Cardiac Catheterization and Percutaneous Coronary Intervention
Christopher P. Cannon
Patrick T. O’Gara
Coronary arteriography, the “gold standard” for identifying the presence or absence of stenoses caused by coronary artery disease (CAD), provides the most reliable anatomic information needed to determine the appropriateness of medical therapy, percutaneous coronary intervention (PCI), or coronary artery bypass graft (CABG) surgery. Coronary arteriography is performed by directly injecting radiopaque contrast material into the coronary arteries and imaging the coronary anatomy on 35-mm cinefilm or, more recently, digital recordings (1). It is estimated that more than two million patients will have coronary arteriography in the United States this year; of these, nearly 1 million will have PCI, using a variety of devices including conventional balloon angioplasty, atherectomy, or coronary stents.
The methods used to perform coronary arteriography have evolved substantially over the past few years. A number of factors have contributed to reduced complications and shorter hospitalization periods in patients having cardiac catheterization and PCI. More efficient preprocedural evaluation systems have been established, and many diagnostic tests are now performed in the preadmission testing centers, allowing patients “same-day” cardiac catheterization within 60 minutes after arrival to the cardiac catheterization laboratory. Smaller (5 to 6 Fr), high-flow injection catheters used during the procedure have replaced larger (8 Fr) thick-walled catheters. The reduced sheath size has allowed coronary arteriography, ambulation, and discharge within 6 to 8 hours following the procedure. The rapid sequence of events that occurs today in patients having cardiac catheterization and PCI lends itself to the establishment of “critical pathways” to coordinate the safe and efficient delivery of care in patients with symptomatic CAD. This chapter outlines the indications for cardiac catheterization and PCI and discusses the perioperative management in patients having these procedures.
Indications for Coronary Angiography
It is important to make certain that the patient has been referred to the cardiac catheterization suite with a clinical history and physical examination that warrant cardiac catheterization. Although the hemodynamic indications for cardiac catheterization are fairly clear (e.g., valvular heart disease, congestive heart failure [CHF]), indications for coronary arteriography are somewhat more vague. Appropriate guidelines for coronary arteriography have been outlined by a recent consensus statement of the American College of Cardiology (ACC) and American Heart Association (AHA) (1).
The following patients are candidates for coronary angiography.
Patients with suspected CAD who have stable angina or asymptomatic ischemia should undergo coronary arteriography if their angina is severe (Canadian Cardiovascular Society [CCS] class III–IV) or if they have “high-risk” criteria for adverse outcome on noninvasive testing.
High-risk features include severe resting left ventricular (LV) dysfunction (LV ejection fraction [LVEF] <35%), or a standard exercise treadmill test demonstrating hypotension or ≥1- to 2-mm ST-segment depression associated with decreased exercise capacity (2) or an exercise-induced LVEF <35% (1). Stress imaging that demonstrates a large perfusion defect (particularly in the anterior wall), multiple defects, a large fixed perfusion defect with LV dilatation or increased thallium-201 lung uptake, or extensive stress or dobutamine-induced wall motion abnormalities also indicate high risk for an adverse outcome (1,3).
Patients resuscitated from sudden cardiac death, particularly those with residual ventricular arrhythmias, are also candidates for coronary arteriography, given the favorable outcomes associated with revascularization in these patients (1).
Patients with unstable angina who develop recurrent symptoms despite medical therapy or who are at “intermediate” or “high” risk of subsequent death or myocardial infarction (MI) are also candidates for coronary arteriography (1,4,5). High-risk features include prolonged, ongoing (>20 minutes) chest pain, pulmonary edema or worsening mitral regurgitation, dynamic ST-segment depression >1 mm, or hypotension (1). Intermediate-risk features include angina at rest (>20 minutes) relieved with rest or sublingual nitroglycerin, angina associated with dynamic electrocardiographic
changes, recent-onset angina with a high likelihood of CAD, pathologic Q waves or ST-segment depression <1 mm in multiple leads, or age >65 years (1).
