Registry-based Randomized Clinical Trials Research Articles

Electronic Nudges to Increase Influenza Vaccination in Patients With Chronic Diseases

Despite strong worldwide guideline recommendations, influenza vaccination rates remain suboptimal among young and middle-aged patients with chronic diseases. Effective scalable strategies to increase vaccination are needed. To investigate whether electronically delivered letter-based nudges informed by behavioral science could increase influenza vaccination uptake among patients aged 18 to 64 years with chronic diseases. Nationwide pragmatic registry-based randomized clinical implementation trial conducted between September 24, 2023, and May 31, 2024, enrolling all Danish citizens aged 18 to 64 years who met criteria for free-of-charge influenza vaccination in light of preexisting chronic disease. All trial data were sourced from nationwide administrative health registries. Randomized in 2.45:1:1:1:1:1:1 ratio to no letter (usual care) or 6 different behaviorally informed electronic letters. The primary end point was receipt of influenza vaccination on or before January 1, 2024, assessed in 7 prespecified coprimary comparisons (all intervention groups pooled vs usual care and each individual intervention group vs usual care). Absolute risk difference in proportions and a crude relative risk were calculated for each comparison. A total of 299 881 participants (53.2% [159 454] female, median age, 52.0 [IQR, 39.8-59.0] years) were randomized. Compared with usual care, influenza vaccination rates were higher among those receiving any intervention letter (any intervention letter, 39.6% vs usual care, 27.9%; difference, 11.7 percentage points; 99.29% CI, 11.2-12.2 percentage points; P < .001). Each individual letter type significantly increased influenza vaccination with the largest effect sizes observed with a repeated letter sent 10 days after the initial letter (repeated letter, 41.8% vs usual care, 27.9%; difference, 13.9 percentage points; 99.29% CI, 13.1-14.7 percentage points; P < .001) and a letter emphasizing potential cardiovascular benefits of vaccination (cardiovascular gain, 39.8% vs usual care, 27.9%; difference, 11.9 percentage points; 99.29% CI, 11.1-12.7 percentage points; P < .001). Vaccination rates were improved across major subgroups. In a nationwide randomized clinical implementation trial, electronically delivered letter-based nudges markedly increased influenza vaccination compared with usual care among young and middle-aged patients with chronic diseases. The results of this study suggest that simple, scalable, and cost-efficient electronic letter strategies may have substantial public health implications. ClinicalTrials.gov Identifier: NCT06030739.

Effects of beta-blockers on quality of life and well-being in patients with myocardial infarction and preserved left ventricular function-a prespecified substudy from REDUCE-AMI.

In the Randomized Evaluation of Decreased Usage of Beta-Blockers after Acute Myocardial Infarction (REDUCE-AMI) study, long-term beta-blocker use in patients after acute myocardial infarction (AMI) with preserved left ventricular ejection fraction demonstrated no effect on death or cardiovascular outcomes. The aim of this prespecified substudy was to investigate effects of beta-blockers on self-reported quality of life and well-being. From this parallel-group, open-label, registry-based randomized clinical trial, EQ-5D, and World Health Organization well-being index-5 (WHO-5) questionnaires were obtained at 6-10 weeks and 11-13 months after AMI in 4080 and 806 patients, respectively. We report results from intention-to-treat and on-treatment analyses for the overall population and relevant subgroups using Wilcoxon rank sum test and adjusted ordinal regression analyses. Of the 4080 individuals reporting EQ-5D (median age 64 years, 22% female), 2023 were randomized to beta-blockers. The main outcome, median EQ-5D index score, was 0.94 [interquartile range (IQR) 0.88, 0.97] in the beta-blocker group, and 0.94 (IQR 0.88, 0.97) in the no-beta-blocker group 6-10 weeks after AMI, OR 1.00 [95% CI 0.89-1.13; P>0.9]. After 11-13 months, results remained unchanged. Findings were robust in on-treatment analyses and across relevant subgroups. Secondary outcomes, EQ-VAS and WHO-5 index score, confirmed these results. Among patients after AMI with preserved left ventricular ejection fraction, self-reported quality of life and well-being was not significantly different in individuals randomized to routine long-term beta-blocker therapy as compared to individuals with no beta-blocker use. These results appear consistent regardless of adherence to randomized treatment and across subgroups which emphasizes the need for a careful individual risk-benefit evaluation prior to initiation of beta-blocker treatment.

