For many years we know that there is a direct relationship between blood levels of cholesterol, especially LDL cholesterol, and the risk of cardiovascular diseases such as myocardial infarction and stroke. It is also not new in the patients with hyperlipidemia (high cholesterol), treatment with drugs called statins group (eg, rosuvastatin, simvastatin, pravastatin, atorvastatin, ...) help reduce the incidence of cardiovascular events.
To date, no other class of drugs proved so effective in reducing mortality as statins, for which this drug is the most consensus indicates as first-line treatment for dyslipidemia.
By 2013, doctors use a table of LDL cholesterol values to decide when to start treatment. If the patient exceed certain amount of LDL and could not narrow it down with diet and lifestyle habit changes, the doctor was allowed to start a statin in order to bring LDL back to that predetermined value. The problem with this protocol is that it was not based on strong scientific evidence and would eventually lead to an excessive use of statins in certain patients, especially those who had moderately high LDL values, but had no other risk factors.
In 2013, several medical cardiology societies have adopted new consensus that altered the way dyslipidemia was treated. We came to the conclusion that there was no clinical studies that supported the indiscriminate use of targets for LDL values to decide who should take statins. Instead of targeting an absolute value of LDL, doctors now use formulas that calculate individually the risk of a cardiovascular event in the next ten years to decide who need to take statins.
This means that young patients with no other risk factors for cardiovascular disease, even if they have a high LDL, no longer need to take statins. On the other hand, patients over 45 years and with multiple cardiovascular risk factors such as hypertension, diabetes, smoking and obesity, may need statins, even if your LDL value is not very high. The current is no longer abjetivo treating amount of LDL, but rather treat patients at high cardiovascular risk.
In this article we will explain what has changed and what are the most current recommendations on the treatment of dyslipidemia with statins.
The traditional way to treat dyslipidemia said that the more risk factors for cardiovascular disease the patient had, the lower should be the value of your LDL cholesterol. Roughly speaking, the targets could summarized as follows:
To a patient with a risk factor - LDL cholesterol should be less than 160 mg / dL.
Patient with two or more risk factors - LDL cholesterol should be less than 130 mg / dL.
Diabetic patients or patients with high cardiovascular risk, especially those already had at least one heart attack or stroke - LDL cholesterol should be less than 100 mg / dL (some protocols were more aggressive and showed LDL less than 70 mg / dL).
Thus, all patients who did not achieve the targets set with diet and lifestyle changes were candidates to using a statin. And the doctor every 6 months should request dosages blood LDL to ensure that the patient was within the desired value. If not there, it is increasing the dose of the statin.
This model has fallen into disuse. Is no longer so decided who need medicines to lower cholesterol or how much medicine should be used.
Since 2013, the way we treat patients with elevated cholesterol changed because a lot of studies accumulated in recent decades has shown that statins were effective in reducing the risk of cardiovascular disease in 20-30% regardless of baseline levels of LDL. What we do today is: instead of valuing the amount of LDL alone, try to identify those patients at higher risk of having a cardiovascular event in the next 10 years and indicate the use of a statin to reduce this risk. Therefore, no longer seek more achieve an LDL target value as before. The simple fact of the patient with multiple risk factors taking a statin is enough to reduce the chance of it having a cardiovascular event, even if the drug can not bring LDL to the values that we considered appropriate before.
Importantly, statins are not effective for everyone. For patients with low cardiovascular risk, even if they have a high LDL cholesterol, the prescription of a statin does not seem to offer many advantages. In the low-risk group, the statin and the reduction of LDL cholesterol did not have significant effects on mortality. Statins are only effective for those who already had a cardiovascular event (eg heart attack, heart failure or stroke) or for those patients with high chance of having a cardiovascular event, as they have multiple risk factors such as obesity, diabetes, hypertension, smoking, etc.
We will explain in more detail how to tell if a particular patient may benefit or not treatment with a statin.
Calculating cardiovascular event risk in the next 10 years
The first step when evaluating whether a patient needs or without a statin is to assess what is your risk of developing a cardiovascular event in the next 10 years. The most widely used way to assess this risk is through the Framingham Risk Score, an already widely studied formula that uses information such as age, blood pressure values, cholesterol levels, smoking, etc., to estimate the risk cardiovascular the next 10 years.
Importantly, over the last few years new versions of the Framingham risk score were being developed. Newer versions take into account more factors, such as body weight and the existence of health problems such as diabetes, atrial fibrillation, claudication (leg pain when walking by arterial insufficiency of the lower limbs) and left ventricular hypertrophy. A more complete version of the calculator can be seen in this link: http://danielpinto.net/ferramentas/risco_cv/. This more complete calculator is harder to be used properly by the lay population, which is why we suggest you choose the calculator from the first link.
Patients who benefit most from statin treatment are those with a risk of cardiovascular events greater than 10% over the next 10 years. If the risk is more than 20%, the benefit is even greater. Patients with less than 10% only benefit a specific case will be explained below.
The new consensus have not been widely accepted by the scientific community, and many doctors still reluctant to adopt them. Despite some criticisms are relevant, as the reliability of the risk calculators, the new guidelines seem to even be better and better informed than before. What is likely to happen in the coming years is an improvement of current recommendations, as new studies are being published.
According to the latest consensus, patients should be treated with a statin are:
1. Patients younger than 75 years who already have some established cardiovascular disease
This includes patients who have had at least one episode of stroke, transient ischemic attack or stroke. Also enter this group patients with angina pectoris, arterial insufficiency of the lower limbs, heart failure, chronic renal failure at an advanced stage (stage III or more than CKD) or patients with a higher risk than 20% on the Framingham risk score.
This group of patients should be treated with high doses of statins, regardless of its baseline LDL. Statins suggested in this case are: 20 Rosuvastatin 40 mg per day or atorvastatin 40 to 80 mg per day. The objective is to reduce the amount of LDL cholesterol by at least 50% or an LDL less than 100 mg / dL.
For patients with established cardiovascular disease but with more than 75 years, the decision to start statins in high doses should be individualized according to the patient's clinical status and life expectancy.
2. Patients with LDL cholesterol greater than 190 mg / dL
These patients with very high LDL tend to have familial hypercholesterolemia and should also be treated with high doses of statins in order to reduce LDL by at least 50%.
3. Patients between 45 and 75 years who present an LDL over 100 mg / dL and are diabetic or have a Framingham risk score higher than 10%
Patients who have established cardiovascular disease, but not fit the criteria above should be treated with statins in moderate dose, for example: Lovastatin 40 mg, Pravastatin 40 mg, Simvastatin 40 mg, Atorvastatin 10 to 20 mg or Rosuvastatin 5 to 10 mg.
In this group of patients is not necessary to monitor LDL values. There is no specific target to be reached, just the patient to take the medicine.
For patients under 45 or over 75 years the decision should be individualized according to the clinical characteristics of the patient.
