Staged PCI
Synonyms and keywords: delayed PCI

# Overview
Staged PCI or delayed PCI is referred to the performance of a percutaneous coronary intervention (PCI) at a later date separate from the performance of the diagnostic catheterization or the performance of an initial PCI.  Ad hoc PCI is defined as performance of the PCI procedure immediately following diagnostic catheterization .  Same day PCI is defined as removing the patient from the cardiac catheterization laboratory following the procedure, and then performing the PCI procedure later in the day.  Databases usually do not allow a distinction between "Ad hoc PCI" and "Same day PCI".  As a result there is no data regarding the prevalence or the impact of same day PCI.

# Historical Perspective
When PCI was first developed, the risk of requiring urgent coronary artery bypass grafting (CABG) surgery was approximately 5%, and this necessitated the availability of onsite CABG.  AS PCI became safer and more predictable, it was more frequently performed immediately following the diagnostic cardiac catheterization ("ad hoc PCI").

# Advantages of Staged PCI
More detailed informed consent can be provided regarding the proposed revascularization procedure and the potential alternatives such as CABG.  Patients who are at risk of contrast induced acute tubular necrosis (patients over age 65, patients with diabetes, patients with impaired renal function), may benefit from a staged PCI procedure by minimizing the dye load required during two separate procedures.

## Risk Factors for Contrast Induced Nephropathy
Three factors have been associated with an increased risk of contrast-induced nephropathy: pre-existing renal insufficiency (such as Creatinine clearance < 60 mL/min  - online calculator), pre-existing diabetes, and reduced intravascular volume. A clinical prediction rule is available to estimate probability of nephropathy (increase 25% and/or 0.5 mg/dl in serum creatinine at 48 h) based upon the following risk factors:
- Systolic blood pressure <80 mm Hg - 5 points
- Intraarterial balloon pump - 5 points
- Congestive heart failure (Class III-IV or history of pulmonary edema)  - 5 points
- Age >75 y - 4 points
- Hematocrit level <39% for men and <35% for women - 3 points
- Diabetes - 3 points
- Contrast media volume - 1 point for each 100 mL
- Renal insufficiency:
Serum creatinine level >1.5 g/dL - 4 points OR
Estimated Glomerular filtration rate (online calculator)
- Serum creatinine level >1.5 g/dL - 4 points OR
- Estimated Glomerular filtration rate (online calculator)
- 2 for 4060 mL/min/1.73 m2
- 4 for 2040 mL/min/1.73 m2
- 6 for < 20 mL/min/1.73 m2

### Scoring:
5 or less points
- Risk of CIN - 7.5
- Risk of Dialysis - 0.04%
610 points
- Risk of CIN - 14.0
- Risk of Dialysis - 0.12%
1116 points
- Risk of CIN - 26.1*
- Risk of Dialysis - 1.09%
16 points
- Risk of CIN -  57.3
- Risk of Dialysis -  12.8%

# Disadvantages of Staged PCI
The disadvantages of staged PCI include the following:
- The patient must be instrumented twice with the attendant risk of bleeding and trauma to the vessel.
- The patient must return to the hospital for the procedure on a separate occasion which is inconvenient.
- A payor must pay for a separate procedure.

# Efficacy and Safety of Staged PCI
There are no randomized trials of staged versus ad hoc PCI and only registry data is available for comparison.  it should be noted that registry data does not adjust for unidentified confounders. There are seven registry is that compare ad hoc and staged PCI and there are no differences in the angiographic success rates either in the era of conventional balloon angioplasty  or in the era of stenting   In one registry experience, the rates of vascular complications were lower in the patients undergoing ad hoc PCI 

# Prevalence of Ad Hoc PCI
Ad hoc PCI is currently performed in approximately 60% to 96% of patients and the proportion of patients continues to increase.

# Guidelines Regarding Staged PCI
Performance of PCI in a non-culprit artery at the time of a ST elevation MI (STEMI) is a class III contraindication.  Only 2% of interventional cardiologist would perform a PCI in a non-culprit vessel in the setting of STEMI in a patient who is hemodynamically stable .  The need for and the timing of staged PCI among patients with unstable angina (UA) or non ST elevation MI (NSTEMI) and stable angina is less clear.

# Timing of a Staged PCI

## STEMI
1. In the setting of STEMI, ad hoc PCI of the culprit artery is recommended if the patient presents within 12 hours of symptoms.
2. 62% of interventional cardiologists recommend that the PCI of the non-culprit artery be performed more than 15 days after the STEMI .
3. Among STEMI patients with cardiogenic shock ad hoc PCI is appropriate. If the culprit lesion cannot be identified with certainty in the setting, then PCI of more than one lesion may be appropriate. Although PCI of a non-culprit lesion is inappropriate in the absence of cardiogenic shock and may be associated with worse outcomes, PCI of a non-culprit vessel may be appropriate if there is a flow limiting lesion and cardiogenic shock persists following PCI the culprit vessel.

## UA / NSTEMI
There is less of a consensus regarding the optimal timing of a staged PCI among UA / NSTEMI patients.  55% of surveyed cardiologists recommend waiting > 2 weeks following the initial revascularization to perform the next PCI, while 22% recommended that the additional PCI be performed during the same hospitalization as the initial revascularization.

## Stable Angina
Among patients with stable angina, 64% of surveyed cardiologist recommend waiting  15 days to perform the second PCI following the initial revascularization while 35% recommend performance of PCI within 2 weeks of the initial revascularization.

# Clinical Scenarios Favoring Delayed Percutaneous Coronary Intervention
In a SCAI consensus statement, the following scenarios may favor the performance of staged PCI:
The Appropriate Use Criteria  indicate that a PCI should not be performed if a patient does not have severe symptoms, if they have not undergone prior functional testing to confirm ischemia, or if they are not on optimal medical therapy.  Furthermore the Appropriate Use Criteria indicate that either intravascular ultrasound (IVUS) or fractional flow reserve (FFR) can be used as substitutes for noninvasive testing if it was not performed prior to angiography to evaluate the functional significance of the target lesion.  Although the appropriate use pretreated does not discuss the timing of procedures, it stands to reason that if the appropriateness of a procedures is uncertain then the procedure should be delayed until the indications are clarified. 

# Clinical Scenarios Favoring Ad Hoc PCI
1. The presence of an Acute Coronary Syndrome(ACS). 
2.The Aprpriate Use Criteria do not explicitly discuss the timing of PCI.  Patients with ongoing ischemia, and those with stable moderate/severe angina who are managed with optimal medical therapy (OMT) are deemed suitable candidates for PCI.