Rationale and design of INFINITY-SWEDEHEART: A registry-based randomized clinical trial comparing clinical outcomes of the sirolimus-eluting DynamX bioadaptor to the zotarolimus-eluting Resolute Onyx stent

Modern drug-eluting stents have seen significant improvements, yet still create a rigid cage within the coronary artery. There is a 2% to 4% annual incidence of target lesion failure (TLF) beyond 1 year, and half of the patients experience angina after 5 years. The DynamX bioadaptor is a sirolimus-eluting, thin (71 µm) cobalt-chromium platform with helical strands that unlock and separate after in vivo degradation of the bioresorbable polymer coating. This allows the vessel to return to normal physiological function and motion, along with compensatory adaptive remodeling, which may reduce the need for reintervention and alleviate angina following percutaneous coronary intervention (PCI). The INFINITY-SWEDEHEART trial is a single-blind, registry-based randomized clinical trial (R-RCT) to evaluate the safety and effectiveness of the DynamX bioadaptor compared to the Resolute Onyx stent in the treatment of patients with ischemic heart disease with de novo native coronary artery lesions. The R-RCT framework allows for recruitment, randomization, and pragmatic data collection of baseline demographics, medications, and clinical outcomes using existing national clinical registries integrated with the trial database. The primary objective is to demonstrate noninferiority in terms of freedom from TLF (cardiovascular death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization) at 1 year. Powered secondary endpoints will be tested sequentially for superiority from 6 months to the end of follow-up (5 years) for the following: 1) TLF in all subjects, 2) target vessel failure in all subjects, and 3) TLF in subjects with acute coronary syndrome (ACS). Subsequent superiority testing will be performed at a time determined depending on the number of events, ensuring sufficient statistical power. Change in angina-related symptoms, function and quality of life will be assessed using the Seattle Angina Questionnaire-short version. Predefined sub-groups will be analyzed. In total, 2400 patients have been randomized at 20 sites in Sweden. Available baseline characteristic reveal relatively old age (68 years) and a large proportion of ACS patients including 25% STEMI and 37% NSTEMI patients. The INFINITY-SWEDEHEART study is designed to evaluate the long-term safety and efficacy of the DynamX bioadaptor compared to the Resolute Onyx stent in a general PCI patient population.

Harnessing the Potential of Real-World Evidence in the Treatment of Colorectal Cancer: Where Do We Stand?

Treatment guidelines for colorectal cancer (CRC) are primarily based on the results of randomized clinical trials (RCTs), the gold standard methodology to evaluate safety and efficacy of oncological treatments. However, generalizability of trial results is often limited due to stringent eligibility criteria, underrepresentation of specific populations, and more heterogeneity in clinical practice. This may result in an efficacy-effectiveness gap and uncertainty regarding meaningful benefit versus treatment harm. Meanwhile, conduct of traditional RCTs has become increasingly challenging due to identification of a growing number of (small) molecular subtypes. These challenges-combined with the digitalization of health records-have led to growing interest in use of real-world data (RWD) to complement evidence from RCTs. RWD is used to evaluate epidemiological trends, quality of care, treatment effectiveness, long-term (rare) safety, and quality of life (QoL) measures. In addition, RWD is increasingly considered in decision-making by clinicians, regulators, and payers. In this narrative review, we elaborate on these applications in CRC, and provide illustrative examples. As long as the quality of RWD is safeguarded, ongoing developments, such as common data models, federated learning, and predictive modelling, will further unfold its potential. First, whenever possible, we recommend conducting pragmatic trials, such as registry-based RCTs, to optimize generalizability and answer clinical questions that are not addressed in registrational trials. Second, we argue that marketing approval should be conditional for patients who would have been ineligible for the registrational trial, awaiting planned (non) randomized evaluation of outcomes in the real world. Third, high-quality effectiveness results should be incorporated in treatment guidelines to aid in patient counseling. We believe that a coordinated effort from all stakeholders is essential to improve the quality of RWD, create a learning healthcare system with optimal use of trials and real-world evidence (RWE), and ultimately ensure personalized care for every CRC patient.

