Patent Foramen Ovale Closure in Older Patients With Stroke: Patient Selection for Trial Feasibility.

BACKGROUND AND OBJECTIVES: Whether patent foramen ovale (PFO) closure benefits older patients with PFO and cryptogenic stroke is unknown because randomized controlled trials (RCTs) have predominantly enrolled patients younger than 60 years of age. Our objective was to estimate anticipated effects of PFO closure in older patients to predict the numbers needed to plan an RCT. METHODS: Effectiveness estimates are derived from major observational studies (Risk of Paradoxical Embolism [RoPE] Study and Oxford Vascular Study, together referred to as the "RoPE-Ox" database) and all 6 major RCTs (Systematic, Collaborative, PFO Closure Evaluation [SCOPE] Consortium). To estimate stroke recurrence risk, observed outcomes were calculated for patients older than 60 years in the age-inclusive observational databases (n = 549). To estimate the reduction in the rate of recurrent stroke associated with PFO closure vs medical therapy based on the RoPE score and the presence of high-risk PFO features, a Cox proportional hazards regression model was developed on the RCT data in the SCOPE database (n = 3,740). These estimates were used to calculate sample sizes required for a future RCT. RESULTS: Five-year risk of stroke recurrence using Kaplan-Meier estimates was 13.7 (95% CI 10.5-17.9) overall, 14.9% (95% CI 10.2-21.6) in those with high-risk PFO features. Predicted relative reduction in the event rate with PFO closure was 12.9% overall, 48.8% in those with a high-risk PFO feature. Using these estimates, enrolling all older patients with cryptogenic stroke and PFO would require much larger samples than those used for prior PFO closure trials, but selectively enrolling patients with high-risk PFO features would require totals of 630 patients for 90% power and 471 patients for 80% power, with an average of 5 years of follow-up. DISCUSSION: Based on our projections, anticipated effect sizes in older patients with high-risk features make a trial in these subjects feasible. With lengthening life expectancy in almost all regions of the world, the utility of PFO closure in older adults is increasingly important to explore.

Association of Atrial Septal Aneurysm and Shunt Size With Stroke Recurrence and Benefit From Patent Foramen Ovale Closure.

Importance: The Patent Foramen Ovale (PFO)-Associated Stroke Causal Likelihood classification system combines information regarding noncardiac patient features (vascular risk factors, infarct topography) and PFO features (shunt size and presence of atrial septal aneurysm [ASA]) to classify patients into 3 validated categories of responsiveness to treatment with PFO closure. However, the distinctive associations of shunt size and ASA, alone and in combination, have not been completely delineated. Objective: To evaluate the association of PFO closure with stroke recurrence according to shunt size and/or the presence of an ASA. Design, Setting, and Participants: Pooled individual patient data from 6 randomized clinical trials conducted from February 2000 to October 2017 that compared PFO closure with medical therapy. Patients in North America, Europe, Australia, Brazil, and South Korea with PFO-associated stroke were included. Analysis was completed in January 2022. Exposures: Transcatheter PFO closure plus antithrombotic therapy vs antithrombotic therapy alone, stratified into 4 groups based on the combination of 2 features: small vs large PFO shunt size and the presence or absence of an ASA. Main Outcomes and Measures: Recurrent ischemic stroke. Results: A total of 121 recurrent ischemic strokes occurred in the pooled 3740 patients (mean [SD] age, 45 [10] years; 1682 [45%] female) during a median (IQR) follow-up of 57 (23.7-63.8) months. Treatment with PFO closure was associated with reduced risk for recurrent ischemic stroke (adjusted hazard ratio [aHR], 0.41 [95% CI, 0.28-0.60]; P < .001). The reduction in hazard for recurrent stroke was greater for patients with both a large shunt and an ASA (aHR, 0.15 [95% CI, 0.06-0.35]) than for large shunt without ASA (aHR, 0.27 [95% CI, 0.14-0.56]), small shunt with ASA (aHR, 0.36 [95% CI, 0.17-0.78]), and small shunt without ASA (aHR, 0.68 [95% CI, 0.41-1.13]) (interaction P = .02). At 2 years, the absolute risk reduction of recurrent stroke was greater (5.5% [95% CI, 2.7-8.3]) in patients with large shunt and ASA than for patients in the other 3 categories (1.0% for all). Conclusions and Relevance: Patients with both a large shunt and an ASA showed a substantially greater beneficial association with PFO closure than patients with large shunt alone, patients with small shunt and ASA, and patients with neither large shunt nor ASA. These findings, combined with other patient features, may inform shared patient-clinician decision-making.

