Cristiano Guedes Bezerra

Improving Cardiac Phase Extraction in IVUS Studies by Integration of Gating Methods

Goal: Coronary intravascular ultrasound (IVUS) is a fundamental imaging technique for atherosclerotic plaque assessment. However, volume-based data retrieved from IVUS studies can be misleading due to the artifacts generated by the cardiac motion, hindering diagnostic, and visualization of the vessel condition. Then, we propose an image-based gating method that improves the performance of the preexisting methods, delivering a gating in an appropriate time for clinical practice. Methods: We propose a fully automatic method to synergically integrate motion signals from different gating methods to improve the cardiac phase estimation. Additionally, we present a local extrema identification method that provides a more accurate extraction of a cardiac phase and, also, a scheme for multiple phase extraction mandatory for elastography-type studies. Results: A comparison with three state-of-the-art methods is performed over 61 in-vivo IVUS studies including a wide range of physiological situations. The results show that the proposed strategy offers: 1) a more accurate cardiac phase extraction; 2) a lower frame oversampling and/or omission in the extracted phase data (error of 1.492 ± 0.977 heartbeats per study, mean ± SD); 3) a more accurate and robust heartbeat period detection with a Bland-Altman coefficient of reproducibility (RPC) of 0.23 s, while the second closest method presents an RPC of 0.36 s. Significance: The integration of motion signals performed by our method shown an improvement of the gating accuracy and reliability.

Dissecção Espontânea de Artéria Coronária: Abordagem Terapêutica e Desfechos de Uma Série Consecutiva de Casos

Background: Spontaneous coronary artery dissection is a rare cause of acute coronary syndrome and diagnosis is made by necropsy in more than 70% of the cases. Optimal treatment is still uncertain, and the treatment options are percutaneous coronary intervention, coronary artery bypass surgery and medical therapy. The objective of this study was to evaluate the clinical characteristics, treatment modalities and outcome of a series of cases with spontaneous coronary artery dissection. Methods: Retrospective, single-center study, based on the analysis of the database at a high-complexity cardiology service. Results: We identified 25 patients with spontaneous coronary artery dissection, 56% were female, with a mean age of 48.8 ± 10 years. Only 24% had no risk factor for atherosclerosis and in 92% of the cases, the clinical presentation was of acute coronary syndrome. The left anterior descending artery was the most commonly affected vessel (48,1%) and there was only one case involving multiple vessels. The conservative approach was used in 56%, percutaneous coronary intervention in 40% and coronary artery bypass grafting in 4%. The in-hospital and late event-free survival was 92% and 84.2%, respectively. Conclusions: Spontaneous coronary artery dissection predominated in young women, with at least one risk factor for coronary artery disease. The choice of different therapeutic strategies confirms the still controversial nature of the optimal approach for spontaneous coronary artery dissection. We believe that individualized therapy is still the optimal modality.

On the search of arterial geometry heritability

BACKGROUND Geometrical risk factors for CAD have been previously proposed before. To date, however, the effect of those factors is not conclusive, and remains as an open research field. Here, we hypothesize that some of these factors have a genetic component explaining inter-individual variability. OBJECTIVE To detect heritability indicators of the coronary arterial geometry. MATERIALS AND METHODS A patient sample of 48 individuals, consisting of 24 siblings, was used. Three dimensional geometry of the LAD, LCx and RCA were reconstructed from standard CCTA. Arterial models were characterized in terms of 20+ geometric descriptors (phenotypes). A comprehensive statistical analysis to detect potential heritability of such phenotypes was employed. Heritability was assessed by means of several statistical indexes. Finally, the association of phenotypes to stenotic lesion is also reported. RESULTS The RCA scored positive indications for heritability in 15+ phenotypes, while the LAD in 10 and the LCx in only 3 phenotypes. Association between presence of lesion and phenotypes was higher in the LAD, 10+ phenotypes, while for the LCx only 2 phenotypes were significantly associated, and none association was found for the RCA. CONCLUSION The RCA showed potential heritability for the largest number of phenotypes, followed by the LAD. The LCx presents the weaker association of morphology among siblings. Regarding lesion-geometry associations, the there are hints of an underlying relation in the LAD, the LCx featured a weaker association and the RCA showed none. This difference could be related to the different hemodynamic environments in these arteries.

