Aspirin has long been used to prevent a first heart attack and even recommended by leading doctors but evidence from several recent studies showed that small benefits of aspirin are actually outweighed by increased risk of bleed. Now, a large study conducted in Japan supports this claim that aspirin is more harmful than helpful in preventing a first heart attack, especially among the elderly.
The Japanese Primary Prevention Project, published in the JAMA, was presented in Chicago at the American Heart Association meeting. This study involved patients between the ages of 60 and 85 years of age who lived with high blood pressure, dyslipidemia, or diabetes.
In all, 14,464 patients were randomized to 100mg of aspirin a day or no aspirin in addition to conventional therapy. These patients were followed for six and a half years to the point of cardiovascular death, nonfatal stroke, or nonfatal MI.
The goal of the study was to gather enough primary endpoints to make produce solid results. However, after a smaller number than expected endpoints were reached, which in turn would make the study insignificant from a statistical standpoint, the independent Data Monitoring Committee discontinued it.
While the study was underway, researchers found no major difference in the primary endpoint at any time. In all, there were 56 fatalities for both the aspirin and placebo groups, as well as 137 nonfatal evens for those taking aspiring compared to 151 among those not taking aspirin.
There was a significant decrease in nonfatal MI for patients taking placebo aspirin and only a slight reduction in TIA. However, for serious extracranial hemorrhages, there was a significant increase. Researchers also found a huge increase of gastrointestinal side effects for the patients taking aspirin, which included 50% more duodenal ulcers and roughly 75% more GI bleeds.
According to the authors of the study, even with the trial being ended, it became clear that using aspirin as a main prevention for cardiovascular events is not nearly as effective as once believed. As stated by J. Michael Gaziano, along with Philip Greenland, the results of the study are consistent with those of other primary prevention trials. The only exception is that this study proved a higher intracranial hemorrhage rate among Asians who participated.
Both Gaziano and Greenland agree that aspirin is beneficial in several situations but patients with extremely low risk of vascular events should not take it even at low dose as a prevention of vascular events. The bottom line, there is no significant benefit of taking aspiring to prevent a first heart attack, instead, increase risk of bleeding, a common side-effect of daily aspirin use.