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Utility and Limitations of Ablation Index for Guiding Therapy in Ventricular Myocardium. JACC Clin Electrophysiol 2023; 9:1668-1680. [PMID: 37354172 DOI: 10.1016/j.jacep.2023.03.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 03/20/2023] [Accepted: 03/29/2023] [Indexed: 06/26/2023]
Abstract
BACKGROUND Ablation index (AI) is used for guiding therapy during pulmonary vein isolation. However, its potential utility in ventricular myocardium is unknown. OBJECTIVES This study sought to examine the correlation between AI and lesion dimensions in healthy and infarcted ventricles. METHODS In ex vivo experiments using healthy swine ventricles, the correlation between AI (400-1,200) and lesion dimensions was examined at fixed power (30 W) and contact force (CF) (15 g). To examine the accuracy of AI in predicting lesion dimensions created by different combinations of ablation parameters, applications with a similar prespecified AI value created using different power (30 vs 40 W), CF (15 vs 25 g) or impedance (130-170 Ω) were created. In in vivo experiments, the correlation between AI and lesion dimensions was examined in healthy and infarcted myocardium. RESULTS Ex vivo experiments (247 lesions, 36 hearts) showed good correlation between AI and lesion depth (R = 0.93; P < 0.001). However, in vivo experiments (9 healthy swine and 10 infarcted swine) showed moderate correlation in healthy myocardium (R = 0.64; P < 0.01) and poor correlation in infarcted myocardium (R = 0.23; P = 0.61). AI values achieved using different combinations of power, CF, and baseline impedance resulted in different lesion depths: Ablation at 30 W produced deeper lesions compared with 40 W, ablation with CF of 15 g produced deeper lesions compared with CF of 25 g, and ablation at lower impedance produced larger lesions at similar prespecified AI values (P < 0.01 for all). CONCLUSIONS AI has limited value for guiding ablation in ventricular myocardium, particularly scar. This may be related to small proportional significance of application duration and complex tissue architecture.
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Atrial Endocardial Unipolar Voltage Mapping for Detection of Viable Intramural Myocardium: A Proof-of-Concept Study. Circ Arrhythm Electrophysiol 2023; 16:e011321. [PMID: 36595639 DOI: 10.1161/circep.122.011321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Endocardial bipolar voltage amplitude is largely derived from endocardial and subendocardial wall layers. This may result in situations of low bipolar voltage amplitude despite the presence of mid-myocardial including epicardial (ie, intramural-epicardial) viable myocardium. This study examined the utility of endocardial unipolar voltage mapping for detection of viable intramural-epicardial atrial myocardium. METHODS In 15 swine, an atrial intercaval ablation line with an intentional gap was created. Animals survived for 6 to 8 weeks before electroanatomical mapping followed by sacrifice. Gaps were determined by the presence of electrical conduction and classified based on the histopathologiclly layer(s) of viable myocardium into the following: (1) transmural, (2) endocardial, and (3) intramural-epicardial. Voltage data from healthy, scar, and gap points were exported into excel. The sensitivity and specificity of bipolar and unipolar voltage amplitude to detect intramural-epicardial gaps were compared using receiver operating characteristic analysis. RESULTS In 9 of 15 (60%) swine, a focal ablation gap was detected in the intercaval line, while in the remainder 6 of 15 (40%), the line was complete without gaps. Gaps were classified into transmural (n=3), endocardial (n=3), or intramural-epicardial (n=3). Intramural-epicardial gaps were characterized by very low bipolar voltage amplitude that was similar to areas with transmural scar (P=0.91). In comparison, unipolar voltage amplitude in intramural-epicardial gaps was significantly higher compared to transmural scar (P<0.001). Unipolar voltage amplitude had higher sensitivity (93% versus 14%, respectively) and similar specificity (95% versus 98%, respectively) to bipolar voltage for detection of intramural-epicardial gaps. CONCLUSIONS Atrial unipolar voltage mapping may be a useful technique for identifying viable intramural-epicardial myocardium in patients with endocardial scar.
