Aspirin,
chemically acetylsalicylic acid, has been a trusted pal of
health-care providers for more than 100 years by now. Many beneficial
effects, including benefits in certain heart diseases &
colo-rectal cancer, came to light in the recent past, adding many
feathers to its’ cap.
Aspirin
has been a staple of primary prevention of cardiovascular disease
(CVD) in at-risk populations based on recommendations by major
organizations including the American Heart Association (AHA) together
with the American College of Cardiology (ACC), US Preventive Services
Task Force (USPSTF) and others. Accordingly, aspirin became one of
the most commonly used medications for primary prevention of CVD, and
it is estimated that 40% of US adults over 50 years of age use
aspirin for this purpose.
The
AHA Prevention Guidelines published in 1997 did not recommend aspirin
use for primary prevention, citing the need for additional research.
Major primary prevention studies completed from 1988 to 2001,
including the British Doctors Study (BDS), US Physicians' Health
Study (PHS), Thrombosis Prevention Trial (TPT), Hypertension Optimal
Treatment (HOT) and low-dose aspirin trial of the Primary Prevention
Project (PPP) trials, led the USPSTF and AHA to adopt recommendations
for aspirin (75-100 mg/day, or 325 mg every other day) for primary
prevention in 2002, particularly for high-risk individuals (5-year
CVD risk ≥3%).
However,
more recent studies did not demonstrate clear benefit of aspirin,
including the Prevention of Progression of Arterial Disease and
Diabetes (POPADAD), Japanese Primary Prevention of Atherosclerosis
with Aspirin for Diabetes (JPAD), Aspirin for Asymptomatic
Atherosclerosis (AAA) and Japanese Primary Prevention Project (JPPP).
In 2016, the USPSTF Guidelines were pared back, recommending aspirin
for CVD and colorectal cancer prevention in adults aged 50 to 59 with
a 10-year ASCVD risk of at least 10% without increased risk of
bleeding and with life expectancy of at least 10 years (Grade B).
Aspirin use in adults aged 60 to 69 who have the same risk requires
an individualized approach based on a weaker recommendation (Grade
C).
The
recent contribution of the ARRIVE (Aspirin to Reduce Risk of Initial
Vascular Events) , ASCEND (A Study of Cardiovascular Events in
Diabetes) and ASPREE (Aspirin in Reducing Events in the Elderly)
trials provides useful insight into the role of aspirin use for
primary prevention in the modern era, when there is decrease in
smoking, better control of cholesterol, lifestyle modification &
increased use of statins.
It can be concluded that for primary prevention, in which risk is determined
largely by age and the presence or absence of diabetes, the
benefit–risk ratio for prophylactic aspirin in current practice is
exceptionally small.
In contrast, for secondary prevention, in which
risk is determined largely by the extent of atherosclerotic disease,
the benefits of aspirin outweigh the risks of bleeding. Visit the NEJM here.
Therefore,
beyond diet maintenance, exercise, and smoking cessation, the best
strategy for the primary prevention of cardiovascular disease may
simply be to replace aspirin with a statin.
Its’
use can be narrowed to the highest-risk populations, including
individuals aged 40 to 70 years old without diabetes with 10-year
ASCVD ≥20% or patients with diabetes with ASCVD ≥10%, provided
they are not at high-risk of bleeding.See the ACC recommendation.
