Angiographic Applications for Modern Percutaneous Coronary Intervention

This thesis sought to explore contemporary applications of invasive coronary angiography in the era of advanced percutaneous coronary intervention. Firstly, it describes the development and validation of dedicated bifurcation quantitative coronary angiography algorithms, in order to facilitate their analysis in a harmonized, reliable and reproducible manner. Then it presents the use of bifurcation quantitative coronary angiography algorithms in clinical studies, in the context of large registries and randomized trials, and discusses the clinical relevance of angiographic measures. Finally, it explores the prognostic value of angiographic scoring sys

SYNTAX score and Clinical SYNTAX score as predictors of very long-term clinical outcomes in patients undergoing percutaneous coronary interventions: a substudy of SIRolimus-eluting stent compared with pacliTAXel-eluting stent for coronary revascularization (SIRTAX) trial

Aims To investigate the ability of SYNTAX score and Clinical SYNTAX score (CSS) to predict very long-term outcomes in an all-comers population receiving drug-eluting stents. Methods and results The SYNTAX score was retrospectively calculated in 848 patients enrolled in the SIRolimus-eluting stent compared with pacliTAXel-Eluting Stent for coronary revascularization (SIRTAX) trial. The CSS was calculated using age, and baseline left ventricular ejection fraction and creatinine clearance. A stratified post hoc comparison was performed for all-cause mortality, cardiac death, myocardial infarction (MI), ischaemia-driven target lesion revascularization (TLR), definite stent thrombosis, and major adverse cardiac events (MACE) at 1- and 5-year follow-up. Tertiles for SYNTAX score and CSS were defined as SSLOW ≤7, 714 and CSSLOW ≤8.0, 8.0 17.0, respectively. Major adverse cardiac events rates were significantly higher in SSHIGH compared with SSLOW at 1- and 5-year follow-up, which was also seen at 5 years for all-cause mortality, cardiac death, MI, and TLR. Stratifying outcomes across CSS tertiles confirmed and augmented these results. Within CSSHIGH, 5-year MACE increased with use of paclitaxel- compared with sirolimus-eluting stents (34.7 vs. 21.3%, P= 0.008). SYNTAX score and CSS were independent predictors of 5-year MACE; CSS was an independent predictor for 5-year mortality. Areas-under-the-curve for SYNTAX score and CSS for 5-year MACE were 0.61 (0.56-0.65) and 0.62 (0.57-0.67), for 5-year all-cause mortality 0.58 (0.51-0.65) and 0.66 (0.59-0.73) and for 5-year cardiac death 0.63 (0.54-0.72) and 0.72 (0.63-0.81), respectively. Conclusion SYNTAX score and to a greater extent CSS were able to stratify risk for very long-term adverse clinical outcomes in an all-comers population receiving drug-eluting stents. Predictive accuracy for 5-year all-cause mortality was improved using CSS. Trial Registration Number: NCT0029766

Reproducibility of computed tomography angiography data analysis using semiautomated plaque quantification software: Implications for the design of longitudinal studies

Reproducibility of the quantitative assessment of atherosclerosis by computed tomography coronary angiography (CTCA) is paramount for the design of longitudinal studies. The purpose of this study was to assess the inter- and intra-observer reproducibility using semiautomated CT plaque analysis software in symptomatic individuals. CTCA was performed in 10 symptomatic patients after percutaneous treatment of the culprit lesions and was repeated after 3 years. The plaque quantitative analysis was performed in untreated vessels with mild-tomoderate atherosclerosis and included geometrical and compositional characteristics using semiautomated CT plaque analysis software. A total of 945 matched crosssections from 21 segments were analyzed independently by a second reviewer to assess inter-observer variability; the first observer repeated all the analyses after 3 months to assess intra-observer variability. The observer variability was also compared to the absolute plaque changes detected over time. Agreement was evaluated by Bland-Altman analysis and co

A Global Risk Approach to Identify Patients With Left Main or 3-Vessel Disease Who Could Safely and Efficaciously Be Treated With Percutaneous Coronary Intervention The SYNTAX Trial at 3 Years

