Acute Coronary Syndrome: What is it? Causes, Symptoms, Treatment and Pharmacological Considerations

It is caused by a sudden reduction or blockage of the blood supply to the heart.

The clinical evidence for the treatment of acute coronary syndrome (ACS) in the elderly is less robust than in patients younger than 75 years. The elderly have the highest incidence of cardiovascular disease and often present with acute coronary syndrome.

This number can be expected to increase over time because society is aging.

Older adults often suffer unfavorable outcomes from acute coronary syndrome due to atypical presentation and delayed recognition.

Because of their high baseline risk of ischemic complications, the elderly also fare worse with even optimal treatment of acute coronary syndrome, as they often have more complex coronary disease, more comorbidities, less cardiovascular reserve, and an increased risk of complications of the heart. treatment.

They are also subject to a wider range of drug treatment. Treatment complications can be mitigated to some extent by meticulously adjusting the dose of antithrombotic and complementary therapies.

Although careful transitions of care and the appropriate use of secondary preventive measures after discharge are important in patients with acute coronary syndrome of all ages, the elderly are more vulnerable to system errors and therefore deserve attention doctor’s special.

What is acute coronary syndrome?

The term “acute coronary syndrome” (ACS) encompasses a variety of disorders, including a heart attack (myocardial infarction) and unstable angina, that are caused by the same underlying problem.

Unstable angina occurs when the blood clot causes reduced blood flow but not complete blockage. This means that the heart muscle supplied by the affected artery does not die (infarct).

The underlying problem is a sudden reduction in blood flow to part of the heart muscle. This is usually caused by a blood clot that forms in a patch of atheroma within a coronary artery.

The types of problems range from unstable angina to a true heart attack. In unstable angina, a blood clot causes reduced blood flow but not a complete blockage.

Therefore, the heart muscle supplied by the affected artery does not die (infarct). The location of the blockage, the amount of time that blood flow is blocked, and the amount of damage that occurs determines the type of acute coronary syndrome.

Causes

Most cases of acute coronary syndrome are due to a narrowing of the blood vessels that supply the heart. This is usually due to the presence of an atheroma within the lining of the artery.

Atheroma is like fatty patches or plaques that develop within the inner lining of the arteries. (This is similar to hairy water pipes.)

Plaques of atheroma can form gradually over several years in one or more places in the coronary arteries. Each plate has a firm outer shell with a smooth inner fat core. Atheroma leads to narrowing of the blood vessels.

Several other rare conditions can also block a coronary artery. For instance:

Inflammation of the coronary arteries (rare). A stab to the heart. A blood clot that forms anywhere in the body (for example, in a chamber of the heart) and travels to a coronary artery where it becomes blocked.

Also using cocaine, which can cause a coronary artery to go into spasm. Complications of heart surgery. Some other rare heart problems.

Epidemiological data

Elderly patients (> 75 years of age) make up a large proportion of patients with acute coronary syndrome, and time trends in the incidence of myocardial infarction document a shift toward older adults.

The median ages at first presentation of acute coronary syndrome in the United States are 65 years for men and 72 years for women. About two-thirds of myocardial infarctions occur in patients older than 65 years and a third in patients older than 75 years.

Randomized clinical trials, on the other hand, have included substantially fewer elderly patients than clinicians meet in real life.

Therefore, the evidence base that forms the basis of acute coronary syndrome treatment may not apply to large numbers of patients, and clinicians must extrapolate the evidence to match the needs and preferences of their older patients.

60% of acute coronary syndrome hospitalizations occur in patients over 65 years of age, and 85% of acute coronary syndrome mortality occurs in the Medicare population.

Most deaths related to myocardial infarction occur in patients older than 65 years of age.

Age is not just a powerful risk factor for cardiovascular disease; it is also an independent risk factor for adverse outcomes after cardiovascular events, complications from cardiovascular procedures and interventions, and side effects of pharmacotherapy, particularly antithrombotic therapies.

The mortality rate after a first non-ST-segment elevation myocardial infarction (non-STEMI) in very elderly patients is very high: relative to 1-year results, among patients who had 65- 79, 80-84, 85-89, and at least 90 years of age, mortality progressively increased from 13.3% to 23.6%, 33.6%, and 45.5%, respectively.

In addition, older patients generally have more complex cardiovascular disease, more comorbidities, and generally a more atypical clinical presentation.

There is a higher prevalence of hypertension, congestive heart failure, atrial fibrillation, cerebrovascular disease, anemia, and kidney failure in older patients with acute coronary syndrome. Age also has important implications for pharmacokinetics and pharmacodynamics.

Challenges in caring for elderly patients with acute coronary syndrome include timely recognition, not withholding, of life-saving therapies on the basis of age alone, and respecting patient preferences and goals of care.

