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PubMed2001

Attrition and retention of ethnically diverse subjects in a multicenter randomized controlled research trial.

Recruitment and retention of subjects is critically important for the conduct of randomized clinical trials. When significant effort is given toward recruiting members of ethnic minorities in a sample, a similar rate of retention for all subgroups of subjects is essential. Little is known about why research subjects withdraw consent to participate in research and whether attrition is influenced by ethnicity or other factors. The purpose of this study was to determine the reasons for withdrawal from a large, multicenter randomized trial and whether these reasons differed among ethnic and gender subgroups. Additionally, we were interested in comparing withdrawn subjects to matched subjects who stayed in the trial to determine what factors encouraged full study completion. Using a cohort survey design, adult subjects (n = 35) who withdrew from a large, multicenter randomized trial and matched subjects who completed the study (n = 35) were interviewed by telephone after study completion. Subjects who withdrew consent tended to be female and members of ethnic minorities. The most frequent problems-reported significantly more often by subjects who withdrew consent compared to matched retained subjects-were interference with work, lack of time, complicated and cumbersome record-keeping requirements, difficult study medicine regimens, and difficulty rescheduling appointments due to lack of flexibility on the part of study personnel. Only 17% of withdrawn subjects were satisfied with the overall research experience compared to 52% of matched retained subjects. Matched subjects who completed all required visits in the randomized controlled trial reported three reasons that promoted completion: remuneration, commitment to finish, and belief that the study was important.

Adult↗
PubMed2002

Implementing the EGASIS trial, an international multicenter acute intervention trial in stroke.

This paper describes some of the problems that were encountered during implementation of the Early GABA-ergic Activation Study In Stroke (EGASIS), a large international multicenter clinical trial evaluating the neuroprotective effect of diazepam in acute stroke. The focus is on obtaining funding for such a large international nonprofit trial, getting approval from all national and local ethics committees, shipping trial medication, and trial insurance. For each topic the specific problems and ways in which they were solved are described. Several recommendations for facilitating the running of a large international multicenter clinical trial such as EGASIS are made.

Clinical Trials as Topic↗
PubMed1999

Relationship between event rates and treatment effects in clinical site differences within multicenter trials: an example from primary Pneumocystis carinii prophylaxis.

The results of multicenter clinical trials may differ across participating clinical sites. We present a diagnostic approach for evaluating this diversity that emphasizes the relationship between the observed event rates and treatment effects. We use as an example a trial of sequential strategies of Pneumocystis prophylaxis in human immunodeficiency virus infection with 842 patients randomly allocated to start prophylaxis with trimethoprim/sulfamethoxazole, dapsone, or pentamidine. Prophylaxis failure rates varied significantly across the 30 clinical sites (0-30.3%, p = 0.002 by Fisher's exact test) with prominent variability in the pentamidine arm (0-63.6%). Starting with oral regimens was better than starting with pentamidine in sites with high rates of events, whereas the three strategies had more similar efficacy in other sites. Sites enrolling fewer patients had lower event rates and had more patients who withdrew prematurely or were lost to follow-up. In a hierarchical regression model adjusting for random measurement error in the observed event rates, starting with trimethoprim/sulfamethoxazole was predicted to be increasingly better than starting with aerosolized pentamidine as the risk of prophylaxis failure increased (p = 0.01), reducing the risk of failure by 47% when the failure rate of pentamidine was 30%, whereas the two regimens were predicted to be equivalent when the failure rate was 17%. Differences in event rates could reflect a combination of heterogeneity in diagnosis, administration of treatments, and disease risk in patients across sites. The evaluation of clinical site differences with a systematic approach focusing on event rates may give further insight in the interpretation of the results of multicenter trials beyond an average treatment effect.

AIDS-Related Opportunistic Infections↗
PubMed2001

[Tomographic studies of myocardial perfusion normality with 99m Tc-Tetrofosmin. Spanish multicenter study].

