Case and Plan:
65-year old male with known long standing history of chronic ischemic heart disease requiring multiple PCI’s over the years after declining CABG, presented with CCS Class III angina and high risk stress MPI for multivessel ischemia. A Cardiac Cath on September 28, 2020 revealed 3 V CAD: 100% proximal RCA due to multilayer DES ISR (J-CTO Score = 3), 90% mid LAD, 80% LAD-D2, 95% small stent jailed LPL1, SYNTAX Score of 22 and normal LV systolic function. Patient underwent successful intervention of mid LAD and D2 using two (Xience Sierra) DES. Patient is now planned for staged PCI of RCA multilayer DES CTO ISR using rotational atherectomy and intravascular brachytherapy (IVBT) with OCT guidance for PCI optimization.
Q&A
Q
How many IBVT procedures are performed at your institution each year?
A.
We restarted our IVBT program in 2012 and procedures numbers have been increasing every year. Now we are performing approximately 100 IVBT procedures every year.
Q
In what percentage of these cases do you use atherectomy before IBVT?
A.
Almost 50% of the IVBT gets Atherectomy (majority Rotational) before the IVBT; especially cases of under expanded stents, long diffuse lesions and CTO ISR lesions.
Q
What is your anti-coagulant strategy for the procedure?
A.
All cases are done with either IV heparin keeping ACT around 300sec or IV Bivalirudin (in these cases we give additional 2000u of IV heparin just before inserting the IVBT catheter).
Q
Long term anti-platelet strategy?
A.
All IVBT pts get DAPT for 3 years and with this strategy along with not re-stenting with IVBT time, we have had 0 case of late stent thrombosis which has been described earlier.
Q
Any use of Cangrelor or Gp2b/3a therapy?
A.
Both IV Cangrelor or GP 2b/3a inhibitors are rarely used (<5%) if intraprocedural thrombosis is encountered.
Q
What is your restenosis rate for these patients treated with IBVT?
A.
We published in Circulation Intervention in 2018, that Restenosis after IVBT is 18-20% over 15mths period compared to 50-52% without IVBT in the case matched study.
Q
Is there any situation where you would use a new stent for a scheduled IBVT procedure?
A.
Our experience of over consecutive 600 IVBT cases has 0% incidence of re-stenting at the time of IVBT. This is the result of proper lesion preparation using atherectomy and atherotomy in majority of recurrent DES ISR before IVBT. Also there is no need to get the perfect angiographic results and residual 30-40% lesion is left many times hoping IVBT will freeze the results in time.
Q
What determines the dwell time?
A.
Both vessel size (most important) and lesion length determines the radiation dwell time. IVBT catheter comes in 40mm and 60mm length. Time usually varies from 3.5 minutes to 5.5 minutes.
Q
What steps do you take to prevent a geographic miss?
A.
Long radiation source (60mm) and at times stepping technique to cover the entire lesion with the radiation source, are most important to avoid the geographic miss; which is very important to avoid ‘candy wrapper’ effect of restenosis.
Q
100% use of adjunct imaging for these procedures?
A.
Presently we use imaging in about 40-50% of these IVBT cases but are in process of creating a imaging protocol for these pts. We then will perform imaging at baseline pre and post IVBT and, then at follow up if restenosis re-occurs. This will help us to understand the mechanism of IVBT failure in the future.
