Noah Rosenthal

Optical coherence tomography (OCT) strut-level analysis of drug-eluting stents (DES) in human coronary bifurcations

Aims: We sought to evaluate the vascular response of stent struts deployed in bifurcation segments using optical coherence tomography (OCT). Methods and results: This study is a sub-analysis of ODESSA, a prospective randomised trial designed to evaluate healing of overlapped drug-eluting stents (DES) vs. bare metal stents (BMS) (sirolimus SES: paclitaxel PES: zotarolimus ZES: Liberte BMS in a 2: 2: 2: 1 ratio) for de novo coronary artery stenosis. OCT was performed at 6-month follow-up. Bifurcation segments with side branch diameters larger than 1.5mm by angiography were analysed. The cross-sectional image at the bifurcation segment was divided into three regions: opposite to the ostium (OO), adjacent to the ostium (AO), or side-branch ostium (SO). Struts were classified in three categories: uncovered (U), covered (C), or proliferative (P). The incidence of each strut category was compared between regions and stent types. There were 12,656 struts in 61 bifurcation segments (PES: 16, SES: 14, ZES: 23, Liberte BMS: 8) from 46 patients obtained at six months. PES had the highest rate of U in SO region (PES 60.1, SES 17.0, ZES 13.2, BMS 12.3 (%), P<0.0001), whereas SES demonstrated the highest rate of U in OO (PES 3.8, SES 14.0, ZES 1.5, BMS 0.0 (%), P=0.0025). Conclusions: This study demonstrates a variable pattern of strut coverage in the bifurcation among stent technologies, with a high percentage of PES floating struts remaining uncovered at 6-month follow-up.

In vivo intracardiac optical coherence tomography imaging through percutaneous access: toward image-guided radio-frequency ablation

Complete catheter-tissue contact and permanent tissue destruction are essential for efficient radio-frequency ablation (RFA) during cardiac arrhythmia treatment. Current methods of monitoring lesion formation are indirect and unreliable. The purpose of this study is to evaluate the feasibility of using optical coherence tomography (OCT) catheter to image endocardial wall in actively beating hearts through percutaneous access. We reported the first in vivo intracardiac OCT imaging through percutaneous access with a thin and flexible OCT catheter. This is a critical step toward image-guided RFA in a clinical setting. A cone-scanning forward-viewing OCT catheter was advanced into beating hearts through percutaneous access in four swine. The OCT catheter was steered by an introducer to touch the endocardial wall. We are able to acquire high quality OCT images in beating hearts, observe the polarization-related artifacts induced by the birefringence of myocardium, and readily evaluate catheter-tissue contact. The observations indicate that OCT could be a promising technique for in vivo guidance of RFA.

Angiographic, IVUS and OCT evaluation of the long-term impact of coronary disease severity at the site of overlapping drug-eluting and bare metal stents: a substudy of the ODESSA trial

Background A potentially adverse vascular response to overlapping drug eluting stents (DES) has been suggested in current research. Objective To evaluate the impact of baseline disease severity at the site of stent overlap. Methods and results This is a substudy of ODESSA, a prospective, randomised controlled trial designed to evaluate healing of overlapping stents. 71/77 patients with a total of 86 overlapping stents were studied: 25 sirolimus, 24 paclitaxel, 26 zotarolimus-eluting stents; and 11 bare metal stents (BMS). Patients were categorised into high-grade stenosis (HGS, ≥70% diameter stenosis) and low-grade stenosis (LGS, <70%) at the site of stent overlap. Angiography and intravascular ultrasound were performed after stent deployment and repeated at 6 months, together with additional optical coherence tomography. Images were analysed by an independent core laboratory. End points were binary restenosis, percentage neointimal hyperplasia (%NIH), mean lumen and stent areas and degree of strut coverage/apposition at overlapping stents at 6 months. Stent overlaps occurred in 49 HGS and 37 LGS. Restenosis was found in 5/6 HGS versus 0/5 LGS treated with overlapping BMS (p=0.01) and 4/43 HGS versus 0/32 LGS treated with overlapping DES. There was a trend towards higher %NIH at BMS overlap in HGS versus LGS (p=0.07). DES overlaps had lower lumen and stent areas and similar %NIH in HGS versus LGS. Any uncovered or malapposed struts occurred more often in overlapping DES at LGS than at HGS (59.4% vs 32.6%, p=0.03). Conclusions Overlapping DES in normal-appearing coronary segments showed a higher incidence of uncovered or malapposed struts, while restenosis occurred exclusively in overlapping stents at HGS. These findings should be considered when deploying overlapping stents.