Dual or single antiplatelet therapy after coronary surgery for acute coronary syndrome (TACSI trial): Rationale and design of an investigator-initiated, prospective, multinational, registry-based randomized clinical trial

The TACSI trial (ClinicalTrials.gov Identifier: NCT03560310) tests the hypothesis that 1-year treatment with dual antiplatelet therapy with acetylsalicylic acid (ASA) and ticagrelor is superior to only ASA after isolated coronary artery bypass grafting (CABG) in patients with acute coronary syndrome. The TACSI trial is an investigator-initiated pragmatic, prospective, multinational, multicenter, open-label, registry-based randomized trial with 1:1 randomization to dual antiplatelet therapy with ASA and ticagrelor or ASA only, in patients undergoing first isolated CABG, with a planned enrollment of 2200 patients at Nordic cardiac surgery centers. The primary efficacy end point is a composite of time to all-cause death, myocardial infarction, stroke, or new coronary revascularization within 12 months after randomization. The primary safety end point is time to hospitalization due to major bleeding. Secondary efficacy end points include time to the individual components of the primary end point, cardiovascular death, and rehospitalization due to cardiovascular causes. High-quality health care registries are used to assess primary and secondary end points. The patients will be followed for 10 years. The TACSI trial will give important information useful for guiding the antiplatelet strategy in acute coronary syndrome patients treated with CABG.

David G. Sherman Lecture Award: 15-Year Experience of the Nationwide Multicenter Stroke Registry in Korea.

The expected growth of stroke burden in Korea in early 2000s led to the initiation of a government-funded clinical research project with the goal of development and implementation of national stroke guidelines. The CRCS-K (Clinical Research Collaboration for Stroke in Korea) began as a part of this project. For stroke epidemiology and quality of care research, the CRCS-K developed a multicenter, prospective, stroke registry and began collection of data in 2008. Now, about 100 000 cases have been registered at 17 university hospitals or regional stroke centers and about 200 articles have been published based on the registry experience. The analysis of the 10-year secular trends showed overall improvement of stroke care and outcomes and areas for improvement. This large-scale, high-quality dataset provides opportunities to explore and compare treatment disparities using the comparative effectiveness research methods, design and conduct a registry-based randomized clinical trial, connect the registry data with other data sources including the national claims data and neuroimaging or genetic data, and collaborate with other international researchers. An international stroke registry consortium may be a viable future direction.

5-Year Outcomes of PCI Guided by Measurement of Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve

BackgroundInstantaneous wave-free ratio (iFR) is a coronary physiology index used to assess the severity of coronary artery stenosis to guide revascularization. iFR has previously demonstrated noninferior short-term outcome compared to fractional flow reserve (FFR), but data on longer-term outcome have been lacking. ObjectivesThe purpose of this study was to investigate the prespecified 5-year follow-up of the primary composite outcome of all-cause mortality, myocardial infarction, and unplanned revascularization of the iFR-SWEDEHEART trial comparing iFR vs FFR in patients with chronic and acute coronary syndromes. MethodsiFR-SWEDEHEART was a multicenter, controlled, open-label, registry-based randomized clinical trial using the Swedish Coronary Angiography and Angioplasty Registry for enrollment. A total of 2,037 patients were randomized to undergo revascularization guided by iFR or FFR. ResultsNo patients were lost to follow-up. At 5 years, the rate of the primary composite endpoint was 21.5% in the iFR group and 19.9% in the FFR group (HR: 1.09; 95% CI: 0.90-1.33). The rates of all-cause death (9.4% vs 7.9%; HR: 1.20; 95% CI: 0.89-1.62), nonfatal myocardial infarction (5.7% vs 5.8%; HR: 1.00; 95% CI: 0.70-1.44), and unplanned revascularization (11.6% vs 11.3%; HR: 1.02; 95% CI: 0.79-1.32) were also not different between the 2 groups. The outcomes were consistent across prespecified subgroups. ConclusionsIn patients with chronic or acute coronary syndromes, an iFR-guided revascularization strategy was associated with no difference in the 5-year composite outcome of death, myocardial infarction, and unplanned revascularization compared with an FFR-guided revascularization strategy. (Evaluation of iFR vs FFR in Stable Angina or Acute Coronary Syndrome [iFR SWEDEHEART]; NCT02166736)

