Repeat Catheterization After Incomplete Initial Assessment
When coronary blockages cannot be adequately determined during the initial catheterization, proceeding with repeat catheterization the next day is appropriate and supported by guideline recommendations, particularly in high-risk patients with ongoing ischemia or hemodynamic instability. 1
Immediate Repeat Catheterization is Indicated When:
Persistent angina or ongoing ischemic symptoms are present – Patients with very high ischemic risk (persistent angina, hemodynamic instability, refractory arrhythmias) should immediately be referred back to the catheterization laboratory 1
Hemodynamic instability exists – This represents a very high-risk situation requiring urgent invasive assessment 1
Technical complications occurred during the first procedure (e.g., thrombotic complication, catheter thrombosis) that prevented complete visualization 1
Failed reperfusion or reocclusion is suspected – Coronary angiography with intent to perform revascularization should be performed as soon as logistically feasible 1
Anticoagulation Management for Next-Day Repeat Procedure:
The golden rule is to continue the initial anticoagulation therapy and avoid switching between antithrombins (with the exception of adding UFH to fondaparinux). 1
Specific Anticoagulation Protocols:
If UFH was used initially: Continue infusion with activated clotting time measurement (target 200-250 seconds with GPIIb-IIIa inhibitors; 250-350 seconds without) 1
If enoxaparin was used:
- Less than 8 hours since last subcutaneous dose: no additional bolus needed
- Within 8-12 hours: add 0.30 mg/kg IV bolus
- Greater than 12 hours: give 0.75 mg/kg IV bolus 1
If bivalirudin was used: Add 0.5 mg/kg IV bolus and increase infusion to 1.75 mg/kg/h before the procedure 1
If fondaparinux was used: Add UFH 50-100 IU/kg when catheterization is performed (to prevent catheter thrombosis) 1
Timing Considerations:
For medium-to-high ischemic risk patients, an invasive strategy should be planned within 24-48 hours. 1 The ISAR-COOL trial demonstrated that immediate invasive strategy (median 2.4 hours) resulted in significantly better outcomes compared to delayed catheterization (median 86 hours), with primary endpoints occurring in 5.9% versus 11.6% of patients (P=0.04). 1
Avoid very early repeat catheterization (<2-3 hours) if fibrinolytic therapy was recently administered, as this increases bleeding risk. This timing restriction should only be bypassed for rescue PCI in cases of failed fibrinolysis with significant myocardial jeopardy. 1
Common Pitfalls to Avoid:
Do not switch anticoagulation regimens between procedures – this significantly increases bleeding complications 1
Formally assess and document bleeding risk before the repeat procedure, adjusting antithrombotic doses based on weight and renal function 1
Ensure adequate visualization capability – if complex anatomy (e.g., pulmonary atresia, anomalous coronaries) prevented complete assessment, confirm that appropriate imaging equipment and expertise are available for the repeat procedure 1