Εξελίξεις και νέες προοπτικές στην καρδιαγγειακή απεικόνιση CT Σταμάτης Κυρζόπουλος Ωνάσειο Καρδιοχειρουργικό Κέντρο
No conflict of interest to disclose
Noninvasive Cardiac Imaging Unresolved Issues-Future Directions Risk stratification in symptomatic and asymptomatic patients Algorithms-Appropriateness criteria-clinical management-cost-effectiveness in the multimodality era Proper combination of anatomy and function data Predicting vulnerable plaques-vulnerable patients Issues of training-accreditation-medical specialties interactions
CONFIRM
AIM-METHODS -Examines the prognostic significance of CCTA -24775 pts without known CAD (with typical or atypical chest pain), CCTA in 64 slice scanners. CAD severity was judged on a per patient, per vessel and per segment basis as follows: None (0%) Mild (0-49%) Moderate (50-69%) Severe (>70%) Pts were followed up for 2.3 years and time to death was primary end-point
Pts without any CAD had annualized death rate 0,28%, >4 years FU 0,22%
-Presence of any and extend of CAD assessed cy CCTA carries prognostic information -Absence of any CAD is related to very low risk of death -Pre-test likelihood of obstructive CAD was predictive of the presence of obstructive CAD but not of DEATH -Open label study-registry, effects to management have not been studied
Promise Trial CCTA fewer ICA showing no obstructive CAD (3,4% vs 4,3%, P=0,02) CCTA lower median cumulative radiation exposure (10 vs 11,3mSv)
-Reduction of ICAs with normal findings -Increase of preventive therapies -Increase in revascularization
CTA IN ACUTE CHEST PAIN - High negative predictive power - CT-STAT, AGRIN-PA, ROMICAT II, CT COMPARE and CATCH trials have shown significant reductions in length of stay, costs and safe discharge in low to intermediate risk pts - Increase in ICA and revascularizations -Triple rule out protocols
CTA IN ACUTE CHEST PAIN
Better long term prognosis
CTA IN ACUTE CHEST PAIN Guidelines
ACS proposed Algorithm
CTA IN ACUTE CHEST PAIN
All these data and the pathophysiology of CAD emphasize the need for combined anatomyfunction approaches, the most promising one being CTA derived FFR
FFR-CT Three principles: -Coronary supply meets myocardial demand at rest (ACS EXCLUDED) Total resting blood flow can be calculated relative to LV mass -Resistance of the microcirculation is inversely but not linearly proportional to the sixe of the epicardial vessel -Microcirculation reacts predictably to maximal hyperemic conditions In pts with normal coronary flow
DEFACTO Trial
CTA-FFR PLATFORM Trial
CT Perfusion Static or dynamic Single or dual energy
CT perfusion
TAG (Transluminal Attenuation Gradient)
CTA-FUNCTIONAL DATA
MSCT Assessment of coronary plaques Achenbach S.EHJ 2010;31;1442
MSCT Rationale -Detection of CAD at an earlier stage than functional imaging -Allows shift from stenosis to atherosclerosis imaging -Differentiation of mild coronary atheromatosis to normal coronaries (1,5% vs 0,7% annual event rates) -Ability to visualize vessel wall -Plaque burden-location -Plaque remodeling and composition Van Werkhoven J. J Nuclear Cardiology 2009;16: 970
MSCT -An increase in plaque burden is associated with increased risk for vulnerable plaques -Number of segments diseased, location and severity are associated with risk Van Werkhoven J. J Nuclear Cardiology 2009;16: 970
MSCT Plaque remodeling and composition - Several studies have shown that pts with ACS have more outward remodeling, noncalcified or mixed plaques (independent risk predictor) -No plaques 0 events -Atherosclerosis no high risk feature (0,49% event rate) -1 high risk feature (3,7% event rate) -2 high risk features (22,2% event rate) Van Werkhoven J. J Nuclear Cardiology 2009;16: 970
-No plaques 0 events -Atherosclerosis no high risk feature (0,49% event rate) -1 high risk feature (3,7% event rate) -2 high risk features (22,2% event rate)
MSCT-PLAQUE CHARACTERIZATION Differentiation Between Stable and Unstable Coronary Artery Culprit Plaques by 64-Slice CT Coronary Angiography Meijs MFL, Meijboom B, Cramer MJ, Kyrzopoulos S, Neoh, Prokop M, Doevendans PA, de Feyter PJ Am J Cardiol. 2009 104(3):305-11. Compared to SA patients, UA patients had larger plaques and more non-calcified plaques and less calcified plaques. In addition to the measurement of stenosis degree, CTCA may improve individual risk estimation by identifying plaque type and relative plaque CSA.
MSCT Limitations -Accuracy (compared to ivus) 95% and 94% for calcified and mixed plaques, but only 83% for noncalcified lesions -Significant overlap in attenuation values -Regarding plaque volume MSCT overestimates calcific plaques, and underestimates noncalcified and mixed plaques Van Werkhoven J. J Nuclear Cardiology 2009;16: 970
Novel Applications High definition CT scanner (in plane resolution of 0,23mm) Iterative reconstruction High pitch CT Dual source CT Second generation 320-detector row scanners Motion correction algorithms
Conclusions Future directions of non-invasive cardiac imaging will most likely involve: Improved risk stratification in symptomatic and asymptomatic patients Algorithms-Appropriateness criteria-clinical management-cost-effectiveness in the multimodality era Proper combination of anatomy and function data Predicting vulnerable plaques-vulnerable patients Issues of training-accreditation-medical specialties interactions