2008 Clinical Practice Guidelines - Canadian Diabetes Association

2008 CLINICAL PRACTICE GUIDELINES
S102
Vascular Protection in People With Diabetes
Canadian Diabetes Association Clinical Practice Guidelines Expert Committee
The initial draft of this chapter was prepared by David Fitchett MD FRCPC and Maria Kraw MD
FRCPC
KEY MESSAGES
• The first priority in the prevention of macrovascular
complications should be reduction of cardiovascular
(CV) risk through a comprehensive, multifaceted
approach, integrating both lifestyle and pharmacologic
measures.
• Treatment with angiotensin-converting enzyme (ACE)
inhibitors has been shown to result in better outcomes
for people with atherosclerotic vascular disease, recent
myocardial infarction, left ventricular impairment and
heart failure. In a similar population, angiotensin II
receptor antagonists have been shown to be noninferior
to ACE inhibitors for vascular protection.
• Low-dose acetylsalicylic acid therapy may be considered
in people with stable CVD.The decision to prescribe
antiplatelet therapy for primary prevention of
CV events, however, should be based on individual
clinical judgment.
VASCULAR PROTECTION
In order to reduce the excessive cardiovascular disease
(CVD) risk associated with diabetes, all coronary risk factors
must be addressed and treated aggressively. The Steno-2
studies (1,2) demonstrated that a target-driven, comprehensive,
multifaceted approach to risk factor management
applied to high-risk patients with type 2 diabetes and
microalbuminuria over a period of 7 years resulted in a
>50% reduction of CVD (HR 0.47, 95% CI, 0.24–0.73)
*See also “Identification of Individuals at High Risk of Coronary Events,” p. S95
BP = blood pressure
CAD = coronary artery disease
CV = cardiovascular
and microvascular events (nephropathy HR 0.39, 95% CI,
0.17–0.87; retinopathy HR 0.42, 95% CI, 0.21–0.86). It is
likely that similar relative benefits would be achieved by
applying a comprehensive, multifaceted approach to risk factor
control in high-risk patients with diabetes who do not
have microalbuminuria.
Patients at the highest risk for CV events include those
who have diabetes and atherosclerotic vascular disease that
includes either clinically recognized disease (e.g. coronary
artery disease [CAD], peripheral arterial disease [PAD] and
cerebrovascular disease) or clinically silent disease (e.g.
silent myocardial ischemia or infarction, and PAD identified
by the presence of bruits or abnormal ultrasound or anklebrachial
index). Other patients at high risk include those
with microvascular disease and multiple risk factors or
extreme levels of a single risk factor (Table 1) (see also
“Identification of Individuals at High Risk of Coronary
Events,” p. S95).
When deciding on appropriate treatment strategies, it is
important to prioritize treatment goals. Since some of the
available treatments, such as angiotensin converting enzyme
(ACE) inhibitors and angiotensin II receptor antagonists
(ARBs), have potential uses in controlling blood pressure
(BP) as well as reducing the risks for CVD and nephropathy,
it can be challenging to integrate the data to make recommendations
for one application over another.Table 2 summarizes
the priorities for vascular and renal protection, while
Table 3 summarizes recommended interventions for vascular
protection.
Table 1. People with diabetes considered at high risk of a CV event*
• Men aged ≥45 years, women aged ≥50 years
• Men 180 mm Hg)
• Duration of diabetes >15 years with age >30 years
LDL-C = low-density lipoprotein cholesterol
MI = myocardial infarction
PAD = peripheral arterial disease