Nighttime hospital blood pressure – a predictor of death, ESRD, and decline in GFR

Nighttime systolic blood pressure (BP) from ambulatory blood pressure monitoring (ABPM) is more predictive than clinic BP for cardiovascular disease, stroke, and death even after controlling for clinic BP. However, ABPM is expensive and burdensome to obtain regularly. BPs obtained in the hospital may provide a window into nighttime BP. We conducted a retrospective cohort study of all hypertensive patients admitted to the Louis Stokes Cleveland Department of Veterans Affairs Medical Center (LSCDVAMC) in 2002 and 2003 with one or more BP recorded between midnight and 6 am on the day of or the day before discharge. The mean age of the study population (n = 1085) was 62 years and 96% were male. Twenty-two percent had coronary artery disease (CAD) and 34% had diabetes. The mean nighttime systolic BP was 132 mmHg and baseline glomerular filtration rate (GFR) was 83 mL/min per 1.73 m2. Over a median follow-up period of 4.3 years, 266 subjects died, 22 developed end-stage renal disease (ESRD), 99 had a 50% decline in GFR, and 136 developed myocardial infarction (MI). The adjusted hazard ratios (HRs) associated with a 10 mmHg increase in nighttime systolic BP were 1.03 (95% confidence interval, 0.93–1.15) for death, 1.30 (0.94–1.80) for ESRD, 1.26 (1.08–1.47) for a 50% decline in GFR, 1.07 (0.92–1.23) for myocardial infarction, and 1.12 (1.03–1.23) for a composite of death, ESRD, or a 50% decline in GFR. In conclusion, nighttime systolic BP in hospitalized patients is an independent predictor of important clinical outcomes such as a composite of death, ESRD, or a 50% decline in GFR.

Use of optical coherence tomography for accurate characterization of atherosclerosis

Optical coherence tomography (OCT) is a novel imaging technology based on low-coherence interferometry that uses scattering of near-infrared light as a signal source to provide vascular cross-sectional imaging with definition far superior to any other available modality. With spatial resolution of up to 10 microm, OCT provides 20-fold higher resolution than intravascular ultrasound (IVUS), currently the most used modality for intra-coronary imaging. OCT has the capacity to provide invaluable insight into the various phases of atherosclerotic disease and vascular response to therapeutics. Studies have shown the ability of OCT to detect arterial structures and assist in the determination of different histological constituents. Its capacity to distinguish different grades of atherosclerotic changes and the various types of plaques, as compared to histology, has recently been demonstrated with acceptable intra-observer and inter-observer correlations for these findings. OCT provides unrivaled real-time in vivo endovascular resolution, which has been exploited to assess the vascular structures and response to device deployment. While depth remains a limitation for OCT plaque characterization beyond 2-mm, near-histological resolution can be achieved within the first millimeter of the vessel wall allowing unique assessment of fibrous cap characteristics and thickness. In addition, assessment of neointimal coverage, para-strut tissue patterns and stent apposition can now be scrutinized for individual struts on the micron scale, the so-called strut-level analysis. OCT has propelled intravascular imaging into micron-level in vivo vascular analysis and is expected to soon become a valuable and indispensable tool for the cardiologists on both clinical and research applications.A Tomografia de Coerencia Otica (TCO) e uma nova tecnologia de imagem baseada em interferometria de baixa coerencia que utiliza a dispersao de luz quase-infravermelha como uma fonte de sinal para fornecer imagens transversais vasculares com definicao muito superior a de qualquer outra modalidade disponivel. Com uma resolucao espacial de ate 10μm, a TCO fornece uma resolucao 20 vezes maior do que o ultrassom intravascular (USIV), a modalidade atualmente mais utilizada para obter imagens intra-coronarias. A TCO tem uma capacidade de fornecer um entendimento das varias fases da doenca aterosclerotica e a resposta vascular ao tratamento. Estudos tem mostrado a capacidade da TCO em detectar estruturas arteriais e ajudar na determinacao de diferentes constituintes histologicos. Sua capacidade de distinguir diferentes graus de alteracoes ateroscleroticas e os varios tipos de placas, quando comparada a histologia, tem sido recentemente demonstrada com correlacoes inter e intra-observador aceitaveis para esses achados. A TCO fornece uma resolucao endovascular excepcional em tempo real in vivo, que tem sido explorada para avaliar as estruturas vasculares e a resposta ao uso do equipamento. Embora a profundidade permaneca uma limitacao para a caracterizacao de placa alem de 2 mm atraves da TCO, uma resolucao proxima a histologica pode ser obtida dentro do primeiro milimetro da parede do vaso, permitindo uma avaliacao extraordinaria das caracteristicas e espessura da capa fibrosa. Alem disso, a avaliacao da cobertura de neointima, padroes de tecido para-haste e aposicao de stent podem agora ser escrutinizados para hastes individuais na escala de microns, a assim chamada analise em nivel de haste. A TCO levou a imagem intravascular ao nivel de micron na analise vascular in vivo e espera-se que breve se torne uma ferramenta valiosa e indispensavel para cardiologistas em aplicacoes clinicas e de pesquisa.