Who is at risk for acute coronary syndrome?

Acute coronary syndrome is common. Around 114,000 people in the UK are admitted to hospital with acute coronary syndrome each year. Most occur in people over the age of 50 and become more common as age increases. Sometimes younger people are affected.

The risk factors for having an acute coronary syndrome are actually the same as the risk factors for having a heart attack or cardiovascular disease.

What are the symptoms?

The most common symptom of an acute coronary syndrome is having severe chest pain. The pain often feels like great pressure on your chest.

Pain can also travel up the jaw and down the left arm or down both arms. You may also sweat, feel sick, and feel weak. You may also feel short of breath.

The pain may be similar to an episode of normal (stable) angina. However, it is generally more severe and lasts longer. (In people with stable angina, angina pain usually goes away after a few minutes. Acute coronary syndrome pain usually lasts more than 15 minutes, sometimes several hours.)

Some people with acute coronary syndrome may not have any chest pain, especially those who are elderly or have diabetes.

Atypical symptoms

There may be several explanations for why the elderly fare worse with acute coronary syndromes.

While chest pain remains the most common presentation for acute coronary syndromes, elderly patients often have atypical symptoms (ie, no chest pain).

In patients who present without chest pain, the diagnosis of acute coronary syndromes is often missed or delayed, leading to worse outcomes.

Notably, chest pain as a presenting symptom occurs in only 40% of patients older than 85 years, but is present in almost 80% of patients younger than 65 years.

Common symptoms in the elderly with acute coronary syndromes include dyspnea, sweating, nausea and vomiting, and syncope.

In patients at least 85 years of age, an atypical presentation of myocardial infarction appears to be the standard, and the physician must be prepared to diagnose acute coronary syndromes in many seriously ill patients of this age.

Acute pulmonary edema is most commonly a presentation in the elderly patient with acute coronary syndromes.

Increased arterial stiffness, manifested by increased pulmonary artery pressure and a higher prevalence of multivessel coronary artery disease (CAD), may explain why older patients with acute coronary syndromes are more likely to have signs and symptoms of congestive heart failure.

What tests are usually done?

Sometimes it can be difficult for doctors to distinguish between acute coronary syndrome and other causes of chest pain. If you are suspected of having an acute coronary syndrome, you should urgently be referred to the hospital.

Upon entering the hospital, several tests are usually performed. They are generally the same as for a suspected heart attack.

What is the treatment for acute coronary syndrome?

Treatment of acute coronary syndrome varies between cases. A heart attack is treated differently from unstable angina. Treatments may vary depending on your situation.

If you have had an ST-segment elevation myocardial infarction, you will receive the same treatment as those who have had a heart attack (myocardial infarction).

Treatment of people with unstable angina or non-ST elevation myocardial infarction consists of two phases: relieving any pain and preventing the progression or limiting the extent of a heart attack.

Your treatment generally varies based on your risk score. This is a risk score for an additional heart attack. Several factors are taken into account for this score, including:

Your age. Your other risk factors for cardiovascular disease (for example, if you smoke, have high cholesterol, or have high blood pressure or diabetes).

Your blood test results. What the heart looks like (electrocardiogram or ECG) when you first go to the hospital. Glycoprotein receptor llb / ll antagonist.

If doctors think you are at high risk for a heart attack, you may be given a medicine called a glycoprotein llb / lA receptor antagonist.

This can help ease your pain. It also works to reduce the chances of blood clots completely blocking the arteries. This medicine is given to you as a drip, directly into your veins.

This medicine is also used if you are going to have treatment to help widen your arteries (for example, angioplasty).

Treatment for acute coronary syndrome in older people

In addition to atypical symptoms, the 12-lead EKG, a standard investigation in patients with suspected acute coronary syndromes, may be nondiagnostic and therefore serial EKGs are recommended to diagnose high-risk findings such as ST-segment elevation. .

The diagnosis of ST elevation myocardial infarction is more challenging in patients with left bundle branch block.

Therefore, the higher prevalence of left bundle branch block in the elderly may contribute to diagnostic uncertainty in the early phase of presentation, when rapid risk stratification and classification are more important.

Prehospital delays also help prevent prompt treatment.

Despite having more severe coronary disease than younger patients on coronary angiography, older patients are more likely to receive medical treatment and experience more adverse outcomes.

Furthermore, the hemodynamic impact of a given infarct size may be more pronounced in the elderly due to reduced cardiac reserve.

The age-related decline in cardiac reserve may be related to a decreased beta-adrenergic responsiveness. There is also an increased likelihood of comorbid conditions with advancing age.

Not only do these comorbidities obscure the presentation of acute coronary syndromes, but they also contribute to worse outcomes.