ObjectivesThe aim of this study was to assess the additional value of the Global Risk—a combination of the SYNTAX Score (SXscore) and additive EuroSCORE—in the identification of a low-risk population, who could safely and efficaciously be treated with coronary artery bypass graft surgery (CABG) or percutaneous coronary intervention (PCI).BackgroundPCI is increasingly acceptable in appropriately selected patients with left main stem or 3-vessel coronary artery disease.MethodsWithin the SYNTAX Trial (Synergy between PCI with TAXUS and Cardiac Surgery Trial), all-cause death and major adverse cardiac and cerebrovascular events (MACCE) were analyzed at 36 months in low (GRCLOW) to high Global Risk groups, with Kaplan-Meier, log-rank, and Cox regression analyses.ResultsWithin the randomized left main stem population (n = 701), comparisons between GRCLOW groups demonstrated a significantly lower mortality with PCI compared with CABG (CABG: 7.5%, PCI: 1.2%, hazard ratio [HR]: 0.16, 95% confidence interval [CI]: 0.03 to 0.70, p = 0.0054) and a trend toward reduced MACCE (CABG: 23.1%, PCI: 15.8%, HR: 0.64, 95% CI: 0.39 to 1.07, p = 0.088). Similar analyses within the randomized 3-vessel disease population (n = 1,088) demonstrated no statistically significant differences in mortality (CABG: 5.2%, PCI: 5.8%, HR: 1.14, 95% CI: 0.57 to 2.30, p = 0.71) or MACCE (CABG: 19.0%, PCI: 24.7%, HR: 1.35, 95% CI: 0.95 to 1.92, p = 0.10). Risk-model performance and reclassification analyses demonstrated that the EuroSCORE—with the added incremental benefit of the SXscore to form the Global Risk—enhanced the risk stratification of all PCI patients.ConclusionsIn comparison with the SXscore, the Global Risk, with a simple treatment algorithm, substantially enhances the identification of low-risk patients who could safely and efficaciously be treated with CABG or PCI

Quantitative multi-modality imaging analysis of a fully bioresorbable stent: a head-to-head comparison between QCA, IVUS and OCT

The bioresorbable vascular stent (BVS) is totally translucent and radiolucent, leading to challenges when using conventional invasive imaging modalities. Agreement between quantitative coronary angiography (QCA), intravascular ultrasound (IVUS) and optical coherence tomography (OCT) in the BVS is unknown. Forty five patients enrolled in the ABSORB cohort B1 study underwent coronary angiography, IVUS and OCT immediately post BVS implantation, and at 6 months. OCT estimated stent length accurately compared to nominal length (95% CI of the difference: −0.19; 0.37 and −0.15; 0.47 mm2 for baseline and 6 months, respectively), whereas QCA incurred consistent underestimation of the same magnitude at both time points (Pearson correlation = 0.806). IVUS yielded low accuracy (95% CI of the difference: 0.77; 3.74 and −1.15; 3.27 mm2 for baseline and 6 months, respectively), with several outliers and random variability test–retest. Minimal lumen area (MLA) decreased substantially between baseline and 6 months on QCA and OCT and only minimally on IVUS (95% CI: 0.11; 0.42). Agreement between the different imaging modalities is poor: worst agreement Videodensitometry-IVUS post-implantation (ICCa 0.289); best agreement IVUS-OCT at baseline (ICCa 0.767). All pairs deviated significantly from linearity (P < 0.01). Passing-Bablok non-parametric orthogonal regression showed constant and proportional bias between IVUS and OCT. OCT is the most accurate technique for measuring stent length, whilst QCA incurs systematic underestimation (foreshortening) and solid state IVUS incurs random error. Volumetric calculations using solid state IVUS are therefore not reliable. There is poor agreement for MLA estimation between all the imaging modalities studied, including IVUS-OCT, hence their values are not interchangeable

Atrial fibrillation in patients with hypertrophic cardiomyopathy: risk stratification with non-invasive techniques

