Resolution of leaflet thrombosis under anticoagulant therapy in patients after transcatheter aortic valve implantation: influence of prosthesis type and size

Introduction

Leaflet thrombosis can frequently be identified by computed tomography angiography (CTA) in patients after transcatheter aortic valve implantation (TAVI). Oral anticoagulation is assumed to lead to resolution of thrombosis. We analyzed the resolution of leaflet thrombosis after TAVI by anticoagulant therapy in serial CTA and assessed the influence of prosthesis type.

Methods

Consecutive TAVI patients who underwent CTA follow-up were screened and individuals with leaflet thrombosis on CTA (defined by the presence of hypo-attenuated leaflet thickening, HALT) in whom oral anticoagulation was initiated and who underwent follow-up CTA were included. The type of anticoagulation was according to physicians' discretion. We assessed the resolution of HALT and compared patients with and without resolution of HALT regarding prosthesis type, prosthesis diameter and type of anticoagulation.

Results

Out of 395 patients screened for participation, 36 patients (mean age 80±7, 67% men) with leaflet thrombosis underwent follow-up CTA at a medial interval of 3 months (IQR: 3; 5.75 months) after anticoagulation was initiated. 36 patients received either vitamin-K antagonists (n=28, 78%) or Factor-Xa Inhibitors (n=8, 22%). A total of 22 (61%) balloon-expandable and 14 (39%) self-expandable transcatheter aortic valves were implanted. Nominal prosthesis diameter was 23, 25, 26, 27 and 29 mm in 7 (19%), 1 (3%), 10 (28%), 7 (19%) and 11 (31%) patients, respectively. 30 patients (83%) with anticoagulation showed resolution of HALT, whereas persistent HALT was detected in 6 patients (17%), of whom 1 patient with balloon-expandable and 5 patients with self-expandable valve. No difference was seen in duration of anticoagulation between patients with and without resolution of HALT (p=0.984). In univariate analysis, prosthesis type (balloon-expandable vs. self-expandable valves) showed a significant association of self-expandable valves with lack of resolution of leaflet thrombosis (p=0.017). In multivariable logistic regression analysis, this association persisted (p=0.043) and was independent of the type of anticoagulation (p=0.660) and prosthesis diameter (p=0.942).

Conclusion

Persisting leaflet thrombosis despite anticoagulation is not infrequent and seems to be associated with prosthesis-type rather than small valve diameter or type of anticoagulation. Further research is necessary to identify structural aortic valve determinants for this finding.

Funding Acknowledgement

Type of funding source: None

Comparison of fractional flow reserve and instantaneous wave-free ratio for the hemodynamic assessment of jailed side branches in bifurcation stenting

Background

Provisional side-branch stenting strategy is one of the preferred strategies for treatment of bifurcation lesions. Whereas using fraction flow reserve (FFR) for the physiologic assessment of jailed side branches is well studied, the reliability of resting indices such as instantaneous wave free ratio (iFR) is unknown.

Methods

Consecutive patients with provisional stenting of a bifurcation and a jailed side branch were enrolled in this study. FFR and iFR were measured and, after assuring absence of baseline shift and drift, both measurements were repeated after 3 minutes. Hyperemia was induced by intra-coronary adenosine with a dose of 48μg for the right coronary artery and 96μg for the left coronary artery. Cut-off for the assumed functional significance of a stenosis was 0.80 for FFR and 0.89 for iFR. The decision to treat the side branch was left to the interventionalist's discretion.

Results

37 jailed side branches in 36 patients (age 68.4±8.2; male 81% (n=29)) were consecutively enrolled in the study. The main vessel was the left main in 3% (n=1), the left anterior descending (LAD) in 65% (n=24), the diagonal branch (D1) in 3% (n=1), the left circumflex artery (LCX) in 24% (n=9) and the right coronary artery (RCA) in 5% (n=2). The Medina classification revealed true bifurcation stenosis defined as Medina 1–1-1 prior to treatment in 35% (n=13).

FFR showed 35% (n=13) of the stenosis to be functionally significant with a high reproducibility of the results (r=0.986). FFR showed a low correlation with angiographic assessment (r=−0.477). iFR indicated hemodynamic relevance in 38% of lesions (n=14) with a high reproducibility (r=0.967) and also correlated poorly with angiographic assessment (r=−0.271). iFR was found to closely correlate with FFR in jailed side branches (r=0.720, Figure 1A). Bland-Altman analysis showed iFR and FFR agreed with a mean difference between FFR and iFR of −0.054±0.146. In 81% (n=30) FFR and iFR showed the same results regarding functional significance. In 8% (n=3) FFR was ≤0.80 and iFR >0.89, in 11% (n=4) FFR was >0.80 and iFR was ≤0.89 (Figure 1B).

Side branch treatment was performed in 32% (n=12). All of these lesions showed functional significance in FFR or iFR. Stent implantation was performed in 8% (n=3), balloon angioplasty in 19% (n=7) and balloon angioplasty with a drug-eluting balloon in 5% (n=2).