Detection of symptoms of late complications after stroke in young survivors with active surveillance versus usual care.

PURPOSE: Stroke survivors develop late complications after stroke (LCAS) that impair return to pre-stroke responsibilities. Optimal strategies for detection have not been developed. We assessed differences in LCAS symptom detection among young stroke survivors undergoing active surveillance versus usual care. METHODS: This was a retrospective cohort study including patients age 18-50 with ischemic stroke, transient ischemic attack, or intracerebral hemorrhage evaluated in a Stroke Clinic between 1/1/2016-12/31/2017 with at least one outpatient evaluation during the first year after stroke. "Active surveillance" involved a semi-structured interview to elicit LCAS symptoms including headache, seizures, lethargy, mood disorders, cognitive impairment, central pain, insomnia, spasticity, dystonia, and orthostasis. "Usual care" did not involve the interview. Rates of LCAS symptom detection were assessed at 0-3 months and 3-12 months. RESULTS: One hundred twenty-one stroke survivors were included, of which 37% (45) underwent active surveillance. There were no differences in baseline characteristics except hospitalization location. Patients undergoing active surveillance were more likely to have at least one LCAS symptom detected (77% vs 49% at 0-3 months, p = 0.02; 81% vs. 54% at 3-12 months, p = 0.008). Active surveillance was more likely to detect symptoms of non-motor LCAS. There were no differences for motor LCAS. CONCLUSIONS: Active surveillance leads to higher rates of early symptom detection of non-motor LCAS in young stroke survivors.Implications for rehabilitationYoung stroke survivors frequently have late complications after stroke (LCAS) that impair return to pre-stroke responsibilities.Active surveillance for LCAS symptoms with a semi-structured interview increases detection of non-motor late complications.A bundled approach to screening for LCAS symptoms is pragmatic as a majority of young stroke survivors have at least one symptom but no single symptom is present in all stroke survivors.

Heterogeneity of Treatment Effects in an Analysis of Pooled Individual Patient Data From Randomized Trials of Device Closure of Patent Foramen Ovale After Stroke.

Importance: Patent foramen ovale (PFO)-associated strokes comprise approximately 10% of ischemic strokes in adults aged 18 to 60 years. While device closure decreases stroke recurrence risk overall, the best treatment for any individual is often unclear. Objective: To evaluate heterogeneity of treatment effect of PFO closure on stroke recurrence based on previously developed scoring systems. Design, Setting, and Participants: Investigators for the Systematic, Collaborative, PFO Closure Evaluation (SCOPE) Consortium pooled individual patient data from all 6 randomized clinical trials that compared PFO closure plus medical therapy vs medical therapy alone in patients with PFO-associated stroke, and included a total of 3740 participants. The trials were conducted worldwide from 2000 to 2017. Exposures: PFO closure plus medical therapy vs medical therapy alone. Subgroup analyses used the Risk of Paradoxical Embolism (RoPE) Score (a 10-point scoring system in which higher scores reflect younger age and the absence of vascular risk factors) and the PFO-Associated Stroke Causal Likelihood (PASCAL) Classification System, which combines the RoPE Score with high-risk PFO features (either an atrial septal aneurysm or a large-sized shunt) to classify patients into 3 categories of causal relatedness: unlikely, possible, and probable. Main Outcomes and Measures: Ischemic stroke. Results: Over a median follow-up of 57 months (IQR, 24-64), 121 outcomes occurred in 3740 patients. The annualized incidence of stroke with medical therapy was 1.09% (95% CI, 0.88%-1.36%) and with device closure was 0.47% (95% CI, 0.35%-0.65%) (adjusted hazard ratio [HR], 0.41 [95% CI, 0.28-0.60]). The subgroup analyses showed statistically significant interaction effects. Patients with low vs high RoPE Score had HRs of 0.61 (95% CI, 0.37-1.00) and 0.21 (95% CI, 0.11-0.42), respectively (P for interaction = .02). Patients classified as unlikely, possible, and probable using the PASCAL Classification System had HRs of 1.14 (95% CI, 0.53-2.46), 0.38 (95% CI, 0.22-0.65), and 0.10 (95% CI, 0.03-0.35), respectively (P for interaction = .003). The 2-year absolute risk reduction was -0.7% (95% CI, -4.0% to 2.6%), 2.1% (95% CI, 0.6%-3.6%), and 2.1% (95% CI, 0.9%-3.4%) in the unlikely, possible, and probable PASCAL categories, respectively. Device-associated adverse events were generally higher among patients classified as unlikely; the absolute risk increases in atrial fibrillation beyond day 45 after randomization with a device were 4.41% (95% CI, 1.02% to 7.80%), 1.53% (95% CI, 0.33% to 2.72%), and 0.65% (95% CI, -0.41% to 1.71%) in the unlikely, possible, and probable PASCAL categories, respectively. Conclusions and Relevance: Among patients aged 18 to 60 years with PFO-associated stroke, risk reduction for recurrent stroke with device closure varied across groups classified by their probabilities that the stroke was causally related to the PFO. Application of this classification system has the potential to guide individualized decision-making.

