Definition and Indications

• Minimally invasive procedure performed by interventional cardiologists that involves introducing catheters to the arterial (via the radial or femoral artery) or venous (via internal jugular or femoral vein) system and advancing them to the left and/or right side of the heart. Cardiac catheterization can be both diagnostic and therapeutic.
• Diagnostic cath – angiography, pressure, shunt evaluation, cardiac output, exercise physiology endovascular ultrasound, endomyocardial biopsy, hemodynamics of valve disease.
• Therapeutic cath – coronary revascularization, structural heart interventions (TAVR, Mitra Clip), temporary pacemaker placement.

Contraindications

Depending on the situation, these contraindications may be relative or absolute:

• Acute renal insufficiency.
• Electrolyte derangement (particularly hypo or hyperkalemia).
• Active bleeding or coagulopathy (INR >1.5).
• Ventricular arrhythmias.
• Inability to lay flat (orthopnea).
• Active, untreated infection or fever.
• Contrast allergy or allergies to medications like aspirin if procedure is done in elective setting.
• Pregnancy.

Pre-cath Management

• Discuss procedure with patient; interventionalist team will do formal consent.
• NPO except meds for ≥8 hours prior to LHC. Discuss specifics with interventional team but general guidance for patients previously on anticoagulation as follows:
  • Warfarin (INR <1.5) +/- heparin gtt that can be turned off immediately prior to cath.
  • Dabigatran: hold 48 hours if CrCl >80 (longer for CrCl <80).
  • Rivaroxaban, apixaban or edoxaban: hold 48 hours if CrCl >30 (longer for CrCl <30).
  • Antiplatelet loading pre-cath prior to coronary or structural intervention.
• Labs: CBC, BMP, coags (PTT and INR).
• Consider isotonic IVF before, during and after procedure to reduce risk of contrast nephropathy.
  • Mehran score predicts risk of CIN and CIN requiring dialysis.
  • Patients without contraindications to volume expansion should receive pre and post hydration.
  • Outpatients: 3 mL/kg over 1 hr pre-procedure then 1-1.5 mL/kg/hr during and 4-6 hours post-procedure.
  • Inpatients: 1 mL/kg/hr for 6-12 hours pre-procedure, during procedure and for 6-12 hours post-procedure.
• Assess and document peripheral pulses: radial, femoral, DP and PT.

Post-cath Management

• Continue post-procedure fluids if indicated.
• Post-procedure ECG for patients receiving PCI.
• Consider CXR after RHC for IJ access to rule out pneumothorax.
• Discuss with interventional team the following management points:
  • Antiplatelet or anticoagulant plan.
  • Antibiotics (rarely indicated).
  • Access site care and activity restrictions. General rules as follows:

• Can shower after 24 hr but no soaking (bath, swimming) for 5 days.
• Avoid lifting >5 lbs. for at least 5 days, regardless of procedure type.

• Monitor for complications below.

Peri-procedural Complications

• Immediate (<24 hour):
  • Retroperitoneal bleed:
    • Typically seen with femoral arterial access, but can be spontaneous in any patient on anticoagulation.
    • Early presentation is tachycardia, and patients may also have abdominal or back pain. Hypotension is a late manifestation after significant blood loss has occurred.
    • If this diagnosis is considered, get stat CBC, type and cross match blood, PT/PTT, non-contrast CTAP and call vascular surgery and interventional team immediately.
    • Treatment is supportive with fluids, blood products, reversal of anticoagulation. Some may require intervention with balloon or covered stent to control bleeding.
  • Acute stent thrombosis:
    • Presents as ACS and diagnosed as such with ECG changes (review post-cath ECG).
    • Requires emergent revascularization.
  • Allergic reaction: often due to iodinated contrast or clopidogrel.
• Early (>24 hours to 1 week):
  • Stroke:
    • In the peri-procedural period, embolic stroke from disruption of plaque is more common than hemorrhagic, though the latter can occur in the setting of aggressive anticoagulation.
    • If concerned for stroke, activate code stroke and contact interventional team.
    • Reverse anticoagulation and discontinue antiplatelet therapy for hemorrhagic stroke.
  • Pseudoaneurysm:
    • Blood flow in and out of hematoma causes pulsatile mass with systolic bruit.
    • Diagnose with ultrasound.
    • Management may require ultrasound-guided compression or injection with thrombin/collagen, and if severe, surgical repair.
  • AV fistula:
    • Most commonly occurs after femoral access with thrill/bruit over site.
    • Diagnose with ultrasound.
    • Management: closure may be percutaneous or surgical.
  • Thrombocytopenia:
    • Consider both HIT and GP IIb/IIIa inhibitor-related.
    • Discuss management with interventional cardiology. Therapy will likely require discontinuing the offending agent and switching to different agent if ongoing antiplatelet therapy is warranted.
  • Contrast induced nephropathy:
    • Defined as 25% increase in Cr or ≥0.5mg/dL above baseline Cr within 48-72 hours of receiving contrast.
    • Care is supportive (avoid further contrast/nephrotoxins, close monitoring of fluid balance) and Cr usually returns to baseline within 7 days. 
• Late:
  • Deep vein thrombosis:
    • More common after prolonged manual holds in femoral artery.
    • Discuss anticoagulation plan with interventional team given potential need for concurrent antiplatelet.

• Late stent thrombosis:
  • Can occur >30 days and up to 1 year following the procedure. Risk factors include diabetes, off antiplatelet (P2Y12).
  • Presents with signs and symptoms of ACS with ischemic ECG; requires emergent revascularization.

Coronary Artery Anatomy

Normal coronary artery anatomy. A. Coronary angiogram showing the left circumflex (LCx) artery and its obtuse marginal (OM) branches. The left anterior descending (LAD) artery is also seen but may be foreshortened in this view. B. The LAD and its diagonal (D) branches are best seen in cranial views. In this angiogram, the left main (LM) coronary artery is also seen. C. The right coronary artery (RCA) gives off the posterior descending artery (PDA), so this is a right dominant circulation.