Conclusions

The results of this study confirm the poor correlation of angiographic and functional assessment of coronary artery stenoses. Our data show close agreement of iFR and FFR in stent-jailed side branches. Therefore, iFR can be considered as a reliable technique for guidance of provisional side branch stenting.

Figure 1

Funding Acknowledgement

Type of funding source: None

The association of pericoronary adipose tissue attenuation with major adverse cardiac events (MACE) and atherosclerosis-relevant inflammatory mediators

Background

Increased attenuation of pericoronary adipose tissue (PCAT) around the right coronary artery (RCA) is a new imaging biomarker to detect coronary inflammation derived from routine coronary CT angiography (CTA).

Purpose

We aimed to investigate a potential association between RCA PCAT attenuation and i) serum levels of atherosclerosis-relevant cytokines, ii) different grades of coronary calcification iii) future coronary revascularization within the same coronary artery and iV) MACE (defined by revascularization, myocardial infarction (MI) and/or cardiac death).

Methods

In 293 stable individuals (59.0±9.8 years, 69% males) with intermediate likelihood for coronary artery disease (CAD) blood was drawn and subsequently analyzed for different atherosclerosis-relevant cytokines interleukin (IL)-2, IL- 4, IL-6, IL-7, IL-8, IL-10, IL-13, Il-15, IL-17, TNF-a, IP-10, CRP, MCP-1, MIP-1a, Eotaxin and GM-CSF, followed by coronary calcium scoring (CCS) in non-contrast CT followed by CTA. PCAT CT attenuation (HU) was measured around the RCA (10 to 50 mm from RCA ostium) and the proximal 40 mm of the left anterior descending artery (LAD) and the circumflex artery (LCX) using semi-automated software. Increased RCA PCAT attenuation was defined as PCAT attenuation above the highest quartile (>−73.5 HU). A long-term follow-up over 9.6 years was performed.

Results

PCAT attenuation was similar in different grades of coronary calcification (CAC=0,-80.3 HU; CAC 1–99, −79.2 HU; CAC 100–400, −79.5 HU; CAC >400, −81.0 HU; p>0.05). Adipocytokine MCP-1 (r=0.23, p<0.01) and pro-inflammatory mediator IL-7 (r=0.12, p=0.04) correlated positively with RCA PCAT attenuation, whereas anti-inflammatory mediators Il-4, -10 and -13 correlated inversely (each r<−0.12, each p<0.05). In patients with increased RCA PCAT attenuation the serum levels of MCP-1 were increased (2.37 vs. 2.20, p<0.01), whereas anti-inflammatory mediators IL-4 and -13 were reduced (each p<0.05). 40 patients experienced MACE during follow-up. In multivariable Cox regression analysis, when adjusted by age, gender, baseline medications, obstructive coronary stenosis and CCS, the highest quartiles of PCAT attenuation are an independent predictor of MACE (HR 7.9, p=0.035). In patients with percutaneous coronary intervention (PCI) of the RCA during follow-up, RCA PCAT attenuation was increased at baseline CTA (−73.1 vs −80.2 HU, p=0.008). In patients with PCI of the LAD or LCX during follow-up, PCAT attenuation of LAD and LCX were not increased at baseline CTA (p>0.05).

Conclusions

The information captured by PCAT attenuation is independent of coronary calcification and showed a trend towards a weak association with serum levels of atherosclerosis-relevant inflammatory biomarkers. Increased RCA PCAT attenuation is an independent predictor of MACE and could guide future prevention strategies in stable patients.

Funding Acknowledgement

Type of funding source: None

Early single center experience with a novel transcatheter anuloplasty system for the treatment of functional tricuspid regurgitation

Background

Functional tricuspid regurgitation (TR) is increasingly recognized as relevant, but undertreated clinical entity. Since surgical repair or replacement of the tricuspid valve is associated with high mortality, many patients with with severe tricuspid regurgitation are not referred to surgery. Transcatheter anuloplasty is a new interventional treatment option for tricuspid regurgitation. We report the outcome of a consecutive single-center series of 11 patients treated with this technique.

Methods

Clinical and procedural data as well as mid-term outcome of a series comprising 11 consecutive patients (9 female, mean age 80±5 years, mean LV-EF 53±7, mean PAP 27±4 mmHg) who underwent transcatheter tricuspid anuloplasty for secondary tricuspid regurgitation in a 12-month period (Octover 2018–October 2019) were systematically collected, including pre- and post-procedural transthoracic/transesophageal echocardiogryphy (TTE/TEE). Patients were selected for the procedure based on clinical, echocardiographic and CT findings. All patients were treated using the Cardioband® system (Hersteller, Ort) in general anesthesia under 4D-TEE guidance.

