Biomedical subjects

Mark Reisman

Publications and source records attributed to Mark Reisman.

22 records · Page 2Linked to original sources

PubMed2002

Percutaneous left atrial appendage transcatheter occlusion to prevent stroke in high-risk patients with atrial fibrillation: early clinical experience.

BACKGROUND: Thromboembolism due to atrial fibrillation (AF) is a frequent cause of stroke. More than 90% of thrombi in AF form in the left atrial appendage (LAA). Obliteration of the appendage may prevent embolic complications. METHODS AND RESULTS: We evaluated the feasibility and safety of implanting a novel device for percutaneous left atrial appendage transcatheter occlusion (PLAATO). LAA occlusion using the PLAATO system was attempted in 15 patients with chronic AF at high risk for stroke, who are poor candidates for long-term warfarin therapy. The implant consists of a self-expanding nitinol cage covered with a polymeric membrane (ePTFE). The LAA was successfully occluded in 15/15 patients (100%). Angiography and transesophageal echocardiography (TEE) during the procedure showed that the device was well-seated in all patients and that there was no evidence of perforation, device embolization, or interference with surrounding structures. In 1 patient, the first procedure was complicated by a hemopericardium, which occurred during LAA access. A second attempt 30 days later was successful with no untoward sequela. No other complications occurred. At 1-month follow-up, chest fluoroscopy and TEE revealed continued stable implant position with smooth atrial-facing surface and no evidence of thrombus. CONCLUSIONS: Thus, transcatheter closure of the LAA is feasible in humans. This novel implant technology may be appropriate for patients with AF who are not suitable candidates for anticoagulation therapy. Further trials are needed to show the long-term safety and its efficacy in reducing stroke.

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PubMed2002

Balloon-based radiation therapy for treatment of in-stent restenosis in human coronary arteries: results from the BRITE I study.

Catheter-based intracoronary radiation therapy demonstrated reduction of the recurrence rate of in-stent restenosis by 35%-50% when compared to conventional therapy. The objectives of this study were to determine the safety and feasibility of a new balloon-shaped source design and a higher applied dose to reduce the restenosis rates. Thirty-two patients with in-stent restenosis who met study eligibility criteria were successfully treated with standard PCI techniques. Following a successful intervention, a P-32 beta-balloon source was positioned to cover the angioplasty site and a dose of a 20 Gy at 1 mm from the surface of the source was administered. The primary endpoint was a composite of major adverse cardiac events (any death, MI, emergent CABG, or repeat target vessel revascularization) during 6 months of follow-up. At 6 months, only one patient underwent repeat PTCA to the target vessel (3%). There were no instances of death, emergency surgery, late thrombosis, total occlusions, or MI. Binary restenosis measured by QCA at the stented segment was 0% and for the whole analysis vessel was 7.5%. Beta-radiation delivered with a balloon P-32 source design for patients with in-stent restenosis results in lower than expected rate of angiographic and clinical restenosis and the absence of late complications.

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PubMed2002

Method for three-dimensional data registration from disparate imaging modalities in the NOGA Myocardial Viability Trial.

Region-by-region comparison of data concerning left ventricular (LV) status is difficult to perform quantitatively if the data was acquired from disparate imaging modalities. We validated a method for comparing measurements obtained by electromechanical mapping (EMM) catheter with dobutamine stress echocardiography (DSE) via biplane contrast ventriculography, with the assistance of three-dimensional (3-D) echocardiographic data. The ventriculograms were traced and the borders were used to reconstruct the LV in 3-D with the aid of a database of 3-D echocardiographic studies. The 3-D LV was oriented to the EMM data based on the body coordinates and then manually scaled and translated to fit. The EMM data were mapped to the 3-D surface. The 3-D surface was divided into the 16 regions defined for echocardiographic assessment. The mean EMM value for local linear shortening, a parameter of function, was computed in each segment. The EMM and semiquantitative echocardiographic assessments of regional myocardial function were compared by segment, and the volume of the 3-D LV was compared with the volume computed from the ventriculogram. The volume of the 3-D surface correlated closely with that of the ventriculogram (r = 0.97, SEE = 27.4 ml) but with a significant overestimation of 63 +/- 35 ml. There was a highly significant (p < 0.0001) agreement in regional function between EMM and echo. Local linear shortening correlated significantly (p < 0.0001) with echocardiographic severity of wall motion, averaging 9.5 +/- 6.5, 8.1 +/- 5.4, 5.9 +/- 4.8, and 6.2 +/- 3.3 in segments read as normal, hypokinetic, akinetic, and dyskinetic, respectively. The method presented is valid for comparing cardiac parameters derived from disparate image data on a region-by-region basis by employing anatomic landmarks on 3-D reconstructions of the LV endocardial surface.

Body Surface Potential Mapping↗

PubMed2002

Carotid stenting and endarterectomy: a clinical and cost comparison of revascularization strategies.

BACKGROUND AND PURPOSE: Investigational carotid stenting for extracranial carotid stenosis has demonstrated procedural results approaching those reported with endarterectomy, but with limited cost and long-term data. This study compared the in-hospital outcomes and costs of these 2 revascularization strategies at a single institution and the long-term effectiveness of carotid stenting. METHODS: Data for 136 endarterectomies and 136 carotid stent procedures at a tertiary-care community hospital were obtained. The primary clinical outcome measures were in-hospital major ipsilateral stroke and death. In-hospital direct variable costs and length of stay were the primary economic measures. Information on restenosis and late ipsilateral stroke for the stent group was available at 2-year follow-up. RESULTS: These nonrandomized groups were similar, but the endarterectomy group had more symptomatic patients (42% versus 31%; P=0.0004), and the stent group had more NASCET-excluded patients (68% versus 35%; P<0.0001). In-hospital major ipsilateral stroke and death occurred more frequently in the surgical group, but the difference was not significant (2.9% versus 0%; P=0.1). Minor ipsilateral strokes were similar (2.2% versus 2.9%; P=NS). Cost ($5409 versus $3417; P<0.0001) and length of stay (3.0 versus 1.4 days; P<0.0001) were significantly greater for the surgical group. In the stent group, 6-month angiographic restenosis was 3.1%, and 2-year ipsilateral major stroke rate was 0%. CONCLUSIONS: In-hospital outcomes with carotid stenting were similar to those with endarterectomy but were achieved in patients with significantly more comorbidities. Cost and resource utilization with stenting were substantially less than those with endarterectomy. At 2 years, carotid stenting appeared not only durable but also effective in stroke prevention.

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