Resumo Fundamento: Faltam dados prospectivos sobre as associações de adiponectina com medidas in-vivo de grau, fenótipo e vulnerabilidade da aterosclerose coronariana. Objetivo: Investigar a associação da adiponectina plasmática com medidas de aterosclerose derivadas de ultrassonografia virtual intravascular (VH-IVUS) e eventos cardíacos adversos importantes (major adverse cardiac events - MACE) em pacientes com doença arterial coronariana estabelecida. Métodos: Em 2008-2011, a VH-IVUS de um segmento coronariano não estenótico não culpado foi realizado em 581 pacientes submetidos à angiografia coronariana para síndrome coronariana aguda (SCA, n = 318) ou angina pectoris estável (APE, n = 263) a partir do estudo de ultrassonografia aterosclerótica-intravascular (ATHEROREMO-IVUS). Sangue foi amostrado antes da angiografia coronária. Foram avaliados a carga de placa coronária, a composição tecidual, as lesões de alto risco, incluindo fibroateroma de capa fina (FCF) derivado de VH-IVUS. Mortalidade por todas as causas, SCA, e revascularização coronária não planejada foram registradas durante um ano de acompanhamento. Todos os testes estatísticos foram bicaudais e os valores de p < 0,05 foram considerados estatisticamente significativos. Resultados: Na coorte completa, os níveis de adiponectina não foram associados à carga de placa, nem a vários tipos de tecido virtual histológico. Entre os pacientes com APE, os níveis de adiponectina (mediana[IIQ]: 2,9(1,9-3,9) µg/mL) foram associados positivamente às lesões FCF derivadas de VH-IVUS, (OR[IC 95%]: 1,78[1,06-3,00], p = 0,030), e inversamente associados a lesões com área luminal mínima (ALM) ≤4,0 mm2 (OR[IC 95%]: 0,55[0,32-0,92], p = 0,025). Em pacientes com SCA, os níveis de adiponectina (mediana[IIQ]: 2,9 [1,8-4,1] µg/mL) não foram associados à carga de placa nem a componentes teciduais. A associação positive de adiponectina ao óbito esteve presente na coorte completa (HR[IC 95%]: 2,52[1,02-6,23], p = 0,045) e (limítrofe) em pacientes com APE (HR[IC 95%]: 8,48[0,92-78,0], p = 0,058). Entre pacientes com SCA, essa associação perdeu significância estatística após ajuste multivariado (HR[IC 95%]: 1,87[0,67-5,19], p = 0,23). Conclusão: Na coorte completa, os níveis de adiponectina foram associados à obito, mas não a medidas de aterosclerose por VH-IVUS. Em pacientes com APE, os níveis de adiponectina foram associados a lesões FCF derivadas de VH-IVUS. Em geral, o papel da adiponectina na vulnerabilidade da placa permanece não confirmado.

Abstract Background: Prospective data on the associations of adiponectin with in-vivo measurements of degree, phenotype and vulnerability of coronary atherosclerosis are currently lacking. Objective: To investigate the association of plasma adiponectin with virtual histology intravascular ultrasound (VH-IVUS)-derived measures of atherosclerosis and with major adverse cardiac events (MACE) in patients with established coronary artery disease. Methods: In 2008-2011, VH-IVUS of a non-culprit non-stenotic coronary segment was performed in 581 patients undergoing coronary angiography for acute coronary syndrome (ACS, n = 318) or stable angina pectoris (SAP, n = 263) from the atherosclerosis-intravascular ultrasound (ATHEROREMO-IVUS) study. Blood was sampled prior to coronary angiography. Coronary plaque burden, tissue composition, high-risk lesions, including VH-IVUS-derived thin-cap fibroatheroma (TCFA), were assessed. All-cause mortality, ACS, unplanned coronary revascularization were registered during a 1-year-follow-up. All statistical tests were two-tailed and p-values < 0.05 were considered statistically significant. Results: In the full cohort, adiponectin levels were not associated with plaque burden, nor with the various VH-tissue types. In SAP patients, adiponectin levels (median[IQR]: 2.9(1.9-3.9) µg/mL) were positively associated with VH-IVUS derived TCFA lesions, (OR[95%CI]: 1.78[1.06-3.00], p = 0.030), and inversely associated with lesions with minimal luminal area (MLA) ≤ 4.0 mm2 (OR[95%CI]: 0.55[0.32-0.92], p = 0.025). In ACS patients, adiponectin levels (median[IQR]: 2.9 [1.8-4.1] µg/mL)were not associated with plaque burden, nor with tissue components. Positive association of adiponectin with death was present in the full cohort (HR[95%CI]: 2.52[1.02-6.23], p = 0.045) and (borderline) in SAP patients (HR[95%CI]: 8.48[0.92-78.0], p = 0.058). In ACS patients, this association lost statistical significance after multivariable adjustment (HR[95%CI]: 1.87[0.67-5.19], p = 0.23). Conclusion: In the full cohort, adiponectin levels were associated with death but not with VH-IVUS atherosclerosis measures. In SAP patients, adiponectin levels were associated with VH-IVUS-derived TCFA lesions. Altogether, substantial role for adiponectin in plaque vulnerability remains unconfirmed.

