Comparison of Stent Expansion Using a Volumetric Versus the Conventional Method Through Optical Coherence Tomography in an All-Comers Population.

INTRODUCTION: A volumetric approach to measure stent expansion derived from optical coherence tomography (OCT) is superior in regards to clinical outcomes when compared to the conventional method. The current software already performs a semi-automatic assessment and it is available as a clinical tool, however data is still scarce. We evaluated the stent expansion analysis that uses a volumetric vessel model, called minimum expansion index - MEI and compared to the conventional model, which utilizes the minimum stent area expansion (MSAx) indexed to the references, and its potential impact on procedural decision-making strategy in percutaneous coronary intervention. METHODS: This was a prospective, all-comers single center study, from all patients undergoing OCT-guided PCI between September 2018 and May 2019. We utilized the APTIVUE™ OPTIS 5.2 software (Abbott, Santa Clara, CA) to evaluate MEI and MSAx measurements after reference adjustments. RESULTS: We included 100 patients with mean age of 64 ± 12.5 years, 68% were men, and the main arteries analyzed through OCT were LAD (48%), RCA (31%) and LCx (21%). The mean MEI was 77.6% ± 16.7% and the mean MSAx was 71.6% ± 16.9%. MEI location differed from MSAx in 70% of cases, and in those cases the mean distance between MEI and MSAx was 15.3 mm ± 12.4 mm. In 53% of the times, the stent underexpansion based on MEI was located proximally to the MSAx by 18.1 mm ± 11.8 mm. Furthermore, in 42% of the total cases, MEI would change the intervention strategy based on the stent underexpansion being in a different location ≥10 mm in comparison to MSAx (34%) associated with the discrepancy between expansion indexes for MEI and MSAx (22%). CONCLUSION: We concluded that MEI location did not correlate to the conventional MSAx in two thirds of the cases. Moreover, compared to MEI, the MSAx assessment yielded lower expansion values in different stent positions, potentially changing the appropriate post-stent optimization, which thus would impact the decision-making strategy in almost half of the patients.

Treatment of In-Stent Restenosis Using Excimer Laser Coronary Atherectomy and Bioresorbable Vascular Scaffold Guided by Optical Coherence Tomography.

The rate of in-stent restenosis (ISR) has become increasingly prevalent with the exponential growth in stent implantation due to an aging population and a higher life expectancy, in addition to the high rates of obesity and diabetes. In this prospective, single operator, all-comer study, we sought to analyze the performance of ELCA followed by bioresorbable vascular scaffold (BVS) placement in patients undergoing percutaneous coronary intervention (PCI) for ISR. A total of 13 patients had ISR treated with a combination of ELCA and BVS, with 9 patients having matched OCT pre, post ELCA and post BVS. Mean age was 65 ± 11.22 and 83% of the patients were male. Hypertension and dyslipidemia were present in 100% of the patients and smoking and diabetes in 50%. After the procedure, we did not detect residual stenosis over 10% in any patient, resulting in a technical success of 100%. No patients had MACE during their hospital stay or within the next six months, resulting in a procedure success of 100%. The mean lumen area increased 0.35 mm2 from pre procedure to post ELCA and 3.58 mm2 from post ELCA to post BVS. The final difference, from pre procedure to post BVS, was a 3.93 mm2 lumen area gain. The mean lumen diameter increased 0.11 mm from baseline to ELCA, 0.95 mm from post laser to BVS implantation and 1.06 mm from pre procedure to post BVS. The NIH area reduced 0.48 mm2 from pre to post ELCA, 1.13mm2 from post ELCA to BVS implantation and 1.61 mm2 from baseline to post BVS implantation. We conclude that ELCA is a safe and feasible debulking method to approach ISR, with high rates of post-procedural BVS success, within six months follow-up.

Novel Indices of Coronary Physiology: Do We Need Alternatives to Fractional Flow Reserve?

Fractional flow reserve is the current invasive gold standard for assessing the ischemic potential of an angiographically intermediate coronary stenosis. Procedural cost and time, the need for coronary vessel instrumentation, and the need to administer adenosine to achieve maximal hyperemia remain integral components of invasive fractional flow reserve. The number of new alternatives to fractional flow reserve has proliferated over the last ten years using techniques ranging from alternative pressure wire metrics to anatomic simulation via angiography or intravascular imaging. This review article provides a critical description of the currently available or under-development alternatives to fractional flow reserve with a special focus on the available evidence, pros, and cons for each with a view towards their clinical application in the near future for the functional assessment of coronary artery disease.

