A few days ago, the British Medical Journal and others published a study on “Should all people over 50 years of age use aspirin?”, “Should people with hypertension use aspirin? and “Should aspirin be used in hypertensive patients?” Professor Hu Dayi discussed the efficacy of aspirin in preventing ICVD, whether aspirin should be used in people over 50 years old, whether aspirin should be used in hypertensive patients, whether aspirin and bleeding, and whether aspirin should be used in Chinese hypertensive patients over 50 years old, and so on.
With the change of people’s lifestyle and diet, as well as the aging of the population, hypertension has become one of the most prevalent diseases in human beings. Statistics show that there are 160 million hypertensive patients in China alone. Hypertensive patients are also at high risk of ischemic cardiovascular disease (ICVD), and data from China show that the incidence of ICVD in hypertensive people is 3-5 times higher than that in people with normal blood pressure, so one aspirin a day to prevent ICVD is also one of the main treatments for hypertensive patients. With the publication of the Physicians’ Health Study, the Optimal Treatment of Hypertension Study and the Women’s Health Study, the British Medical Journal and others have published studies on “Should all people over 50 years of age use aspirin?”, “Should hypertensive patients use aspirin? and “Should aspirin be used in people with hypertension?” In the case of Chinese people, should all hypertensive patients over 50 years of age use aspirin?
I. Efficacy of aspirin in preventing and treating ICVD
The efficacy of aspirin in the secondary prevention of ICVD is beyond doubt. The 2006 AHA/ACC guidelines recommend that aspirin should be given at 75-162 mg/d for life in patients with atherosclerosis, unless contraindicated (I A).
The evidence for primary prevention of aspirin is relatively sparse, with six randomized controlled clinical studies to date. A 2002 meta-analysis showed that the benefit of aspirin use increased as patients’ risk of coronary heart disease increased, while the risk remained the same (Figure 1). 10% of the population to prevent the first cardiovascular event (I A). That is, primary prevention is not suitable for all populations and requires a balance of patient benefit and risk, with only those whose benefit exceeds their risk being suitable for use.
How is the 10-year risk of cardiovascular disease evaluated? In the United States, there is the Framingham Assessment Scale, and in Europe, there is the SCORE Assessment Scale. In China, Wu Yangfeng et al. published the ICVD risk assessment scale in 2003, but it should be noted that the scale does not include angina pectoris, and its predicted value is low (3-5% lower than the 10-year absolute value for people over 40 years old). A simple clinical evaluation method is commonly used: men >40 years old with two or more risk factors or >50 years old with one or more risk factors; women >50 years old with two or more risk factors or >60 years old with one risk factor, their 10-year ICVD risk is mostly 6%-10% or more. Risk factors included: hypertension, diabetes, hyperlipidemia, abdominal obesity, smoking, and family history of coronary heart disease (first-degree relatives <55 years old for men and <65 years old for women).
The American Diabetes Association 2006 guidelines recommend that aspirin 75-162 mg/d be used for primary prevention of cardiovascular disease (A) in patients with type 2 diabetes mellitus with any of the following risk factors. Risk factors include: age >40 years, smoking, obesity, hypertension (>130/80 mmHg), dyslipidemia, micro or significant albuminuria, and family history of coronary artery disease.
Second, should people over 50 years of age use aspirin?
In the Physicians’ Health Study, published in 1989, 22,071 U.S. physicians themselves showed that aspirin reduced the incidence of first myocardial infarction in healthy men by 44% (p<0.0001), and subgroup analysis showed significant benefits in all age groups over 50 years compared with the 40-49 age group (p=0.02). The 10-year Women's Health Study, published in 2005, showed that aspirin reduced the incidence of first-time cerebral infarction by 24% (p=0.009) in healthy women over 45 years of age (10-year icvd risk only 2.3%). The above two studies established the evidence-based medical basis that aspirin should be used in the majority of people over 45-50 years of age, and many foreign experts have proposed and discussed that aspirin should be used in the majority of people over 50 years of age.
According to China’s “Tenth Five-Year Plan”, the 10-year risk of ICVD in the 45-55 age group is 1.64% (men) and 3.88% (women), while the risk in the 55-60 age group is 4.24% and 5.77%, respectively, and if the risk of angina pectoris (+3%-4%) is taken into account, the risk for the majority of the population exceeds 6%. If the risk of angina pectoris (+3%-4%) is taken into account, the risk for most of the population exceeds the guideline standard of 6% (the average risk for the 50-55 age group in the United States is 8%).