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Effect of Pulsed-Field and Radiofrequency Ablation on Heterogeneous Ventricular Scar in a Swine Model of Healed Myocardial Infarction. Circ Arrhythm Electrophysiol 2022; 15:e011209. [PMID: 36194542 DOI: 10.1161/circep.122.011209] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pulsed-field ablation (PFA) is a nonthermal energy with higher selectivity to myocardial tissue in comparison to radiofrequency ablation (RFA). We compared the effects of PFA and RFA on heterogeneous ventricular scar in a swine model of healed infarction. METHODS In 9 swine, myocardial infarction was created by balloon occlusion of the left anterior descending artery. After a survival period of 8 to 10 weeks, ablation with PFA or RFA was performed at infarct border zones identified by abnormal electrograms. In the PFA group (4 swine), ablation was performed with a lattice catheter (Sphere-9, Affera, Inc). In the RFA group (5 swine), ablation was performed using a 3.5-mm tip catheter (Thermocool ST-SF; Biosense Webster). To further investigate the effect of RFA on temperature development in scar tissue, intramyocardial temperature was measured in healthy and infarcted myocardium using an ex vivo bath model. RESULTS A total of 11 PFA and 15 RFA lesions were created at infarct border zones with heterogeneous scar. PFA produced uniform and well-demarcated lesions exhibiting irreversible injury characterized by cardiomyocyte death, contraction bands, and lymphocytic infiltration. This effect of PFA extended from the subendocardium through collagen and fat to the epicardial layers. In contrast, the effect of RFA is less uniform and largely limited to the subendocardium with minimal effect on viable myocardium deeper to separating layers of collagen and fat. PFA produced deeper and more transmural lesions (6.4 [interquartile range, 5.5-7.5) versus 5.4 [interquartile range, 4.8-5.9]), 72% versus 30%, respectively; P≤0.02 for each comparison). The limited effect of RFA on viable myocardium at deeper infarct layers was related to a lower intramyocardial maximal temperature compared with healthy myocardium (P=0.01). CONCLUSIONS PFA may be advantageous for ablation in ventricular scar, producing lesions that unlike RFA are not limited to the subendocardium, but also eliminate viable myocardium separated from the catheter by collagen and fat.
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PO-705-02 EFFECT OF INTERELECTRODE SPACING ON BIPOLAR VOLTAGE AMPLITUDE AND ELECTROGRAM CHARACTERISTICS IN POST INFARCTION VENTRICULAR SCAR. Heart Rhythm 2022. [DOI: 10.1016/j.hrthm.2022.03.1073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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BS-400-21 MULTIPOLAR ELECTROGRAMS: A NOVEL ALGORITHM FOR ACCURATE ANNOTATION OF NEAR-FIELD POTENTIALS IN SCAR. Heart Rhythm 2022. [DOI: 10.1016/j.hrthm.2022.03.1203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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PO-617-01 MULTIPOLAR ELECTROGRAMS: A NOVEL ALGORITHM FOR ACCURATE ANNOTATION OF NEAR-FIELD POTENTIALS IN SCAR. Heart Rhythm 2022. [DOI: 10.1016/j.hrthm.2022.03.805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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CA-527-01 THE EFFECT OF PULSED FIELD ELECTROPORATION ON VENTRICULAR SCAR IN PRE-CLINICAL MODEL OF MYOCARDIAL INFARCTION. Heart Rhythm 2022. [DOI: 10.1016/j.hrthm.2022.03.091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Increasing Lesion Dimensions of Bipolar Ablation by Modulating the Surface Area of the Return Electrode. JACC Clin Electrophysiol 2022; 8:498-510. [PMID: 35450605 DOI: 10.1016/j.jacep.2022.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/21/2021] [Accepted: 01/01/2022] [Indexed: 11/16/2022]
Abstract
