Unstable angina or mild heart attack may appear on the surface to look like stable angina, a lower risk condition, or a typical heart attack, a high-risk condition. It is important that your condition is accurately diagnosed because the recommended treatments differ depending on whether you are at a high or lower risk.
How is unstable angina/mild heart attack different from stable angina?
The major way that unstable angina is distinguished from stable angina is by the description of your chest pain characteristics. In stable angina, chest pain is usually brought on by exertion or stress and relieved with rest. Episodes last about 1 to 15 minutes, and they follow a predictable pattern. Unstable angina often occurs when a person is at rest, and there is no discernable pattern. Unstable angina episodes occur more frequently than stable angina, are more severe, and may last longer than 15 minutes.
How is unstable angina/mild heart attack different from a typical heart attack?
Unstable angina or a mild heart attack is distinguished from a typical heart attack by examining the pattern produced during ECG (electrocardiogram) testing. An ECG is a graph of your heart's electrical activity; if there is a rise in a specific area of the graph— ST-segment elevation—you will be diagnosed with a typical heart attack. If the pattern is described as non-ST-segment elevation, you will be diagnosed with unstable angina or a mild heart attack.
What other tests are used if I have unstable angina/mild heart attack?
If stable angina and typical heart attack are ruled out you will then be diagnosed with either unstable angina or mild heart attack. These two conditions are differentiated on the basis of blood tests for certain proteins that are only released when the heart muscle is damaged by a heart attack.
Once unstable angina or mild heart attack is diagnosed, it is likely that you will undergo further testing to determine the location and severity of the blockages in the arteries of the heart. Possible noninvasive tests include stress ECG, an echocardiogram ( ultrasound of the heart), or nuclear imaging. A more detailed but invasive test is an angiogram, or X-ray of the coronary arteries.
What are the treatment goals for unstable angina/mild heart attack?
There are several goals for the treatment of unstable angina, including reducing chest pain and preventing future heart attacks and heart problems by reducing your overall heart disease risk. 6, 7 These are accomplished with medication and by reducing heart disease risk factors.
The ABCDE mnemonic summarizes the recommended treatments and lifestyle changes:
Aspirin and anti-angina medication
Beta blockers and blood pressure
Cholesterol and cigarettes
Diet and diabetes
Education and exercise
What medications are used to treat unstable angina/mild heart attack?
There are several types of medication that you may be given if you have unstable angina. Most likely you will be given nitroglycerin (usually as a spray to use in your mouth) to take when experiencing angina pain that does not go away after 2 or 3 minutes. Nitroglycerin widens and opens your blood vessels, and allows blood and oxygen to reach your heart more easily. Nitroglycerin is an anti-ischemic drug meaning itprevents ischemia—when blood flow to the heart is restricted and the heart doesn't get enough oxygen. You may be given other anti-ischemic drugs such as beta blockers or calcium channel blockers. These medications also work by allowing more blood and oxygen flow to the heart, which reduces the chance of chest pain occurring.
You may also be told to take aspirin once a day because it reduces inflammation and prevents blood clots from developing. In addition, you may be prescribed clopidogrel (Plavix), which is also a blood thinning medication. Plavix works by making the blood less sticky and thus less likely to clot. It is important to note that some studies have shown that women with unstable angina are less likely than men to receive certain medications, such as aspirin and other antiplatelets.3, 8, 9
What if I also have heart disease risk factors?
Because most people with unstable angina have some form of heart disease, it is also important to control your heart disease risk factors to reduce your chances of suffering a heart attack. If you smoke, you should quit. You should also try to exercise several times a week and maintain a healthy weight and heart-healthy diet. Your healthcare provider should discuss with you what type of exercise is appropriate for you. If you have high cholesterol, you may be given a lipid-lowering medication, such as a statin (e.g., Lipitor). It is also important to control high blood pressure; this can by accomplished with beta blockers or calcium channel blockers that you may already be taking. If you have diabetes, it is important that you keep this under control as well. Modifying your heart disease risk factors is also the only way to prevent unstable angina from developing in the first place.
Some people with unstable angina or mild heart attack can be managed with medication alone, but others may need to undergo angioplasty and stenting or bypass surgery. Whether you need one of these procedures depends on the severity of your underlying heart disease and whether medicine successfully relieves your chest pain.
