Magnetic Resonance Imaging-Guided Intravenous Thrombolysis in Cardioembolic Stroke Patients With Unknown Time of Onset　- Subanalysis of the THAWS Randomized Control Trial.

BACKGROUND: We investigated the clinical effect of intravenous thrombolysis using a magnetic resonance imaging (MRI)-guided approach in cardioembolic stroke (CE) patients with unknown time of onset.Methods and Results: This subanalysis of the THAWS trial assessed the efficacy and safety of alteplase 0.6 mg/kg in CE patients with unknown time of onset and showing diffusion-weighted imaging-fluid-attenuated inversion recovery mismatch. Patients were classified as CE and non-CE using the SSS-TOAST classification system during the acute period. The efficacy outcome was a modified Rankin Scale score of 0-1 at 90 days. In all, 126 patients from the THAWS trial were included in this study, of whom 45 (35.7%) were diagnosed with CE. In the CE group, a favorable outcome was numerically more frequent in the alteplase than control group (52% vs. 35%; adjusted odds ratio [aOR] 2.25; 95% confidence interval [CI] 0.50-9.99). However, in the non-CE group, favorable outcomes were comparable between the alteplase and control groups (44% vs. 55%, respectively; aOR 0.39; 95% CI 0.12-1.21). Treatment-by-cohort interaction for a favorable outcome was modestly significant between the CE and non-CE groups (P=0.069). In the CE group, no patients experienced symptomatic intracranial hemorrhage (ICH) or parenchymal hematoma Type II following thrombolysis. CONCLUSIONS: When an MRI-guided approach is used, CE patients with unknown time of onset appear to be suitable candidates for thrombolysis.

Metabolic syndrome is linked to the incidence of pancreatic cancer.

Background: Although previous studies have showed that metabolic syndrome is one of the contributors of pancreatic cancer, there is no clear consensus that early stages of metabolic syndrome are linked to increased incidence of pancreatic cancer. Therefore, we confirmed the linkage between metabolic syndrome and pancreatic cancer, and shown that even early stage of metabolic syndrome is linked to pancreatic cancer in the retrospective observational study. Methods: We recruited approximately 4.6 million Japanese in 2005 and followed up these subjects for more than 10 years. At the time of the enrollment, after obtaining clinical data with prescribed drugs and examining the presence or absence of metabolic syndrome (MetS), we followed up on these subjects with and without MetS to examine the incidence of pancreatic cancer. The modified criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATPIII) were used to define MetS. Findings: During the 40.7-month average follow-up period for 2,707,296 subjects with complete data for identifying MetS and important risk factors without pancreatic cancer before the enrollment, 87,857 suffered from pancreatic cancer. Pancreatic cancers occurred in 16,154 of 331,229 subjects (4.9%) in the MetS group and 71,703 of 2,376,067 patients (3.0%) in the non-MetS group (hazard ratio (HR), 1.37; 95% confidence interval [CI], 1.34-1.39; p < 0.0001 after the adjustment with age, smoking and sex). As the number of the constituent factors of MetS increased from one to five, the incidence of pancreatic cancer correspondingly increased (HR: 1.11, 1.23, 1.42, 1.66 and 2.03 using Cox proportional hazard models, p < 0.0001 each). When we defined MetS using the Japanese criteria, the results are in accord with the results using NCEP/ATPIII. Especially pre-metabolic syndrome (pre-MetS) in the Japanese criteria was tightly linked to the incidence of pancreatic cancers. Interpretation: MetS is confirmed to be linked to pancreatic cancer. Although we cannot conclude causality. We also demonstrated the link between pre-MetS and pancreatic cancer. Funding: The sponsors of the study were Japanese Heart Foundation and Japan Cardiovascular Research Foundation. This is also partially supported by Grants-in-Aid from the Ministry of Education, Culture, Sports, Science and Technology of Japan; and Grants-in-Aid from the Japan Agency for Medical Research and Development.

Intravenous Alteplase at 0.6 mg/kg for Unknown Onset Stroke with Prior Antithrombotic Medication: THAWS Randomized Clinical Trial.