As a first phase in a nationwide multicenter study to obtain myocardial perfusion normality patterns, this work presents the study design and quality control methodology used to guarantee that the gammacameras fulfilled some minimum quality requirements. The following aspects were considered in the study design in order to guarantee the homogeneity and interchangeability of the results: creation and structure of the work group, data interchange system, data selection and acquisition, centralized archiving and processing, assessment system, study acceptance criteria and distribution of the results. To carry out the instrumental quality control, three phantom studies were established, one to control the rotation center, another to verify tomographic uniformity and a third to simulate the shape and orientation of the left ventricle. The three phantoms circulated through all of the 18 participating centers in this project, which corresponded to 19 gammacameras. Very strict guidelines had to be followed in the acquisition and processing of these phantom studies. If any camera and/or center did not fulfill the criteria established, it was advised of the problem detected in order to correct it. Once the defect was repaired, all the phantoms were sent again for verification. Uniformity of the rotation center was quantified by means of the eccentricity of a 360 degrees orbit, admitting up to a maximum of 10%. Tomographic uniformity was visually assessed, taking in account the number of slices with rings and their contrast and finally no artifacts could be present in the reconstructed study of the ventricle. The center of rotation was within limits in all the cameras except one case while the tomographic uniformity was incorrect in 6 cases. All the departments, except one, corrected the defects detected, and passed the acceptance test. The results made it possible to guarantee adequate homogeneity and instrumental quality in this multicenter study.

Coronary Circulation↗
PubMed1999

Comparison of double-bag and Y-set disconnect systems in continuous ambulatory peritoneal dialysis: a randomized prospective multicenter study.

We performed a multicenter, single-blinded, prospective randomized study on the use of a double-bag disconnect system (B) versus a Y-set disconnect system (Y). The peritonitis rate, exit site infection, clinical outcome, and patients' acceptance to the procedure were assessed. A total of 120 new end-stage renal failure patients of three regional hospitals were randomized: 60 each to the B and the Y systems. The results of 60 patients on the B system and 51 on the Y system were analyzable. They were followed up for a median of 16 months. Peritonitis rates for the B and the Y systems were 33.5 and 29.4 patient-months per episode, respectively. Exit site infection rates for the B and Y systems were 17.4 and 16.0 patient-months per episode, respectively. Four catheters were removed in each group. Patients on the B system were hospitalized for 2.1 days per patient per year related to peritonitis and exit site infection, and those on the Y system were hospitalized for 1.2 days. There was no significant difference between the B and Y systems in the incidences of peritonitis (all causes and those due to coagulase-negative staphylococci), exit site infection, and in hospitalization days. However, there was a higher percentage of gram-positive infections in the Y system (52%) than in the B system (32%) and a lower percentage of gram-negative infections in the Y system (16%) than in the B system (32%). Patients on the B system had a better acceptance of the procedure than patients on the Y system, as assessed by a six-item, 10-point questionnaire (total score, 43.1 +/- 10.2 v 37.6 +/- 9.4; P < 0.005 at 1 month; 44.6 +/- 9.1 v 39.8 +/- 8.6; P < 0.01 at 6 months). From this study, it is concluded that the B and Y systems are similar in the incidences of peritonitis and exit site infection, although the B system is better accepted by patients. This is probably the first multicenter randomized study comparing the double-bag and Y-set disconnect system using only new patients who had never used other systems of continuous ambulatory peritoneal dialysis.

Adult↗
PubMed2002

[Use of the Internet in a multicenter study of chronic obstructive pulmonary disease in primary care. Pilot phase of the EFEMAP study].

