Patients with disabling (Canadian Cardiovascular Society [CCS] class III and IV) chronic stable angina despite medical therapy. (Level of evidence: B)
High-risk criteria on noninvasive testing regardless of anginal severity. (Level of evidence: B) (Display 20-1).
Patients with angina who have survived sudden cardiac death or serious ventricular arrhythmia. (Level of evidence: B)
Patients with angina and symptoms and signs of heart failure (HF). (Level of evidence: C)
Patients with clinical characteristics that indicate a high likelihood of severe CAD. (Level of evidence: C)
Patients with high-risk criteria suggesting ischemia on noninvasive testing. (Level of evidence: C)
Patients with inadequate prognostic information after noninvasive testing. (Level of evidence: C)
Patients with clinical characteristics that indicate a high likelihood of severe CAD. (Level of evidence: C)
Severe resting left ventricular dysfunction (LVEF <0.35)
High-risk treadmill score
Severe exercise left ventricular dysfunction (exercise LVEF <0.35)
Stress-induced large perfusion defect (particularly if anterior)
Stress-induced multiple perfusion defects of moderate size
Large, fixed perfusion defect with left ventricular dilatation or increased lung uptake (thallium-201)
Stress-induced moderate-size perfusion defect with left-ventricular dilatation or increased lung uptake (thallium-201)
Echocardiographic wall motion abnormality (involving more than two segments) developing at low-dose dobutamine or at low heart rate
Stress echocardiographic evidence of extensive ischemia
An early invasive strategy (i.e., diagnostic angiography with intent to perform revascularization) is indicated in UA/NSTEMI patients who have refractory angina or hemodynamic or electrical instability (without serious comorbidities or contraindications to such procedures. (Level of evidence: C) (See Table 20-1).
An early invasive strategy (i.e., diagnostic angiography with intent to perform revascularization) is indicated in initially stabilized UA/NSTEMI patients (without serious comorbidities or contraindications to such procedures) who have an elevated risk for clinical events. (Level of evidence: A)
Diagnostic investigation is indicated in patients with a clinical picture suggestive of coronary spasm, with investigation for the presence of transient myocardial ischemia and ST-segment elevation during chest pain. (Level of evidence: A)
Patients with episodic chest pain accompanied by transient ST-segment elevation. (Level of evidence: B)
Suspected abrupt closure or subacute stent thrombosis after percutaneous revascularization. (Level of evidence: B) (Chapter 23).
Recurrent angina or high-risk criteria on noninvasive evaluation within 9 months of percutaneous revascularization. (Level of evidence: C) (Display 20-1).
Coronary angiography and primary PCI should be performed in patients with STEMI or myocardial infarction (MI) with new or presumably new left bundle-branch block who can undergo PCI of the infarct artery within 12 hours of symptom onset. (Level of evidence: A)
Patients younger than 75 years with ST elevation or presumably new left bundle-branch block who develop shock within 36 hours of MI and are suitable for revascularization that can be performed within 18 hours of shock. (Level of evidence: A)
Patients with severe congestive heart failure and/or pulmonary edema and onset of symptoms within 12 hours. (Level of evidence: B)
A strategy of coronary angiography with intent to perform PCI (or emergency coronary artery bypass graft surgery) is recommended for patients who have received fibrinolytic therapy and have any of the following:
Cardiogenic shock in patients younger than 75 years who are suitable candidates for revascularization. (Level of evidence: B)
Severe congestive HF and/or pulmonary edema. (Level of evidence: B)
Hemodynamically compromising ventricular arrhythmias. (Level of evidence: C)
Table 20-1 ▪ SHORT-TERM RISK OF DEATH OR NONFATAL MI IN PATIENTS WITH UNSTABLE ANGINA/NSTEMI* | ||||||||||||||||||||||||||||||||||||||||||
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Standard 12-lead electrocardiogram (ECG).
Laboratory tests: complete blood count including platelets and differential, electrolytes, blood urea nitrogen (BUN), and creatinine.
Nothing by mouth after midnight (or after a light breakfast if catheterization is to be in the afternoon).
Premedication with a mild sedative may be given. During the procedure, a procedural sedation protocol should be followed.
Patients with renal insufficiency should be adequately hydrated before and after the procedure and a minimum amount of radiographic low-osmolar contrast medium should be used. The combination of N-acetylcysteine and sodium bicarbonate infusion before and after contrast infusion has shown to reduce the risk of contrast induced nephropathy in patients with renal insufficiency.15
Patients with a history of allergy to previous contrast administration, asthma, or drug or food allergies with iodine-containing substances should receive low-osmolar contrast medium and pretreatment with steroids, antihistamine (diphenhydramine), and an H2 blocker (cimetidine or ranitidine) are also sometimes used.16
Patients who are fasting should take a reduced dose of insulin or hold dose as directed by physician. Oral diabetic agents are usually held the morning of the procedure. Metformin is held the day of the procedure and 48 hours after the catheterization.