Predicted Coronary Occlusion and Impella Salvage During Valve-in-Valve Transcatheter Aortic Valve Replacement.

We describe an interesting case of a 71 years old fragile female, with progressive shortness of breath on exertion and ankle swelling, cardiac failure NYHA class III. She also had chest irradiation due to Hodgkin's disease many years before, previous surgical aortic valve replacement using bioprosthetic stent-less Freestyle #25 mm valve (Medtronic, Inc) in 2000 for severe aortic stenosis, history of cardiac arrest in 2012 and angioplasty to ostial RCA, PCI to ostial RCA in 2014, CABG (RA graft to RCA) in 2014 (RCA intra-stent restenosis with refractory ischemia), anemia requiring regular transfusions, bronchiectasis and chronic kidney disease. Because of the great comorbidities, STS 4.9% and worsening of the symptoms due to severe aortic valve regurgitation, heart team decided to perform "valve-in-valve" Transcatheter Aortic Valve Replacement (VIV-TAVR), but we already predicted coronary occlusion while performing this procedure because of the low left main coronary ostium and short aortic valve sinus. So regarding the probable left main coronary occlusion during the valve implantation, we decided to perform the placement of a not deployed stent inside the left main prior to the valve procedure, and to deploy it in case the predicted left main occlusion occurred. So just after the VIV-TAVR procedure, we observed left main coronary occlusion and the patient got ischemic cardiogenic shock and cardiac arrest, so we performed immediate PCI and deployed the bailout stent. After some minutes of chest compressions, an Impella mechanical circulatory support system (Abiomed, Danvers, MA) had to be installed. Patient recovered spontaneous circulation, and after hemodynamic stabilization, she was sent to the Intensive Coronary Unit, without further complications. She was discharged successfully without neurological or cardiac sequelae after 1 week.

Rotational Atherectomy and Mechanical Support to Treat Left Main.

We describe a complex percutaneous coronary intervention using rotational atherectomy (Rotablator, Boston Scientific, Marlborough, Massachusetts) and mechanical circulatory support (Impella, Abiomed, Danvers, Massachusetts) in a patient with multiple comorbidities scheduled to undergo a left main coronary percutaneous coronary intervention using a 2-stent technique based on angiography. However, intracoronary optical coherence tomography changed our strategy to a successful single-stent procedure. (Level of Difficulty: Advanced.).

Impact of Neointimal Calcifications on Acute Stent Performance during the Treatment of In-Stent Restenosis.

Optical coherence tomography (OCT) has become the invasive imaging modality of choice for coronary stent assessment due to its unmatched spatial resolution. Neointimal calcification (NC) is a rare finding, observed in 5-10% of in-stent restenosis (ISR) neointima. The impact of NC on percutaneous coronary intervention of ISR is unknown. We therefore present the outcome of six unique cases of ISR and NC in which OCT was used to evaluate the impact of NC on the quality of stent-in-stent deployment for the treatment of ISR. This series demonstrates for the first time the impact of NC on stent expansion, a finding which might help guiding percutaneous coronary intervention for ISR with NC.

Impacto dos stents e do sirolimus por via oral na vasomotilidade coronariana dependente e independente do endotelio / Impact of stenting and oral sirolimus on endothelium-dependent and independent coronary vasomotion