AIM: This study aimed to assess the potential effect of prior antithrombotic medication for thrombolysis in an unknown onset stroke. METHODS: This was a predefined sub-analysis of the THAWS trial. Stroke patients with a time last known well ＞4.5 h who had a DWI-fluid-attenuated inversion recovery mismatch were randomly assigned (1:1) to receive alteplase at 0.6 mg/kg (alteplase group) or standard medical treatment (control group). Patients were dichotomized by prior antithrombotic medication. RESULTS: Of 126 patients (intention-to-treat population), 40 took antithrombotic medication (24 with antiplatelets alone, 13 with anticoagulants alone, and 3 with both), and the remaining 86 did not before stroke onset. Of these, 17 and 52 patients, respectively, received alteplase, and 23 and 34, respectively, had standard medical treatment. Antithrombotic therapy was initiated within 24 h after randomization less frequently in the alteplase group (12% vs. 86%, p＜0.01). Both any intracranial hemorrhage within 22-36 h (26% vs. 14%) and a modified Rankin Scale score of 0-1 at 90 days (good outcome) (47% vs. 48%) were comparable between the two groups. A good outcome was more common in the alteplase group than in the control group in patients with prior antithrombotic medication [relative risk (RR) 2.25, 95% confidence interval (CI) 1.02-4.99], but it tended to be less common in the alteplase group in those without (RR 0.69, 95% CI 0.46-1.03) (p＜0.01 for interaction). The frequency of any intracranial hemorrhage did not significantly differ between the two groups in any patients dichotomized by prior antithrombotic medication. CONCLUSION: Alteplase appears more beneficial in patients with prior antithrombotic medication.

Impact of cascade screening for catecholaminergic polymorphic ventricular tachycardia type 1.

OBJECTIVE: Human cardiac ryanodine receptor 2 (RYR2) shows autosomal-dominant inheritance in catecholaminergic polymorphic ventricular tachycardia type 1 (CPVT1); however, de novo variants have been observed in sporadic cases. Here, we investigated CPVT1-related RYR2 variant inheritance and its clinical significance between familial and de novo cases. METHODS: We enrolled 82 independent CPVT1 probands (median age: 10.0 (7.0-13.0) years; 45 male) carrying the RYR2 variants and whose biological origin could be confirmed by parental genetic analysis: assured familial inheritance (familial group: n=24) and de novo variants (de novo group: n=58). We examined the clinical characteristics of the probands and their family members carrying the RYR2 variants. RESULTS: In the de novo group, the RYR2 variants were more likely located in the C-terminus domain and less likely in the N-terminus domain than those in the familial group. The cumulative incidence of the first cardiac events (syncope and cardiac arrest (CA) or CA only) of the probands at the age of 5 and 10 years was higher in the de novo group than in the familial group. Nearly half of the probands in both groups experienced CA events before diagnosis. Only 37.5% of their genotype-positive parents had symptoms; however, at least 66.7% of the genotype-positive siblings were symptomatic. CONCLUSIONS: CPVT1 probands harbouring de novo RYR2 variants showed an earlier onset of symptoms than those with assured familial inheritance. Cascade screening may enable early diagnosis, risk stratification and prophylactic therapeutic intervention to prevent sudden cardiac death of probands and potential genotype-positive family members.

Cerebral microbleeds development after stroke thrombolysis: A secondary analysis of the THAWS randomized clinical trial.