Patients with Q-wave or non–Q-wave MI who develop spontaneous ischemia or with ischemia at a minimal workload or when the MI is complicated by CHF, hemodynamic instability, cardiac arrest, mitral regurgitation, or ventricular septal rupture should undergo coronary arteriography. Patients with angina or provocable ischemia after MI should also undergo coronary arteriography (6).
Patients presenting with chest pain of unclear cause, particularly those who have high-risk criteria on noninvasive testing, may benefit from coronary arteriography to diagnose or exclude the presence of significant CAD (1). Patients who have undergone prior revascularization should undergo coronary arteriography if suspicion exists of abrupt vessel closure or when recurrent angina develops with high-risk noninvasive criteria in patients who have undergone PCI within the past 9 months.
Coronary arteriography should be performed in patients scheduled to undergo noncardiac surgery who develop high-risk criteria on noninvasive testing, have angina unresponsive to medical therapy, develop unstable angina, or have equivocal noninvasive test results and are scheduled to undergo high-risk surgery. Coronary arteriography is also recommended for patients scheduled to undergo surgery for valvular heart disease or congenital heart disease, particularly those with multiple cardiac risk factors and those with infective endocarditis and evidence of coronary embolization (1).
Coronary arteriography should be performed annually in patients after cardiac transplantation in the absence of clinical symptoms because of the diffuse and asymptomatic nature of graft atherosclerosis (7). Coronary arteriography is useful in potential donors for cardiac transplantation whose age or cardiac risk profile increases the likelihood of CAD. Coronary arteriography often provides important diagnostic information about the presence of CAD in patients with intractable arrhythmias who are planned to undergo electrophysiologic testing or in patients who present with a dilated cardiomyopathy of unknown cause.
No absolute contraindications are seen for coronary arteriography (1), although cardiac catheterization should be performed with extreme caution in patients with unexplained fever, untreated infection, severe anemia with hemoglobin less than 8 g/dL, severe electrolyte imbalance, severe active bleeding, uncontrolled systemic hypertension, digitalis toxicity, previous contrast allergy but no pretreatment with corticosteroids, or ongoing stroke. Other relative contraindications include acute renal failure, decompensated CHF, severe coagulopathy, and active endocarditis (1).
Risk factors for significant complications after catheterization include advanced age, as well as several general medical, vascular, and cardiac characteristics. Patients with these risk factors should be monitored closely for a minimum of 18 to 24 hours after coronary arteriography, and admission is indicated in patients with severe renal insufficiency (creatinine >2.0 mg/dL) for fluid hydration, uncompensated CHF for diuresis, or advanced age. Coronary arteriography performed under emergency conditions is associated with a higher risk of procedural complications. Careful discussion of the risks and benefits of the procedure and its alternatives should be reviewed with the patient and family in all circumstances before coronary arteriography is performed.
Indications for Percutaneous Coronary Intervention
The major value of coronary revascularization, whether performed by surgical or percutaneous methods, is the relief of symptoms and signs of ischemic CAD caused by obstructive epicardial disease. A careful assessment of the risks and benefits of coronary revascularization must be reviewed with the patient and family members, if appropriate, before these procedures are performed. The following guidelines for the performance of PCI and CABG have been published by the ACC/AHA (8,9).
Patients who are asymptomatic or have only mild symptoms are generally best treated with medical therapy, unless one or more significant lesions subtend a large area of viable myocardium that is shown using objective noninvasive testing, the patient prefers to maintain an aggressive lifestyle or has a high-risk occupation, and the procedure can be performed with a high chance of success and low likelihood of complications (8).
Patients with classes II to IV angina, particularly those who are refractory to medical therapy, are suitable candidates for coronary revascularization, provided that the lesion subtends a moderate to large area of viable myocardium by noninvasive testing (8).
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