Type 2 myocardial infarctions, which result from increased myocardial oxygen demand in the setting of severe obstructive coronary artery disease, are generally caused by comorbidities such as tachycardia, pneumonia with hypoxemia , chronic lung disease, and bleeding episodes. .

These comorbidities frequently complicate the hospital admissions of elderly patients and must be recognized, since they require treatment strategies different from those of type 1 myocardial infarctions.

In general, elderly patients are more likely to experience complications from acute coronary syndromes, such as congestive heart failure, heart block, ventricular rupture, and atrial fibrillation.

In addition, frailty and disability can complicate acute hospitalization, as well as convalescence and rehabilitation. On the other hand, frailty is not considered in clinically accepted risk scores.

General considerations

The treatment of acute coronary syndromes has evolved significantly in the last 40 years.

Classically, acute coronary syndromes are caused by thrombotic obstruction of an epicardial coronary artery. Therefore, treatment is mainly focused on early coronary revascularization supported by the use of antithrombotic drug therapy.

In general, the more aggressive use of invasive coronary procedures and antithrombotic medications is associated with a lower risk of ischemic complications, but with an increased risk of a bleeding complication. Outcome research has revealed that the elderly have been treated less effectively.

Presumably, professionals consider the risk-benefit ratio of cardiac procedures to be less favorable in the elderly.

While the elderly patients did not share the best survival rates observed in younger patients in the first days of coronary interventions (1979-1994).

The most recent data showed that mortality after hospital admission of elderly patients with acute myocardial infarction has decreased substantially in the past 15 years.

This improvement is probably mediated by an increasing use of recommended management strategies; therefore, applying guidelines derived from trials that primarily include younger patients may also benefit older populations.

However, adverse outcomes increase with age across the spectrum of acute coronary syndromes. Observational data suggest that outcomes for older patients improve when they receive guideline-directed cardiac procedures.

Data from the Acute Coronary Syndromes Event Registry for England and Wales between 2003 and 2010 show a substantial reduction in hospital mortality in all age groups, including the elderly and very old, men and women, and myocardial infarction with elevation ST segment and non-ST segment elevation myocardial infarction.

Within the time frame of the study, the use of percutaneous coronary intervention (PCI) and evidence-based drug therapies increased significantly for all age groups.

Although elderly patients still received fewer coronary revascularizations than younger patients, it is notable that almost half of all patients with ST-elevation myocardial infarction over the age of 85 received percutaneous coronary intervention, and compliance with the drug therapy in this group

The Italian Elderly Acute Coronary Syndromes Study suggests that elderly patients with elevated troponin benefit from an early invasive approach.

Data from the same trial, when combined with registry data, suggested that coronary revascularization in elderly women was associated with lower 1-year mortality compared with an early conservative approach, without an increase in severe bleeding.

The results of the After Eighty study support the use of an invasive strategy in patients at least 80 years of age. Even in nonagenarians and centenarians with acute coronary syndromes, there is evidence that compliance with the therapies recommended by the guidelines is associated with a decrease in mortality.

Despite the increased risk of major bleeding in patients older than 75 years, a routine early invasive strategy significantly improved outcomes in elderly patients with acute coronary syndromes.

Registry data suggest that, in the last 15 years, the progressive shift from a conservative approach to a more invasive one in elderly patients may have contributed to a reduction in mortality across the spectrum of acute coronary syndromes, regardless of the age and sex.

Consequently, the absolute benefit of early invasive therapies in the elderly appears to be greater than in younger patients due to their high mortality at baseline.

Pharmacological Considerations

The risk of adverse drug reaction has been reported to increase with the number of drugs taken simultaneously.

With two concurrent medications, there is a 13% risk of an adverse drug interaction, and the risk increases to 38% for four medications and 82% for seven or more medications prescribed simultaneously.

In light of these data, it is crucial to balance the risks of polypharmacy with the benefit of not retaining guideline-directed medications, which have been shown to be beneficial for the elderly.

Age-related decline in organ function, muscle mass, and volume of distribution, and changes in pharmacokinetics require meticulous drug dosage adjustments by the treating physician.

As the risk of bleeding increases with age, dose adjustments are particularly important when it comes to anticoagulant therapies.

Creatinine clearance is preferably calculated using the Cockcroft-Gault equation and should form the basis for renal dose medications rather than serum creatinine level.

Observational data revealed that patients with acute coronary syndromes often receive antithrombotic therapies in excessive doses.

Factors associated with overdosing included older age as well as female gender, kidney failure, low body weight, diabetes mellitus, and congestive heart failure.

Among patients who recently had an acute coronary syndrome, a high-dose statin regimen is known to provide greater protection against death or major cardiovascular events than a low- or moderate-dose statin regimen.