Results

Mean procedural duration was 259±46 min across all 11 patients. Device success was 91%. In one patient extensive tricuspid annular excursions prevented anuloplasty band implantation. The mean grade of TR severity was reduced from 3.5 to 2.1, p=0,00016 (vena contracta decreased from 11±4 to 6±3 mm, p=0,0047).73% of all patients achieved pos-procedure TR severity ≤2. Procedural complications were infrequent: one patient required coronary stent implantation to the RCA kinking and in an further patient, transient 3rd degree AV bock occurred during the procedure. No patient died during the index hospital stay or during the follow up period (median follow up of 4 months). The NYHA classification improved from a median of III before the procedure to a median of II at follow-up (p=0,00022).

Conclusion

Transcatheter tricuspid annuloplasty permits effective treatment of functional tricuspid regurgitation with a low complication rate and sustained symptomatic improvement.

Funding Acknowledgement

Type of funding source: None

Influence of lesion location on the accuracy of CT derived FFR: head-to-head comparison with invasive FFR

Background

The accuracy of CT-derived FFR (FFRCT) has been repeatedly reported. However, the influence of lesion location on accuracy is unknown. Therefore, we evaluated the diagnostic accuracy of FFRCT to detect lesion-specific ischemia and determined the influence of lesion location (proximal vs. distal vessel segments) compared to invasively measured FFR in patients with suspected CAD.

Methods

A total of 136 vessels in which “Dual-Source”-CT coronary angiography had been performed due to suspected CAD and who were further referred for invasive coronary angiography with invasive FFR measurement within three months of the index CT examination were retrospectively identified and screened for inclusion in this analysis. Patients with either left main coronary artery stenoses, bifurcation or ostial stenoses were excluded. Invasive FFR was measured using a pressure wire (CERTUS®, St. Jude Medical, Minnesota, USA or Verrata®, Volcano, San Diego, USA). FFRCT was calculated using an on-site prototype (cFFR Version 3.0, Siemens Healthineers, Forchheim, Germany). All vessels were analyzed by an experienced observer blinded to the results of invasive FFR. Stenoses with invasively measured FFR ≤0.80 were classified as hemodynamically significant. We evaluated the diagnostic accuracy of FFRCT in proximal vs. non-proximal vessel segments. Proximal lesions included stenoses located in segment one, six, eleven and twelve. All other stenoses were categorized as distal lesions.

Results

Out of 136 coronary stenoses, 47 (35%) were located in proximal segments and 89 (65%) lesions were located in distal segments. Compared to invasive FFR, the sensitivity of FFRCT to correctly identify/exclude hemodynamically significant stenoses in proximal vessel segments was 93% (95% CI: 68–99.8%) and the specificity was 100% (95% CI: 89–100%), compared to a sensitivity of 72% (95% CI: 46.5–90%) and a specificity of 87% (95% CI: 77–94%) for FFRCT in distal lesions. The positive predictive value was 100% and the negative predictive value was 97% (95% CI: 82.8–99.5%) compared to a positive predictive value of 59% (95% CI: 42–93.9%) and a negative predictive value of 93% (95% CI: 85.4–96.3%) for proximal vs. distal vessel segment, respectively. This corresponds to an accuracy of 98% vs. 84%, respectively (p=0.02). ROC-Curve analysis showed a slightly higher – albeit non-significant – area under the curve for FFRCT to detect hemodynamic relevance in proximal lesions compared to distal lesions (AUC 0.95, p<0.001 vs. AUC: 0.86, p<0.001, respectively, p=0.2).

Conclusion

FFRCT obtained using an on-site prototype shows overall a high diagnostic accuracy for detecting lesions causing ischemia as compared to invasive FFR with a trend towards better diagnostic performance in proximal vessel segments.

Funding Acknowledgement

Type of funding source: None

Changes of tricuspid valve geometry after interventional implantation of an anuloplasty band

Background

Implantation of an anuloplasty band (Cardioband, Edwards Lifesciences) is a new treatment option for patients with functional tricuspid regurgitation (TR). The initial clinical results are promising. Nevertheless very few details about the mechanism of reducing TR beyond the basic principle of reducing the annular perimeter are known. Therefore we sought to study the changes of the tricuspid valve geometry after Cardioband implantation.

Methods

In all patients, that were treated by Cardioband implantation for tricuspid valve implantation at our institution, fluoroscopic images of the implant were optained at an angle, which would correspond to an echocardiographic “enface” view of the tricuspid valve. In these images the area enclosed by the implant, the perimeter of this area, the septal to lateral diameter, the anterior to posterior diameter and the length of the implant before and after contracting the band was measured. In all patients an echocardiographic evaluation of the tricuspid regurgitation before and after cardioband implantation was performed. These clinical finding were correlated to changes of the above mentioned dimension in the fluoroscopic images.