Risk of Paradoxical Embolism (RoPE)-Estimated Attributable Fraction Correlates With the Benefit of Patent Foramen Ovale Closure: An Analysis of 3 Trials.

BACKGROUND AND PURPOSE: In patients with cryptogenic stroke and patent foramen ovale (PFO), the Risk of Paradoxical Embolism (RoPE) Score has been proposed as a method to estimate a patient-specific "PFO-attributable fraction"-the probability that a documented PFO is causally-related to the stroke, rather than an incidental finding. The objective of this research is to examine the relationship between this RoPE-estimated PFO-attributable fraction and the effect of closure in 3 randomized trials. METHODS: We pooled data from the CLOSURE-I (Evaluation of the STARFlex Septal Closure System in Patients With a Stroke and/or Transient Ischemic Attack due to Presumed Paradoxical Embolism through a Patent Foramen Ovale), RESPECT (Randomized Evaluation of Recurrent Stroke Comparing PFO Closure to Established Current Standard of Care Treatment), and PC (Clinical Trial Comparing Percutaneous Closure of Patent Foramen Ovale [PFO] Using the Amplatzer PFO Occluder With Medical Treatment in Patients With Cryptogenic Embolism) trials. We examine the treatment effect of closure in high RoPE score (≥7) versus low RoPE score (<7) patients. We also estimated the relative risk reduction associated with PFO closure across each level of the RoPE score using Cox proportional hazard analysis. We estimated a patient-specific attributable fraction using a PC trial-compatible (9-point) RoPE equation (omitting the neuroradiology variable), as well as a 2-trial analysis using the original (10-point) RoPE equation. We examined the Pearson correlation between the estimated attributable fraction and the relative risk reduction across RoPE strata. RESULTS: In the low RoPE score group (<7, n=912), the rate of recurrent strokes per 100 person-years was 1.37 in the device arm versus 1.68 in the medical arm (hazard ratio, 0.82 [0.42-1.59] P=0.56) compared with 0.30 versus 1.03 (hazard ratio, 0.31 [0.11-0.85] P=0.02) in the high RoPE score group (≥7, n=1221); treatment-by-RoPE score group interaction, P=0.12. The RoPE score estimated attributable fraction anticipated the relative risk reduction across all levels of the RoPE score, in both the 3-trial (r=0.95, P<0.001) and 2-trial (r=0.92, P<0.001) analyses. CONCLUSIONS: The RoPE score estimated attributable fraction is highly correlated to the relative risk reduction of device versus medical therapy. This observation suggests the RoPE score identifies patients with cryptogenic stroke who are likely to have a PFO that is pathogenic rather than incidental.

Differences in presenting symptoms of acute stroke among young and older adults.