Aortic Counterpulsation Therapy in Patients with Advanced Heart Failure: Analysis of the TBRIDGE Registry

Background The use of aortic counterpulsation therapy in advanced heart failure is controversial. Objectives To evaluate the hemodynamic and metabolic effects of intra-aortic balloon pump (IABP) and its impact on 30-day mortality in patients with heart failure. Methods Historical prospective, unicentric study to evaluate all patients treated with IABP betwen August/2008 and July/2013, included in an institutional registry named TBRIDGE (The Brazilian Registry of Intra-aortic balloon pump in Decompensated heart failure - Global Evaluation). We analyzed changes in oxygen central venous saturation (ScvO2), arterial lactate, and use of vasoactive drugs at 48 hours after IABP insertion. The 30-day mortality was estimated by the Kaplan-Meier method and diferences in subgroups were evaluated by the Log-rank test. Results A total of 223 patients (mean age 49 ± 14 years) were included. Mean left ventricle ejection fraction was 24 ± 10%, and 30% of patients had Chagas disease. Compared with pre-IABP insertion, we observed an increase in ScvO2 (50.5% vs. 65.5%, p < 0.001) and use of nitroprusside (33.6% vs. 47.5%, p < 0.001), and a decrease in lactate levels (31.4 vs. 16.7 mg/dL, p < 0.001) and use of vasopressors (36.3% vs. 25.6%, p = 0.003) after IABP insertion. Thirty-day survival was 69%, with lower mortality in Chagas disease patients compared without the disease (p = 0.008). Conclusion After 48 hours of use, IABP promoted changes in the use of vasoactive drugs, improved tissue perfusion. Chagas etiology was associated with lower 30-day mortality. Aortic counterpulsation therapy is an effective method of circulatory support for patients waiting for heart transplantation.

Thermodynamic analogies for the characterization of 3D human coronary arteries

Abstract The thermodynamics of three-dimensional curves is explored through numerical simulations, providing room for a broader range of applications. Such approach, which makes use of elements of information theory, enables the processing of parametric as well as non-parametric data distributed along the curves. Descriptors inspired in thermodynamic concepts are derived to characterize such three-dimensional curves. The methodology is applied to characterize a sample of 48 human coronary arterial trees and compared with standard geometric descriptors. As an application, the usefulness of the thermodynamic descriptors is tested by assessing statistical associations between arterial shape and diseases. The feature space defined by arterial descriptors is analyzed using multivariate kernel density classification methods. A two-tailed U -test with 95% confidence interval showed that some of the proposed thermodynamic descriptors have different mean values for healthy/diseased left anterior descending (LAD) and left circumflex (LCx) arteries. Specifically: in the LAD, the temperatures based on mean number of intersection points and curvature are larger in healthy arteries ( p p p

TCT-573 Head-to-head comparison between coronary computed tomography angiography (CCTA) and intravascular ultrasound (IVUS) tridimensional models: a geometric point of view

Tridimensional reconstruction of the coronary arteries have played a major role in the understanding of the onset and progression of atherosclerotic plaque, plaque rupture and its hemodynamics repercussion. Our aim is to validate an automated algorithm that allows obtaining tridimensional model from

TCT-535 Coronary computed tomography angiography (CCTA) blood flow model, how we can improve it? Insights based on comparison with intravascular ultrasound (IVUS) tridimensional model.

RESULTS For deferred lesions, the risk of MACE had significant inverse relationship with FFR (adjusted hazard ratio [aHR], 1.06; 95% confidence interval [CI], 1.05 1.08; P<0.001). However, this relationship was not observed in revascularized lesions (aHR, 1.00; 95% CI, 0.99 1.02; P1⁄40.69). For lesions with FFR of 0.76, the risk of MACE was not significantly different between deferred and revascularized lesions. Conversely, in lesions with FFR of 0.75, the risk of MACE was significantly lower in revascularized lesions than in the deferred lesions (for FFR 0.71 0.75, aHR, 0.47; 95% CI, 0.24 0.89; P1⁄40.021, and for FFR 0.70, aHR 0.47; 95% CI, 0.26 0.84; P1⁄40.012).