BACKGROUND AND AIM: We determined to investigate the incidence and clinical impact of new cerebral microbleeds after intravenous thrombolysis in patients with acute stroke. METHODS: The THAWS was a multicenter, randomized trial to study the efficacy and safety of intravenous thrombolysis with alteplase in patients with wake-up stroke or unknown onset stroke. Prescheduled T2*-weighted imaging assessed cerebral microbleeds at three time points: baseline, 22-36 h, and 7-14 days. Outcomes included new cerebral microbleeds development, modified Rankin Scale (mRS) ≥3 at 90 days, and change in the National Institutes of Health Stroke Scale (NIHSS) score from 24 h to 7 days. RESULTS: Of all 131 patients randomized in the THAWS trial, 113 patients (mean 74.3 ± 12.6 years, 50 female, 62 allocated to intravenous thrombolysis) were available for analysis. Overall, 46 (41%) had baseline cerebral microbleeds (15 strictly lobar cerebral microbleeds, 14 mixed cerebral microbleeds, and 17 deep cerebral microbleeds). New cerebral microbleeds only emerged in the intravenous thrombolysis group (seven patients, 11%) within a median of 28.3 h, and did not additionally increase within a median of 7.35 days. In adjusted models, number of cerebral microbleeds (relative risk (RR) 1.30, 95% confidence interval (CI): 1.17-1.44), mixed distribution (RR 19.2, 95% CI: 3.94-93.7), and cerebral microbleeds burden ≥5 (RR 44.9, 95% CI: 5.78-349.8) were associated with new cerebral microbleeds. New cerebral microbleeds were associated with an increase in NIHSS score (p = 0.023). Treatment with alteplase in patients with baseline ≥5 cerebral microbleeds resulted in a numerical shift toward worse outcomes on ordinal mRS (median [IQR]; 4 [3-4] vs. 0 [0-3]), compared with those with <5 cerebral microbleeds (common odds ratio 17.1, 95% CI: 0.76-382.8). The association of baseline ≥5 cerebral microbleeds with ordinal mRS score differed according to the treatment group (p interaction = 0.042). CONCLUSION: New cerebral microbleeds developed within 36 h in 11% of the patients after intravenous thrombolysis, and they were significantly associated with mixed-distribution and ≥5 cerebral microbleeds. New cerebral microbleeds development might impede neurological improvement. Furthermore, cerebral microbleeds burden might affect the effect of alteplase.

Magnetic Resonance Imaging-Guided Thrombolysis (0.6 mg/kg) Was Beneficial for Unknown Onset Stroke Above a Certain Core Size: THAWS RCT Substudy.

BACKGROUND AND PURPOSE: We determined to identify patients with unknown onset stroke who could have favorable 90-day outcomes after low-dose thrombolysis from the THAWS (Thrombolysis for Acute Wake-Up and Unclear-Onset Strokes With Alteplase at 0.6 mg/kg) database. METHODS: This was a subanalysis of an investigator-initiated, multicenter, randomized, open-label, blinded-end point trial. Patients with stroke with a time last-known-well >4.5 hours who showed a mismatch between diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery were randomly assigned (1:1) to receive alteplase at 0.6 mg/kg intravenously or standard medical treatment. The patients were dichotomized by ischemic core size or National Institutes of Health Stroke Scale score, and the effects of assigned treatments were compared in each group. The efficacy outcome was favorable outcome at 90 days, defined as a modified Rankin Scale score of 0 to 1. RESULTS: The median DWI-Alberta Stroke Program Early CT Score (ASPECTS) was 9, and the median ischemic core volume was 2.5 mL. Both favorable outcome (47.1% versus 48.3%) and any intracranial hemorrhage (26% versus 14%) at 22 to 36 hours were comparable between the 68 thrombolyzed patients and the 58 control patients. There was a significant treatment-by-cohort interaction for favorable outcome between dichotomized patients by ASPECTS on DWI (P=0.026) and core volume (P=0.035). Favorable outcome was more common in the alteplase group than in the control group in patients with DWI-ASPECTS 5 to 8 (RR, 4.75 [95% CI, 1.33-30.2]), although not in patients with DWI-ASPECTS 9 to 10. Favorable outcome tended to be more common in the alteplase group than in the control group in patients with core volume >6.4 mL (RR, 6.15 [95% CI, 0.87-43.64]), although not in patients with volume ≤6.4 mL. The frequency of any intracranial hemorrhage did not differ significantly between the 2 treatment groups in any dichotomized patients. CONCLUSIONS: Patients developing unknown onset stroke with DWI-ASPECTS 5 to 8 showed favorable outcomes more commonly after low-dose thrombolysis than after standard treatment. Registration: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT02002325. URL: https://www.umin.ac.jp/ctr; Unique Identifier: UMIN000011630.

Interim Monitoring for Futility in Clinical Trials with Two Co-primary Endpoints Using Prediction.