Results

Between October 2018 und January 2019 17 patients with severe tricuspid regurgitation were treated by Cardioband implantation. In one patient the procedure had to be aborted due to extensive movement of the tricuspid annulus. In the remaining 16 patients (mean age 78±8 years, 7 males) the procedure could be completed successfully and the required measurements were done. The mean severity grade (5 grade scale) of the TR was 3.5±0.6 before and 2±0.7 (p<0.0001) after the implantation, the corresponding mean vena contracta changed from 12±4 mm to 6±3 mm (p<0.000, 51% reduction). The area decreased after band contraction from 10.6±1.4 cm2 to 4.7±1.4 cm2 (p<0.0001; 56% reduction), the perimeter from 13.4±1.8 cm to 9.6±1.6 cm (p<0.0001; 28% reduction) the septal to lateral diameter from 2.8±0.5 cm to 1.6±0.2 cm (p<0.0001; 40% reduction), the anterior to posterior diameter from 4.8±0.9 cm to 3.8±1.0 cm (p<0.005; 19% reduction) and the measured device length from 8.6 cm±1.0 to 5.8±0.8 cm (p<0.0001; 32% reduction). The strongest correlation was seen between area reduction and reduction of the vena contracta (r=0.5), reduction of the septal to lateral dimension as well as the reduction of the device length had a weaker correlation (r=0.3 and r=0.2). The reduction of the anterior posterior diameter and perimeter reduction showed no relevant correlation with regard to TR reduction.

Conclusion

In our patient population Cardioband implantation lead to effective TR reduction. Area reduction and reduction of the septal to lateral diameter of the tricuspid valve seem to have the strongest impact. These findings may be considered when implantations techniques are being optimized or when new devices for TR treatment are developed.

Funding Acknowledgement

Type of funding source: None

P3376Software-based automated CT analysis for planning TAVI-Procedures: Systematic validation against expert and novice human interpretation

Introduction

Cardiac computed tomography (CT) is an established modality for planning TAVI procedures.

We validated CT parameters measured by automated software analysis and by newly trained readers against expert readers.

Methods

Consecutive patients with symptomatic severe aortic valve stenosis referred for CT assessment of the aortic root prior to TAVI were included in this analysis. Measurements were performed manually by an expert reader, a newly trained reader as well as semi-automatically using a commercially available workstation. Manual measurements were performed as per clinical standard. For semi-automatic analysis, CT data sets were exported to a dedicated workstation with fully automated detection of the aortic annulus plane.

Results

Out of 159 consecutive patients, 146 patients were included in this analysis (83+10 years). The median annulus area for expert reader, newly trained reader and software measurement was 468 mm2, 511 mm2 and 513 mm2, respectively (p=0.28) whereas the mean annulus diameter showed a mean±SD of 25.6±2 mm, 25.5±2 mm and 25.6±2 mm, respectively, p=0.47. Agreement between expert and newly trained reader for annulus area was good with Bland-Altman analysis showing a systematic overestimation of the annulus area for the newly trained reader of 16 mm2 (95% limits of agreement 42 to −74 mm2) and for automatic software of 20 mm2 (95% limits of agreement 60 to −99 mm2). Assuming an annulus area-based recommendation for a balloon-expandable Sapien 3 prosthesis (23, 26 or 29 mm prosthesis), kappa statistics revealed moderate agreement between expert measurement, newly trained reader and software measurement (κ 0.60 for newly trained reader, κ 0.58 for software measurement, p<0.0001 for all). The time needed for annulus adjustment measurement for the newly trained reader compared to software measurement was 2±0.6 minutes vs. 1±0.5 minutes, respectively, p<0.0001). The software correctly identified the annulus plane without reader correction in 49% of cases and in 51% of cases manual correction of the cusp insertion point or annular tracing had to be performed. Agreement between expert predicted angulation and software predicted angulation was excellent in 55%, good in 29% vs. 31%, moderate in 11% vs. 6% and fair in 5% vs. 8% for LAO/RAO orientation, CAU/CRA orientation, respectively (assuming excellent agreement when difference: <5°, good agreement: 5–10°, moderate agreement: 10–15° and fair agreement: >15°).

Conclusion

Novice human interpretation manually and with semi-automatic assessment of the aortic root for planning TAVI procedures is feasible with good agreement with expert measurement for annulus dimensions and prediction of implantation angles, however with a trend for systematic overestimation of the annulus area. For semi-automatic assessment, reader correction of cusp insertion point and annular dimensions have to corrected for in 50% of cases

5963Automated quantification of epicardial adipose tissue from non-contrast CT on multi-center and multi-vendor data using deep learning

Background

Epicardial adipose tissue (EAT), a metabolically active visceral fat depot surrounding the coronary arteries, has been shown to promote the development of atherosclerosis in underlying coronary vasculature.

Purpose

We evaluate the performance of deep learning (DL), a sub-group of machine learning algorithms, for robust and fully automated quantification of EAT on multi-center cardiac CT data.