FUNDAMENTO: Não há consenso sobre o impacto do implante de stent sobre a função endotelial no longo prazo. Há relatos de disfunção endotelial aumentada com stent com sirolimus quando comparado com o stent metálico convencional (BMS). OBJETIVO: Este estudo visa a avaliar o impacto do BMS e o efeito do sirolimus por via oral sobre a função endotelial. MÉTODOS: Quarenta e cinco pacientes foram randomizados em três grupos: BMS + altas doses de sirolimus oral (dose inicial de 15 mg, seguida de 6 mg/dia durante quatro semanas); BMS + baixa dose de sirolimus (6 mg, seguida de 2 mg por dia durante quatro semanas) e BMS sem sirolimus. Mudanças na vasoconstrição ou vasodilatação, em um segmento de 15 milímetros começando pelo extremo distal do stent em resposta a acetilcolina e nitroglicerina, foram avaliadas por angiografia quantitativa. RESULTADOS: Os grupos apresentaram características angiográficas semelhantes. A variação percentual de diâmetro em resposta a acetilcolina foi semelhante em todos os grupos, nos dois momentos (p = 0,469). Quatro horas após o implante de stent, o segmento alvo apresentou uma disfunção endotelial que se manteve após oito meses em todos os grupos. Em todos os grupos, a vasomotricidade independente de endotélio em resposta a nitroglicerina foi semelhante, às quatro horas e aos oito meses, com diâmetro do segmento alvo aumentado após a infusão de nitroglicerina (p = 0,001). CONCLUSÃO: A disfunção endotelial esteve igualmente presente no segmento distal de 15 milímetros do segmento tratado, às 4 horas e aos 8 meses após implante do stent. O sirolimus administrado por via oral durante quatro semanas para evitar a reestenose não afetou o estado de vasomotricidade endotélio dependente e independente.

BACKGROUND: There is no consensus regarding the impact of stenting on long-term endothelial function. There have been reports of increased endothelial dysfunction with sirolimus-eluting stents as compared to bare metal stenting (BMS). OBJECTIVE: This study aims to assess the impact of BMS and the effect of oral sirolimus on endothelial function. METHODS: Forty-five patients were randomized into three groups: BMS + high-dose oral sirolimus (initial dose of 15 mg, followed by 6 mg/day for four weeks); BMS + low-dose sirolimus (6 mg followed by 2 mg daily for four weeks); and BMS without sirolimus. Changes in vasoconstriction or vasodilation in a 15 mm segment starting at the distal stent end in response to acetylcholine and nitroglycerin were assessed by quantitative angiography. RESULTS: The groups had similar angiographic characteristics. The percent variation in diameter in response to acetylcholine was similar in all groups at the two time points (p = 0.469). Four hours after stenting, the target segment presented an endothelial dysfunction that was maintained after eight months in all groups. In all groups, endothelium-independent vasomotion in response to nitroglycerin was similar at four hours and eight months, with increased target segment diameter after nitroglycerin infusion (p = 0.001). CONCLUSION: The endothelial dysfunction was similarly present at the 15 mm segment distal to the treated segment, at 4 hours and 8 months after stenting. Sirolimus administered orally during 4 weeks to prevent restenosis did not affect the status of endothelium-dependent and independent vasomotion.

Impact of stenting and oral sirolimus on endothelium-dependent and independent coronary vasomotion.

BACKGROUND: There is no consensus regarding the impact of stenting on long-term endothelial function. There have been reports of increased endothelial dysfunction with sirolimus-eluting stents as compared to bare metal stenting (BMS). OBJECTIVE: This study aims to assess the impact of BMS and the effect of oral sirolimus on endothelial function. METHODS: Forty-five patients were randomized into three groups: BMS + high-dose oral sirolimus (initial dose of 15 mg, followed by 6 mg/day for four weeks); BMS + low-dose sirolimus (6 mg followed by 2 mg daily for four weeks); and BMS without sirolimus. Changes in vasoconstriction or vasodilation in a 15 mm segment starting at the distal stent end in response to acetylcholine and nitroglycerin were assessed by quantitative angiography. RESULTS: The groups had similar angiographic characteristics. The percent variation in diameter in response to acetylcholine was similar in all groups at the two time points (p = 0.469). Four hours after stenting, the target segment presented an endothelial dysfunction that was maintained after eight months in all groups. In all groups, endothelium-independent vasomotion in response to nitroglycerin was similar at four hours and eight months, with increased target segment diameter after nitroglycerin infusion (p = 0.001). CONCLUSION: The endothelial dysfunction was similarly present at the 15 mm segment distal to the treated segment, at 4 hours and 8 months after stenting. Sirolimus administered orally during 4 weeks to prevent restenosis did not affect the status of endothelium-dependent and independent vasomotion.

Assessment of coronary stent by optical coherence tomography, methodology and definitions.

Optical coherence tomography has emerged as a powerful tool for stent assessment, and in a short time, has become the modality of choice for studying stent and vascular interactions in vivo. In this review, we discuss qualitative and quantitative parameters used for stent assessment by OCT. Various qualitative/quantitative variables of stent assessment are discussed in the perspective of the clinical and research values of each of them.