OBJECTIVE: To determine the reliability of clinical data collection and transmission by Internet in a multicenter primary care study. PATIENTS AND METHODS: Multicenter, observational study of a population of patients with exacerbated chronic obstructive pulmonary disease (COPD). All data were gathered in a specifically designed digital program on a palm-held pocket computer. Information was transmitted on-line by modem to a central database. RESULTS: Thirty-nine researchers participated in this pilot phase. Over three months 324 patients were treated. Thirty-seven telephone consultations were generated, most (54%) in reference to how the digitized questionnaire worked. Questions were solved in a mean 5.44 minutes. No important technical problems occurred and no information was lost. CONCLUSIONS: The use of the Internet to transfer data for multicentric studies in primary care is possible. This system should be more widely used in the future, as it allows faster data collection and eliminates the need to input data at the end of the study.

Acute Disease↗
PubMed2002

Outcome and patterns of failure in testicular lymphoma: a multicenter Rare Cancer Network study.

PURPOSE: To assess the outcome and patterns of failure in patients with testicular lymphoma treated by chemotherapy (CT) and/or radiation therapy (RT). METHODS AND MATERIALS: Data from a series of 36 adult patients with Ann Arbor Stage I (n = 21), II (n = 9), III (n = 3), or IV (n = 3) primary testicular lymphoma, consecutively treated between 1980 and 1999, were collected in a retrospective multicenter study by the Rare Cancer Network. Median age was 64 years (range: 21-91 years). Full staging workup (chest X-ray, testicular ultrasound, abdominal ultrasound, and/or thoracoabdominal computer tomography, bone marrow assessment, full blood count, lactate dehydrogenase, and cerebrospinal fluid evaluation) was completed in 18 (50%) patients. All but one patient underwent orchidectomy, and spermatic cord infiltration was found in 9 patients. Most patients (n = 29) had CT, consisting in most cases of cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) with (n = 17) or without intrathecal CT. External RT was delivered to scrotum alone (n = 12) or testicular, iliac, and para-aortic regions (n = 8). The median RT dose was 31 Gy (range: 20-44 Gy) in a median of 17 fractions (10-24), using a median of 1.8 Gy (range: 1.5-2.5 Gy) per fraction. The median follow-up period was 42 months (range: 6-138 months). RESULTS: After a median period of 11 months (range: 1-76 months), 14 patients presented lymphoma progression, mostly in the central nervous system (CNS) (n = 8). Among the 17 patients who received intrathecal CT, 4 had a CNS relapse (p = NS). No testicular, iliac, or para-aortic relapse was observed in patients receiving RT to these regions. The 5-year overall, lymphoma-specific, and disease-free survival was 47%, 66%, and 43%, respectively. In univariate analyses, statistically significant factors favorably influencing the outcome were early-stage and combined modality treatment. Neither RT technique nor total dose influenced the outcome. Multivariate analysis revealed that the most favorable independent factors predicting the outcome were younger age, early-stage disease, and combined modality treatment. CONCLUSIONS: In this multicenter retrospective study, CNS was found to be the principal site of relapse, and no extra-CNS lymphoma progression was observed in the irradiated volumes. More effective CNS prophylaxis, including combined modalities, should be prospectively explored in this uncommon site of extranodal lymphoma.

Adult↗
PubMed2003

The impact of contouring uncertainty on rectal 3D dose-volume data: results of a dummy run in a multicenter trial (AIROPROS01-02).