Methods

In this study, 850 non-contrast calcium scoring CT scans, from multiple cohorts, scanners and protocols, with manual measurements of EAT from 3 different readers were considered. The DL method was based on a convolutional neural network trained to reproduce the expert measurement. DL global performance was first assessed using all the scans, and then compared to inter-observer variability on a subset of 141 scans. Finally, automated EAT progression was compared to manual measurement using baseline and follow-up serial scans available for 70 subjects. The proposed model was validated using 10-fold cross validation.

Results

Automated quantification was performed in 1.57±0.49 seconds compared to 15 minutes for manual measurement. DL provided high agreement with expert manual quantification for all scans (R=0.974, p<0.001) with no significant bias (0.53 cm3, p=0.13). EAT volume was higher in patients with hypertension (+18.02 cm3, p<0.001, N=442), with diabetes (+18.33 cm3, p<0.001, N=75) and with hypercholesterolemia (+7.33 cm3, p=0.039, N=508). Manual EAT volumes measured by two experienced readers on 141 scans were highly correlated (R=0.984, p<0.001) but presented a significant difference of 4.35 cm3 (p<0.001). On these 141 scans, DL quantifications were highly correlated to both experts' measurements (R=0.973, p<0.001; R=0.979, p<0.001) with significant and non-significant bias for readers 1 and 2 (5.19 cm3, p<0.001; 0.84 cm3, p=0.26), respectively. In 70 subjects, EAT progression quantified by DL correlated strongly with EAT progression measured by the expert reader (R=0.905, p<0.001) with no significant bias (0.64 cm3, p=0.43), and was related to increased non-calcified plaque burden quantified from coronary CT angiography (5.7% vs 1.8%, p=0.026).

Automated vs. manual EAT volume

Conclusion

Deep learning allows rapid, robust and fully automated quantification of EAT from calcium scoring CT. It performs as an expert reader and can be implemented for routine cardiovascular risk assessment.

Acknowledgement/Funding

1R01HL133616/01EX1012B/Adelson Medical Research Foundation

3258Perivascular fat attenuation index stratifies the cardiac risk associated with high-risk plaque features on coronary computed tomography angiography

Background

Qualitative high-risk plaque (HRP) features detected on coronary computed tomography angiography (CCTA) are associated with increased risk of adverse cardiac events. Coronary inflammation is a key determinant of plaque progression and instability and can now be captured on routine CCTA as inflammation-induced changes in perivascular adipose tissue composition, detectable by the perivascular Fat Attenuation Index (FAI).

Purpose

To explore the ability of perivascular FAI phenotyping to stratify the cardiac risk associated with the presence of adverse plaque morphology on routine CCTA.

Methods

This was a post-hoc analysis of the CRISP-CT (Cardiovascular RISk Prediction using Computed Tomography) study, which involved 3912 patients (mean age 55.7±13.7 years, 41.1% females) undergoing clinically-indicated CCTA in two centres (Erlangen, Germany & Cleveland, USA). Perivascular FAI mapping was performed around the proximal 10–50 mm of the right coronary artery and defined as the weighted mean attenuation of the perivascular adipose tissue, as previously validated. HRP features were defined as the presence of ≥1 of the following: positive remodelling, low-attenuation plaque, spotty calcification or napkin-ring sign (A). Cox regression models (adjusted for age, sex, epicardial fat volume and coronary artery disease [≥50% stenosis]) were used to explore the association between FAI, HRP, and future major adverse cardiac events (MACE: defined as the composite of cardiac mortality and non-fatal myocardial infarction).

Results

At baseline the prevalence of HRP and high FAI (≥-70.1 Hounsfield Units, as previously validated) was 23.6% (n=923) and 24.3% (n=952) respectively. Over a median follow-up period of 5.6 years (25th-75th percentile: 4.0–7.0 years) there were 91 confirmed MACE. Patients with both HRP features (HRP+) and high FAI (FAI+) had a 6.3-fold (P<0.001) higher adjusted risk of MACE compared to individuals with neither of these risk features (HRP-/FAI-) (B). Furthermore, patients without HRP features but with high FAI (HRP-/FAI+) had a 4.9-fold (P<0.001) higher adjusted risk of MACE compared to the reference (HRP-/FAI-) group. However, among patients with low FAI, there was no significant difference in the prospective risk of MACE between HRP+ and HRP- patients (P=0.87).

Conclusion

FAI is associated with an increased risk of adverse events in both patients with and without high-risk plaques, highlighting coronary inflammation as a major determinant of plaque vulnerability, independent of adverse plaque morphology. Non-invasive characterization of coronary inflammation using CCTA-derived FAI can improve risk stratification by supplementing the traditional anatomical assessment of the coronary vasculature with a functional marker of disease activity.