Objective: Atrial fibrillation is the most common sustained arrhythmia in patients with hypertrophic cardiomyopathy (HCM). Chronic and paroxysmal atrial fibrillation (PAF) can prove equally detrimental. In a retrospective case-control study we investigated the potential of non-invasive risk stratification regarding development of PAF episodes in HCM patients.Methods: We enrolled 30 patients (17 males, mean age 57.9 ± 13.6 years) reporting at least one documented PAF episode together with 32 sex- and age-matched arrhythmia-free control patients, and 25 healthy volunteers, free of cardiovascular disease. Orthogonal electrocardiogram recordings were obtained and digitized, in order to study the duration as well as the mean and maximum energy of the P-wave after continuous wavelet transform using the Morlet mother wavelet. In addition, echocardiographic studies were performed to assess the left atrium and left ventricle according to the current standards; data were also acquired in pulsed-wave and colour Doppler myocardial imaging mode.Results: There was a pronounced left atrial enlargement in HCM-PAF patients; the antero-posterior diameter was significantly increased (46.1±5.9mm vs. 40.0±4.7mm, P<0.001), whereas maximal left atrial volume was also increased compared to control HCM patients, the difference however not reaching statistical significance (85.5±37.5ml vs. 67.1±34.6ml, P=0.07). Left atrial function was significantly reduced in HCM-PAF patients compared with the control patients. On one hand, the left atrial ejection fraction along with the left atrial emptying fraction showed a significant reduction (45.2±16.3% vs. 55.8±18.3%, P=0.03 and 28.1±13.8% vs. 38.5±18.1, P=0.02 respectively) in HCM-PAF patients. On the other hand, the values of the peak strain rate of the left atrium lateral wall were significantly decreased during the reservoir phase (1.93±0.51 sec-1 vs. 2.55±0.83sec-1, P<0.01). In addition, a significant prolongation of the P-wave duration in all 3 orthogonal leads was recorded in HCM-PAF patients compared with the control group; this finding was particularly pronounced along the Z axis (106.9±24.6msec vs. 86.2±14.3msec, P<0.001), and was independent of amiodarone administration. On the contrary, there was no significant difference in the mean/median values of the energy variables between patient groups. Following multivariable logistic regression, analysis resulted in an optimal model combining left atrial antero-posterior diameter, peak strain rate of the left atrium lateral wall during the reservoir phase and the P-wave duration on the Z axis. This model could identify the HCM-PAF patients among our study population with high sensitivity (0.87) and specificity (0.91); the model still holds after adjusting for amiodarone administration. At 4-year follow-up of our study population 6 out of 32 control patients developed AF, paroxysmal and/or chronic. Based on the original measurements, our model had a modest predictive power (area under the ROC curve equaled 0.65).Conclusions: Our findings demonstrate the feasibility of a non-invasive multimodality approach to assess the risk of PAF development in HCM patients, making the most of novel echo- and electrocardiographic techniques. Preemptive antiarrhythmic and anticoagulant treatment in HCM patients being at greater PAF risk according to our model may prevent adverse events due to the sudden loss of left atrial contractile function or a stroke.