PURPOSE: To estimate the impact of the uncertainty in contouring the rectum on rectal dose-volume parameters and normal tissue complication probability (NTCP) in a prospective (AIROPROS01-02) investigation about rectal toxicity. METHODS AND MATERIALS: The participants in a prospective trial (18 observers) were asked to draw the external contour of the rectum of 4 sample patients (3 patients undergoing radical conformal radiotherapy, 1 patient undergoing post-prostatectomy) on CT images (0.5 cm spacing) using a 3D treatment planning system. A previously accepted definition of cranial and caudal borders of the rectum was applied. For each patient, four- and six-field 3D-conformal techniques (70-76 Gy, ICRU dose) were planned and DVH/dose statistics of the rectum were calculated. The impact of interobserver variability on rectal volume, cranial and caudal borders, mean, maximum, and median rectal dose, percentage of rectum receiving more than 40, 45, 50, 55, 60, 65, 70, and 75 Gy (V(40)-V(75)), and NTCP were investigated. RESULTS: Concerning DVHs, 9/18 observers tended to have some systematic deviation. However, deviations from the mean values greater than 5% were found only in 1/9 because of a systematic discrepancy in the caudal limit assessment (mean deviation from the most frequently chosen slice: 8 mm). No other observers showed a mean deviation in the cranial or the caudal limit definition greater than 5.8 mm. For another observer, it was possible to clearly assess the cause of a relatively large systematic deviation for DVH parameters. In both cases, the observers were contacted to avoid these systematic deviations. When considering the remaining 16/18 observers, the average values of SD for V(40)-V(75) ranged between 1% and 4% and were found to be lower (<3%) for the 3 nonoperated patients. The average values of the SD were around 1.5-2 Gy and less than 1.5% for mean/median dose and NTCPs, respectively. CONCLUSIONS: Concerning the uncertainty in rectum definition, the collection of rectal dose-volume data in multicenter investigations seems to be feasible after a clear and previously accepted definition of rectum is assessed. However, even with a general agreement on rectum definition, contouring appears to be a quite significant source of uncertainty. A dummy run procedure is useful in identifying possible discrepancies among single observers and in assessing reliable confidence levels on dose-volume constraints because of contouring uncertainty, making the dummy run mandatory in multicenter trials evaluating 3D dose-volume data.

Humans↗
PubMed1996

Accelerated radiation therapy for locally advanced squamous cell carcinomas of the oral cavity and oropharynx selected according to tumor cell kinetics--a phase II multicenter study.

PURPOSE: A Phase II multicenter trial testing an accelerated regimen of radiotherapy in locally advanced and inoperable cancers of the head and neck, in patients selected on the basis of 5-bromo-2-deoxyuridine/DNA flow cytometry-derived tumor potential doubling time (Tpot). METHODS AND MATERIALS: From September 1992 to September 1993, 23 patients consecutively diagnosed to have locally advanced, inoperable carcinomas of the oral cavity and the oropharynx, with Tpot of < or = 5 days, received an accelerated radiotherapy regimen (AF) based on a modification of the concomitant boost technique: 2 Gy/fraction once a day, delivered 5 days a week up to 26 Gy, followed by 2 Gy/fraction twice a day, with a 6-h interval, one of the two fractions being delivered as a concomitant boost to reduced fields, up to 66 Gy total dose (off-cord reduction at 46 Gy), shortening the overall treatment time to 4.5 weeks. A contemporary control group of 46 patients with Tpot of >5 days or unknown was treated with conventional fractionation (CF): 2 Gy/fraction once a day, 5 days a week, up to 66 Gy in 6.5 weeks, with fields shrinkage after 46 Gy. RESULTS: All patients completed the accelerated regimen according to protocol and in the prescribed overall treatment time. Immediate tolerance was fairly good: 65% of the patients in the AF group experienced Grade 3 mucositis vs. 45% in the CF group (p = n.s.). Symptoms related to mucosal reactions seemed to persist longer in AF than in CF patients. The crude proportion of mild (Grades 1 and 2) late effects on skin (p < 0.01) and salivary glands (p < 0.05) was higher in AF than in CF patients, although these reactions did not exceed the limits of tolerance. Three patients in the AF and 1 in the CF arm experienced a late Grade 4 bone complication. Actuarial estimates of severe (Grades 3 and 4) late complications showed a 2-year hazard of 33.3% in the AF arm and 49.7% in CF (p = NS). The actuarial 2-year local control rate of the AF patients was 49.4%, while actuarial 2-year overall survival for the same patients was 43.5%. CONCLUSION: The results suggested that this accelerated regimen is worth testing in a controlled randomized trial to compare different accelerated schedules. Our findings also confirmed the 5-bromo-2-deoxyuridine/DNA flow cytometry technique as a suitable method of evaluating tumor cell kinetics in multicenter clinical studies, on condition that all measurements are carried out by one most experienced laboratory.