OBJECTIVES This study sought to examine the effect of the return electrode's surface area on bipolar RFA lesion size. BACKGROUND Bipolar radiofrequency ablation (RFA) is typically performed between 2 3.5-mm tip catheters serving as active and return electrodes. We hypothesized that increasing the surface area of the return electrode would increase lesion dimensions by reducing the circuit impedance, thus increasing the current into a larger tissue volume enclosed between the electrodes. METHODS In step 1, ex vivo bipolar RFA was performed between 3.5-mm and custom-made return electrodes with increasing surface areas (20, 80, 180 mm2). In step 2, ex vivo bipolar RFA was performed between 3.5-mm and 3.5-mm or 8-mm electrode catheters positioned perpendicular or parallel to the tissue. In step 3, in vivo bipolar RFA was performed between 3.5-mm and either 3.5-mm or 8-mm parallel electrode at the: 1) left ventricular summit; 2) interventricular septum; and 3) healed anterior infarction. RESULTS In step 1, increasing the surface area of the return electrode resulted in lower circuit impedance (R = -0.65; P < 0.001), higher current (R = +0.80; P < 0.001), and larger lesion volume (R = +0.88; P < 0.001). In step 2, an 8-mm return electrode parallel to tissue produced larger and deeper lesions compared with a 3.5-mm return electrode (P = 0.014 and P = 0.02). Similarly, in step 3, compared with a 3.5-mm, bipolar RFA with an 8-mm return electrode produced larger (volume: 1,525 ± 871 mm3 vs 306 ± 310 mm3, respectively; P < 0.001) and more transmural lesions (88% vs 0%; P < 0.001). CONCLUSIONS Bipolar RFA using an 8-mm return electrode positioned parallel to the tissue produces larger lesions in comparison with a 3.5-mm return electrode.
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How to Use Bipolar and Unipolar Electrograms for Selecting Successful Ablation Sites of Ventricular Premature Contractions. Heart Rhythm 2022; 19:1067-1073. [PMID: 35031494 DOI: 10.1016/j.hrthm.2021.12.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/09/2021] [Accepted: 12/24/2021] [Indexed: 11/04/2022]
Abstract
BACKGROUND Local activation time is often determined the maximal negative derivative of the extracellular unipolar potential (-dV/dTmax). While this is accurate in a two-dimensional uniform tissue, propagation through nonuniform or tri-dimensional structures have shown discordance between -dV/dTmax and local activation time. OBJECTIVE Examine the relationship between bipolar and unipolar electrograms for selecting successful ablation sites of endocardial (superficial) vs intramural (deep) ventricular premature contractions (VPCs). METHODS This cohort consisted of 66 patients with VPCs presenting for ablation in a bigeminy, trigeminy, or quadrigeminy pattern. VPCs were classified as endocardial if ablation at the earliest endocardial site resulted in immediate suppression (<10sec) or as intramural if ablation resulted in delayed suppression (≥10sec), required multiple applications, or was not achieved. Unipolar and bipolar electrograms were analyzed. RESULTS In endocardial VPCs, the first rapid bipolar deflection corresponded with unipolar -dV/dTmax, occurring 20.5msec (17.8-26.0) and 16.0msec (6.8-22.0) before the QRS onset, respectively. In successfully ablated intramural VPCs, the first rapid bipolar deflection preceded the QRS onset by 14.0 msec (11.2-22.6) and coincided with the first rapid unipolar deflection although -dV/dTmax occurred 10.5msec (0.0-20.8) after the QRS onset and often coincided with far-field activity. In unsuccessfully ablated intramural VPCs, the first rapid bipolar deflection to QRS onset interval was shorter in comparison to successfully ablated intramural VPCs (1.5 vs 14.0ms; p<0.001) while the unipolar -dV/dTmax to QRS onset interval was similar (p=0.095). CONCLUSIONS Mapping of VPCs should be guided by the first rapid bipolar deflection that corresponds with a similarly early unipolar deflection but not with -dV/dTmax.
