Discussion
Myocardial infarction (MI) and ischemic stroke are the leading causes of mortality and morbidity in patients with type 2 diabetes.18 The strength of the evidence for the use of antiplatelet agents as secondary prevention19-22has led to the suggestion that Aspirin might be helpful for primary prevention of cardiovascular events in diabetes.
In order to evaluate the role of Aspirin in the prevention of cardiovascular events, especially in diabetic patients, the primitive search of the present meta-analysis was compared to its risk of bleeding. Similarly, to compare the benefits over the harms of Aspirin, the chances of risk of all-cause death, CVS-related death, MI, stroke, and risk of bleeding were compared between the patients taking Aspirin and no aspirin group (placebo).
When the odds ratio of all-cause death was compared with Aspirin plus placebo in diabetic patients, the confidence intervals slightly crossed the line of no effect, which shows an average odds ratio of 0.86. It signifies that the p>0.05 has no specific effect of Aspirin on all-cause death in diabetes. The average odds ratio of CVS-related death compared to Aspirin with placebo in diabetic patients was insignificant with a value of 1.0; CI varied from 0.61 to 1.63, showing no significant role of Aspirin in CVS-related death. The chances of the risk of MI in aspirin patients were also insignificant compared with placebo with a confidence interval of 0.9, slightly crossing the line of no effect. The possibility of a chance of stroke in the aspirin group was also insignificant, with a p-value of 0.93, resulting in no specific risk of Aspirin for stroke in diabetic patients. There were no differences in the rates of bleeding outcomes between patients who received Aspirin and those who received a placebo.
All included trials were consistent in reporting that no significant effect of Aspirin on primary prevention of CV events in individuals with diabetes, which is similar to the present meta-analysis except for the JPAD trial15; which significantly reported lower risk in the aspirin group when compared with placebo showing an inefficacy of low dose of Aspirin. A follow-up study of 10 years was performed for the same trial, which together constitutes the JPAD2 study23 which concluded that a low dose of Aspirin has no role in the risk of CV events but included an increased risk of gastrointestinal bleeding. A recent trial by ASCEND group17 only showed the beneficial effect of Aspirin in preventing serious vascular events in diabetic patients with no cardiovascular events.
Several Meta-analyses and randomized trials have been previously conducted to rule out the role of Aspirin in the primary prevention of cardiovascular events, including diabetic patients. However, due to the low ratio of diabetic patients in the studies as mentioned in Table 1, these studies were excluded in the present meta-analysis to reduce the chances of risk of bias as there was the inability to perceive event rate data specifically for patients with diabetes.