Opportunities and barriers for the use of Australian cancer registries as platforms for randomized clinical trials

It is well recognized that randomized controlled trials (RCTs) are a powerful tool to investigate causal relationships, and are considered the gold standard level of research evidence. However, RCTs can be expensive and time-consuming, and when they employ strict eligibility criteria, it results in an unrepresentative population and limited external validity. Recently, the registry-based randomized clinical trial (RRCT) has emerged as an alternative trial design. Utilizing registries to underpin such studies, RRCTs can have advantages including rapid recruitment, and enhanced generalizability. In Australia, legislated mandatory reporting of cancer diagnoses means that jurisdictional cancer registries are a rich source of systematically collected patient details, representing sound platforms for comprehensive data capture that can serve as a key tool for further research. We review the roles of cancer registries in Australia, discuss important considerations relevant to the design of RRCTs, and outline the opportunities provided by cancer registries to strengthen cancer research.

Registry-based randomized clinical trials in cardiology: opportunities and challenges

Registry-based randomized clinical trials in cardiology: opportunities and challenges

The Full Revasc (Ffr-gUidance for compLete non-cuLprit REVASCularization) Registry-based randomized clinical trial

BackgroundComplete revascularization in ST elevation myocardial infarction (STEMI) patients with multivessel disease has resulted in reduction in composite clinical endpoints in medium sized trials. Only one trial showed an effect on hard clinical endpoints, but the revascularization procedure was guided by angiographic evaluation of stenosis severity. Consequently, it is not clear how Fractional Flow Reserve (FFR)-guided percutaneous coronary intervention (PCI) affects hard clinical endpoints in STEMI. Methods and ResultsThe Ffr-gUidance for compLete non-cuLprit REVASCularization (FULL REVASC) – is a pragmatic, multicenter, international, registry-based randomized clinical trial designed to evaluate whether a strategy of FFR-guided complete revascularization of non-culprit lesions, reduces the combined primary endpoint of total mortality, non-fatal MI and unplanned revascularization. 1,545 patients were randomized to receive FFR-guided PCI during the index hospitalization or initial conservative management of non-culprit lesions. We found that in angiographically severe non-culprit lesions of 90-99% severity, 1 in 5 of these lesions were re-classified as non-flow limiting by FFR. Considering lesions of intermediate severity (70%-89%), half were re-classified as non-flow limiting by FFR. The study is event driven for an estimated follow-up of at least 2.75 years to detect a 9.9%/year>7.425%/year difference (HR = 0.74 at 80% power (α = .05)) for the combined primary endpoint. ConclusionThis large randomized clinical trial is designed and powered to evaluate the effect of complete revascularization with FFR-guided PCI during index hospitalization on total mortality, non-fatal MI and unplanned revascularization following primary PCI in STEMI patients with multivessel disease. Enrollment completed in September 2019 and follow-up is ongoing.

ENSAT registry-based randomized clinical trials for adrenocortical carcinoma.

Adrenocortical carcinoma (ACC) is an orphan disease lacking effective systemic treatment options. The low incidence of the disease and high cost of clinical trials are major obstacles in the search for improved treatment strategies. As a novel approach, registry-based clinical trials have been introduced in clinical research, so allowing for significant cost reduction, but without compromising scientific benefit. Herein, we describe how the European Network for the Study of Adrenal Tumours (ENSAT) could transform its current registry into one fit for a clinical trial infrastructure. The rationale to perform randomized registry-based trials in ACC is outlined including an analysis of relevant limitations and challenges. We summarize a survey on this concept among ENSAT members who expressed a strong interest in the concept and rated its scientific potential as high. Legal aspects, including ethical approval of registry-based randomization were identified as potential obstacles. Finally, we describe three potential randomized registry-based clinical trials in an adjuvant setting and for advanced disease with a high potential to be executed within the framework of an advanced ENSAT registry. Thus we, therefore, provide the basis for future registry-based trials for ACC patients. This could ultimately provide proof-of-principle of how to perform more effective randomized trials for an orphan disease.

