DRG Category: 287
Mean LOS: 3.0 days
Description: Medical: Circulatory Disorders Except Acute Myocardial Infarction, With Cardiac Catheterization Without Major Complication or Comorbidity
DRG Category: 311
Mean LOS: 2.4 days
Description: Medical: Angina Pectoris
Angina pectoris is a symptom of ischemic heart disease characterized by paroxysmal and usually recurring substernal or precordial chest pain or discomfort. The term comes from the Latin words meaning “choking of the chest.” About 10 million Americans experience angina each year, and approximately 500,000 new cases of angina occur every year. Angina pectoris is caused by varying combinations of increased myocardial demand, decreased myocardial perfusion, and reduced oxygen-carrrying capacity of the blood. Blood flow through the coronary arteries is partially or completely obstructed because of coronary artery spasm, fixed stenosing plaques, disrupted plaques, thrombosis, platelet aggregation, and/or embolization. Pain or discomfort results from chemical and mechanical stimulation of nerve endings in the coronary circulation and heart muscle as myocardial cells switch from aerobic to anaerobic metabolism.
Angina can be classified as chronic exertional (stable, typical) angina, variant angina (Prinzmetal), unstable or crescendo angina, or silent ischemia (Table 1). Chronic exertional angina is usually caused by obstructive coronary artery disease that causes the heart to be vulnerable to further ischemia whenever there is increased demand or workload. Variant angina may occur in people with normal coronary arteries who have cyclically recurring angina at rest, unrelated to effort. Unstable angina is diagnosed in patients who report a changing character, duration, and intensity of their pain. Experts are also recognizing that not all ischemic events are perceived by patients, even though such events, called silent ischemia, may have adverse implications for the patient.
Table 1 Classification of Angina Pectoris
| TYPE | CAUSE | DESCRIPTION | DURATION | CESSATION |
|---|
| Stable (typical) | Reduction of coronary perfusion by chronic stenosing coronary atherosclerosis; relieved by rest; related to activities that increase myocardial demand | Chest discomfort is produced by exertion; pain may occur after meals or be brought on by emotional tension or exertion; reproducible pattern of symptoms | 3–15 min | Relieved by rest and/or nitroglycerin (NTG) | | Prinzmetal variant angina | Coronary artery spasm without increased myocardial oxygen demand; coronary arteries are normal with angiogram | Occurs at rest, often during sleep in early morning hours or with exertion; associated with elevation of the ST segment of the electrocardiogram, which indicates transmural ischemia | Tends to last longer than other forms of angina | May subside with exercise | | Unstable angina | Disruption of an atherosclerotic plaque or vasospasm or both; myocardial ischemia without detectable biomarkers of myocardial necrosis | Pattern of pain with progressively increasing frequency and precipitated with progressively less effort; may occur at rest | Prolonged duration longer than that of stable angina | May not be relieved by NTG or rest; 10%–20% of untreated patients may progress to myocardial infarction (MI) | | Microvascular angina or cardiac syndrome X | Normal (or near normal) coronary arteries and without a known cause; may be due to inadequate flow reserve in the microvascular circulation of the heart | Chest pain, chest heaviness, squeezing chest pressure, triggered by exertion, travels to back, neck, jaw, shoulder, arm | Lasts longer than 10 min | Usually relieved with rest and/or nitrates | | Silent ischemia | Exact mechanism is unknown, but possible explanations include autonomic dysfunction, high threshold, and production of excessive quantities of endorphins | Angina without pain; as many as 90% of attacks of angina may be silent; most happen in the early morning hours; may result in problems with contractility | Transient ST depression persisting for at least 1 min | Usually unrecognized by patients |
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Most recurrent angina pectoris is caused by atherosclerosis, which is the most common cause of coronary artery disease (CAD) and continues to be the leading cause of death for both women and men in the United States. Atherosclerotic lesions lead to decreased myocardial blood supply. However, angina may occur in patients with normal coronary arteries as well. Approximately 90% of patients with recurrent angina pectoris have hemodynamically significant stenosis or occlusion of a major coronary artery. Other causes include severe myocardial hypertrophy, severe aortic stenosis or regurgitation, cardiac dysrhythmias, increased metabolic demand, marked anemia, or inadequate flow reserve in the microcirculation. Risk factors include tobacco use, diabetes mellitus, hypertension, sedentary lifestyle, alcohol abuse, obesity, elevated cholesterol, older age, and stress.