Eficácia do Balão Farmacológico no Tratamento de Reestenose Intra-Stent em Óstio da Artéria Descendente Anterior

Percutaneous coronary intervention with drug-eluting balloons has emerged as an adjunctive strategy in the setting of Interventional Cardiology. When compared to drug-eluting stents, drug-eluting balloons offer advantages such as immediate and homogeneous drug release in the arterial wall, absence of polymers that can induce chronic inflammatory reactions, and the potential for using dual antiplatelet therapy for a shorter period of time. Furthermore, in some situations, additional stenting is not desirable, which turns this modality into an interesting option. We report the case of a patient with acute coronary syndrome in whom this intervention was chosen to treat an ostial left anterior descending artery in-stent restenosis.

Valvuloplastia aórtica por cateter balão na estenose aórtica degenerativa: impacto terapêutico em pacientes em condição clínica in extremis

INTRODUCAO: A valvuloplastia aortica por cateter balao (VAB) e utilizada como estrategia paliativa em pacientes inelegiveis tanto para troca valvar cirurgica quanto para implante valvar aortico transcateter, ou como ponte para essas modalidades de tratamento. Nao se sabe o impacto terapeutico da VAB quando realizada como medida de salvamento para pacientes em condicoes clinicas extremas (in extremis). METODOS: Foram analisados pacientes com estenose aortica grave de etiologia degenerativa submetidos a VAB entre julho de 2008 e janeiro de 2013. Os pacientes foram divididos entre o grupo in extremis (definido pela presenca de duas ou mais das seguintes disfuncoes orgânicas: ventilacao mecânica, instabilidade hemodinâmica, terapia renal dialitica, coagulopatia ou disfuncao hepatica graves) e o grupo controle, que incluiu os demais pacientes. RESULTADOS: Um total de 19 pacientes realizaram VAB no periodo. A condicao clinica in extremis esteve presente em 42,1%. Os pacientes do grupo in extremis tiveram EUROSCORE II mais elevado (41,1 ± 24,7 vs. 15,9 ± 14,0; P = 0,01) e fracao de ejecao do VE mais baixa que o grupo controle (33,9 ± 17,3% vs. 49,0 ± 12,5%; P = 0,04). Nenhum paciente do grupo in extremis sobreviveu ao periodo intra-hospitalar, enquanto que, no grupo controle, a mortalidade foi de 27,3% (P < 0,01). CONCLUSOES: Para o tratamento de pacientes com estenose aortica grave de etiologia degenerativa, a VAB tem resultado desfavoravel quando indicada para pacientes com duas ou mais disfuncoes orgânicas, ou seja, em condicao clinica in extremis.

Influência da Localização das Lesões nos Desfechos Clínicos Tardios após Intervenção Coronária Percutânea em Enxertos de Veia Safena

BACKGROUND: Little is known about the late clinical outcomes of patients undergoing saphenous vein graft percutaneous coronary intervention (SVG-PCI), and there are controversies regarding the role of lesion location (aorto-ostial or graft body). METHODS: Single-center registry including patients undergoing SVG-PCI between 2006 and 2011. Aorto-ostial lesion was defined as a lesion within the first 8 mm of the graft; graft body lesion was defined as a lesion located in the remaining portions of the graft. Interventions approaching only the distal anastomosis or the native coronary bed were excluded. We evaluated the rates of major adverse cardiac events (MACE), death, myocardial infarction (MI), and target vessel revascularization (TVR) between the groups. RESULTS: One hundred and ninety-five patients were evaluated, 69 in the Aorto-Ostial Group and 126 in the Graft Body Group. Mean age was 69.6 ± 10.2 years, 41% were diabetic, 65.1% had acute coronary syndromes and most of them were treated with bare metal stents (82.5%). There was no statistical difference between groups for most of the characteristics evaluated. In the late follow-up, the TVR rate (50.8% vs. 22%; P = 0.03) was greater in the Aorto-Ostial Group. The MACE rate (67.7% vs. 63.3%; P = 0.33), death (31.7% vs. 35.6%; P = 0.95) and MI (55% vs. 42%; P = 0.64) were similar between the two groups. CONCLUSIONS: This population included a high-risk subgroup, with high late mortality rates, regardless of the location of the lesion in the graft. In patients treated predominantly by bare-metal stents, aorto-ostial lesions had a higher reintervention rate when compared to graft body lesions.