Three studies, published online on Sept 16, 2018 by the New England Journal of Medicine, examine the effect of prophylactic aspirin in healthy elderly patients. The subjects received 100 mg of aspirin daily or a placebo for five years. Trial participants were community-dwelling men and women from Australia and the United States who were 70 years of age or older (or ≥65 years of age among blacks and Hispanics in the United States).
Effect of Aspirin on Disability-free Survival in the Healthy Elderly
Effect of Aspirin on Cardiovascular Events and Bleeding in the Healthy Elderly
Effect of Aspirin on All-Cause Mortality in the Healthy Elderly
Aspirin has been shown to reduce the recurrence of strokes and heart attacks in patients with cardiovascular disease – secondary prevention. Despite lack of persuasive evidence for the drug’s efficacy as a preventative for the development of a first stroke or heart attack (primary prevention) it has been widely used by subjects who do not have a medical indication for such use. The first paragraph of the first of these three papers by the same group of investigators gives the rationale for all three studies.
Several large, randomized trials have shown the efficacy of aspirin for the secondary prevention of cardiovascular disease among persons with a history of coronary heart disease or stroke.1-3 The evidence supporting a benefit of aspirin therapy in the primary prevention of cardiovascular or other chronic disease is less conclusive despite favorable trends suggesting that aspirin use reduces the incidence of cardiovascular events and possibly reduces the incidence of cancer and cancer-related mortality, particularly from colorectal cancer. Among elderly persons (more so than among younger persons), a higher risk of cardiovascular disease may increase the benefit of aspirin, but this benefit may be accompanied by an increased risk of bleeding. Despite the widespread use of low-dose aspirin in elderly persons who do not have a medical indication for aspirin, there is limited evidence that the beneficial effects outweigh the risks in this age group.
The three conclusion statements from these papers nicely sum up their findings:
Aspirin use in healthy elderly persons did not prolong disability-free survival over a period of 5 years but led to a higher rate of major hemorrhage than placebo.
The use of low-dose aspirin as a primary prevention strategy in older adults resulted in a significantly higher risk of major hemorrhage and did not result in a significantly lower risk of cardiovascular disease than placebo.
Higher all-cause mortality was observed among apparently healthy older adults who received daily aspirin than among those who received placebo and was attributed primarily to cancer-related death. In the context of previous studies, this result was unexpected and should be interpreted with caution.
The finding of higher cancer death rates was unexpected as earlier studies had suggested a beneficial effect of the drug on colon cancer. This reduction in the placebo treated group barely achieved statistical significance and likely has no clinical significance. But the lack of benefit of aspirin in the primary prevention of CVD is quite clear. Statin therapy is often employed to achieve primary prevention of CVD and also appears to lack the desired effect.
So what’s a worried person to do. The best advice is to live your life as best you can and face the fact that you’re mortal and that there’s a bullet out there that will inevitably find you. Most of my patients, virtually all, thought this recommendation to be far from what they wanted to hear. So here’s another. Keep your blood pressure below 140/90 – the recent guide of 130 systolic is, in my opinion, overkill. Aim for a BMI of about 25-30, but don’t be a fanatic about your weight – high or low. Treat comorbid conditions like diabetes. Take a walk every now and then. And most important – have the right parents.
What about younger subjects. Well, as mentioned above they’re less likely to develop CVD and thus aspirin is even less likely to be beneficial. Studies on younger people have uniformly showed no reduction in overall mortality from prophylactic aspirin treatment.