The symptoms often occur at rest and are aggravated by exercise or any type of physical activity. Often the symptoms fail to respond to nitroglycerin. In many cases, the patient may complain of symptoms at rest.
Physical exam may reveal:
Auscultation may reveal:
Over the years several classifications have been developed to grade unstable angina. These include the Braunwald Classification, Canadian Cardiovascular Society Grading System, Acute Coronary Syndrome Risk Assessment and Thrombolysis in Myocardial Infarction Risk Score. In general, all these scoring system grade the angina based on severity of chest pain, the precipitating factor and response to therapy.
The most important thing to determine in a patient with unstable angina is the degree of coronary artery disease and how serious it is. Routine workup of a patient with unstable angina requires the following:
ECG is the first line assessment in patients with unstable angina which should be obtained soon after admission to the ER. Any patient with chest pain with ECG evidence of ST-segment elevation or development of a new left bundle branch block needs an urgent cardiology consult. These patients often benefit from immediate revascularization treatment. Subsequent ECGs depend on the symptoms. If there is any clinical or laboratory evidence of worsening of the patient, serial ECGs should be ordered at least every 30 minutes to follow progression of ST-segment changes. It should be noted that primary T-wave changes alone are not sensitive indicators for ischemia.
The treatment of unstable angina requires admission with bed rest  . All patients must be continuously monitored and have at least two intravenous lines. Oxygen is often provided if the patient saturation is below 94%. It is important to realize that unstable angina is a very unpredictable disorder and is life threatening. These patients are best monitored in an ICU setting or a cardiology floor where continuous monitoring is available.
The treatment of unstable angina is guided at the cause of ischemia and reinstitution of blood flow to the heart . Many guidelines have been published about management of unstable angina patients. While some patients will benefit from medical therapy, others may require intensive care admission or emergency revascularization. Patients who are symptomatic despite therapy or are hemodynamically unstable should have emergency revascularization. Patients who respond to treatment still should observed closely with continuous telemetry. The classes of medications that are used to treat unstable angina include:
Aspirin is started on all patients within 30 mins of admission to those who are not at risk for bleeding or have any allergies to the agent. Beta-blockers do relieve ischemic symptoms but are contraindicated in patients with shock or bradycardia. Oral beta blockers are preferred to the IV drugs. Newer anti-platelet agents that can be used to treat unstable angina patients include use of prasugrel, ticagrelor, abciximab, eptifibatide or tirofiban. These agents can decrease symptoms but often do not affect the long-term risk of major adverse events.
During the initial period of admission, the patient should be kept nil per os just in case an invasive procedure or other study is anticipated. For the stable patient, a low sodium and a low cholesterol diet is recommended.
For patients who remain unstable despite maximal therapy, cardiac catheterization is recommended. These include patients with:
So far, there is debate on benefits of non-invasive therapy versus invasive therapy. Not all patients with unstable angina have triple vessel coronary disease and in some cases, there is only minimal disease. In general, coronary artery bypass is recommended for patients with:
The prognosis of patients with unstable angina is greatly dependent on comorbidity, response to medication, time to diagnosis and treatment, presence of cardiogenic shock and type of therapeutic intervention. In general, patients with new ST-segment changes seen on the initial ECG have a worse prognosis compared to patients with isolated T-wave inversion. Over the years several negative prognostic factors have been identified for unstable angina patients and include the following:
In many patients with unstable angina who are on intense antianginal therapy, repeat attacks are not rare.
Causes and risk factors for unstable angina include the following:
The metabolic syndrome is characterized by abdominal obesity (waist circumference > 40 inches for men and 35 inches in women), decreased HDL <40 mg/dl for men and <50 mg/dl in women, hypertriglyceridemia (> 150mg/dl) and hypertension (>130/85 mmHg). Patients suffering from the metabolic syndrome tend to have a 3-4 fold increased risk for development of coronary artery atherosclerosis and stroke compared to those who do not have this syndrome .
The incidence of unstable angina is on the increase globally based on stats from emergency rooms. In addition, there is a gross underestimate of the real numbers because many cases of unstable angina are not clinically recognized and other are managed in outpatient settings. Unstable angina typically presents in patients aged 60 and over. Women with unstable angina tend to be 5 years older and African Americans tend to presents at a slightly younger age than other races.
Unstable angina in women is frequently associated with comorbid disorders like diabetes, hypertension, congestive heart failure and a family history of coronary artery disease. Men on the other hand, tend to present with a history of prior myocardial infarction and/or coronary revascularization. Overall, unstable angina tends to have the worst outcomes in African Americans compared to other races.
The pathology of unstable angina is related to several factors that include the following:
Conditions causing a mismatch of oxygen supply versus demand include the following:
Once unstable angina has resolved, preventive steps should be encouraged . It is important to wait at least 4-12 weeks to allow that risk of major adverse event to subside before making any sudden changes in the lives of these patients. Secondary prevention requires changes in lifestyle such as:
One of the clinical spectrums of acute coronary syndrome (ACS) is unstable angina. Patients who have unstable angina present exactly like those who have myocardial ischemia or a myocardial infarction but they do not have elevated levels of cardiac enzyme in the blood. When worked up, these patients do not always have severe coronary disease but in fact tend to have coronary artery vasospasm. Often the chest pain is unresponsive to nitroglycerin and patients seek assistance in the emergency room. Even though unstable angina is not associated with elevated levels of cardiac biomarkers, it is a serious disorder that can be life threatening. The treatment involves the use of a variety of cardiac medications and in some cases, interventional therapy   .
Unstable angina is a serious heart disorder that often presents with chest pain at rest. When the chest pain does not respond to nitroglycerin, it is highly recommended that the patient be seen in the emergency room. Unstable angina is very unpredictable and needs immediate medical attention.
Other common symptoms are:
Patients may have a varied course in hospital ranging from a heart attack, heart failure or development of abnormal heart rhythm. Once the diagnosis is made, the treatment starts with medications to reduce angina symptoms and improve blood flow. Some patients may need procedure to open up the coronary vessels if there is a blockage. Prevention rests on a healthy low fat diet, discontinuation of smoking, regular exercise and compliance with medications.