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Direction-aware mapping algorithms have minimal impact on bipolar voltage maps created using high-resolution multielectrode catheters. J Cardiovasc Electrophysiol 2021; 33:73-80. [PMID: 34822200 DOI: 10.1111/jce.15299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/11/2021] [Accepted: 10/27/2021] [Indexed: 01/05/2023]
Abstract
INTRODUCTION Direction-aware mapping algorithms improve the accuracy of voltage mapping by measuring the maximal voltage amplitude recorded in the direction of wavefront propagation. While beneficial for stationary catheters, its utility for roving catheters collecting electrograms (EGMs) at multiple angles is unknown. OBJECTIVE To compare the directional dependence of bipolar voltage amplitude between stationary and roving catheters. METHODS In 10 swine, a transcaval ablation line with a gap was created. The gap was mapped using an array catheter (Optrell™; Biosense Webster). In Step 1, the array was kept stationary over the gap, and four voltage maps were created during activation of the gap from superior, inferior, septal, and lateral directions. In Step 2, four additional maps were created; however, the catheter was allowed to move with points acquired at multiple angles. In Step 3, the gap was remapped; however, bipoles were computed using a direction-aware mapping algorithm. RESULTS In a stationary catheter position, bipolar voltage distribution was influenced by the direction of activation with maximal differences obtained between orthogonal directions 32% (13%-53%). However, roving the catheter produced similar bipolar voltage maps irrespective of the direction of activation 11% (5%-18%). A direction-aware mapping algorithm was beneficial for reducing the directional dependence of voltage maps created by stationary catheters but not by roving catheters. CONCLUSION The directional dependency of bipolar voltage amplitude is greatest when the catheter is stationary. However, when the catheter is allowed to rove and collect EGMs at multiple angles as occurs clinically, the directional dependence of bipolar voltage is minimal.
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Pulsed-Field Ablation in Ventricular Myocardium Using a Focal Catheter: The Impact of Application Repetition on Lesion Dimensions. Circ Arrhythm Electrophysiol 2021; 14:e010375. [PMID: 34459210 DOI: 10.1161/circep.121.010375] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Circular Multielectrode Pulsed Field Ablation Catheter Lasso Pulsed Field Ablation: Lesion Characteristics, Durability, and Effect on Neighboring Structures. Circ Arrhythm Electrophysiol 2021; 14:e009229. [PMID: 33417475 DOI: 10.1161/circep.120.009229] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pulsed field ablation (PFA) is a nonthermal energy with potential safety advantages over radiofrequency ablation. This study investigated a novel PFA system-a circular multielectrode catheter (PFA lasso) and a multichannel generator designed to work with Carto 3 mapping system. METHODS A 7.5F bidirectional circular catheter with 10 electrodes and variable expansion was designed for PFA (biphasic, 1800 Volts). This study included a total of 16 swine used to investigate the following 3 experimental aims: Aim 1 examined the feasibility to create a right atrial ablation line of block from the superior vena cava to the inferior vena cava. Aim 2 examined the effect of PFA on lesion maturation including durability after a 30-day survival period. Aim 3 examined the effect of high-intensity PFA (10 applications) on esophageal and phrenic nerve tissue in comparison to normal intensity radiofrequency ablation (1-2 applications). Histopathologic analysis of all cardiac, esophageal, and phrenic nerve tissue was performed. RESULTS Acute line of block was achieved in 12/12 swine (100%) and required a total PFA time of 14 seconds (interquartile range [IQR], 9-24.5) per line. Ablation line durability after 28±3 days was maintained in 11/12 (91.7%) swine. PFA resulted in transmural lesions in 179/183 (97.8%) sections and a median lesion width of 14.2 mm. High-intensity PFA (9 [IQR, 8-14] application) had no effect on the esophagus while standard intensity radiofrequency ablation (1.5 [IQR, 1-2] applications) resulted in deep esophageal tissue injury involving the muscularis propria and adventitia layers. High-intensity PFA (16 [IQR, 10-28] applications) has no effect on phrenic nerve function and structure while standard dose radiofrequency ablation (1.5 [IQR, 1-2] applications) resulted in acute phrenic nerve paralysis. CONCLUSIONS In this preclinical model, a multielectrode circular catheter and multichannel generator produced durable atrial lesions with lower vulnerability to esophageal or phrenic nerve damage.