Combination of genetics and environment appear to account for the vast majority of cases of coronary heart disease (CHD) and angina. First-degree relatives of patients with CHD are at higher risk of developing the disease and developing it earlier than the general population. Over 250 genes have been implicated in the onset of CHD, making it a prime example of the combination of multiple genes and environment seen in complex disease. Defects in genes involved with low-density lipoprotein (LDL) metabolism, homocysteine metabolism, muscle development, and blood pressure regulation have been associated with CAD development. Other associated genes include the apolipoprotein A1 gene, apolipoprotein E4 gene, and glycoprotein IIb/IIIa gene. Familial hypercholesterolemia (FH) is caused by a defective LDL receptor, and this mutation is inherited in an autosomal dominant pattern. In individuals affected by FH, they may have elevated LDL levels, up to double the normal range, which may be seen as early as 2 years of age. Often, signs of CHD can be found by the age of 30 years.
The risk of ischemic heart disease increases with age and when predispositions to atherosclerosis (smoking, hypertension, diabetes mellitus, hyperlipoproteinemia) are present. Nearly 10% of MIs occur in people under age 40 years, however, and 45% occur in people under age 65 years. The incidence of new and recurrent angina increases with age until 85 years, when it declines. Men are at greater risk than women for MI, but the differential progressively declines with advancing age. In people 40 to 74 years old, the age-adjusted prevalence of angina is higher among women than men. In addition, atypical presentations of angina are also more common among women than men. Recent research has been conducted about pain and ischemia in people with no obstructed coronary arteries during angiogram. The findings indicate that this group is predominantly women with vasomotor disorders or coronary microvascular dysfunction. Unique risk factors for women include pregnancy-related disorders, autoimmune dysfunction, chronic inflammation, and psychological risk factors.
The Centers for Disease Control and Prevention reports that 11.5% of White persons, 9.5% of Black persons, 7.4% of Hispanic persons, and 6.0% of Asian persons have heart disease. In people between the ages of 55 and 64 years, new episodes of angina occur in 11.2% of non-Black and 19.3% of Black women and in 11.9% of non-Black and 10.6% of Black men. Prior to age 64 years, the highest prevalence of new angina is in Black women. Significant health disparities exist in the cardiac care of underrepresented groups as compared to White persons. Black, Indigenous, or other people of color are known to receive care less often guided by standard cardiac care guidelines than White persons. Unless patients have health insurance, White patients are more likely to receive coronary angiograms and other coronary interventions than Black and Hispanic patients. Black, Indigenous, or other people of color are also less likely to be referred to cardiologists and cardiac surgeons than White persons (Batchelor et al., 2019).
Transgender is a term used to describe persons whose gender identity is different from their sex assigned at birth. Approximately 1% of the U.S. population identify themselves as transgender. Sexual and gender minority persons have higher odds for multiple chronic conditions, cancer, and poor quality of life, and are more apt to have disabilities than cisgender males and females (cisgender are persons whose gender identity and gender expression are aligned with their assigned sex listed on their birth certificate). Gender-affirming hormone therapy is the use of hormone therapy for gender transition or gender affirmation and can be masculinizing or feminizing. It may also affect cardiovascular health in transgender women. In a large sample, researchers have found that transgender men and women are more likely to be overweight than cisgender women. Compared to cisgender women, transgender women reported higher rates of diabetes, ischemic stroke, angina/coronary disease, and MI. Gender-nonconforming men and women reported higher odds of MI than cisgender women. Transgender women also had higher rates of any cardiovascular disease than cisgender men (Caceres, Jackman, et al., 2020; Connelly et al., 2019). While large-scale studies are not available, these factors may place some sexual and gender minority persons at risk for angina pectoris.
