Cardiovascular Risk Reduction in Patients with Type 2 Diabetes
Journal of Clinical Outcomes Management. 2017 February;24(2)
References
Should this patient start ASA therapy?
Whether to start daily low-dose ASA for primary prevention of coronary artery disease has been a long-standing question in patients with diabetes. The benefits of ASA therapy with regards to coronary artery disease have long been known from a secondary prevention standpoint, and given the low risk and long experience, primary prevention seemed reasonable. However, no high-quality randomized controlled trials enrolling large numbers of patients with diabetes have been performed in the current era of medical therapy, specifically in the era of widespread statin use. The initial studies examining ASA use in primary prevention were analyzed in a meta-analysis in 1994 and showed a trend towards benefit for ASA in patients with diabetes [52]. Further trials increased the number of diabetes patient-years studied but did not change the initial result. Five meta-analyses have been conducted on the currently available trials, and all but one do not show a significant reduction in coronary artery disease or stroke in patients with diabetes [53–57]. In addition, ASA is known to cause a small absolute increase in the risk for gastrointestinal hemorrhage that is consistent across all studies, with a number needed to harm of approximately 100 over 2.5 years. Therefore, the possible small absolute benefit that was seen in ASA trials with regards to coronary artery disease in the era before statin therapy must be weighed against the known risk of bleeding. Because of this, the CDA and European Society of Cardiology have recommendations against the routine use of ASA for primary prevention in patients with diabetes [12,20].
Since these meta-analyses, one further trial has been completed, the Japanese Primary Prevention Project (JPPP). In a subset of 4903 patients with diabetes, there was no significant benefit to ASA 100 mg for primary prevention of cardiovascular disease [58]. In the near future, 2 large trials looking specifically at patients with diabetes are planned, ASCEND [59] and ACCEPT-D [60], which will help definitively answer the question of whether ASA is beneficial for primary prevention in the era of widespread statin usage.
A summary of pharmacotherapy for cardiovascular risk reduction is shown in the Figure.
Case Continued
The patient is started on a statin because of his elevated LDL-C level in the context of being over the age of 40 years with T2DM. He is also started on an ACE inhibitor to address the hypertension. In addition, a dipeptidyl peptidase-4 inhibitor is added to his metformin to address the elevated A1c. He continues to follow up every 3 to 6 months.
Six years later, he experiences an episode of retrosternal chest discomfort while exercising. He is brought to hospital and is found to have a non-ST elevation myocardial infarction. He is admitted to hospital, undergoes percutaneous revascularization of a single lesion, and is discharged to a rehabilitation center. He is discharged on aspirin, clopidogrel, an ACE inhibitor, a beta blocker, and a high-intensity statin. His blood pressure is well managed, and he has lost further weight since he was last seen. When he returns to clinic, he wonders if there is anything more he can do to prevent further events.