Acknowledgement/Funding

British Heart Foundation, National Institute of Health Research, Oxford Biomedical Research Centre

6114Indications, procedural parameters, complications and consequences of fractional flow reserve measurements in a multicenter cohort

Background

Determination of the Fractional Flow Reserve (FFR) has become part of routine clinical practice. Contemporary clinical use, consequences as well as complications in consecutive, large cohorts have not been thoroughly investigated. We report the results of the prospective Fractional Flow Reserve Fax Registry F (FR2) conducted in Germany.

Purpose

To systematically analyze indications, procedural parameters, complications and consequences of intracoronary pressure measurements in a large contemporary cohort.

Methods

Data of 2000 consecutive patients undergoing clinically indicated FFR, iFR or pd/pa measurements in 8 interventional centres in Germany were prospectively collected in a systematic fashion. Data included basic patient characteristics, procedural aspects of intracoronary pressure measurements, associated complications, visual stenosis degree, measurement results and treatment decisions.

Results

Mean patient age was 68±11 years, 73% of patients were male. Of all patients, 300 patients (15%) had an acute coronary syndrome (STEMI: 9; NSTEMI: 94; unstable angina: 197) and 1002 patients (50%) had undergone previous revascularization. A mean of 1.7±0.9 measurements were performed per patient, for which an average of 1.02 pressure wires were required (more than 1 wire in 64 patients). For all 3373 interrogated lesions, median stenosis degree was 60%. Vasodilator-free measurements were performed in 415/3373 cases (12%, iFR: 346; pd/pa: 69). For vasodilation, i.v. adenosine was used in 396 cases (13%), i.c. adenosine in 2628 cases (87%), and other drugs in 10 cases (0.3%). Measurement was performed before potential revascularization in 3232 cases (96%) and during or following PCI in 141 cases. In 2958 lesions analyzed by FFR, mean FFR was 0.87, with 588 FFR measurements ≤0.80 (19.8%). Median FFR values were higher for i.c than i.v. adenosine administration (0.88 vs. 0.84), but not significantly different after adjustment for stenosis degree. In 735 cases (20.2%), intracoronary pressure measurement was followed by revascularization measures, while in 2637 cases (79.8%), no revascularization or no further revascularization was performed. In 36 out of 117 stenoses visually estimated to be ≥90%, revascularization was deferred following pressure measurement (31%). In 75 out of 2958 lesions analyzed by FFR, revascularization was performed even though FFR was >0.80 (3%). Severe complications (vessel dissection or occlusion) occurred in 5 out of 2000 patients as a consequence of intracoronary pressure measurement, resulting in death of 1 patient.

Conclusion

In clinical practice, the majority of intracoronary pressure measurements are performed in stenoses of intermediate angiographic severity and revascularization is deferred in approximately 80% of lesions. Vasodilator-free measurements are infrequent and route of adenosine administration has no effect on results. Complication rate is low but not negligible.

Acknowledgement/Funding

Abbott Vascular

P6164High level of EPA is associated with lower perivascular coronary attenuation as measured by coronary CTA

Introduction

Pericoronary adipose tissue (PCAT) composition has been recently shown to be a potential novel marker of coronary inflammation with higher PCAT attenuation shown to indicate increased cardiac mortality. Polyunsaturated fatty acids (PUFAs), especially Omega-3 fatty acids (n3), are thought to alter inflammatory response and intake of high dose Eicosapentaenoic acid (EPA, C20_5 n3) was shown to decrease mortality, however exact pathophysiological mechanisms are unclear. Therefore, we sought to determine whether blood levels of PUFAs are associated with differences in pericoronary fat attenuation.

Methods

In 64 symptomatic patients with intermediate pretest-likelihood for coronary artery disease presenting with atypical angina, coronary CTA was performed. PCAT attenuation was measured in Hounsfield Units (HU) around the proximal 40mm of the right coronary artery (RCA) using semi-automated software. Erythrocyte membrane fatty acid composition (in percentage) was analyzed with a standardized analytical methodology, displaying a variety of fatty acids including n-3 fatty acids using gas chromatography.

Results

Patients were divided into two groups (each n=32) using the median PCAT attenuation of −78.1 Hounsfield units (HU), resulting in one group with low (−95.58 to −78.17 HU) and one with high (−78.06 to −62.92 HU) PCAT attenuation. Among both groups, no differences were seen in age, sex, BMI, traditional cardiovascular risk factors or the number of cardiovascular risk factors (all p>0.05). In univariate analysis, significantly higher values of EPA (1.00% [0.78; 1.26] vs. 0.78% [0.63; 0.99]; p=0.02) were seen in patients with lower PCAT attenuation. All other fatty acids showed no significant differences (all p>0.05). Moreover, a significant negative correlation was seen between PCAT attenuation and EPA (Pearson correlation coefficient −0.38; p=0.002), but not for age, sex, BMI or number of cardiovascular risk factors (all p>0.1). Multivariable linear regression analysis confirmed this association and showed a significant inverse association of EPA to PCAT attenuation (β=−0.31, p=0.017), independent of age, gender, BMI and number of CV risk factors (all p>0.1).