Adult↗
PubMed1997

A prospective, randomized, double-blind multicenter trial of a single bolus injection of the novel modified t-PA E6010 in the treatment of acute myocardial infarction: comparison with native t-PA. E6010 Study Group.

OBJECTIVES: This prospective, randomized, double-blind multicenter trial evaluated the efficacy and safety of a single bolus injection of the novel modified tissue-type plasminogen activator (t-PA) E6010 in the treatment of acute myocardial infarction compared with that of native t-PA. BACKGROUND: E6010 is a novel modified t-PA with a prolonged half-life (t1/2 alpha > or = 23 min) compared with native t-PA (t1/2 alpha = 4 min). E6010 can be administered in patients as a single intravenous bolus injection, and early recanalization can be expected. METHODS: The efficacy of E6010 was compared with that of native t-PA in 199 patients with acute myocardial infarction who were treated within 6 h of onset in a prospective, randomized, double-blind multicenter trial. Patients were given either 0.22 mg/kg body weight of E6010 intravenously over 2 min or native t-PA (tisokinase) 28.8 mg or 14.4 million IU (10% of the total dose over 1 to 2 min, the remainder infused over 60 min). RESULTS: The primary end point was the recanalization rate of the infarct-related coronary artery at 60 min after the start of treatment. Time to reperfusion was shorter in the E6010 group than in the native t-PA group. Thrombolysis in Myocardial Infarction flow grade 2 or 3 recanalization at 15, 30, 45 and 60 min after administration was observed in 37%, 62%, 74% and 79% (95% confidence interval [CI] 70% to 87%) of the E6010-treated patients and in 14%, 32%, 50% and 65% (95% CI 55% to 74%) of native t-PA-treated patients, respectively (p = 0.032 at 60 min). CONCLUSIONS: The present study indicates that, compared with native t-PA, a single bolus injection of E6010 over 2 min produces a higher rate of early recanalization of the infarct-related coronary artery without fatal bleeding complications.

Aged↗
PubMed1998

Phase III multicenter trial comparing the efficacy of 2% dodecafluoropentane emulsion (EchoGen) and sonicated 5% human albumin (Albunex) as ultrasound contrast agents in patients with suboptimal echocardiograms.

OBJECTIVES: This study was performed to compare the safety and efficacy of intravenous 2% dodecafluoropentane (DDFP) emulsion (EchoGen) with that of active control (sonicated human albumin [Albunex]) for left ventricular (LV) cavity opacification in adult patients with a suboptimal echocardiogram. BACKGROUND: The development of new fluorocarbon-based echocardiographic contrast agents such as DDFP has allowed opacification of the left ventricle after peripheral venous injection. We hypothesized that DDFP was clinically superior to the Food and Drug Administration-approved active control. METHODS: This was a Phase III, multicenter, single-blind, active controlled trial. Sequential intravenous injections of active control and DDFP were given 30 min apart to 254 patients with a suboptimal echocardiogram, defined as one in which the endocardial borders were not visible in at least two segments in either the apical two- or four-chamber views. Studies were interpreted in blinded manner by two readers and the investigators. RESULTS: Full or intermediate LV cavity opacification was more frequently observed after DDFP than after active control (78% vs. 31% for reader A; 69% vs. 34% for reader B; 83% vs. 55% for the investigators, p < 0.0001). LV cavity opacification scores were higher with DDFP (2.0 to 2.5 vs. 1.1 to 1.5, p < 0.0001). Endocardial border delineation was improved by DDFP in 88% of patients versus 45% with active control (p < 0.001). Similar improvement was seen for duration of contrast effect, salvage of suboptimal echocardiograms, diagnostic confidence and potential to affect patient management. There was no difference between agents in the number of patients with adverse events attributed to the test agent (9% for DDFP vs. 6% for active control, p = 0.92). CONCLUSIONS: This Phase III multicenter trial demonstrates that DDFP is superior to sonicated human albumin for LV cavity opacification, endocardial border definition, duration of effect, salvage of suboptimal echocardiograms, diagnostic confidence and potential to influence patient management. The two agents had similar safety profiles.