We discuss using prediction as a flexible and practical approach for monitoring futility in clinical trials with two co-primary endpoints. This approach is appealing in that it provides quantitative evaluation of potential effect sizes and associated precision, and can be combined with flexible error-spending strategies. We extend prediction of effect size estimates and the construction of predicted intervals to the two co-primary endpoints case, and illustrate interim futility monitoring of treatment effects using prediction with an example. We also discuss alternative approaches based on the conditional and predictive powers, compare these methods and provide some guidance on the use of prediction for better decision in clinical trials with co-primary endpoints.

"BAX602" in Preventing Surgical Adhesion after Extracorporeal Ventricular Assist Device Implantation for Refractory Congestive Heart Failure: Study Protocol for a Multicenter Randomized Clinical Trial.

BACKGROUND: The high surgical risk in redo cardiac surgery is largely attributed to adhesions around the epicardium and the great vessels. BAX602 is an adhesion prevention reagent composed of two synthetic polyethylene glycols. Spraying BAX602 over the epicardium and the great vessels reportedly contributes to adhesion prevention after pediatric cardiac surgery. The present study aims to evaluate the safety and effectiveness of BAX602 spray in patients undergoing extracorporeal ventricular assist device implantation surgery to treat refractory congestive heart failure. METHODS AND DESIGN: This investigator-initiated, multicenter, pivotal, two-arm, open-label, randomized trial will include a total of 30 patients. The primary outcome measure is the severity of adhesions, which will be evaluated during re-sternotomy surgery performed 2-12 weeks after the primary extracorporeal ventricular assist device implantation surgery. The adhesion severity will be evaluated at five predefined sites using a four-grade adhesion evaluation score (0 = no adhesion; 1 = filmy and avascular adhesion; 2 = dense/vascular adhesion; 3 = cohesive adhesion). This measure will be summarized in two ways to evaluate the effect of BAX602: (1) the total score of the severity of adhesions at all five sites (ranging from 0 to 15), and (2) the total number of sites with dense/vascular or cohesive adhesions (ranging from 0 to 5). ETHICS AND DISSEMINATION: The study findings will be disseminated at regional, national, and international conferences and through peer-reviewed scientific journals. TRIAL REGISTRATION: The trial was registered in the UMIN Clinical Trials Registry (UMIN-CTR: UMIN000038998) on 6 January 2020.

Thrombolysis With Alteplase at 0.6 mg/kg for Stroke With Unknown Time of Onset: A Randomized Controlled Trial.

Background and Purpose- We assessed whether lower-dose alteplase at 0.6 mg/kg is efficacious and safe for acute fluid-attenuated inversion recovery-negative stroke with unknown time of onset. Methods- This was an investigator-initiated, multicenter, randomized, open-label, blinded-end point trial. Patients met the standard indication criteria for intravenous thrombolysis other than a time last-known-well >4.5 hours (eg, wake-up stroke). Patients were randomly assigned (1:1) to receive alteplase at 0.6 mg/kg or standard medical treatment if magnetic resonance imaging showed acute ischemic lesion on diffusion-weighted imaging and no marked corresponding hyperintensity on fluid-attenuated inversion recovery. The primary outcome was a favorable outcome (90-day modified Rankin Scale score of 0-1). Results- Following the early stop and positive results of the WAKE-UP trial (Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke), this trial was prematurely terminated with 131 of the anticipated 300 patients (55 women; mean age, 74.4±12.2 years). Favorable outcome was comparable between the alteplase group (32/68, 47.1%) and the control group (28/58, 48.3%; relative risk [RR], 0.97 [95% CI, 0.68-1.41]; P=0.892). Symptomatic intracranial hemorrhage within 22 to 36 hours occurred in 1/71 and 0/60 (RR, infinity [95% CI, 0.06 to infinity]; P>0.999), respectively. Death at 90 days occurred in 2/71 and 2/60 (RR, 0.85 [95% CI, 0.06-12.58]; P>0.999), respectively. Conclusions- No difference in favorable outcome was seen between alteplase and control groups among patients with ischemic stroke with unknown time of onset. The safety of alteplase at 0.6 mg/kg was comparable to that of standard treatment. Early study termination precludes any definitive conclusions. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT02002325.

Rationale and Design of a Prospective, Multicenter, Single-Arm Clinical Trial to Investigate the Safety and Effectiveness of Rotablator Atherectomy System as an Adjunctive Device for Endovascular Treatment of Occlusive Atherosclerotic Lesions in Below-the-Knee Arteries With Critical Limb Ischemia (RESCUE-BTK).