Resumo Fundamento: A pós-dilatação com balão (PDB) é normalmente necessária para otimização do implante da válvula cardíaca transcateter (THV), uma vez que o “escape” ou leak paravalvar (PVL) após implante de valva aórtica transcateter está associada com desfecho ruim e mortalidade. A avaliação quantitativa da gravidade do PVL antes e após a PDB é mandatória para se avaliar adequadamente o PVL e, assim, melhorar os resultados e os desfechos do implante. Objetivo: Investigar uma avalição angiográfica quantitativa da regurgitação aórtica (RA) por videodensitometria (VD-RA) antes e após a PDB. Métodos: Resultados da VD-RA antes e após a PDB foram analisados em 61 casos. Resultados Houve diminuição significativa da VD-RA de 24,0(18,0-30,5)% para 12,0(5,5-19,0)% (p < 0,001; p < 0,05 bilateral foi definido como significância estatística). O delta relativo de VD-RA após a PDB variou de -100% (melhora) a +40% (piora) e o valor mediano foi -46,2%. As frequências de melhora, ausência de mudança, e piora foram 70% (n = 43), 25% (n = 15) e 5% (n = 3), respectivamente. Observou-se RA significativo (VD-RA > 17%) em 47 pacientes (77%) antes e em 19 pacientes (31%) após a PDB. Conclusões: A VD-RA após o implante de THV possibilita a avaliação quantitativa da regurgitação pós-TAVI, e pode auxiliar na tomada de decisão quanto à realização ou não da PDB, bem como na avaliação de sua eficácia.

Abstract Background: Balloon post-dilatation (BPD) is often needed for optimizing transcatheter heart valve (THV) implantation, since paravalvular leak (PVL) after transcatheter aortic valve implantation is associated with poor outcome and mortality. Quantitative assessment of PVL severity before and after BPD is mandatory to properly assess PVL, thus improving implantation results and outcomes. Objective: To investigate a quantitative angiographic assessment of aortic regurgitation (AR) by videodensitometry before and after BPD. Methods: Videodensitometric-AR assessments (VD-AR) before and after BPD were analysed in 61 cases. Results: VD-AR decreased significantly from 24.0[18.0-30.5]% to 12.0[5.5-19.0]% (p < 0.001, a two-tailed p < 0.05 defined the statistical significance). The relative delta of VD-AR after BPD ranged from -100% (improvement) to +40% (deterioration) and its median value was -46.2%. The frequency of improvement, no change, and deterioration were 70% (n = 43), 25% (n = 15) and 5% (n = 3), respectively. Significant AR (VD-AR > 17%) was observed in 47 patients (77%) before and in 19 patients (31%) after BPD. Conclusions: VD-AR after THV implantation provides a quantitative assessment of post-TAVI regurgitation and can help in the decision-making process on performing BPD and in determining its efficacy.

