Chronic Total Occlusions Flashcards
(30 cards)
What is the association of CTO revascularization with a BMS compared to stenting of nonocclusive lesions?
Higher rates of restenosis and reocclusion
In the TOSCA-1 study, the rates of restenosis and reocclusion at 6-month follow-up were 55% and 11%, respectively.
Which group of patients derives the greatest relative improvement in ejection fraction (EF) following successful revascularization?
Patients with global LV dysfunction
Baseline LV dysfunction was an independent predictor of improvement in LV function.
What was the relative reduction in in-stent restenosis at 6-month follow-up when using sirolimus-eluting stents (SES) compared to BMS?
81% relative reduction
In the only randomized trial comparing SES and BMS, the rates were 36% vs. 7% (p < 0.0001).
True or False: Successful total occlusion revascularization is associated with an increased need for repeat revascularization.
False
Successful revascularization is associated with significant improvement in event-free survival from bypass surgery.
What is the most common mode of failure in total occlusion revascularization?
Inability to pass a guidewire across the occluded segment
Inability to cross the lesion occurred in 63% of cases in a study of 397 patients.
How does cardiac tamponade typically present following PCI?
Diagnosed on average of 4.4 hours post-procedure
Cardiac tamponade is associated with a high likelihood of in-hospital death and MI.
What factor has been related to recovery of impaired LV function after CTO revascularization?
Fibroblast growth factor expression
This factor is related to both the duration of occlusion and collateral function.
What is the success rate of crossing lesions using laser wire compared to conventional guidewires?
53% for laser wire vs. 47% for conventional wire
This was observed in a randomized trial comparing the two techniques.
Fill in the blank: Guidewires with a tapering tip diameter of _______ may facilitate wire engagement in microchannels of CTOs.
0.009 to 0.011 in.
These guidewires may penetrate occluded segments more easily.
Which angiographic appearance has been associated with an increased likelihood of procedural success?
Tapered occlusion
This is compared to a blunted appearance or presence of side branches at the occlusion site.
What does the hybrid algorithm for CTO revascularization assess?
Lesion length, proximal CTO cap ambiguity, distal vessel suitability, presence of collaterals
This algorithm improves procedural success and reduces contrast and radiation use.
What percentage of diagnostic coronary angiograms identify a CTO?
Approximately one-third
However, attempted percutaneous revascularization of a total occlusion accounts for less than 10% of all PCIs.
According to the National Heart, Lung, and Blood Dynamic Registry, where are CTOs most prevalent?
Right coronary artery (RCA)
CTOs are least common in the left circumflex artery (LCx).
What is a common cause of CTO development?
Thrombotic occlusion
Followed by thrombus organization and collagen deposition.
True or False: The extent of angiographic collateral flow predicts improvement in regional wall motion following successful revascularization.
False
Angiographic collateral flow does not predict improvement in wall motion or occurrence of restenosis.
What access method for CTO PCI has been associated with similar technical success compared to femoral access?
Radial artery access
This includes bilateral radial artery approaches.
What histological characteristic is common in approximately half of CTOs?
<99% stenotic despite thrombolysis in MI-0 flow
Inflammation is prevalent in the intima of CTOs, regardless of lesion age.
What percentage of patients with STEMI not treated with reperfusion therapy have an occluded infarct-related artery within 4 hours?
87%
This percentage decreases over time, with 65% within 12 to 24 hours.
What is the long-term mortality trend between failed and successful total occlusion revascularization?
Increased long-term mortality in failed attempts
Studies show consistently higher mortality among patients undergoing failed revascularization.
What was the target lesion failure rate over a median follow-up period of 5.1 years for patients undergoing CTO revascularization?
16.0%
This data is based on a survey of 406 patients with extensive stenting.
What were the predictors of target lesion failure identified in multivariable analysis?
- Number of stents implanted
- Persistent luminal narrowing
These predictors were identified despite the lesion complexity.
True or False: The presence of a CTO in a non-IRA is a weak predictor of 5-year mortality.
False
It is a strong and independent predictor, especially in high-risk patients.
What hazard ratio indicates the risk of mortality due to the presence of a CTO during the first 30 days following STEMI?
3.6
This hazard ratio was noted after adjusting for other factors.
In the retrospective analysis by Valenti et al., what was reported as a survival advantage?
Complete revascularization involving successful treatment of the CTO
This study involved 486 patients with MVD.
