Summary:
In 15,480 adults with diabetes mellitus (mean age 63 years) without evident cardiovascular disease, aspirin 100 mg daily for a mean 7.4 years reduced serious vascular events (MI, stroke/TIA, vascular death) by 12% (8.5% vs 9.6%, RR 0.88, P=0.01) compared to placebo with standard diabetes care, though major bleeding events increased by 29% (4.1% vs 3.2%, RR 1.29, P=0.003), largely offsetting benefits.
| PICO | Description |
|---|---|
| Population | 15,480 adults ≥40 years with diabetes (T1D or T2D) without evident CVD. Mean age 63, 63% male. |
| Intervention | Aspirin 100 mg daily (enteric-coated) for mean 7.4 years follow-up. |
| Comparison | Matching placebo with standard diabetes care (75% on statins). |
| Outcome | Vascular events -12%. Major bleeding +29%. NNT 91, NNH 112. Benefits/harms roughly balanced. |
ASCEND: Aspirin in Diabetes
RCT · type 1/2 diabetes · 7.4 years
Aspirin cut serious vascular events by 12%, but a 29% rise in major bleeding largely offset that benefit. Not recommended for routine primary prevention in diabetes.
Clinical Context
Aspirin’s role in primary prevention has been controversial. Diabetes increases cardiovascular risk 2-4 fold but also increases bleeding risk.
Clinical Pearls
1. Benefits and Harms Essentially Cancel Out: NNT 91, NNH 112 over 7.4 years.
2. Most Bleeding Was Gastrointestinal: No increase in fatal or intracranial bleeding.
3. Well-Managed Modern Population: 75% on statins, good BP control, lower baseline risk.
4. No Apparent Cancer Benefit: No difference in GI cancer incidence.
Practical Application
Avoid routine aspirin for primary prevention in diabetes. Reserve for selected higher-risk patients (10-year ASCVD >10%) at low bleeding risk. Consider PPI co-prescription if aspirin used.
Study Limitations
Well-controlled population may not represent all diabetic patients. Couldn’t identify subgroups who might benefit substantially.
Bottom Line
Aspirin reduces vascular events by 12% but increases major bleeding by 29%. Benefits and harms roughly equivalent.
Source: The ASCEND Study Collaborative Group. “Effects of Aspirin for Primary Prevention in Persons with Diabetes Mellitus.” NEJM, 2018;379(16):1529-1539. Read article