Heart disease remains the leading cause of death in developed countries but is now also the leading cause of death in low-income countries (India, Pakistan) and middle-income countries (Mexico, Russia). Eastern European countries have among the highest prevalence of heart disease in the world. The reasons for the increase in cardiovascular disease deaths in developing countries are complex but related to improvements in infectious disease management, urbanization with the accompanying lifestyle changes that predispose people to heart disease, and genetic susceptibility of some populations.
PLANNING AND IMPLEMENTATION
Collaborative
For any patient who is experiencing an acute anginal episode, pain management is the priority not only for patient comfort but also to decrease myocardial oxygen consumption. The physician orders selected therapies that either decrease myocardial oxygen demand or increase coronary blood and oxygen supply. These therapies may include medications for pain relief; short-term bedrest; oxygen therapy; cardiac monitoring to prevent potential complications; and small, frequent, easily digested meals. Surgical and other invasive options are discussed under Coronary Heart Disease, p. 315.
Diet
A collaborative effort among the patient, dietitian, physician, and nurse plans for a diet low in cholesterol, fat, calories, and sodium. Drinks in the coronary care unit or step-down unit are usually decaffeinated and not too hot or cold.
Vital Signs
During unstable periods, the nurse and physician closely monitor the patient's vital signs and the patient's response to pain-relieving therapies (narcotics, nitrates). Often the patient is placed on a cardiac monitor to determine if life-threatening dysrhythmias occur during an anginal episode, particularly if the angina may be a symptom that the patient is having an MI.
| Medication or Drug Class | Dosage | Description | Rationale |
|---|
| Nitroglycerin | 0.3–0.6 mg prn SL for stable angina; IV for unstable angina—IV dose varies | Nitrate | Relieves ischemic symptoms by vasodilation of coronary arteries; reduces left ventricular preload and afterload |
| Antiplatelet agents such as enteric-coated aspirin or clopidogrel | Varies by drug | NSAID and antiplatelet agent | Inhibits platelet aggregation to reduce risk of coronary artery blockage |
| Ranolazine | 500–1,000 mg BID | Antianginal, anti-ischemic agent | Used to treat chronic angina; alters the transcellular late sodium current and indirectly prevents calcium overload |
| Beta-adrenergic antagonists (atenolol, propranolol, metoprolol, etc.) | Varies by drug | Beta-adrenergic antagonists | Reduce myocardial oxygen demands by decreasing heart rate, blood pressure, and contractility |
Other Therapies: Goal-directed therapy usually includes beta-adrenergic antagonists, antiplatelet agents, and HMG-CoA reductase inhibitors (statins such as atorvastatin or rosuvastatin). There are numerous drugs to decrease myocardial oxygen consumption: IV NTG by infusion, long-acting nitrates, narcotics for pain control, calcium channel–blocking agents, vasodilators, diuretics, antihypertensive agents, and anticoagulants.
Independent
To decrease oxygen demand, encourage the patient to maintain bedrest until the pain subsides, even though bedrest is usually short term. Encourage rest throughout the entire hospitalization or emergency department visit.
Because anxiety and fear are common among both patients and families, attempt to have them discuss concerns and express their feelings. With the patient and family, discuss the diagnosis, the activity and diet restrictions, and the medical treatment. Refer the patient to a smoking-cessation program or alcohol counseling if appropriate. Numerous lifestyle changes may be needed. Cardiac rehabilitation is helpful in limiting risk factors and providing additional guidance, social support, and encouragement. Adequate education and support are essential if the patient is to adhere to the prescribed therapy and treatment plan.
Evidence-Based Practice and Health Policy
Aggarwal, R., Chiu, N., Pankayatselvan, V., Shen, C., & Yeh, R. (2020). Prevalence of angina and use of medical therapy among U.S. adults: A nationally representative estimate. American Heart Journal, 228, 44–46.
- The authors sought to determine the prevalence of angina in the United States and to determine the use of first-line therapy by patients with angina. They used individual patient data from the National Health and Nutrition Examination Survey from 2007 to 2016.
- Of patients with angina, 61.7% were taking beta blockers, 66.8% were on statins, and 54.4% were taking antiplatelet agents. An overall proportion of 32.6% was taking all three first-line medications. The authors encouraged strategies to improve the use of these three medications for patients with angina.