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Temperature-Controlled Radiofrequency Ablation Using Irrigated Catheters: Maximizing Ventricular Lesion Dimensions While Reducing Steam-Pop Formation. JACC Clin Electrophysiol 2019; 6:83-93. [PMID: 31971910 DOI: 10.1016/j.jacep.2019.08.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The goal of this study was to examine the safety and efficacy of radiofrequency ablation (RFA) with irrigated catheters operated in a temperature-controlled mode for ventricular ablation. BACKGROUND Techniques to increase RFA dimensions are associated with higher risk for steam-pops. A novel irrigated catheter with circumferential thermocouples embedded in its ablation surface provides real-time surface temperature data. This study hypothesized that RFA operated in a temperature-controlled mode may allow maximizing lesion dimensions while reducing the occurrence of steam-pops. METHODS RFA with an irrigated catheter incorporating surface thermocouples was examined in 6 swine thigh muscle preparations and 15 beating ventricles at higher (50 W/60 s, Tmax50oC) and lower (50 W/60 s, Tmax45oC) temperature limits. Biophysical properties, lesion dimensions, and steam-pop occurrence were compared versus RFA with a standard catheter operated in power-control mode at higher (50 W/60 s) and lower (40W/60 s) power, and additionally at high power with half-normal saline (50 W/60 s). RESULTS In the thigh muscle preparation, lesion depth and width were similar between all groups (p = 0.90 and p = 0.17, respectively). Steam-pops were most frequent with power-controlled ablation at 50 W/60 s (82%) and least frequent with temperature-controlled ablation at 50 W/60 s, Tmax45oC (0%; p < 0.001). In the beating ventricle, lesion depth was comparable between all RFA settings (p = 0.09). Steam-pops were most frequent using power-controlled ablation at 50 W/60 s (37%) and least frequent with temperature-controlled ablation at 50 W/60 s, Tmax45oC (7%; p < 0.001). Half-normal saline had no incremental effect on lesion dimensions at 50 W in either the thigh muscle or the beating heart. CONCLUSIONS RFA using a novel irrigated catheter with surface thermocouples operated in a temperature-controlled mode can maximize lesion dimensions while reducing the risk for steam-pops.
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Safety and efficacy of delivering high-power short-duration radiofrequency ablation lesions utilizing a novel temperature sensing technology. Europace 2018; 20:f444-f450. [DOI: 10.1093/europace/euy031] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 02/13/2018] [Indexed: 11/13/2022] Open
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Evaluation of ablation catheter technology: Comparison between thigh preparation model and an in vivo beating heart. Heart Rhythm 2017; 14:1234-1240. [PMID: 28455271 DOI: 10.1016/j.hrthm.2017.04.035] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND An in vivo animal thigh model is the standard technique for evaluation of ablation catheter technologies, including efficacy and safety of ablation. However, the biophysics of ablation in a thigh model may not be similar to a beating heart. OBJECTIVE The purpose of this study was to compare efficacy and safety of ablation between a thigh preparation model and a beating heart. METHODS In 7 swine, radiofrequency ablation using a 3.5-mm open irrigated catheter (ThermoCool Smart Touch) was performed sequentially in a thigh muscle and in vivo beating ventricles. Ablation was performed at low (30 W for 40 s) and high (40 W for 60 s) energy settings and at similar contact force. Ablation lesions were scanned in high resolution and measured using electronic calipers. RESULTS A total of 152 radiofrequency ablation lesions were measured (86 thigh and 66 heart). At low energy, lesion width was greater in the thigh model (12.19 ± 1.8 mm vs 8.99 ± 2.1 mm; P <.001), whereas lesion depth was similar between the thigh and heart (5.71 ± 0.8 mm vs 5.95 ± 1.3 mm, respectively; P = .18). The planar cross-sectional lesion area was greater in the thigh model (thigh 54.8 ± 10.8 mm2 vs heart 43.1 ± 16.1 mm2; P <.001). At the high-energy setting, lesion depth, width, and area were all greater in the thigh model (thigh 91.5 ± 16.8 mm2 vs heart 56.0 ± 15.5 mm2; P <.001). The incidence of steam pop and char formation was similar between the models. CONCLUSION The thigh preparation model is a reasonable technique for evaluation of ablation catheter technology; however it often results in overestimation of lesion size, especially at higher energy settings.