Anticoagulation issues are directed by the physician. Acetylsalicylic acid (ASA) and antiplatelet medications are usually given before catheterization. Warfarin is generally discontinued 3 to 4 days before the procedure until the international normalized ratio is <2.0. Warfarin can be reversed with vitamin K or fresh frozen plasma. If the patient is receiving heparin therapy, heparin can be continued during the catheterization and discontinued for sheath removal.
Patient to void before going to catheterization laboratory.
There is no evidence-based data to support the prophylactic use of antibiotics.
Patients who wear dentures, glasses, or hearing aids should be sent to the laboratory wearing them. The patient is better able to communicate when dentures and hearing aids are in place. Glasses allow the patient to view the angiogram on the monitor and help keep the patient oriented to the surroundings.
Is this the patient’s first cardiac catheterization?
What are the patient’s apprehensions about the procedure?
What has the patient heard about cardiac catheterization? (Patients have sometimes heard “horror stories” from friends or acquaintances about catheterization experiences and may, therefore, need reassurance about the safety of the procedure.)
What decisions are being faced? (Patients may be facing good or bad news about the absence or presence and extent of disease. Thus, the period before catheterization most likely is a time of anxiety and fear for a variety of reasons. Discussion and reassurance may help to relieve some of these feelings.)
The patient is given nothing by mouth for 6 to 8 hours before the catheterization and is asked to void before arriving at the catheterization laboratory.
Medication is given before or during the procedure, if prescribed, but the patient is awake during the procedure.
The patient should be instructed in deep breathing, how to stop a breath without bearing down, and in coughing on request. With deep inspiration, the diaphragm descends, preventing it from obstructing the view of the coronary arteries in some radiographic projections. Bearing down (Valsalva maneuver) increases intra-abdominal pressure and may raise the diaphragm, obstructing the view. After the injection of contrast medium, coughing is requested to help clear the material from the coronary arteries. The rapid movement of the diaphragm also acts as a mechanical stimulant to the heart and helps prevent the bradycardia that may accompany the injection of contrast medium.18,19
The appearance of the laboratory should be explained to the patient, including the general function of the equipment.
The patient wears a gown to the laboratory.
The patient lies on a table that is hard and narrow.
The catheter insertion site is washed with an antibacterial scrub and hair is removed using a shaver. Usually, both groins are prepped to provide easy access to the other side for patients with peripheral vascular disease and obstructive disease preventing catheter advancement or sudden instability during the procedure requiring an intra-aortic balloon pump (IABP). The right groin is generally used because the operator standing on that side of the table has easier access.
The expected length of the procedure should be explained to the patient (approximately 1 hour for coronary angiogram and 2 hours with PCI). Complex procedures will be longer.
The patient is given a local anesthetic at the catheter entry site.
The patient may have warm sensation or experience nausea during injection of the coronary arteries with contrast medium, most commonly occurring with the injection of the ventricle during ventriculogram.
The patient should report angina, shortness of breath (SOB), and other symptoms to the staff.
The patient should be told the expected length of bed rest after the catheterization.
A patient support table, adjustable height, flat top whose locks can be released to allow the table top to move horizontally head-to-toe and side-to-side for “panning.”
Equipment for monitoring intracardiac pressures, CO determination, and physiologic recordings.
A suspended C-arm that rotates around the patient and allows variable angulations of the x-ray beam.
The image chain consists of a generator and cine pulse system, an x-ray tube, an image intensifier, an optical distributor, a 35-mm cine camera, and a television camera and monitor. The image chain produces fluoroscopy, which is the continuous presentation of an x-ray image on a fluorescent screen, allowing the viewing of structures in motion. The image intensifier receives the fluoroscopic image and increases its brightness, permitting filming (cinefluoroscopy) or digital acquisition of motion pictures and viewing of the image with a television camera, television screen, and videotape recorder. Although 35-mm film was originally used for recording, since 1998 all new images are permanently recorded digitally.
Single or biplane imaging system can be used. Biplane imaging provides simultaneous viewing of cardiac structures from two angles, which is helpful for congenital heart disease, transseptal punctures, and electrophysiology ablations.
Advanced cardiac life support drugs and equipment with a cardioverter-defibrillator available for emergency treatment.
Monitoring electrocardiographic activity with continuous ECG monitor display.
A standby pacemaker, either a temporary transvenous electrode and pulse generator system or an external transthoracic pacemaker.
IABP.