Refining PCI: the role of physiology and intracoronary imaging
By: Prof. Jacek Legutko & Prof. Jun Jiang
Patient History
Male, 44-Year-old
Diabetes>3yrs
Chest distress for half month
Primary PCl to proximal and mid RCA NSTEMI
A1C 5.5%, Tn 0.019 ng/mL↑
Case challenges
1. 90% diffuse stenosis in the mid-segment of LAD, and 70% stenosis in D1. Should all vessels be treated?
2. If PCI is performed on any of the vessel, should all stenotic lesions be treated?
Techniques Used
1. Pre-PCI and Post-PCI FFR/cRR measurements with pullback assessment
2. Pre-PCI and Post-PCI IVUS examinations
3. Stenting
Key learnings
This case highlights:
1. The pullback curves from pressure microcathether clarifies the lesion type and reveals the greatest ΔP position, which facilitates the decision of procedural strategy.
2. The IV imaging plays a pivotal role in localization by precisely identifying the landing zone from the distal to proximal.
3. The co-registration intelligently displays the pullback pathway and streamlines the precise selection of the landing zone, progressing the precise choosing of the appropriate therapeutic devices.
4. The combination of the Physiology and IV Imaging Guided PCI improves the effectiveness of stent implantation, greatly contribute to enhance the long-term procedure’s outcomes.
Procedure
Pre-PCI
1. A 0.014” sion guidewire was delivered to the distal LAD and RCA do angiography examination.
LAD: middle LAD 90%DS,TIMI III.
D1: 70%DS, TIMI III.
LCX: Proximal LCX 30%DS, TIMI III.
RCA: no stenosis.
2. A TruePhysio Pressure microcatheter was advanced to the distal LAD.
cRR:0.68, resting Pd/Pa:0.76, FFR:0.55.
Using TruePhysio do the cRR pullback and FFR pullback
There are two obvious pressure gradients from FFR pullback cureve, ΔP: 24mmHg(mid-proximal) and ΔP:12 mmHg(distal-mid).
4. Using TrueVision and VivoHeart do the IVUS imaging examination with coregistration.
Diffuse Lesion in LAD.
D1 is unsuitable as the landing point, due to the abundance of attenuated plaques and the existence of several calcified plaques in this area.
Treatment Strategy:
Place 2 stents in LAD, one in the middle-distal of LAD, another in the proximal-middle of LAD.
Based on the 1st IVUS to decide the landing zone and the size of the stent in the mid-distal LAD.
After the placement of the first stent, do the 2nd IVUS to find the landing zone of the second stent.
Place semi-NC balloon in D1 for JBT.
Observe blood flow after PCI.
In PCI
1. Pre-dilation: using a 2.5x20mm NC balloon at 10-14atm in the proximal end of LAD.
2. 1st stenting: placed a 2.5x38mm at 12atm in the mid-distal of LAD.
3. IVUS examination:
Distal landing point: maximum diameter is 2.87mm and the minimum diameter is 2.40mm.
Landing zone length: 27.16mm.
4. 2nd stenting: placed a 3.0x28mm in the proximal-middle of LAD.
5. Pre-placed balloon: Placed a 1.5x15mm semi-NC balloon in D1 for JBT.
6. Stent dilation: expand the 3.0x28mm stent at 12atm.
7. Balloon dilation: expand the 1.5x15mm NC balloon at 12atm.
8. Post dilation:
Placed a 3.25x15mm NC balloon inside the stent at the proximal-middle of LAD.
Expand the balloon at 16atm
9. IVUS measurement in the distal landing zone:
Lumen: area:4.33 mm² , maximum diameter:2.44mm, minimum diameter:2.26mm;
Vessel: area 7.03 mm², maximum diameter:3.09mm, minimum diameter:2.87mm.
10. Post-dilation:using a 2.75x15mm NC balloon at 16-24atm inside the stent at the mid-distal of LAD.
Post PCI
1. IVUS with Insight Auxiliary marker
No area with plaque burden≥70%
No area with lumen area≤4.0 mm²
MLA is 4.48 mm²
2. Physiology measurement:
cRR:0.90; FFR:0.86
Post CAG
No stenosis
TIMI III
Summary:
Considering the large myocardial perfusion area supplied by LAD, prioritize physiology assessment of LAD to evaluate its blood flow condition.
Utilize the FFR/cRR pressure pullback curve to identify culprit lesions and reduce unnecessary interventions.
Utilize IVUS to accurately determine lesion length and select appropriate balloons and stents.