2018.07.31 23:37
Journal Scan / Research · June 29, 2018
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A population-based study of new users of low-dose aspirin was conducted to estimate incidence rates of upper and lower gastrointestinal bleeding.
The incidence of lower gastrointestinal bleeding was higher than that of upper gastrointestinal bleeding in new users of low-dose aspirin. However, upper gastrointestinal bleeding events were more deadly and required higher rates of hospitalization. The authors suggest that these data may be useful the risk–benefit analysis for physicians prescribing low-dose aspirin for prevention of cardiovascular disease or colorectal cancer.
This is a methodologically strong study simultaneously evaluating the rates of upper and lower gastrointestinal bleeding in a large population of new users of low-dose aspirin. With the rate of appropriate (and inappropriate) prophylactic use of low-dose aspirin increasing, it is becoming increasingly important for clinicians to consider and evaluate the cardiovascular and gastrointestinal risks and benefits of such therapy. This study significantly adds to our understanding of aspirin-associated GI toxicity in that the rate of lower GI bleeding was considerably higher than that of upper GI bleeding in both men and women. Despite the fact that many of these patients with lower GI bleeds were not hospitalized, suggesting lesser clinical acuity, there was still significant absolute mortality in the lower GI bleeding cohort.
I believe that this study serves as a better springboard to investigate the actual causes of bleeding and to take into account other GI or non-GI comorbidities in determining absolute and relative risks of aspirin use.
This abstract is available on the publisher's site.
There are few data on the incidence of upper and lower gastrointestinal bleeding (UGIB and LGIB) from observational studies of low-dose aspirin users. We aimed to estimate incidence rates of UGIB and LGIB in a large cohort of new users of low-dose aspirin in the United Kingdom, with sub-analyses of hospitalization status and fatalities.
We performed a population-based study of 199,079 new users of low-dose aspirin (median age, 64.0 years) identified from the Health Improvement Network primary care database (2000-2012). Individuals were followed for a median 5.4 years (maximum, 14 years) to identify new cases of UGIB and LGIB. Following multi-step validation, we calculated overall and age- and sex-specific incidence rates; we performed sub-analyses for healthcare use and death within 30 days of GIB. We also estimated rates within a matched (1:1) cohort of non-users of low-dose aspirin at the start of the follow-up period.
The low-dose aspirin users had 1115 UGIB events and 1936 LGIB events; most subjects with UGIB events (58.9%) were hospitalized, whereas most subjects with LGIB events were referred to secondary care (72.8%). Crude incidence rates of GIB per 1000 person-years were 0.97 for subjects with UGIB (95% CI, 0.91-1.02) and 1.68 for subjects with LGIB (95% CI, 1.60-1.75). Incidence rates per 1000 person-years for hospitalized patients with GIB were 0.57 for UGIB (95% CI, 0.53-0.61) and 0.45 for LGIB (95% CI, 0.42-0.49); for referred (but not hospitalized) cases, these values were 0.39 for UGIB (95% CI, 0.36-0.43) and 1.22 for LGIB (1.16-1.29). Incidence rates per 1000 person-years were 0.06 for fatal UGIB (95% CI, 0.04-0.07), 0.01 for fatal LGIB (95% CI, 0.01-0.02), 0.91 for non-fatal UGIB (95% CI, 0.86-0.97), and 1.66 for non-fatal LGIB (95% CI, 1.59-1.74). Among non-users of low-dose aspirin, incidence rates per 1000 person-years were 0.67 (95% CI, 0.63-0.75) for UGIB and 0.76 (95% CI, 0.72-0.82) for LGIB.
In a population-based study of low-dose aspirin users, the incidence of LGIB was higher than the incidence of UGIB. However, patients with LGIB had higher rates of hospitalization or death within 30 days than patients with UGIB. These estimates are valuable for benefit-risk assessments of low-dose aspirin for cardiovascular and colorectal cancer prevention.
2018.07.31 23:47
2018.08.01 13:25
I took low dose aspirin (81mg/day) for a long time about 4-5 years ago.
Then, taking low-dose aspirin was a very popular "fad" thing to do
at the encouragement of medical authorities and every damn cardiologists.
Whenever I worked in my yard and got a scratch or two,
I noticed the capillary bleeding on my hands or legs would not stop for a long time.
Knowing that my mother passed away due to a stroke of some kind (either infarction or bleeding.
The damn Korean hospital and the doctors would not tell me what it was !!)
So, I quit taking aspirin.
Anyway, it shows how powerful the "low-dose aspirin" is.