BACKGROUND: Prior studies demonstrated that young adults with stroke present later to medical attention, have lower initial NIHSS, and are frequently misdiagnosed as compared to older adults. We sought to assess potential differences in temporal and clinical characteristics of stroke symptoms between young (age 18-50 years) and older adults (age > 50). METHODS: This retrospective cohort study included patients age ≥ 18 years hospitalized at a comprehensive stroke center with acute ischemic stroke (AIS), transient ischemic attack (TIA), or intracerebral hemorrhage (ICH). Outcomes included progression of neurologic deficits over the first 24 h, fluctuation in neurologic deficits, and characterization of the triage chief complaint as typical or atypical (less specific) for stroke. Univariate analyses for baseline covariates were performed with Chi-square and Mann-Whitney U tests. Associations with the three outcomes were assessed with multivariable logistic regression. RESULTS: 432 adults (73 young adults, 359 older adults) were included in the analysis. Overall, 28% demonstrated progression of neurologic deficits, 14% had fluctuating deficits, and 26% presented with symptoms considered atypical for stroke. After adjustment for demographics, stroke subtype, diabetes, admission blood pressure, and acute revascularization treatments, increased age was inversely associated with progression of deficits (OR 0.97 per year of age, 95% CI 0.95-0.98) and fluctuation in deficits (OR 0.98 per year of age, 95% CI 0.96-0.99). Hemorrhagic stroke subtype was inversely associated with fluctuation in neurologic deficits (OR 0.050, CI 0.0028-0.24). CONCLUSION: Young adults are more likely to have progression or fluctuation of neurologic deficits in acute stroke. Patients with ischemic stroke are more likely to have fluctuation in neurologic deficits.

Prior Stroke in PFO Patients Is Associated With Both PFO-Related and -Unrelated Factors.

Background and Purpose: To identify factors associated with prior stroke at presentation in patients with cryptogenic stroke (CS) and patent foramen ovale (PFO). Methods: We studied cross-sectional data from the International PFO Consortium Study (NCT00859885). Patients with first-ever stroke and those with prior stroke at baseline were analyzed for an association with PFO-related (right-to-left shunt at rest, atrial septal aneurysm, deep venous thrombosis, pulmonary embolism, and Valsalva maneuver) and PFO-unrelated factors (age, gender, BMI, hypertension, diabetes mellitus, hypercholesterolemia, smoking, migraine, coronary artery disease, aortic plaque). A multivariable analysis was used to adjust effect estimation for confounding, e.g., owing to the age-dependent definition of study groups in this cross-sectional study design. Results: We identified 635 patients with first-ever and 53 patients with prior stroke. Age, BMI, hypertension, diabetes mellitus, hypercholesterolemia, coronary artery disease, and right-to-left shunt (RLS) at rest were significantly associated with prior stroke. Using a pre-specified multivariable logistic regression model, age (Odds Ratio 1.06), BMI (OR 1.06), hypercholesterolemia (OR 1.90) and RLS at rest (OR 1.88) were strongly associated with prior stroke.Based on these factors, we developed a nomogram to illustrate the strength of the relation of individual factors to prior stroke. Conclusion: In patients with CS and PFO, the likelihood of prior stroke is associated with both, PFO-related and PFO-unrelated factors.

Patients' responses to incidentally discovered silent brain infarcts - a qualitative study.

BACKGROUND: Incidentally discovered silent brain infarcts (id-SBIs) are an understudied condition with probable clinical significance, but it is not known how patients respond to or prioritize this condition. We sought to assess reporting of id-SBIs and how patients approach their diagnosis. METHODS: Patients with id-SBIs were identified from sequential scans between 12/2015-5/2016, were referred by treating clinicians, or self-referred for the study. This study used qualitative semi-structured interviews. Purposeful sampling was used to achieve diversity in acuity, setting, and recruitment strategy. Interviews were audio-recorded and transcribed. A constant comparative method was used to develop a coding schema, find consensus, and iteratively explore emergent themes until thematic saturation was achieved. RESULTS: Only 10 of 102 patients prospectively identified by neuroimaging were informed of the imaging findings. Twelve participants in total were interviewed. Among the study participants, the primary themes were cognitive, emotional, and behavioral responses to diagnostic, prognostic, and therapeutic uncertainty regarding id-SBIs. Clinicians described id-SBIs to participants as an ambiguous condition. Participants feared potential consequences of id-SBIs, including symptomatic stroke, dementia, and disability. Participants attempted to reduce uncertainty with strategies including equating id-SBIs with symptomatic stroke, self-education about stroke, and seeking second opinions. CONCLUSION: Participants considered id-SBIs to be a serious medical condition. Ambiguous counseling by clinicians on id-SBIs provoked or failed to attenuate fear, leading to participants adopting strategies aimed at reducing uncertainty.