Conclusion

High levels of EPA are associated with lower PCAT attenuation on coronary CTA indicating different composition of pericoronary adipose tissue potentially caused by a lesser degree of coronary inflammation.

P815Tako-Tsubo Cardiomyopathy: clinical correlations of typical and atypical left ventricular contraction patterns

Background

Takotsubo cardiomyopathy (TCM) is diagnosed in 1–2% of all patients presenting with acute coronary syndrome (ACS). Clinical differences in individuals presenting with either the typical (apical) or atypical (midventricular, basal and focal) localization of left ventricular contraction abnormalities are not well understood.

Methods

We retrospectively analyzed 102 consecutive patients diagnosed with TCM based on clinical presentation, coronary angiography, and laevocardiography. Patients with different contraction abnormality patterns were compared regarding sex, clinical presentation, trigger for TCM, LV-function and LV enddiastolic pressure (LVEDP) as well as coronary artery disease.

Results

Of all TCM 102 patients, 69 (68%) presented with the typical pattern of apical contraction abnormality. 33 patients (32%) had an atypical pattern: 22 (22%) with the midventricular type, 2 (2%) with the basal type and 9 (9%) with a focal type. There was no difference in sex distribution among the different types of TCM (female: typical 86% vs atypical 85% p=0.83).

Presentation as a ST-elevation ACS was more common in patients with atypical compared to typical TCM (21% vs. 17%; p=0.85), but without statistical significance. Cardiogenic shock (typical 6% vs atypical 3%; p=0.91) as well as intra-hospital death (typical 3% vs atypical 3%; p=0.56) were rare in both types.

A trigger was not more common in patients with typical TCM (58% vs atypical 55%; p=0.91). The trigger was more often physical in typical (73%) and atypical TCM (78%) than psychological, but the distribution did not differ between the two types (p=0.92).

83.6% of the patients showed an impaired LV-EF. Median LV-EF in patients with typical TCM (35% (IQR 25–40)) tended to be lower than in patients with atypical TCM (40% (IQR 25–40); p=0.63; LV-EF ≤30% typical TCM 45% vs. atypical TCM 39%; p=0.75). In 72% (73/102) of the patients the LVEDP was determined. In 75% (55/73) the LVEDP was elevated (>15mmHg). LVEDP tended to be more often elevated in patients with typical TCM (83% vs. atypical 52%; p=0.11).

Extent of coronary artery disease did not differ in the different types of TCM. Coronary stenosis >50% was rare (typical TCM 20% vs atypical TCM 9%; p=0.26), whereas exclusion of coronary artery disease was common in both types (typical TCM 71%; atypical TCM 76%; p=0.79).

Conclusion

While an apical contraction anomaly is the most common type of presentation in TCM, atypical contraction patterns are found in 32% of the patients. Overall, psychological triggers are not found as frequently in TCM as previously described. Patients with typical and atypical TCM do not differ in clinical presentation, LV-EF, LVEDP and extent of coronary artery disease.

CT-derived left ventricular global strain: a head-to-head comparison with speckle tracking echocardiography

We assessed CT-derived left ventricular strain in a cohort of patients referred for transcatheter aortic valve implantation (TAVI) and validated it against 2 dimensional speckle tracking echocardiography as the gold standard. 65 consecutive patients with symptomatic aortic valve stenosis referred for CT imaging prior to TAVI were included in this analysis. For all patients, retrospectively ECG-gated multi-phase functional CT data sets acquired with identical reconstruction parameters were available. All data sets were acquired using a third generation dual source system. In all patients, multiphase reconstructions in increments of 10% of the cardiac cycle were rendered (slice thickness 0.75, increment 0.5 mm, medium smooth reconstruction kernel) and transferred to a dedicated workstation (Ziostation2, Ziosoft Inc., Tokyo, Japan). Additional functional reconstructions for dynamic assessment and quantification of strain were processed. Multiplanar reconstructions (MPR) of the left ventricle similar to standard echocardiographic 4, 2 and apical 3 chamber views were rendered in CT. Similar to echocardiographic longitudinal strain, the perimeter of the left ventricle was manually traced within the myocardium and peak maximal shortening as a parameter representing longitudinal strain was calculated for each view and averaged to obtain a marker for global longitudinal strain (CT perimeter-derived strain). Furthermore, for quantification of 3-dimensional strain, endocardial and epicardial borders of myocardium were marked in six short axis views and peak maximum 3- dimensional strain of the myocardium was calculated in standard six basal, six mid and four apical segments. 3-dimensional strain values of the 16 standard segments as well as perimeter-derived strain values in the three standard windows were averaged to obtain global strain. Echocardiography was performed in all patients before CT data acquisition. Digital loops were acquired from three apical views (four-, two-, and three chamber views). For assessment of 2 dimensional global longitudinal strain (GLS), recordings were processed with acoustic-tracking software allowing offline semiautomated speckle-based strain analyses. The mean age of all 65 patients was 81 ± 5 years. The mean echocardiographic ejection fraction and mean echocardiographic GLS were 50 ± 12% and -13.6 ± 4.5%, respectively. The mean CT-derived peak 3-dimensional global strain and mean peak strain derived by perimeter was 43.2 ± 13.5% and -11.2 ± 3.5%, respectively. Both CTderived global 3D-strain and perimeter derived strain showed a significant correlation to GLS derived by echocardiography (r = -0.8, p < 0.0001 for 3D strain and r = 0.71, p < 0.0001 for perimeter-derived strain). Bland-Altman analysis showed a systematic underestimation (i. e. worse strain values) of CT perimeter-derived strain compared to GLS by echocardiography (mean difference -2.4% with 95% limits of agreement between 4% to -9%). ROC Curve analysis assuming a normal GLS when less than -18% showed that a CT-derived peak 3-dimensional global strain cut-off-value of 45% has a sensitivity of 91% and a specificity of 60% for detecting normal left ventricular strain (AUC 0.81, p = 0.001). For CT perimeter-derived strain, a cut-off value of -12%-assuming a normal echocardiographic GLS when less than -18%-achieved a sensitivity of 82% and a specificity of 61% (AUC of 0.82, p = 0.001) for detecting abnormal left ventricular strain. Using dedicated software, assessment of CT-derived left ventricular strain is feasible and comparable to strain derived by echocardiographic 2 dimensional speckle tracking.