Adult↗
PubMed2000

Hospital cost of endovascular versus open repair of abdominal aortic aneurysms: a multicenter study.

BACKGROUND: Technology-driven innovation in medicine is frequently associated with higher costs than conventional therapy. A significantly higher cost for endovascular ($21,250, n = 190) versus open abdominal aortic aneurysm (AAA) repair ($12,342, n = 60) was suggested by a direct cost analysis of patients in a multicenter trial. Estimated inpatient costs (not charges) incurred nationwide by hospitals for endovascular and open repair of AAA were studied to validate these observed trends. METHODS: A retrospective analysis of 131 patients undergoing endovascular AAA repair was compared with 49 patients undergoing open repair as part of a Food and Drug Administration phase II prospective multicenter clinical investigation (AneuRx-Medtronic). A model to estimate costs was constructed using important clinical descriptors of these patients. These clinical characteristics where then matched with those from 22, 460 patients undergoing AAA repair obtained from a large national database (Medicare Provider Analysis and Review). Estimated hospital cost was then assigned to each study patient according to the national average of the total hospital costs for the respective matched patients in Medicare Provider Analysis and Review. RESULTS: Total inpatient hospital costs of endovascular repair were significantly higher than that of open repair ($19,985 +/- 7396 versus $12,546 +/- 5944, respectively, P =.0001). Endograft device cost ($10,400) accounted for 52% of the total cost of endovascular repair. The 1999 mean blended Medicare reimbursement for AAA repair was $18,989. CONCLUSION: In this early development stage, hospital cost for endovascular AAA repair is significantly greater than open repair when device cost greatly exceeds $5000. Although incremental reductions in cost of endovascular repair may be anticipated if use of diagnostic studies, operating time, and length of stay decrease, device cost has the single greatest impact on the expense of endovascular AAA repair. At current device pricing, mean blended Medicare reimbursement does not cover the cost of endovascular AAA repair.

Aged↗
PubMed2000

Multicenter study of the Artisan phakic intraocular lens.

PURPOSE: To assess the Artisan intraocular lens to correct myopia in phakic eyes. SETTING: European multicenter study sponsored by Ophtec BV, Groningen, The Netherlands. METHODS: In this prospective multicenter clinical study, the Artisan lens was implanted in 518 eyes between September 1991 and October 1999. The power of the lenses ranged from -5.0 to -20.0 diopters (D). Follow-up examinations were performed at 6 months and 1, 2, and 3 years. Follow-up ranged from 6 months (n = 454) to 3 years (n = 249). The preoperative uncorrected visual acuity (UCVA) was not recorded but was estimated to be worse than 0.1. The preoperative mean best spectacle-corrected visual acuity (BSCVA) was 0.67 +/- 0.26 (SD). Endothelial cell counts were done at 6 months and 1, 2, and 3 years in a subgroup of 129 eyes. RESULTS: A UCVA of 20/40 or better was observed in 76.8% of eyes regardless of the postoperative goal. A BSCVA of 20/40 or better was observed in 93.9% of eyes and remained stable throughout the follow-up. Of the eyes with extremely high myopia (>-15.0 D), 63.3% gained 2 or more lines of BSCVA; of those with moderate myopia (-5.0 to -10.0 D), 23.5% gained 2 or more lines. The mean endothelial cell density change was 4.8% at 6 months, 2.4% at 1 year, 1.7% at 2 years, and 0.7% at 3 years. The incidence of persistent adverse events at 3 years was relatively low. Secondary surgical interventions included repositioning of the lens because of poor initial placement and lens exchange because of preoperative power calculation errors. Glare and halo effects during night driving were noted and were related to large pupils in young patients. CONCLUSION: The Artisan lens is a safe, stable, efficacious, and predictable method to correct -5.0 to -20.0 D of myopia. This study suggests that the corneal endothelial cell loss is stabilized to the physiologically normal level after 3 years.