Closure of Patent Foramen Ovale and Cryptogenic Stroke: Unresolved Issues.

PURPOSE OF REVIEW: This review summarises the results of randomised trials comparing closure of patent foramen ovale (PFO) with antithrombotic therapy in patients with cryptogenic stroke. RECENT FINDINGS: Initially, three randomised trials failed to show superiority of PFO closure over antithrombotic therapy in patients with cryptogenic stroke. Three recently performed trials and the prolongation of an earlier trial provided evidence that PFO closure in patients with cryptogenic stroke and an age range of 18-60 years is superior to stroke prevention with antiplatelet therapy. PFO closure was not superior to anticoagulation. Anticoagulation, however, has a higher long-term bleeding risk. PFO closure could result in atrial fibrillation (AF) in a small number of patients. In most patients, AF was transient in duration. Optimal patient selection requires future research. In patients with cryptogenic stroke aged < 60 years, PFO closure is superior to antiplatelet therapy in the prevention of recurrent stroke.

Cost-Effectiveness of Patent Foramen Ovale Closure Versus Medical Therapy for Secondary Stroke Prevention.

BACKGROUND AND PURPOSE: Percutaneous transcatheter closure of patent foramen ovale (PFO closure) plus antiplatelet therapy has been shown to reduce the risk of recurrent stroke compared with medical therapy alone in carefully selected patients after cryptogenic stroke presumed to be from paradoxical embolism. Our objective was to determine the cost-effectiveness of PFO closure after cryptogenic stroke compared with conservative medical management from a US healthcare payer perspective. METHODS: A decision analytic Markov model estimated the 15-year cost and outcomes associated with the additional benefit of PFO closure compared with medical management alone. Model inputs were obtained from published literature, national databases, and a meta-analysis of 5 published randomized clinical trials on PFO closure. Health outcomes were measured in quality-adjusted life years (QALY). Cost-effectiveness used the incremental cost per QALY gained, whereas the net monetary benefit assumed a willingness to pay of $150 000/QALY. One-way and probabilistic sensitivity analyses estimated the uncertainty of model results. RESULTS: At 15 years, PFO closure compared with medical therapy alone improved QALY by 0.33 at a cost saving of $3568, representing an incremental net monetary benefit of $52 761 (95% interval -$8284 to $158 910). When the meta-analysis hazard ratio for stroke was increased to the 95% interval's upper bound of 0.77, one-way sensitivity analyses suggested that PFO closure's cost-effectiveness was $458 558 per additional QALY. Probabilistic sensitivity analysis suggested cost-effectiveness in 90% of simulation runs. CONCLUSIONS: PFO closure for cryptogenic strokes in the right setting is cost-effective, producing benefit in QALYs gained and potential cost savings. However, patient selection remains vitally important as marginal declines in treatment effectiveness can dramatically affect cost-effectiveness.

Correction: Clinicians' perspectives on incidentally discovered silent brain infarcts - A qualitative study.

[This corrects the article DOI: 10.1371/journal.pone.0194971.].

Clinicians' perspectives on incidentally discovered silent brain infarcts - A qualitative study.

BACKGROUND: While silent brain infarcts (SBIs) in screened cohorts are associated with risk of symptomatic stroke and dementia, the clinical significance of incidentally discovered SBIs (id-SBIs) is unknown. Detection may offer an opportunity to initiate prevention measures, but uncertainties about id-SBIs may impede clinicians from addressing them and complicate further study of this condition. METHODS AND RESULTS: This study used semi-structured interviews of practicing clinicians. Interviews were audio recorded, transcribed, and analyzed using a grounded theory approach. A constant comparative method was used to organize emergent themes and examine new themes. Purposeful sampling was employed to achieve participant diversity. Fifteen clinicians were interviewed. Emergent themes centered on uncertainty about id-SBIs, clinical decision making in response to uncertainty, and evidence needed to resolve uncertainty. All clinicians reported uncertainty about id-SBIs: diagnostic, prognostic, or therapeutic. Differential responses to uncertainties resulted in practice variation within and between specialties. Diagnostic and prognostic uncertainty discouraged disclosure of imaging findings to patients. Vascular neurologists viewed the prognostic significance of id-SBIs as similar to symptomatic stroke. Therapeutic uncertainty was common, but most participants endorsed using stroke secondary prevention strategies. Regarding future research, all internists indicated they would consider changing practices in response to observational studies, whereas half of the neurologists expressed reluctance to modify practices based on non-randomized data. Several expressed concerns about clinical trial feasibility and lack of equipoise. CONCLUSIONS: id-SBIs are a focus of uncertainty for clinicians, leading to practice variation. Future studies must address diagnostic and prognostic uncertainty to facilitate implementation of prevention strategies.