Cardiac mapping and stem cell delivery for the damaged myocardium

Despite improvements in revascularization therapies, access to advanced medical facilities and community awareness of coronary artery disease, heart failure remains one of the most common and costly reasons for hospital admission in the USA. Perhaps a victim of our own success, as patients survive myocardial infarction and live longer, more live with the sequelae of damaged myocardium. As scientific and clinical focus has shifted to regenerative medicine, the promise of stem cell therapy to aid in the improvement of myocardial function has nurtured the investigation of optimal therapeutic strategies. Systemic, intracoronary, intraventricular and direct myocardial delivery of stem cells have produced mixed results. Limitations in available stem cell lines and delivery methods remain challanges to a firm foundation for future clinical success. The advent of sophisticated intracardiac electro mechanical mapping (EMM) systems and catheters equipped with injection ports represents a new horizon for stem cell delivery. This article will provide insights into intracardiac EMM for stem cell delivery for damaged myocardium and the future directions with this exciting new therapeutic approach. Heart failure affects millions of patients worldwide. The socioeconomic burden of this disease is exemplified by the fact that heart failure remains the most common reason for hospital admission in the USA [1] and cases are expected to double in the next 40 years [2]. Associated with this enormous disease burden is the extraordinary cost of treatment, estimated at US

In vivo intracardiac OCT imaging through percutaneous access: Towards image guided radio-frequency ablation

18 billion per year [2]. The increasing prevalence of this disease is probably the result of improved pharmacological regimens and increased survival for patients after myocardial infarction [3]. Heart transplantation remains a viable option for certain patients; however, the limited pool of available donors and the relatively poor long-term survival of patients undergoing transplantation remain areas for improvement. This has spawned the development of novel invasive strategies to treat heart failure patients, including more portable, sustainable ventricularassist devices and ultrafiltration machines capable of removing large volumes of isotonic fluid through peripheral veins, permitting more advanced outpatient treatment options. Recently, increasing interest has focused on the role of regenerative medicine through the use of stem cell therapy to improve or restore damaged myocardium and enhance cardiac function. The long-held paradigm that mature cardiac myocytes are incapable of regeneration has recently been confronted by intense research focused on the role of stem cell-based therapy. The hope that postnatal cardiomyogenesis and vasculogenesis will reset or slow the morbidity and mortality burden associated with heart failure fuels this burgeoning area of research.

