Aspirin: Protecting victims of infarction

Aspirin could have a preventive effect against many diseases: cancer, infarction, accidents of pregnancy ... Can we consider this medicine as a miracle cure? The answer is more nuanced.

Aspirin is beneficial for arteries if predisposed

We have known for a long time that aspirin (acetysalicylic acid) can serve other than to relieve the flu or the headaches. But do experts today recommend a preventive use of this drug?

Sometimes useful during pregnancy

Over the last twenty years or so, several studies have followed, indicating the preventive virtues of this drug against cardiovascular diseases. Aspirin inhibits the aggregation of platelets, thus the formation of blood clots inside the vessels. A dose as low as 80 mg per day for one week (while adult tablets usually range between 300 mg and 1 g) is sufficient to reduce platelet aggregation by 90% and lengthen bleeding time. An anti-inflammatory effect is added to this antiaggregative action which is beneficial to the vascular wall.

Preventing cancer

Therapeutic trials have shown that the regular intake of low doses of aspirin reduced (approximately 25%) the risk of recurrence in people who had a first infarction. Efficacy is even greater if aspirin is combined with other drugs. A similar preventive effect was observed on recurrences of stroke. Thus, specialists routinely offer low-dose aspirin therapy to people who have had an infarction or stroke and who have no contraindications to this drug (allergy, ulcer and hemorrhagic risk). >

No systematic treatment

What about people who have never had vascular problems? In this case, the data are much less convincing. Some studies do not show a reduction in the risk of infarction and others indicate an increase in stroke. In reality, treatment seems to have a favorable effect only when there is at least one factor predisposing to cardiovascular events. Based on five studies, the results of a large-scale analysis 1 showed a 28% decrease in cardiac events and 15% in the deaths associated with aspirin. But this beneficial action only affects those most exposed to cardiovascular disease. In those with no risk factors, the benefit of reducing heart disease is reversed by an increase in stroke and gastrointestinal hemorrhage. Thus, treatment with aspirin is generally reserved for people with a factor predisposing to cardiovascular events, such as atrial fibrillation, angina pectoris, diabetes, hyperlipidemia or arterial hypertension (provided, however, that Be properly processed). According to a study presented at the 17th Annual American Society of Hypertension, it is best to take aspirin at night, as this results in a slight decrease in blood pressure
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By its effects on the vessels, aspirin also reduces the risk of complications in pregnant women with pregnant hypertension (hypertension occurring during pregnancy). Low dose (100 mg / d) reduces the incidence of eclampsia, the retroplacental hematoma and the risk of fetal death.

Other studies indicate that aspirin, administered from the 15th week of pregnancy to women with a history of stunting in utero, increases the birth weight of the newborn. Finally, aspirin can prevent miscarriages late in women with a history of repeat abortions. Finally, studies carried out during in vitro fertilization show that it can promote the implantation of the embryo and reduce the risk of early abortions. It may be useful to administer it early in pregnancy, or even before conception, in women with a history of repeated early miscarriages of autoimmune diseases that increase the risk of abortion.

On the other hand, specialists do not recommend treating women with no previous history, those with multiple pregnancies or permanent arterial hypertension.

Above all, they point out that it is important to respect the contraindications and to stop the treatment at 35 weeks of pregnancy. At the end of pregnancy, aspirin increases the risk of haemorrhagic complications and a particular vascular abnormality in the fetus: premature closure of the ductus arteriosus. If you are pregnant never decide on your own to take a medication. Speak with your doctor.

Concerning the prevention of cancerous tumors, studies on aspirin were so far contradictory. A large trial of 20,000 American physicians, the Physicians Health Study, showed no positive effect of aspirin on the risk of colon or rectal cancer in these men without particular risk factors. Br>

It might be otherwise for people with a history of colon cancer or polyps, precancerous lesions of the intestine. Including a few hundred patients, two studies 3,4 argue in favor of preventive action. In the first and after 13 months, only 17% of patients treated with aspirin after ablation of colon or rectum cancer had polyps again compared with 27% of untreated patients.

Less significant, the second study involved people operated on for polyps. After 33 months, the risk of development of new polyps or cancer was 38% in the group treated with 81 mg of aspirin per day, 45% in that treated with 325 mg and 47% in that treated with placebo .

However, systematic screening and removal of cancers and precancerous lesions remain the basis of care for people at high risk of cancer of the colon and rectum. Treatment with aspirin is certainly not able to change this rule.

Other studies suggest that aspirin may prevent other cancers: esophagus, ovary, pancreas, lung, mouth, larynx and pharynx. Among other examples, analysis of nine studies in the general population Aspirin, for whatever reason, is associated with a 50% reduction in the risk of cancer of the esophagus 5. These results encourage therapeutic trials in people at risk to confirm its preventive action

Could this centennial drug benefit all of us? It would be tempting to conclude, especially since some studies 6 indicate that it could also prevent Alzheimer's disease. But others are more reserved 7.

Thus, the current set of data does not advocate systematic treatment. Indeed, trials conducted on the general population generally do not show any favorable effects on cardiovascular disease, when people do not have a particular risk factor.

As far as cancer is concerned, the results are most often based on retrospective testimonials, which does not make it possible to assert with certainty that the observed effects are related to aspirin. Last but not least, this drug has well known side effects. It increases the risk of haemorrhagic accidents, including cerebral and digestive hemorrhages, even at low doses used in prevention.

For a person in good health and without a history, these hemorrhagic risks exceed the expected benefits of the treatment. The benefit of taking aspirin should be decided on a case-by-case basis, depending on the risks of each individual. Recent reservations to menopausal replacement therapy demonstrate the need for caution before recommending routine preventive treatment.

Sources

1 - Ann Intern Med. 2002,136: 161-172; 2 - Ann Intern Med. 1998 May 1,128 (9): 713-20; 3 - N Engl J Med. 2003 Mar 6,348 (10): 883-90; 4 - N Engl J Med. 2003 Mar 6,348 (10): 891-9; 5 - Gastroenterology, 2003 Jan, 124 (1): 47-56; 6 - Neurology, 2002 Sep 24,59 (6): 880-6; Am J Geriatr Psychiatry . 2003 Mar-Apr, 11 (2): 179-85