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High-Resolution Mapping of Ventricular Scar. JACC Clin Electrophysiol 2017; 3:220-231. [DOI: 10.1016/j.jacep.2016.12.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/17/2016] [Accepted: 12/01/2016] [Indexed: 10/20/2022]
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Prediction of radiofrequency ablation lesion formation using a novel temperature sensing technology incorporated in a force sensing catheter. Heart Rhythm 2017; 14:248-254. [DOI: 10.1016/j.hrthm.2016.11.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Indexed: 12/29/2022]
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P085 Treatment of steroid refractory graft vs. host disease by intra-arterial infusion. Leuk Res 2007. [DOI: 10.1016/s0145-2126(07)70433-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Treatment of post-hematopoietic stem cell transplantation hemorrhagic cystitis with intravesicular sodium hyaluronate. Bone Marrow Transplant 2006; 38:507-11. [PMID: 16921402 DOI: 10.1038/sj.bmt.1705474] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hemorrhagic cystitis (HC) is a well-known complication of HSCT. Its overall incidence has been reported to vary from 7-68%. The spectrum of clinical presentation varies from asymptomatic microhematuria to life-threatening bleeding. Sodium hyaluronate is a glycosaminoglycan present on the bladder mucosa, which serves as an important protective substance against uroepithelial damage. Preparations of this component have been shown to be effective in the treatment of interstitial cystitis. We report our experience in the treatment of post-transplant HC with intravesical instillation of sodium hyaluronate. Five out of the seven patients included in this study achieved complete response, while one patient had only partial response. Sodium hyaluronate administration was not associated with any local or systemic adverse effects. We consider that the results of our study are promising and the efficacy of sodium hyaluronate in the treatment of post-transplant HC should be tested in larger cohorts of patients.
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Rapid response to alefacept given to patients with steroid resistant or steroid dependent acute graft-versus-host disease: a preliminary report. Bone Marrow Transplant 2005; 36:1097-101. [PMID: 16247429 DOI: 10.1038/sj.bmt.1705185] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We evaluated the effect of alefacept (Amevive), a novel dimeric fusion protein, in steroid resistant/dependent acute graft-versus-host-disease (aGVHD). Seven patients were treated in eight aGVHD episodes. GVHD grade at treatment initiation and at peak ranged 2-4 (median 2.5) and 2-4 (median 4), respectively. System involvement at GVHD peak included skin (n=7), gastrointestinal tract (n=5) and liver (n=3). All patients responded. However, one patient with skin GVHD and two with gastrointestinal GVHD featuring an early initial response (IR) exacerbated and CR was not achieved. Skin GVHD responded rapidly with a median of 1 day to IR and 7 days to CR. Intestinal response was slower with median 7.5 days to IR. Of the four patients that achieved IR, CR was achieved in only one (40 days to CR). None of the patients had significant hepatic GVHD before treatment so no hepatic effect of alefacept could be determined. No immediate alefacept-related side effects were observed. Late side effects included infections (aspergillus sinusitis, pneumonia, bacteremia, pharyngeal thrush), pancytopenia and hemorrhagic cystitis. Three patients had CMV reactivation while on alefacept. We conclude that alefacept may have a beneficial effect in controlling aGVHD. Further investigations in larger cohorts of patients and controlled studies are warranted.
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Low transplant-related mortality with allogeneic stem cell transplantation in elderly patients. Bone Marrow Transplant 2004; 34:155-9. [PMID: 15235577 DOI: 10.1038/sj.bmt.1704540] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Historically, age >60 years was considered a contraindication for allogeneic stem cell transplantation (allo-SCT). In recent years, elderly (>60 years) patients have become eligible for allo-SCT due to the application of reduced intensity conditioning (RIC). The present report summarizes our cumulative experience in a cohort of 17 elderly patients (age 60-67, median 62.5 years) with hematological malignancies treated with 18 allo-SCT procedures, mostly nonmyeloablative. In all, 14 patients received fludarabine and busulfan/busulfex regimen, three patients were conditioned with the fludarabine and low-dose TBI and one patient received busulfan alone. All patients displayed tri-lineage engraftment. The time to recovery of absolute neutrophil count >/=0.5 x 10(9)/l was 9-27 days (median 14 days). The time interval to platelet recovery >/=20 x 10(9)/l was 3-96 days (median 11 days). Veno-occlusive disease occurred only in 3/18 procedures and subsided with conventional treatment. Nonfatal transplant-related complications occurred in 6/18 (33.3%) procedures including: renal failure, arrhythmia, CNS bleeding, cystitis, typhlitis and gastrointestinal bleeding. Transplant-related mortality occurred in 6/18 (33.3%) episodes. Of the 17 patients, 12 (12/18 episodes) were discharged. Five of 17 (29%) patients survived (median follow-up 11 m, range 8-53 m). Our data suggest that RIC-allo-SCT may be safely applied in the elderly, suggesting that allogeneic immunotherapy may become an important tool for treatment of hematological malignancies without an age limit.