Uso da tomografia de coerência ótica intracoronariana para caracterização precisa da aterosclerose

BACKGROUND Complete catheter-tissue contact and permanent tissue destruction are essential for efficient radio-frequency ablation (RFA) during cardiac arrhythmia treatment. Current methods of monitoring lesion formation are indirect and unreliable. We aim to develop optical coherence tomography (OCT) as an imaging guidance for RFA. OBJECTIVES The purpose of this study is to evaluate the feasibility of using OCT catheter to image endocardia wall in active beating hearts through percutaneous access. This is a critical step toward image guided RFA in a clinic setting. METHODS A cone-scanning forward-viewing OCT catheter was advanced into active beating hearts through percutaneous access in four swine. The OCT catheter was steered by an introducer to touch the endocardia wall. The images were then acquired at 10 frames per second at an axial resolution and lateral resolution of 15 μm. RESULTS We report the first in vivo intracardiac OCT imaging through percutaneous access with a thin and flexible OCT catheter. We are able to acquire high quality OCT images in active beating hearts, observe the polarization-related artifacts induced by the birefringence of myocardium and readily evaluate catheter-tissue contact. CONCLUSIONS It is feasible to acquire OCT images in beating hearts through percutaneous access. The observations indicate that OCT could be a promising technique for in vivo guidance of RFA.

Uso de la tomografía de coherencia óptica intracoronaria para caracterización precisa de la aterosclerosis

Optical coherence tomography (OCT) is a novel imaging technology based on low-coherence interferometry that uses scattering of near-infrared light as a signal source to provide vascular cross-sectional imaging with definition far superior to any other available modality. With spatial resolution of up to 10 microm, OCT provides 20-fold higher resolution than intravascular ultrasound (IVUS), currently the most used modality for intra-coronary imaging. OCT has the capacity to provide invaluable insight into the various phases of atherosclerotic disease and vascular response to therapeutics. Studies have shown the ability of OCT to detect arterial structures and assist in the determination of different histological constituents. Its capacity to distinguish different grades of atherosclerotic changes and the various types of plaques, as compared to histology, has recently been demonstrated with acceptable intra-observer and inter-observer correlations for these findings. OCT provides unrivaled real-time in vivo endovascular resolution, which has been exploited to assess the vascular structures and response to device deployment. While depth remains a limitation for OCT plaque characterization beyond 2-mm, near-histological resolution can be achieved within the first millimeter of the vessel wall allowing unique assessment of fibrous cap characteristics and thickness. In addition, assessment of neointimal coverage, para-strut tissue patterns and stent apposition can now be scrutinized for individual struts on the micron scale, the so-called strut-level analysis. OCT has propelled intravascular imaging into micron-level in vivo vascular analysis and is expected to soon become a valuable and indispensable tool for the cardiologists on both clinical and research applications.A Tomografia de Coerencia Otica (TCO) e uma nova tecnologia de imagem baseada em interferometria de baixa coerencia que utiliza a dispersao de luz quase-infravermelha como uma fonte de sinal para fornecer imagens transversais vasculares com definicao muito superior a de qualquer outra modalidade disponivel. Com uma resolucao espacial de ate 10μm, a TCO fornece uma resolucao 20 vezes maior do que o ultrassom intravascular (USIV), a modalidade atualmente mais utilizada para obter imagens intra-coronarias. A TCO tem uma capacidade de fornecer um entendimento das varias fases da doenca aterosclerotica e a resposta vascular ao tratamento. Estudos tem mostrado a capacidade da TCO em detectar estruturas arteriais e ajudar na determinacao de diferentes constituintes histologicos. Sua capacidade de distinguir diferentes graus de alteracoes ateroscleroticas e os varios tipos de placas, quando comparada a histologia, tem sido recentemente demonstrada com correlacoes inter e intra-observador aceitaveis para esses achados. A TCO fornece uma resolucao endovascular excepcional em tempo real in vivo, que tem sido explorada para avaliar as estruturas vasculares e a resposta ao uso do equipamento. Embora a profundidade permaneca uma limitacao para a caracterizacao de placa alem de 2 mm atraves da TCO, uma resolucao proxima a histologica pode ser obtida dentro do primeiro milimetro da parede do vaso, permitindo uma avaliacao extraordinaria das caracteristicas e espessura da capa fibrosa. Alem disso, a avaliacao da cobertura de neointima, padroes de tecido para-haste e aposicao de stent podem agora ser escrutinizados para hastes individuais na escala de microns, a assim chamada analise em nivel de haste. A TCO levou a imagem intravascular ao nivel de micron na analise vascular in vivo e espera-se que breve se torne uma ferramenta valiosa e indispensavel para cardiologistas em aplicacoes clinicas e de pesquisa.