Adolescent↗
PubMed2000

Lessons learned from enrollment in the BEST study--a multicenter, randomized trial of group psychosocial support in metastatic breast cancer.

The BEST study, a multicenter randomized trial of group psychosocial support in metastatic breast cancer, had several unusual features that may have influenced recruitment, notably the group nature of the intervention and the need for close collaboration between medical and psychosocial investigators. The recruitment process was examined in light of these features. Establishment of study centers was facilitated by involvement of experienced medical investigators who had successfully collaborated in previous research projects. Systematic evaluation of potential subjects or direct recruitment by psychosocial investigators optimized recruitment; however, the group nature of the intervention prolonged recruitment. Overall, 652 women were approached and 237 (43.3% of those medically eligible) randomized. Using population-based estimates, 24.3% of women with metastatic breast cancer were assessed for the study and 8.7% randomized. A randomization ratio of 2:1 was required to form and maintain groups. Competing clinical trials were the greatest barrier to recruitment. Five lessons were learned during recruitment for this trial: (1) multicenter randomized trials of psychosocial interventions are feasible, even in very ill patients, (2) the use of a group intervention effectively increased the required sample size by 50%, (3) similarity of randomization rates suggests that generalizability of study results will probably be comparable to that of other randomized cancer trials, (4) multidisciplinary collaborations and involvement of experienced researchers facilitated enrollment, and (5) most challenges encountered in recruitment were similar to those seen in all clinical trials.

Breast Neoplasms↗
PubMed1999

Multicenter results of TADpole heart wire system used to treat postoperative atrial fibrillation.

OBJECTIVE: Postoperative atrial fibrillation (AF) affects 20-30% of patients undergoing open-heart surgery, delays mobilization and impairs hemodynamics. Implantation of TADpole Heart Wires offers a new method of applying internal low-energy-shocks to terminate AF. The safety and efficacy of the TADpole system to treat postoperative AF was evaluated in this multicenter trial. METHODS: Two atrial wires, configured with a highly flexible 11.5 cm distal shocking and a 0.5 cm proximal pacing electrode were sutured onto the right and left atrium. Upon detection of AF, R-wave synchronized low-energy-shocks were administered via an energy attenuating External Defibrillator Interface Module or ICD programmer. RESULTS: A total of 296 patients (65+/-9.2 years, 74.7% male) have been enrolled to date in six European centers. The wire placement time was 4.2+/-2.2 min, 65 patients had a total of 83 episodes of AF treated by the TADpole Heart Wire system with a conversion rate of 88.5% (approximate energy of 6+/-2 J), early recurrence of AF was observed in ten patients (12.8%). No clinical complications were reported. The shocks were well tolerated with slight sedation. The ease of withdrawal was 2.3+/-1.2 on a graded scale of 0 (easy) to 10 (difficult). CONCLUSIONS: These multicenter results indicate that postoperative atrial cardioversion using TADpole Heart Wires is both safe and efficient. It is expected that hospital length of stay and its associated economic impact can be reduced with this therapy.

Aged↗
PubMed2000

Current practice of temporary vena cava filter insertion: a multicenter registry.

PURPOSE: To evaluate the current practice of temporary vena cava filter placement and its complications. MATERIALS AND METHODS: A multicenter registry was conducted from May 1995 until May 1997 using a standardized questionnaire. One hundred eighty-eight patients were evaluated. Patient characteristics, filter indications, filter characteristics, and complications were registered. RESULTS: Deep vein thrombosis was proven in 95.2% of the patients. Main filter indication was thrombolysis therapy (53.1%). Average filter time was 5.4 days. An Antheor filter was inserted in 56.4%, a Guenther filter in 26.6%, and a Prolyser filter in 17.%. Transfemoral filter implantation was slightly preferred (54.8%). Four patients died of pulmonary embolism (PE) during filter protection. Major filter problems were filter thrombosis (16%) and filter dislocation (4.8%). When thrombus was found in or at the filter before explantation, additional thrombolysis was performed in 16.7%, additional filter implantation in 10%, and thrombus aspiration in 6.7%; 4.8% of filters were replaced with permanent filters. DISCUSSION: Temporary vena cava filters are placed to prevent PE in a defined patient population. Despite their presence, PEs still occur in a small percentage. Problems of filter thrombosis and dislocation have to be solved. CONCLUSION: The results of this multicenter registry support the need for innovative filter design, as well as a randomized, prospective study.