Background: Endovascular treatment with balloon angioplasty plays a major role in revascularization of below-the-knee (BTK) arteries in patients with critical limb ischemia (CLI). However, with severely calcified lesions, achieving optimal revascularization with balloon angioplasty alone is difficult. Therefore, we are evaluating the safety and effectiveness of the Rotablator atherectomy system as an adjunctive device in the treatment of severely calcified lesions in BTK arteries in the RESCUE-BTK trial, a multicenter, single-arm, open-label, exploratory investigator-initiated clinical study of medical devices. In this paper we describe the design of the trial. Methods and Results: Seventeen patients with CLI in whom balloon angioplasty has failed are enrolled in the study. The primary endpoint is the procedural success rate of balloon angioplasty after rotational atherectomy. Success is defined as the fulfillment of 3 requirements upon assessment by the core laboratory: (1) final residual diameter stenosis <50%; (2) the absence of a delay in flow or vessel perforation in the target artery, or both; and (3) brisk antegrade flow to the foot. Key secondary endpoints are the number of complications associated with the trial procedures and the limb salvage rate. Participants are followed-up for 6 months after the trial procedures. Conclusions: The RESCUE-BTK trial will clarify the safety and effectiveness of the adjunctive use of the Rotablator system in severely calcified lesions of BTK arteries in patients with CLI.

Japanese Antibacterial Drug Management for Cardiac Sarcoidosis (J-ACNES): A multicenter, open-label, randomized, controlled study.

BACKGROUND: Cardiac sarcoidosis (CS) is a noncaseating granulomatous disease of unknown etiology. Lifelong immunosuppressive therapy, most frequently using corticosteroids, is a standard therapy to control hypersensitivity of immune reactions and prevent inflammation. However, it sometimes causes various systemic adverse effects and requires dose escalation. Thus, additional therapy may be required for the treatment of this disease. Recently, Propionibacterium acnes (P. acnes) was reported as one of the etiologic agents of CS, indicating that antibacterial drugs (ABD) may be effective for the treatment of CS. The objective of this study was to investigate the effect of ABD treatment, in addition to standard corticosteroid therapy, in patients with CS. METHODS: The Japanese Antibacterial Drug Management for Cardiac Sarcoidosis (J-ACNES) trial was designed as a prospective, multicenter, randomized, open-label, controlled clinical trial. The patients will be randomized to receive either standard corticosteroid therapy plus ABD therapy (ABD group) or standard corticosteroid therapy (standard group). The primary endpoint is change in the total standardized uptake value at 6 months vs baseline using fluorine-18 fluorodeoxyglucose positron emission tomography and computed tomography. Secondary endpoints include efficacy, prognosis, and safety. RESULTS: The results of this study are currently under investigation. CONCLUSION: The J-ACNES trial will be the first prospective study assessing the clinical benefit and safety of ABD therapy, in addition to corticosteroid treatment, in patients with CS. Our findings may improve treatment of patients with CS, as additional ABD therapy reduces recurrence of inflammation and elucidates the mechanism of sarcoidosis.

Functional mitral stenosis after mitral valve repair for Type II dysfunction: determinants and impacts on long-term outcome.

OBJECTIVES: This study was performed to analyse the impacts of functional mitral stenosis (MS) following mitral valve (MV) repair on late cardiac function and new onset of atrial fibrillation or survival. METHODS: We retrospectively reviewed 602 patients with mitral regurgitation who underwent MV repair for Type II dysfunction from 2001. Functional MS was diagnosed when the mean transmitral pressure gradient (MTPG) was ≥5 mmHg on postoperative echocardiography. We analysed preoperative and surgical risk factors for functional MS (MS group). We then compared long-term outcomes and late cardiac function over time between patients in the MS and no-MS groups using a mixed-effects model with repeated measures. RESULTS: On postoperative echocardiography, 51 patients had an MTPG of ≥5 mmHg (MS group) and 551 had an MTPG of <5 mmHg (no-MS group). Only the ring size was an independent predictor of MS (28.8 ± 2.1 mm in the no-MS group vs 28.0 ± 1.9 mm in the MS group, P = 0.004). During follow-up, increases in the tricuspid regurgitation (TR) pressure gradient (PRV-RA) and TR severity over time were significantly greater in the MS group than in the no-MS group (PRV-RA: 0.72 ± 0.16 vs 0.35 ± 0.17 mmHg per year, respectively, P = 0.03; TR severity: 0.072 ± 0.014 vs 0.034 ± 0.015 per year, respectively, P = 0.0113). Moreover, the 10-year rate of new onset of atrial fibrillation was significantly lower in the MS group than in the no-MS group (37.5% vs 16.9%, respectively; log-rank P = 0.003). CONCLUSIONS: Annuloplasty using a small-sized ring in MV repair caused a postoperative high MTPG, which induced an elevation in the pulmonary artery pressure and residual TR grade and causing new onset of atrial fibrillation despite a competent MV.