The impact of an eccentric intravascular ImageWire during coronary optical coherence tomography imaging.

Optical coherence tomography (OCT) is a novel imaging technology based on low-coherence interferometry that uses scattering of near-infrared light as a signal source to provide vascular cross-sectional imaging with definition far superior to any other available modality. With spatial resolution of up to 10 microm, OCT provides 20-fold higher resolution than intravascular ultrasound (IVUS), currently the most used modality for intra-coronary imaging. OCT has the capacity to provide invaluable insight into the various phases of atherosclerotic disease and vascular response to therapeutics. Studies have shown the ability of OCT to detect arterial structures and assist in the determination of different histological constituents. Its capacity to distinguish different grades of atherosclerotic changes and the various types of plaques, as compared to histology, has recently been demonstrated with acceptable intra-observer and inter-observer correlations for these findings. OCT provides unrivaled real-time in vivo endovascular resolution, which has been exploited to assess the vascular structures and response to device deployment. While depth remains a limitation for OCT plaque characterization beyond 2-mm, near-histological resolution can be achieved within the first millimeter of the vessel wall allowing unique assessment of fibrous cap characteristics and thickness. In addition, assessment of neointimal coverage, para-strut tissue patterns and stent apposition can now be scrutinized for individual struts on the micron scale, the so-called strut-level analysis. OCT has propelled intravascular imaging into micron-level in vivo vascular analysis and is expected to soon become a valuable and indispensable tool for the cardiologists on both clinical and research applications.A Tomografia de Coerencia Otica (TCO) e uma nova tecnologia de imagem baseada em interferometria de baixa coerencia que utiliza a dispersao de luz quase-infravermelha como uma fonte de sinal para fornecer imagens transversais vasculares com definicao muito superior a de qualquer outra modalidade disponivel. Com uma resolucao espacial de ate 10μm, a TCO fornece uma resolucao 20 vezes maior do que o ultrassom intravascular (USIV), a modalidade atualmente mais utilizada para obter imagens intra-coronarias. A TCO tem uma capacidade de fornecer um entendimento das varias fases da doenca aterosclerotica e a resposta vascular ao tratamento. Estudos tem mostrado a capacidade da TCO em detectar estruturas arteriais e ajudar na determinacao de diferentes constituintes histologicos. Sua capacidade de distinguir diferentes graus de alteracoes ateroscleroticas e os varios tipos de placas, quando comparada a histologia, tem sido recentemente demonstrada com correlacoes inter e intra-observador aceitaveis para esses achados. A TCO fornece uma resolucao endovascular excepcional em tempo real in vivo, que tem sido explorada para avaliar as estruturas vasculares e a resposta ao uso do equipamento. Embora a profundidade permaneca uma limitacao para a caracterizacao de placa alem de 2 mm atraves da TCO, uma resolucao proxima a histologica pode ser obtida dentro do primeiro milimetro da parede do vaso, permitindo uma avaliacao extraordinaria das caracteristicas e espessura da capa fibrosa. Alem disso, a avaliacao da cobertura de neointima, padroes de tecido para-haste e aposicao de stent podem agora ser escrutinizados para hastes individuais na escala de microns, a assim chamada analise em nivel de haste. A TCO levou a imagem intravascular ao nivel de micron na analise vascular in vivo e espera-se que breve se torne uma ferramenta valiosa e indispensavel para cardiologistas em aplicacoes clinicas e de pesquisa.