It's not something that can be "casually" recommended to the general public.
There are so "many and frequent" medical fiascos like this over the years.
The so-called research scientists and medical doctors wrote directly to the general population
on what they thought were good ideas ( for the moment) for the good health.
Lowering cholesterol seems to be the fad of the last few years.
I do not know how long this fad(?) will last.
Anyway, the pharmaceutical companies have made tons of money out of this
orchestrated by the dubious(?) medical authorities. We will see...
I won't be surprised if they found something else other than low cholesterol.
2018.08.01 23:46
One of my med school class mate living in Korea was hospitalized twice because of severe
anemia yrs ago. Low dose aspirin caused upper GI bleeding. It is not very common, but
routine preoperative H&H revealed anemia and it was linked to low dose aspirin.
I do not think we know the dosage of aspirin to take for the optimal effect. There is no simple
test to monitor the antiplatlet function. It seems to me that the individual variation is wide.
Take aspirin for your headache. Be aware of side effect, GI bleeding!
2018.08.02 02:30
I followed hundreds of postCABG patients and post coronary stent patients for many years and
some of them as long as some 40 years. They all were taking aspirin 81 mg a day with or without
another antiplatele agent such as Plavix.
After a good number of years, many would develop mild anemia with Hgb dropping from 14, then 13,
then 12 and then 11 very slowly. All these patients would remain asymptomatic.
As long as they are symptom free, cardiac patients handle mild anemia very well hemodynamically.
You would routinely work them up as you follow them over the years as conservatively as you would.
Sometimes you stop aspirin for several weeks and may note that Hgb would bounce back, let's say from 11 to 12.
Acute GI bleed is rare and often is associated with other pathology such as hemorrhoids, ulcers and cancers, etc.
The point I am making is that early in my practice even before many advocated low dose aspirin I came to
appreciate and respect the powerfullness of aspirin's injurious effect to GI and the brain.
The original aspirin study which gave some 22000 physicians aspirin 325mg every other day for 5 years
and demonstrated the efficacy in preventing heart attacks had shown incidence of some 70 hemorrhagic stroke
which was statistically insignificant and was ignored by the academia, which I personally took seriously.
This study was done by Harvard staff and was published in NEJM in 1989, I believe.
Throughout my practice years over 40 years I had argued against the routine use of aspirin for the primary prevention.
The only indication of low dose aspirin for me has been a secondary prevention in the presence of atherosclerosis or
possibly presence of multiple coronary risk factors including family history.
2018.08.02 03:38
The Physicians' Health Study is a randomized, double-blind, placebo-controlled trial designed to determine whether low-dose aspirin (325 mg every other day) decreases cardiovascular mortality and whether beta carotene reduces the incidence of cancer. The aspirin component was terminated earlier than scheduled, and the preliminary findings were published. We now present detailed analyses of the cardiovascular component for 22,071 participants, at an average follow-up time of 60.2 months.
There was a 44 percent reduction in the risk of myocardial infarction (relative risk, 0.56; 95 percent confidence interval, 0.45 to 0.70; P<0.00001) in the aspirin group (254.8 per 100,000 per year as compared with 439.7 in the placebo group). A slightly increased risk of stroke among those taking aspirin was not statistically significant; this trend was observed primarily in the subgroup with hemorrhagic stroke (relative risk, 2.14; 95 percent confidence interval, 0.96 to 4.77; P = 0.06). No reduction in mortality from all cardiovascular causes was associated with aspirin (relative risk, 0.96; 95 percent confidence interval, 0.60 to 1.54).
Further analyses showed that the reduction in the risk of myocardial infarction was apparent only among those who were 50 years of age and older. The benefit was present at all levels of cholesterol, but appeared greatest at low levels. The relative risk of ulcer in the aspirin group was 1.22 (169 in the aspirin group as compared with 138 in the placebo group; 95 percent confidence interval, 0.98 to 1.53; P = 0.08), and the relative risk of requiring a blood transfusion was 1.71.
This trial of aspirin for the primary prevention of cardiovascular disease demonstrates a conclusive reduction in the risk of myocardial infarction, but the evidence concerning stroke and total cardiovascular deaths remains inconclusive because of the inadequate numbers of physicians with these end points. (N Engl J Med 1989; 321: 129–35.)
This is indeed a very useful information.
Physicians have been aware for a long time that
low dose aspirin can cause a significant GI bleed,
either acutely or chronically in a significant number of patients.
Now we have some numbers available to quantitate the risk.
One other concern is cerebral bleed, which is not covered by this study.