Design, data monitoring, and analysis of clinical trials with co-primary endpoints: A review.

We review the design, data monitoring, and analyses of clinical trials with co-primary endpoints. Recently developed methods for fixed-sample and group-sequential settings are described. Practical considerations are discussed, and guidance for the application of these methods is provided.

Should annuloplasty prosthesis be selected dependent on the location of prolapse in mitral valve repair for type II dysfunction?

OBJECTIVE: This study explored the influence of prosthesis selection on long-term outcomes in patients who underwent mitral valve repair for mitral insufficiency (MI) due to type II dysfunction. METHODS: We retrospectively reviewed 452 patients with MI who underwent mitral valve repair for type II dysfunction between 2001 and 2014. Of these, 167 patients (37%) presented with anterior leaflet prolapse (anterior group) and 285 (63%) presented with posterior prolapse (posterior group). Full rings were applied in 95 patients (57%) in the anterior group and in 54 patients (19%) in the posterior group, and partial bands were applied in all others. We compared long-term outcome and change of MI severity over time between patients with partial-band and full-ring repair in the anterior and in the posterior groups using a mixed-effect model with repeated measures and propensity score-matched analysis. RESULTS: Ten-year survival of the cohort was 90.5%. Echocardiography revealed MI ≥ 3 at follow-up in 58 patients (12.8%). Twenty-one patients (4.6%) required reoperation; freedom from reoperation was 92.1% at 10 years. The MI severity over time in patients in the anterior group was higher than that in patients in the posterior group (P < .0001). Moreover, MI severity over time in patients with the partial band was higher than patients with the full ring in the anterior group (P = .0176). Propensity score-matched analysis in the anterior group, but not in the posterior group, revealed a significantly higher MI severity in patients with the partial band than those with the full ring over the study period (P = .04). CONCLUSIONS: Full-ring annuloplasty is indicated in the setting of anterior prolapse to prevent recurrent MI, whereas prosthesis type is not a determinant of recurrent MI in the setting of posterior prolapse.

Arrhythmia risk and ß-blocker therapy in pregnant women with long QT syndrome.

BACKGROUND: Pregnancy is one of the biggest concerns for women with long QT syndrome (LQTS). OBJECTIVES: This study investigated pregnancy-related arrhythmic risk and the efficacy and safety of ß-blocker therapy for lethal ventricular arrhythmias in pregnant women with LQTS (LQT-P) and their babies. METHODS: 136 pregnancies in 76 LQT-P (29±5 years old; 22 LQT1, 36 LQT2, one LQT3, and 17 genotype-unknown) were enrolled. We retrospectively analysed their clinical and electrophysiological characteristics and pregnancy outcomes in the presence (BB group: n=42) or absence of ß-blocker therapy (non-BB group: n=94). RESULTS: All of the BB group had been diagnosed with LQTS with previous events, whereas 65% of the non-BB group had not been diagnosed at pregnancy. Pregnancy increased heart rate in the non-BB group; however, no significant difference was observed in QT and Tpeak-Tend intervals between the two groups. In the BB group, only two events occurred at postpartum, whereas 12 events occurred in the non-BB group during pregnancy (n=6) or postpartum period (n=6). The frequency of spontaneous abortion did not differ between the two groups. Fetal growth rate and proportion of infants with congenital malformation were similar between the two groups, but premature delivery and low birthweight infants were more common in those taking BB (OR 4.79, 95% CI 1.51 to 15.21 and OR 3.25, 95% CI 1.17 to 9.09, respectively). CONCLUSIONS: Early diagnosis and ß-blocker therapy for high-risk patients with LQTS are important for prevention of cardiac events during pregnancy and the postpartum period, and ß-blocker therapy may be tolerated for babies in LQT-P cases.