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Reduction of the Allylic Substituents in NiI(1,8-dipropenyl-1,4,8,11-tetraazacyclotetradecane)+ by the Central Ni(I) in Aqueous Solutions. Inorg Chem 2003; 42:7156-61. [PMID: 14577784 DOI: 10.1021/ic034284a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The complex Ni(II)(1,8,-di-2-propenyl-1,4,8,11-tetraazacyclotetradecane)(2+), (NiL(1))(2+), was synthesized. X-ray crystallography demonstrates that the complex obtained is the trans-III isomer. The allylic substituents shift the redox couples (NiL(1))(3+/2+) and (NiL(1))(2+/+) anodically relative to the corresponding couples for Ni(II)(1,4,8,11-tetraazacyclotetradecane)(2+), (NiL(2))(2+), as expected. Surprisingly, the lifetime of (NiL(1))(+) in neutral aqueous solutions is shorter than that of (NiL(2))(+). Pulse radiolysis experiments reveal that the allylic substituents are reduced by the central Ni(I) ion. The first step in this reduction is a general acid catalyzed process. The results suggest that this step involves schematically the reaction Ni(I)[bond]NCH(2)CH[double bond]CH(2)(+) + H(+) --> Ni(III)[bond]NCH2CH2CH(2)(2+). The latter transient decomposes slowly with a half-life time of several minutes. Preliminary results support the suggestion that (NiL(2))(+), or other Ni(I)L complexes of this family, might reduce many alkenes present in the solution.
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A new minimally ablative stem cell transplantation procedure in high-risk patients not eligible for nonmyeloablative allogeneic bone marrow transplantation. Bone Marrow Transplant 2003; 32:557-61. [PMID: 12953126 DOI: 10.1038/sj.bmt.1704190] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nonmyeloblative stem cell transplantation (NST, SCT) aims to induce host-versus-graft tolerance for subsequent immunotherapy of underlying disease with alloreactive donor lymphocytes, focusing on well-tolerated conditioning suitable for elderly individuals or for other risk factors. However, there is a subset of high-risk patients who cannot tolerate NST. A new protocol consisting of fludarabine 30 mg/m(2) x 6 days (days -8 to -2), very-low-dose busulfan (2 mg/kg x 2 days, days -6 to -5), without anti thymocyte globulin (ATG), was employed in 11 high-risk patients aged 26-58 years. Graft-versus-host-disease (GVHD) prophylaxis consisted of low-dose and short-course cyclosporine-A (CSA) alone. One patient died during the nadir due to pulmonary complications. Other patients showed rapid three-lineage engraftment, without complete aplasia; 6/10 patients did not require platelet transfusion and 8/10 had full donor chimerism without transient mixed chimerism. Owing to intentional selection of highly poor-risk patients, overall mortality was high and only one patient survived. Acute GVHD (>/=grade I) occurred in 8/10 evaluable patients, 5/8 while off CSA; 5/8 developed grade III-IV acute GVHD. It appears that our modified, minimally ablative stem cell transplantation (MST) may be used for high-risk patients in need of allo-SCT. Furthermore, although the MST conditioning is not myeloablative, it results in myeloablation of the host hematopoietic system, mediated by alloreactive lymphocytes.