Spontaneous Coronary Artery Dissection: Current State of the Science: A Scientific Statement From the American Heart Association.

Spontaneous coronary artery dissection (SCAD) has emerged as an important cause of acute coronary syndrome, myocardial infarction, and sudden death, particularly among young women and individuals with few conventional atherosclerotic risk factors. Patient-initiated research has spurred increased awareness of SCAD, and improved diagnostic capabilities and findings from large case series have led to changes in approaches to initial and long-term management and increasing evidence that SCAD not only is more common than previously believed but also must be evaluated and treated differently from atherosclerotic myocardial infarction. High rates of recurrent SCAD; its association with female sex, pregnancy, and physical and emotional stress triggers; and concurrent systemic arteriopathies, particularly fibromuscular dysplasia, highlight the differences in clinical characteristics of SCAD compared with atherosclerotic disease. Recent insights into the causes of, clinical course of, treatment options for, outcomes of, and associated conditions of SCAD and the many persistent knowledge gaps are presented.

Cryptogenic Stroke and Patent Foramen Ovale Risk Assessment.

Stroke is a devastating condition. It is the fifth leading cause of death in the United States, and a leading cause of serious long-term disability. Stroke occurs at any age. Younger patients tend to have strokes of undetermined cause, termed cryptogenic. Herein, the authors describe the classification of stroke cause; the risk of recurrent cryptogenic stroke with patent foramen ovale (PFO); a risk assessment model to stratify incidental versus a pathogenic PFO in patients presenting with stroke; and patient selection for device occluder therapy in the context of the long-term follow-up of the RESPECT randomized clinical trial.

Long-Term Outcomes of Patent Foramen Ovale Closure or Medical Therapy after Stroke.

BACKGROUND: Whether closure of a patent foramen ovale reduces the risk of recurrence of ischemic stroke in patients who have had a cryptogenic ischemic stroke is unknown. METHODS: In a multicenter, randomized, open-label trial, with blinded adjudication of end-point events, we randomly assigned patients 18 to 60 years of age who had a patent foramen ovale (PFO) and had had a cryptogenic ischemic stroke to undergo closure of the PFO (PFO closure group) or to receive medical therapy alone (aspirin, warfarin, clopidogrel, or aspirin combined with extended-release dipyridamole; medical-therapy group). The primary efficacy end point was a composite of recurrent nonfatal ischemic stroke, fatal ischemic stroke, or early death after randomization. The results of the analysis of the primary outcome from the original trial period have been reported previously; the current analysis of data from the extended follow-up period was considered to be exploratory. RESULTS: We enrolled 980 patients (mean age, 45.9 years) at 69 sites. Patients were followed for a median of 5.9 years. Treatment exposure in the two groups was unequal (3141 patient-years in the PFO closure group vs. 2669 patient-years in the medical-therapy group), owing to a higher dropout rate in the medical-therapy group. In the intention-to-treat population, recurrent ischemic stroke occurred in 18 patients in the PFO closure group and in 28 patients in the medical-therapy group, resulting in rates of 0.58 events per 100 patient-years and 1.07 events per 100 patient-years, respectively (hazard ratio with PFO closure vs. medical therapy, 0.55; 95% confidence interval [CI], 0.31 to 0.999; P=0.046 by the log-rank test). Recurrent ischemic stroke of undetermined cause occurred in 10 patients in the PFO closure group and in 23 patients in the medical-therapy group (hazard ratio, 0.38; 95% CI, 0.18 to 0.79; P=0.007). Venous thromboembolism (which comprised events of pulmonary embolism and deep-vein thrombosis) was more common in the PFO closure group than in the medical-therapy group. CONCLUSIONS: Among adults who had had a cryptogenic ischemic stroke, closure of a PFO was associated with a lower rate of recurrent ischemic strokes than medical therapy alone during extended follow-up. (Funded by St. Jude Medical; RESPECT ClinicalTrials.gov number, NCT00465270 .).