Adolescent↗
PubMed1997

Outcome-based management of retinopathy of prematurity. Multicenter Trial of Cryotherapy for Retinopathy of prematurity Cooperative Group.

PURPOSE: A system is presented for sequentially computing the risk of progression of retinopathy of prematurity (ROP) for infants born weighing not more than 1250 gm. A personal computer program is used to monitor infants' risk of threshold ROP from first appearance of ROP, and the progression in severity is tracked with multiple logistic risk models developed from data in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity. METHODS: After entry of the infant's birth weight, gestational age, ethnicity, birth in the current hospital or elsewhere, single or multiple birth, and maturity zone of retinal vessels, risk of progression to threshold severity is calculated. New estimates of risk are computed at onset of ROP and prethreshold ROP (any zone I ROP, zone II stage 2+ or 3) according to the extent of retinal vascularization when ROP first appears, how rapidly ROP progresses, and how severe it is. When threshold ROP (8 total or 5 contiguous clock hours of stage 3+ in zone I or II) is reached,the system provides separate estimates of risk that the eye will have an unfavorable 3-month outcome if treated or not. RESULTS: Estimates of risk of progression to threshold disease among the 4099 patients in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity natural history study varied from less than 1% to more than 70%. For eyes with threshold disease, the risk of an unfavorable outcome at 3 months without treatment varied from less than 10% to more than 90%. CONCLUSION: This method of tracking identifies infants at high risk for severe ROP and poor structural outcome. It provides information about prognosis with a specificity heretofore impossible.

Algorithms↗
PubMed1999

Fludarabine and epirubicin in the treatment of chronic lymphocytic leukaemia: a German multicenter phase II study.

PURPOSE: Fludarabine has been reported to be the most effective single-agent in previously treated chronic lymphocytic leukaemia (CLL). Based on the in vitro synergism of fludarabine with anthracyclines and on results showing a higher efficacy of CHOP against COP we attempted to improve treatment results with a combination of fludarabine and an anthracycline. PATIENTS AND METHODS: The aim of the multicenter study was to evaluate the rate and duration of remissions and investigate the toxic and immunosuppressive effects of fludarabine and epirubicin in the treatment of CLL in Binet stages B and C as first-line therapy or in first relapse. Thirty-eight patients were treated with fludarabine 25 mg/m2 on days 1-5 and epirubicin 25 mg/m2 on days 4 and 5. RESULTS: The overall response rate (OR) was 82% (95% confidence interval (95% CI): 66%-92%) with a CR rate of 32% (95% CI: 18%-49%). For the 25 previously untreated patients the OR was 92% (95% CI: 74%-99%) including 40% CRs (95% CI: 21%-61%). Granulocytopenia grade 3 occurred in 23% of all evaluable cycles, and grade 4 in 17%. The median remission duration was 19 months (range 6-37 months). CONCLUSION: The results show that the combination of fludarabine and epirubicin is tolerable and highly effective in the treatment of CLL. With the addition of epirubicin to fludarabine, it appears possible to achieve a higher response rate and a more rapid response, especially of nodal manifestations. This regimen can be administered in an outpatient facility except for the first cycle because of the risk of a tumour lysis. The possible benefit of the combination presented here in the treatment of CLL in comparison to single-agent fludarabine treatment is presently under study in a prospective randomized multicenter study.

Adult↗