Στόχος: Η κολπική μαρμαρυγή αποτελεί τη συχνότερη εμμένουσα αρρυθμία σε ασθενείς με υπερτροφική μυοκαρδιοπάθεια (ΥΜΚ). Τόσο η χρόνια όσο και η παροξυσμική κολπική μαρμαρυγή (ΠΚΜ) μπορεί να αποβούν καταστροφικές για τον ασθενή. Στα πλαίσια μιας αναδρομικής μελέτης παρατήρησης μαρτύρων-ασθενών διερευνήσαμε τη δυνατότητα διαστρωμάτωσης κινδύνου με αναίμακτες τεχνικές για την ανάπτυξη επεισοδίων ΠΚΜ σε ασθενείς με ΥΜΚ.Μεθοδολογία: Μελετήθηκαν 30 ασθενείς (17 άνδρες, 57.9±13.6 έτη) με ένα τουλάχιστον τεκμηριωμένο επεισόδιο ΠΚΜ, 32 ασθενείς χωρίς ιστορικό κολπικής μαρμαρυγής (Ομάδα ελέγχου) σταθμισμένοι κατά ηλικία και φύλο προς τους ασθενείς της πρώτης ομάδας, και 25 άτομα με ιστορικό ελεύθερο καρδιαγγειακής νόσου (υγιείς μάρτυρες). Μελετήθηκαν το έπαρμα Ρ του ηλεκτροκαρδιογραφήματος κατόπιν ψηφιακής καταγραφής του σε τρεις ορθογώνιους άξονες και κυματιδιακού μετασχηματισμού με το κυματίδιο του Morlet, όπως επίσης ο αριστερός κόλπος και η αριστερά κοιλία της καρδιάς με τη χρήση συμβατικών και νεώτερων υπερηχοκαρδιογραφικών τεχνικών, κυρίως του ιστικού Doppler.Αποτελέσματα: Στους ασθενείς με επεισόδια ΠΚΜ παρατηρήθηκε σημαντική αύξηση της προσθιοπισθίας διαμέτρου του αριστερού κόλπου συγκριτικά με τους ασθενείς της Ομάδας ελέγχου (46.1±5.9mm έναντι 40.0±4.7mm, P<0.001). Ο μέγιστος όγκος του αριστερού κόλπου ήταν και αυτός αυξημένος, χωρίς ωστόσο στατιστικά σημαντική διαφορά (85.5±37.5ml έναντι 67.1±34.6ml, P=0.07). Η λειτουργικότητα του αριστερού κόλπου ήταν σημαντικά μειωμένη στους ασθενείς με επεισόδια ΠΚΜ. Αφ’ενός το κλάσμα εξώθησης του αριστερού κόλπου και το κλάσμα ενεργητικής κένωσης ήταν σημαντικά μειωμένα συγκριτικά με τους ασθενείς της Ομάδας ελέγχου (45.2±16.3% έναντι 55.8±18.3%, P=0.03 και 28.1±13.8% έναντι 38.5±18.1, P=0.02 αντίστοιχα), αφ’ετέρου και οι τιμές του ρυθμού παραμόρφωσης του κολπικού μυοκαρδίου ήταν σημαντικά μειωμένες στο πλάγιο τοίχωμα του αριστερού κόλπου κατά τη φάση της κολπικής πλήρωσης (1.93±0.51 sec-1 έναντι 2.55±0.83sec-1, P<0.01). Επίσης, στους ασθενείς με επεισόδια ΠΚΜ παρατηρήθηκε μια σημαντική παράταση της διάρκειας του επάρματος P και στους τρεις ορθογώνιους άξονες, ιδιαίτερα στον άξονα Ζ (106.9±24.6msec έναντι 86.2±14.3msec, P<0.001), η οποία ήταν ανεξάρτητη από τη χορήγηση αμιωδαρόνης σε μερίδα ασθενών. Αντίθετα, δεν υπήρχε σημαντική διαφορά στις μέσες/διάμεσες τιμές των ενεργειακών μεταβλητών μεταξύ των ασθενών των δύο ομάδων. Σε μελέτη πολυπαραγοντικής λογιστικής παλινδρόμησης ανεδείχθη ένα βέλτιστο μοντέλο το οποίο συνδύαζε την προσθιοπίσθια διάμετρο του αριστερού κόλπου, τη διάρκεια του επάρματος P στον άξονα Ζ και τον μέγιστο ρυθμό παραμόρφωσης στο πλάγιο τοίχωμα του αριστερού κόλπου κατά τη φάση της κολπικής πλήρωσης. Το μοντέλο αυτό διέκρινε με τον καλύτερο συνδυασμό ευαισθησίας (0.87) και ειδικότητας (0.91) τους ασθενείς με επεισόδια ΠΚΜ ανάμεσα στον συνολικό πληθυσμό των ασθενών της μελέτης, και ίσχυε και μετά τη διόρθωση για τη χορήγηση αμιωδαρόνης σε μερίδα ασθενών. Στην τετραετή προοπτική παρακολούθηση του πληθυσμού της μελέτης, 6 ασθενείς της Ομάδας ελέγχου εκδήλωσαν παροξυσμική ή/και χρόνια κολπική μαρμαρυγή. Χρησιμοποιώντας τις μετρήσεις από τις αρχικές καταγραφές επιβεβαιώθηκε ως ένα βαθμό η προγνωστική ισχύς του πολυπαραγοντικού μοντέλου (μέτρο επιφανείας 0.65 υπό την καμπύλη ROC).Συμπεράσματα: Τα ευρήματά μας καταδεικνύουν τη δυνατότητα μιας υβριδικής αναίμακτης εκτίμησης του κινδύνου εκδήλωσης ΠΚΜ σε ασθενείς με ΥΜΚ αξιοποιώντας τις σύγχρονες τεχνικές της υπερηχο- και ηλεκτροκαρδιογραφίας. Με την προληπτική έναρξη αντιαρρυθμικής και αντιπηκτικής αγωγής μπορούμε ενδεχομένως να περιορίσουμε τα ανεπιθύμητα συμβάματα που οφείλονται στην αιφνίδια απώλεια της κολπικής συστολής ή/και σε αγγειακό εγκεφαλικό επεισόδιο