to
avoid both hyperglycemia and
hypoglycemia:
–Blood glucose should be measured on
admission and monitored throughout the
hospitalization [Grade D, Consensus]
–Patients with acute MI and blood glucose
on admission of >11 mmol/L may receive
glycemic control in the range of
Recommendation 6 (continued)
.6In-hospital management of diabetes
in ACS should include strategies to
avoid both hyperglycemia and
hypoglycemia:
–Insulin therapy may be required to
achieve these targets [Grade D, consensus]. A
similar approach may be taken in those
with diabetes and admission blood glucose
<11.0 mmol/L [Grade D, consensus]
–An appropriate protocol should be
Thank You
21-22/9/2016
Grand Hyatt H. Nile tower,Cairo