For the past few years, researchers have been comparing two types of treatment: a conservative strategy using medications first and saving invasive procedures (such as stents and bypass surgery) for patients who do not respond to medication treatment versus a more aggressive strategy where the patient is sent immediately for cardiac catheterization and then treated with stents or bypass surgery. The aggressive strategy reduces the risk of dying or having a heart attack in high-risk patients, including women.10-12 High-risk patients are those who show signs of damage to their heart muscle—high levels of proteins show up in their blood tests.
It is not as clear, however, whether patients at lower risk receive the same benefits. Some studies have shown that men, but not women, have better outcomes when an early invasive procedure is used,11, 12 but other studies have shown that both men and women do better when an early invasive procedure is performed.13 If you are lower risk and your pain persists after medication treatment, stents or bypass surgery may still be your best option for getting rid of your chest pain and improving your quality of life.
1.Canto JG, Fincher C, Kiefe CI, et al. Atypical presentations among Medicare beneficiaries with unstable angina pectoris. Am J Cardiol. Aug 1 2002;90(3):248-253.
2.Detailed diagnoses and procedures: National Hospital Discharge Survey, 1996. Hyattsville, MD: National Center for Health Statistics; 1998.
3.Scirica BM, Moliterno DJ, Every NR, et al. Differences between men and women in the management of unstable angina pectoris (The GUARANTEE Registry). The GUARANTEE Investigators. Am J Cardiol. Nov 15 1999;84(10):1145-1150.
4.Hochman JS, Tamis JE, Thompson TD, et al. Sex, clinical presentation, and outcome in patients with acute coronary syndromes. Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes IIb Investigators. N Engl J Med. Jul 22 1999;341(4):226-232.
5.Ridker PM. Inflammation, infection, and cardiovascular risk: how good is the clinical evidence? Circulation. May 5 1998;97(17):1671-1674.
6.Braunwald E, Antman EM, Beasley JW, et al. ACC/AHA 2002 guideline update for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction--summary article: a report of the American College of Cardiology/American Heart Association task force on practice guidelines (Committee on the Management of Patients With Unstable Angina). J Am Coll Cardiol. Oct 2 2002;40(7):1366-1374.
7.Gibbons RJ, Abrams J, Chatterjee K, et al. ACC/AHA 2002 guideline update for the management of patients with chronic stable angina--summary article: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on the Management of Patients With Chronic Stable Angina). J Am Coll Cardiol. Jan 1 2003;41(1):159-168.
8.Stone PH, Thompson B, Anderson HV, et al. Influence of race, sex, and age on management of unstable angina and non-Q-wave myocardial infarction: The TIMI III registry. Jama. Apr 10 1996;275(14):1104-1112.
9.Hochman JS, McCabe CH, Stone PH, et al. Outcome and profile of women and men presenting with acute coronary syndromes: a report from TIMI IIIB. TIMI Investigators. Thrombolysis in Myocardial Infarction. J Am Coll Cardiol. Jul 1997;30(1):141-148.
10.Mueller C, Neumann FJ, Roskamm H, et al. Women do have an improved long-term outcome after non-ST-elevation acute coronary syndromes treated very early and predominantly with percutaneous coronary intervention: a prospective study in 1,450 consecutive patients. J Am Coll Cardiol. Jul 17 2002;40(2):245-250.
11.Lagerqvist B, Safstrom K, Stahle E, Wallentin L, Swahn E. Is early invasive treatment of unstable coronary artery disease equally effective for both women and men? FRISC II Study Group Investigators. J Am Coll Cardiol. Jul 2001;38(1):41-48.
12.Fox KA, Poole-Wilson PA, Henderson RA, et al. Interventional versus conservative treatment for patients with unstable angina or non-ST-elevation myocardial infarction: the British Heart Foundation RITA 3 randomised trial. Randomized Intervention Trial of unstable Angina. Lancet. Sep 7 2002;360(9335):743-751.
13.Boden WE. "Routine invasive" versus "selective invasive" approaches to non-ST-segment elevation acute coronary syndromes management in the post-stent/ platelet inhibition era. J Am Coll Cardiol. Feb 19 2003;41(4 Suppl S):113S-122S