Low-dose aspirin for CVD and colorectal cancer prevention no longer recommended

Low-dose aspirin use for the primary prevention of coronary vascular disease (CVD) in adults 60 years or older is no longer recommended, according to the U.S. Preventative Services Task Force (USPSTF). The newly issued statement also recommended a change in approach for its use for the primary prevention of CVD in adults aged 40 to 59 years, saying that its use in those in that age group who have a 10% or greater 10-year CVD risk should be an individual decision with their healthcare provider. Details were published in JAMA Internal Medicine, along with commentaries. It also said that the data for using low-dose ASA for preventing colorectal cancer are insufficient to recommend its use. Read: Aspirin beneficial to hospitalized COVID-19 patients The statement changes a number of its recommendations from 2016. The earlier statement recommended initiating low-dose aspirin use for the primary prevention of CVD and colorectal cancer in adults aged 50 to 59 years with a 10% or greater 10-year CVD risk, with no increased risk for bleeding, a life expectancy of at least 10 years, and willing to take low-dose aspirin daily for at least 10 years. That statement concluded “the decision to initiate low-dose aspirin use for the primary prevention of CVD and colorectal cancer in adults aged 60 to 69 years who have a 10% or greater 10-year CVD risk should be an individual one.” But since the 2016 recommendations were published, three new important trials of aspirin for primary prevention were published. For the new recommendations, USPSTF researchers analyzed data from 11 randomized controlled trials encompassing a total of 134,470 patients, and one trial of 400 patients using low-dose aspirin for primary CVD prevention. The primary outcomes sought for CVD benefits were major events, total MI, total stroke, total ischemic stroke, CVD mortality, and all-cause mortality. The key question asked in the USPSTF review was: Does regular aspirin use in patients without known CVD reduce CVD and colorectal cancer incidence and mortality, or all-cause mortality? The studies covered a broad range of populations, including people with CVD risk factors. The newer trials focused on special populations such as those with older age, CV risk factors, and diabetes. The rates of major CVD events in the control groups varied widely, the review said. As for mortality, CVD deaths were inconsistently defined with some deaths due to rheumatic fever, pulmonary embolism, or other conditions included. But overall, pooled analyses showed no statistically significant association of aspirin use with either CVD mortality nor all-cause mortality. But, pooled analyses from the trials did show that aspirin use was associated with a statistically significant drop in major CVD events, MI (both total and nonfatal), and total stroke. As for studies looking at low dose aspirin for colorectal cancer prevention, methodology varied and there were differences in length of follow-up, duration of aspirin use and other factors. But, “No single RCT reported a statistically significant beneficial association between low-dose aspirin and colorectal cancer incidence,” the study said. The study also noted that low-dose aspirin was significantly associated with increases in bleeding, including intracranial and extracranial hemorrhage. But low-dose aspirin still has important roles for secondary prevention of CVD events. An accompanying editorial addressed issues relating to who to treat for primary prevention of atherosclerotic CVD. It stated “Despite important advances, including widespread use of high-intensity statins and novel antiplatelet and antithrombotic therapies, low-dose aspirin remains of major importance in the secondary prevention of ASCVD, with an approximate 20% relative-risk reduction in serious ASCVD events.” Overall, the findings are consistent with several other international recommendations and guidelines, including the Canadian ones, according to Dr. Jean-Francois Tanguay, a cardiologist and professor of medicine at the University of Montreal. He chaired the 2010 Canadian Cardiovascular Society (CCS) guideline committee for the Use of Antiplatelet Therapy in the Outpatient Setting and co-chaired related CCS antiplatelet guidelines. He was not part of the USPSTF team. “The USPSTF statement is in line with what the CCS antiplatelet guidelines recommended for aspirin in primary prevention and secondary prevention,” he said. As background, he explained that the 2011 version of the CCS guidelines, did not recommend aspirin for primary prevention. “At that point that was quite a shock for many people, even for many cardiologists. We were trained that patients over 50 years old, specifically males, should take an aspirin a day,” he said. In the absence of benefit in trials and the bleeding risk associated, ASA was not recommended in primary prevention of CVD. Generally, the CCS Antiplatelet Guidelines committee members suggested it was better to address lifestyle issues and treat risk factors to prevent heart disease or cancer. Stop smoking, watch for diabetes, cholesterol and blood pressure instead of taking an aspirin a day. “That’s the spirit of what the 2011 CCS guidelines suggested,” he said. There is also the more recent CCS focused update on antiplatelet therapy for 2018. Whether individual patients should take daily low-dose aspirin depends on their individual risk profile and risk for bleeding – but it’s not the right approach for most people for primary prevention. The Canadian Stroke Best Practice Recommendations, published in the CMAJ in 2020, also concur with many of the findings. They state that low dose aspirin is still strongly indicated for secondary prevention in patients who have had manifest cardiovascular, cerebrovascular or peripheral artery disease. But, it is no longer recommended for primary prevention in individuals without a history of symptomatic cardiovascular disease, stroke or peripheral artery disease. They added “the harms of daily ASA use could potentially outweigh the benefits.” Generally, it’s good reminder that an aspirin a day might not keep the doctor away in primary prevention.

Low-dose aspirin for CVD and colorectal cancer prevention no longer recommended

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