Stent implantation was developed to overcome the acute recoil and high restenosis rate of balloon angioplasty, but resulted in the development of chronic in-stent restenosis related to specific factors regarding patient, stent, lesion and procedural characteristics. Some factors are not modifiable, such as patient and lesion characteristics, whereas procedural characteristics may be improved by better implantation technique and stent design. Drug-eluting stents are a novel approach in stent technology and design with local drug delivery to inhibit intimal thickening by interfering with different pathways involved in the development of inflammation, migration, proliferation and/or secretion of the extracellular matrix. Both the drug and the delivery vehicle must fulfill pharmacological, pharmacokinetic and mechanical requirements. Current successful drug eluting stents require a polymer coating for drug delivery. Clinical trials examining several pharmaceutical agents, particularly sirolimus and paclitaxel, have demonstrated marked reduction in restenosis following stenting. Sirolimus is a natural macrocyclic lactone and paclitaxel is a cytotoxic agent against many tumors. Both compounds block cell cycle progression and thus inhibit smooth muscle cell proliferation. The development of drug-eluting stents is one of the major revolutions in the field of Interventional Cardiology. Restenosis rate has been significantly reduced, in comparison to bare metal stents. The ideal drug to prevent restenosis must have an anti-proliferative and anti-migratory effect on smooth muscle cells but on the other hand must also enhance re-endothelialization, in order to prevent late thrombosis. Additionally, it should effectively inhibit the anti-inflammatory response after balloon induced arterial injury. Currently sirolimus, paclitaxel and more recently, ABT-578-eluting stents are commercially available, but ongoing research and clinical trials will result in new stents coming to market with novel designs loaded with a variety of compounds. As drug-eluting stent implantation becomes more liberal leading to an extensive use of this technology, the problem of restenosis in drug-eluting stents will become more common. However, for the time being, little is known regarding optimal treatment of in-stent restenosis following drug-eluting stent implantation. Future research is mandatory to further clarify, whether these patients should be treated with the same drug-eluting stent, with a different drug-eluting stent or with increased doses. Further improvements, including expansion of drug-loading capacity, coatings with programmable pharmacokinetic capacity and the discovery of new drugs may in the future further enhance the efficacy and safety of these stents. Although, drug-eluting stents have significantly reduced angiographic restenosis rate and have improved the clinical outcome, late thrombosis and restenosis remain an important subject of ongoing research. As drug-eluting stents are extensively used to treat all lesions, more efficacious agents and improved stent platforms are required. Synthetic or biological polymers can be used as matrixes for drug incorporation, but concerns have been raised regarding bio-compatibility, sterility or potential induction of inflammation. Currently, alterations on stent-backbone design (biodegradable, bioabsorbable, nanoporous etc.) are being explored. Clearly, the anti-proliferative compounds sirolimus and paclitaxel have dominated up to date clinical practice, whereas their analogues are readily emerging. In the future, however, it is likely that drugs, currently under investigation, will address additional mechanisms associated with neointimal formation leading to restenosis, either as single agents or in combination with anti-proliferative compounds.

Mejoras ulteriores, como la elevación de la capacidad de carga de los fármacos, su revestimiento con capacidad farmacocinética programable y la preparación de nuevos fármacos, podrían aumentar a futuro la eficacia y la seguridad de los stents liberadores de fármacos. Aunque dichos stents han reducido de manera significativa el número de reestenosis angiográficas y mejorado el resultado clínico, la trombosis tardía y la reestenosis quedan como temas importantes de investigaciones futuras. Puesto que los stents liberadores de fármacos se utilizan en toda lesión, se necesitan agentes más eficaces y mejores estructuras de tales instrumentos. Pueden utilizarse polímeros sintéticos o biológicos como matrices para incorporar los fármacos, pero han surgido preocupaciones acerca de la biocompatibilidad, la esterilidad y la capacidad potencial de inducir inflamación. Habitualmente se examinan posibles alteraciones del diseño estructural del stent (biodegradable, bioabsorbible, nanoporoso, etc.). Los compuestos antiproliferativos sirolimus y paclitaxel han dominado claramente la práctica clínica hasta la fecha, mientras que sus análogos están apareciendo prontamente. No obstante es probable que, a futuro, los fármacos actualmente sometidos a investigación, intervengan sobre mecanismos asociados con modelación de la capa neoíntima que lleva a la reestenosis. Éstos podrían actuar por sí solos o en combinación con los compuestos antiproliferativos ya mencionados.