Group-sequential three-arm noninferiority clinical trial designs.

We discuss group-sequential three-arm noninferiority clinical trial designs that include active and placebo controls for evaluating both assay sensitivity and noninferiority. We extend two existing approaches, the fixed margin and fraction approaches, into a group-sequential setting with two decision-making frameworks. We investigate the operating characteristics including power, Type I error rate, maximum, and expected sample sizes, as design factors vary. In addition, we discuss sample size recalculation and its impact on the power and Type I error rate via a simulation study.

Interim evaluation of efficacy or futility in group-sequential trials with multiple co-primary endpoints.

We discuss group-sequential designs in superiority clinical trials with multiple co-primary endpoints, that is, when trials are designed to evaluate if the test intervention is superior to the control on all primary endpoints. We consider several decision-making frameworks for evaluating efficacy or futility, based on boundaries using group-sequential methodology. We incorporate the correlations among the endpoints into the calculations for futility boundaries and sample sizes as a function of other design parameters, including mean differences, the number of analyses, and efficacy boundaries. We investigate the operating characteristics of the proposed decision-making frameworks in terms of efficacy/futility boundaries, power, the Type I error rate, and sample sizes, while varying the number of analyses, the correlations among the endpoints, and the mean differences. We provide an example to illustrate the methods and discuss practical considerations when designing efficient group-sequential designs in clinical trials with co-primary endpoints.

Sample Size Considerations in Clinical Trials when Comparing Two Interventions using Multiple Co-Primary Binary Relative Risk Contrasts.

The effects of interventions are multi-dimensional. Use of more than one primary endpoint offers an attractive design feature in clinical trials as they capture more complete characterization of the effects of an intervention and provide more informative intervention comparisons. For these reasons, multiple primary endpoints have become a common design feature in many disease areas such as oncology, infectious disease, and cardiovascular disease. More specifically in medical product development, multiple endpoints are utilized as co-primary to evaluate the effect of the new interventions. Although methodologies to address continuous co-primary endpoints are well-developed, methodologies for binary endpoints are limited. In this paper, we describe power and sample size determination for clinical trials with multiple correlated binary endpoints, when relative risks are evaluated as co-primary. We consider a scenario where the objective is to evaluate evidence for superiority of a test intervention compared with a control intervention, for all of the relative risks. We discuss the normal approximation methods for power and sample size calculations and evaluate how the required sample size, power and Type I error vary as a function of the correlations among the endpoints. Also we discuss a simple, but conservative procedure for appropriate sample size calculation. We then extend the methods allowing for interim monitoring using group-sequential methods.

Group-Sequential Strategies in Clinical Trials with Multiple Co-Primary Outcomes.

We discuss the decision-making frameworks for clinical trials with multiple co-primary endpoints in a group-sequential setting. The decision-making frameworks can account for flexibilities such as a varying number of analyses, equally or unequally spaced increments of information and fixed or adaptive Type I error allocation among endpoints. The frameworks can provide efficiency, i.e., potentially fewer trial participants, than the fixed sample size designs. We investigate the operating characteristics of the decision-making frameworks and provide guidance on constructing efficient group-sequential strategies in clinical trials with multiple co-primary endpoints.

Sample size determination in group-sequential clinical trials with two co-primary endpoints.

We discuss sample size determination in group-sequential designs with two endpoints as co-primary. We derive the power and sample size within two decision-making frameworks. One is to claim the test intervention's benefit relative to control when superiority is achieved for the two endpoints at the same interim timepoint of the trial. The other is when superiority is achieved for the two endpoints at any interim timepoint, not necessarily simultaneously. We evaluate the behaviors of sample size and power with varying design elements and provide a real example to illustrate the proposed sample size methods. In addition, we discuss sample size recalculation based on observed data and evaluate the impact on the power and Type I error rate.