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Inhibition of human immunodeficiency virus type 1 transcription by chemical cyclin-dependent kinase inhibitors. J Virol 2001; 75:7266-79. [PMID: 11461999 PMCID: PMC114962 DOI: 10.1128/jvi.75.16.7266-7279.2001] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cyclin-dependent kinases (cdk's) have recently been suggested to regulate human immunodeficiency virus type 1 (HIV-1) transcription. Previously, we have shown that expression of one cdk inhibitor, p21/Waf1, is abrogated in HIV-1 latently infected cells. Based on this result, we investigated the transcription of HIV-1 in the presence of chemical drugs that specifically inhibited cdk activity and functionally mimicked p21/Waf1 activity. HIV-1 production in virally integrated lymphocytic and monocytic cell lines, such as ACH(2), 8E5, and U1, as well as activated peripheral blood mononuclear cells infected with syncytium-inducing (SI) or non-syncytium-inducing (NSI) HIV-1 strains, were all inhibited by Roscovitine, a purine derivative that reversibly competes for the ATP binding site present in cdk's. The decrease in viral progeny in the HIV-1-infected cells was correlated with a decrease in the transcription of HIV-1 RNAs in cells treated with Roscovitine and not with the non-cdk general cell cycle inhibitors, such as hydroxyurea (G(1)/S blocker) or nocodazole (M-phase blocker). Cyclin A- and E-associated histone H1 kinases, as well as cdk 7 and 9 activities, were all inhibited in the presence of Roscovitine. The 50% inhibitory concentration of Roscovitine on cdk's 9 and 7 was determined to be approximately 0.6 microM. Roscovitine could selectively sensitize HIV-1-infected cells to apoptosis at concentrations that did not impede the growth and proliferation of uninfected cells. Apoptosis induced by Roscovitine was found in both latent and activated infected cells, as evident by Annexin V staining and the cleavage of the PARP protein by caspase-3. More importantly, contrary to many apoptosis-inducing agents, where the apoptosis of HIV-1-infected cells accompanies production and release of infectious HIV-1 viral particles, Roscovitine treatment selectively killed HIV-1-infected cells without virion release. Collectively, our data suggest that cdk's are required for efficient HIV-1 transcription and, therefore, we propose specific cdk inhibitors as potential antiviral agents in the treatment of AIDS.
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Subjective experience and attitudes towards participation in clinical trials among patients with anxiety disorders. THE ISRAEL JOURNAL OF PSYCHIATRY AND RELATED SCIENCES 1997; 34:265-9. [PMID: 9409083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Fifty-two subjects with panic disorder and generalized anxiety disorder were interviewed 12-18 months after they completed an acute treatment study (9-11 weeks) with alprazolam followed by blind and controlled drug discontinuation. Patients were questioned about the severity of their anxiety disorder and degree of functional impairment at the time of follow-up, as well as about their subjective experience as participants in a clinical trial. At the time of follow-up 78% of the patients reported none or minimal anxiety symptoms and 89% had none or only minimal functional deficit, as compared to 100% reporting moderate to severe anxiety symptoms and 57% reporting significant functional deficit before entering the study. Overall, patients felt that the participation in the study was a very positive and beneficial experience and 64% said they would not hesitate to participate in a clinical trial in the future.
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Clinical similarity and biological diversity in the response to alprazolam in patients with panic disorder and generalized anxiety disorder. Acta Psychiatr Scand 1995; 92:399-408. [PMID: 8837965 DOI: 10.1111/j.1600-0447.1995.tb09604.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Thirty-six patients with panic disorder (PD) and 35 patients with generalized anxiety disorder (GAD) participated in an open alprazolam treatment phase that preceded controlled withdrawal from alprazolam. Clinical ratings, blood pressure and heart rate were obtained along with plasma measurements of cortisol, ACTH, growth hormone and catecholamines. A similar clinical response profile was evident in both groups with rapid onset of improvement within the first week. The two diagnostic groups differed in their biological response to alprazolam. PD patients had a significant reduction in blood pressure, plasma cortisol and a trend toward significant reduction in plasma epinephrine, which were not seen in the GAD patients. GAD patients showed a significant reduction in plasma norepinephrine. These findings provide further evidence that PD and GAD are biologically distinct syndromes.
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