• Left heart catheterization is performed to diagnose and treat coronary artery conditions. It allows real-time visualization of the coronary arterial circulation via injection of contrast under fluoroscopic guidance. Indications include the following (1):
  • Diagnostic procedures: Confirm and assess the severity of suspected heart disease (chambers and circulation) after a failed stress test.
  • Therapeutic procedures: Percutaneous coronary interventions (PCI); valvuloplasties and percutaneous valve insertions; septostomy and septal reduction; myocardial biopsy.
• Diagnostic uses: Vascular sheaths are introduced, typically into the femoral arteries, and function as a conduit by which other instruments are then inserted.
  • Coronary angiography is performed by advancing a balloon-tipped catheter into the aorta and through the coronary ostia to access the coronary circulation; dye is injected to delineate the anatomy, collaterals, and blockages.
  • Ventriculogram is performed by subsequently pulling the catheter back into the ascending aorta and advancing it through the aortic valve (AV); dye is injected into the left ventricle (LV) to assess its function.
  • Pressures in chambers and gradients across valves are also measured.
• Therapeutic uses
  • Percutaneous transluminal coronary angioplasty (PTCA) consists of inflating a balloon at the level of the narrowed coronary artery to improve blood flow.
  • Stenting consists of deployment of mesh-like structures that are loaded onto angioplasty balloons. They fixate to the coronary wall via hooks and prevent acute recoil. Bare metal stents (BMS), introduced in the 1990s, are metallic mesh-like structures. Drug-eluting stents (DES), FDA approved in 2003, are similar to BMS but release a medication designed to inhibit restenosis.
  • The presence of a raw surface on the coronary artery (stent) mandates preprocedure loading with dual antiplatelet therapy (DAPT) and treatment continuation until stent endothelialization is complete; BMS require ~2 months, whereas DES require 1 year or more.
  • Valvuloplasties are performed to dilate stenotic valves (aortic, mitral) by inflating a balloon at the level of the valve. More recently, aortic valves have been successfully inserted percutaneously.
  • Septal reductions are performed in patients with hypertrophic obstructive cardiomyopathies. During cardiac catheterization, alcohol is injected in the septal perforator artery that supplies the area of hypertrophied interventricular septum (induces necrosis of the area and thus reduces outflow tract obstruction).
  • Septostomies are performed in patients with congenital heart disease requiring a right-to-left shunt. A balloon-tipped catheter is inserted percutaneously into the venous system and advanced via the right atrium into the fossa ovalis, which is dilated by balloon inflation.
• Right heart cardiac catheterization allows for measurement of right heart and pulmonary circulation pressures as well as oxygen saturation via blood sampling (not addressed here).
• Advantages of PCI over coronary artery bypass surgery (CABG) include the following:
  • Less invasive treatment of coronary artery disease (CAD)
  • Decreased impact on major organ function
  • Decreased intensive care unit (ICU) or hospital stay
  • Faster recovery to full activity, reduced postoperative pain
  • Outcome studies in patients with 3-vessel or left main disease show similar rates of major adverse cardiac events or cerebrovascular events at 1 or 2 years when comparing PCI with DES versus CABG (2,3,4)
• Disadvantages of PCI over CABG
  • Prolonged treatment with DAPT and increased risk of spontaneous or surgical bleeding
  • May require repeat target lesion revascularization
  • No long-term survival benefit

Supine

• Femoral artery puncture
• Other possible puncture sites: Axillary, brachial, or radial artery

1–2 hours

• Usually minimal
• Potential for significant blood loss with major vessel or cardiac injury

• In elective cases, may be discharged home the same day
• In acute coronary syndrome (ACS) situations, 2–3 days, possibly longer
• In cardiogenic shock, prolonged ICU stays may be necessary

• Cardiac catheterization laboratory
• Fluoroscopy machine, IV contrast dye injector, intravascular ultrasound
• Ideally: Cardiac operating room available within the same building

Incidence

• 1 million PCI/year in the US
• During PCI, 90% of patients receive at least 1 stent

• Coronary artery restenosis manifests as reoccurrence of anginal symptoms
  • PTCA: 30–40%
  • BMS: 20–30%
  • DES: <10%
• Late stent thrombosis manifests as death or myocardial infarction
  • BMS rare
  • DES 0.5–3.1%, possibly higher

• At the time of PCI: 1%
• Acute vessel recoil post-PTCA: 20%
• Late stent thrombosis: 45–75%

History

• Often identified as a failed stress test
• Associated comorbidities: Hypertension, heart failure, arrhythmias, diabetes, peripheral vascular disease, smoking history, chronic obstructive pulmonary disease (COPD), chronic kidney injury

Signs/Physical Exam

S3, S4 heart sounds and bibasilar crackles in patients with heart failure

Labs/Studies

• Hematocrit/hemoglobin, potassium, creatinine, coagulation profile; platelet function assay (if available)
• Echocardiography results (if available)
• Stress test results (if available)

• Loading with high-dose clopidogrel (300–600 mg) and aspirin (PO or orogastric tube/nasogastric tube)
• Anxiolysis as appropriate

• Low ejection fraction (EF) or high-grade left main disease patients may require pre-PCI placement of intra-aortic balloon pump (IABP)
• Cardiogenic shock patients may require pre-PCI placement of a percutaneous LV assist device (pVAD) like the Impella^® or TandemHeart^®
• Potential for conversion to open heart surgery
• Consent for possible blood transfusions

• Most cases are performed without anesthesia care under mild/moderate sedation administered by a cath lab nurse (6).
• Situations where anesthesia services are required include patients that are critically ill, hemodynamically unstable, morbidly obese with significant sleep apnea, cannot lie flat, claustrophobic, or mentally impaired. General anesthesia (usually with endotracheal tube [ETT]) is often performed.

• Standard ASA monitors
• Arterial waveform can be derived from the groin access lines placed by the cardiologist.
• Good IV access for rapid resuscitation in case of vascular damage or emergency cardiac surgery
• Foley catheter
• Transesophageal echocardiography/transthoracic echocardiography (TEE/TTE) is useful to assess cardiac function, detect complications, and guide management.

• Controlled induction to avoid hemodynamic instability
• Emergency airway tools readily available (LMA, indirect video laryngoscopy)

• Volatile or IV agents can be used for maintenance of anesthesia. Volatile agents offer the theoretical advantage of ischemic preconditioning of the myocardium. There is no data to suggest that decreases in myocardial contractility seen with volatile or IV anesthetics impact overall patient outcome.
• Anticoagulation
  • Systemic heparinization is administered to a desired activated clotting time (ACT) of 300–350 seconds. for patients with heparin-induced thrombocytopenia, direct thrombin inhibitors, factor Xa inhibitors, or defibrinogenating agents are used. No test is available to monitor the effect of these agents. Patients may be overdosed (manifests as generalized bleeding).
  • IV antiplatelet drugs (glycoprotein IIb/IIIa inhibitors) may be required.
• Significant hypotension suggests cardiogenic shock or hypovolemic shock due to massive hemorrhage (cardiac or vascular injury).

• Standard extubation criteria; consider postoperative intubation if the patient is hemodynamically unstable.
• Control BP and heart rate during emergence with IV agents such as beta-blockers, nitroglycerin, diltiazem, and clevidipine.
• Neurologic exam (potential for cerebral embolic event)