Leaflet thrombosis following transcatheter aortic valve implantation

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is increasingly being offered to high-risk patients with symptomatic aortic valve stenosis. Recent reports have suggested a high incidence of subclinical leaflet thrombosis following bioprosthestic aortic valve replacement. We report the frequency and clinical presentation of leaflet thrombosis identified by cardiac CT in patients referred for follow-up contrast enhanced CT angiography following TAVI.

METHODS

91 consecutive patients referred for follow-up contrast-enhanced CT angiography following TAVI were screened for inclusion in this analysis. Out of these, 13 patients were excluded. All CT examinations were performed using a 2nd or a 3rd generation dual-source system (Somatom Definition Flash/Force, Forchheim, Germany). In all patients, retrospectively ECG-gated spiral acquisition with tube modulation was performed to allow for assessment of leaflet motion. All prostheses were analyzed for presence of leaflet thrombosis defined as hypo-attenuated leaflet thickening with or without leaflet restriction. Post-procedural antithrombotic regimen as well as symptom status was documented in all patients.

RESULTS

78 consecutive patients (35 males, 81 ± 4 years) were analyzed. TAVI had been performed in all patients (76 transfemoral access, 2 transapical access) with either balloon-expandable prostheses (4 Sapien XT, 64 Sapien 3) or self-expandable prostheses (5 SJM Portico, 5 Symetis Acurate). Follow-up CT angiography was performed at a median of 4 months following index procedure (Interquartile range 1 month). Leaflet thrombosis was detected in 18 patients (23%, 14 Sapien 3, 1 Sapien XT, 2 SJM Portico, 1 Symetis Acurate). In patients with leaflet thickening on CT, only 11% were on either oral anticoagulation or new oral anticoagulants versus 50% for patients with no leaflet thickening (p 0.002). In patients with leaflet thrombosis, 3 leaflets were affected in 5 patients, 2 leaflets in 5 patients and in 8 patient only 1 leaflet was affected. Clinical symptoms (angina, dyspnea or both) were reported in 2/18 patients with leaflet thrombosis (11%) and in both patients a significant increase of the mean echocardiographic gradient over the prosthesis was documented. The peak and mean echocardiographic gradients obtained at the day of CT examination was significantly higher in symptomatic patients versus asymptomatic patients (peak 46 ± 7 vs. 23 ± 11 mmHg, mean 29 ± 7 vs. 12 ± 6 mmHg, p = 0.01 and 0.002, respectively). Follow-up CT was available for 4 patients with complete resolution of the hypo-attenuated leaflet thickening following treatment.

CONCLUSION

Leaflet thrombosis following TAVI is a relatively frequent finding in patients referred for contrast enhanced CT angiography following TAVI. In the majority of patients it follows a subclinical course and is substantially more frequent in individuals who are not on oral anticoagulation. However, in patients with relevant increase in prosthetic gradients, symptomatic presentations are possible.

Recurrent shock and pulmonary edema due to acetazolamide medication after cataract surgery

OBJECTIVE

We report a patient with recurrent shock and transient non-cardiogenic pulmonary edema within a period of two months - every time occurring after cataract surgery and a single oral dose of standard post-operative medication with acetazolamide.

DATA SOURCES

Records of the intensive care unit, review of the literature.

CONCLUSIONS

This case demonstrates a rare but severe side effect of acetazolamide. We also present a review of the literature to raise the awareness of health care providers for this special form of non-cardiogenic pulmonary edema.