C. Should aspirin be used in patients with hypertension?
The results of the HOT trial in 18790 hypertensive patients showed that aspirin resulted in good blood pressure control (target diastolic blood pressure <90 p="0.03) and a 36% reduction in myocardial infarction (p=0.002). Subgroup analysis showed a more pronounced benefit in the subgroup with increased creatinine (">1.3 mg/dl) and in the subgroup with higher baseline blood pressure (systolic blood pressure ≥180 mmHg, or diastolic blood pressure ≥107 mmHg), with no significant increase in fatal or intracranial bleeding (p=NS), but a significant increase in nonfatal gastrointestinal bleeding (p<0.001). 2005 Women's Health Study also showed The 2005 Women's Health Study also showed more significant decreases in stroke and cerebral infarction in the hypertensive subgroup, 24% (p=0.04) and 27% (p=0.02), respectively. < div="">
To reduce the risk of bleeding, blood pressure control before aspirin is important in hypertensive patients.Meade et al looked at 5499 patients, and the benefit of aspirin came mainly from those with good blood pressure control (the benefit was largely offset by the risk in those with systolic blood pressure <145>145 mmHg. In combination with the above HOT results, guidelines such as JNC7 and ESC/ESH recommend that aspirin should be used in well-controlled hypertensive patients over 50 years of age with a moderately increased risk of coronary artery disease or moderately increased creatinine, or with high baseline blood pressure.
IV. Aspirin and bleeding
A meta-analysis of 6 trials of primary prevention showed that low-dose aspirin did not increase the incidence of intracranial hemorrhage (Table 1), and the absolute increase in intracranial hemorrhage was -1.2 to +2 cases per 10,000 patients per year. Gastrointestinal bleeding increased (Table 2), with an absolute increase of 0.4 to 1.7 cases per 1,000 patients per year of treatment, occurring in smaller amounts, while fatal gastrointestinal bleeding did not differ from placebo. Bleeding is a complication of all antiplatelet agents, and a meta-analysis of 330,000 patients by Victor et al. in 2004 showed that the incidence of bleeding with aspirin increased with dose, and that the overall incidence of bleeding was lower with aspirin at doses below 100 mg/d than with platelet glycoprotein IIb/IIIa receptor antagonists and clopidogrel, emphasizing the importance of applying small doses (75-150 mg/d). importance.
V. Should aspirin be used in Chinese hypertensive patients over 50 years of age?
Should aspirin be used in Chinese hypertensive patients over 50 years of age? If the patient has a history of ICVD, he/she belongs to the category of secondary prevention and should use aspirin as long as there is no contraindication and the blood pressure is well controlled. In the case of simple hypertension, according to the “15-year survey” scale by Wu Yangfeng et al, the 10-year risk of ICVD (including angina pectoris, +4%) in people over 50 years of age with simple hypertension (without other risk factors) can be estimated to be >6.1% (men) and >5.8% (women), with the vast majority meeting the guideline 6% standard (Framingham score of 9%, +4%). The Framingham score was 9%, which is higher than ours). Therefore, for hypertensive patients over 50 years of age in China, as long as there are no contraindications and blood pressure control is satisfactory, the vast majority of men should use aspirin, while the proportion of women is slightly lower than that of men. It should be noted that the proportion of hypertensive patients with other risk factors, such as smoking (especially in men), body mass index (BMI) >24, and hyperlipidemia, is higher than 30%, and these patients are at higher risk and have a stronger indication for aspirin use.
Even in patients <50 years of age with hypertension who have other risk factors (smoking, diabetes, hyperlipidemia, abdominal obesity, family history of coronary heart disease, etc.), the 10-year risk of icvd may still be higher than 6%, and aspirin should be considered as well. < p="">
VI. Summary
In summary, for secondary prevention, patients with atherosclerotic disease without contraindications should use aspirin at 75-150 mg/d for a long time. For primary prevention, the benefit-risk ratio should be taken into account, and aspirin should be considered if the 10-year risk of ischemic cardiovascular disease is ≥6%-10% and there is no contraindication. For hypertensive patients over 50 years of age in China, aspirin should be used in the vast majority of patients if there are no contraindications and blood pressure is satisfactorily controlled.
Another advantage of aspirin is its cost-effectiveness. Marshall et al. showed that the combined cost of averting one cardiovascular event with aspirin treatment was £3500, while the cost of averting one event with antihypertensive drugs, clopidogrel or simvastatin was 5.28, 17.14 and 17.54 times that of aspirin, respectively. Aspirin is an affordable drug for everyone, and as a developing country, it is the responsibility of each of our physicians to guide our patients in the appropriate use of this inexpensive and affordable drug.