No-touch saphenous vein grafts in coronary artery surgery (SWEDEGRAFT): Rationale and design of a multicenter, prospective, registry-based randomized clinical trial

The SWEDEGRAFT study (ClinicalTrials.gov Identifier: NCT03501303) tests the hypothesis that saphenous vein grafts (SVGs) harvested with the "no-touch" technique improves patency of coronary artery bypass grafts compared with the conventional open skeletonized technique. This article describes the rationale and design of the randomized trial and baseline characteristics of the population enrolled during the first 9 months of enrollment. The SWEDEGRAFT study is a prospective, binational multicenter, open-label, registry-based trial in patients undergoing first isolated nonemergent coronary artery bypass grafting (CABG), randomized 1:1 to no-touch or conventional open skeletonized vein harvesting technique, with a planned enrollment of 900 patients. The primary end point is the proportion of patients with graft failure defined as SVGs occluded or stenosed >50% on coronary computed tomography angiography at 2 years after CABG, earlier clinically driven coronary angiography demonstrating an occluded or stenosed >50% vein graft, or death within 2 years. High-quality health registries and coronary computed tomography angiography are used to assess the primary end point. The secondary end points include wound healing in the vein graft sites and the composite outcome of major adverse cardiac events during the first 2 years based on registry data. Demographics of the first 200 patients enrolled in the trial and other CABG patients operated in Sweden during the same time period are comparable when the exclusion criteria are taken into consideration. RCT# NCT03501303.

Swedish guidelines for registry-based randomized clinical trials

During the last decade Sweden has invested in a national infrastructure for collection of structured clinical data in the form of healthcare registries (in Sweden known as Kvalitetsregister). These data can be combined with other public data using the national personal identifiers that are issued to Swedish citizens. The healthcare registries have an almost complete coverage of Swedish healthcare, and a large network of clinicians is involved in the quality assurance and continuous improvement of healthcare using these registries. Uppsala Clinical Research Center (UCR) has been a technology provider of large-scale national registries and has a strong background in clinical trial management. This effort combines the areas of healthcare registries and clinical trials into a novel way of performing clinical trials to be able to: 1) run clinical trials as an integrated part of normal clinic workflow; and 2) leverage the nationwide network of outcome reporting. This strategy was shown to be successful in the TASTE (Thrombus Aspiration in Myocardial Infarction) study. When TASTE had been published, the New England Journal of Medicine wrote a perspective on the study calling it ‘The randomized registry trial—the next disruptive technology in clinical research?’ Since then several studies have been conducted in this way with great success. UCR has been appointed, by Clinical Studies Sweden and the Swedish Research Council, to develop the Swedish national guidelines for registry-based randomized clinical trials in order to ensure the possibility for more organizations to run this kind of study. This paper describes key concepts of register-based randomized clinical trials and the development of Swedish national guidelines.

Long-Term Effects of Oxygen Therapy on Death or Hospitalization for Heart Failure in Patients With Suspected Acute Myocardial Infarction

In the DETO2X-AMI trial (Determination of the Role of Oxygen in Suspected Acute Myocardial Infarction), we compared supplemental oxygen with ambient air in normoxemic patients presenting with suspected myocardial infarction and found no significant survival benefit at 1 year. However, important secondary end points were not yet available. We now report the prespecified secondary end points cardiovascular death and the composite of all-cause death and hospitalization for heart failure. In this pragmatic, registry-based randomized clinical trial, we used a nationwide quality registry for coronary care for trial procedures and evaluated end points through the Swedish population registry (mortality), the Swedish inpatient registry (heart failure), and cause of death registry (cardiovascular death). Patients with suspected acute myocardial infarction and oxygen saturation of ≥90% were randomly assigned to receive either supplemental oxygen at 6 L/min for 6 to 12 hours delivered by open face mask or ambient air. A total of 6629 patients were enrolled. Acute heart failure treatment, left ventricular systolic function assessed by echocardiography, and infarct size measured by high-sensitive cardiac troponin T were similar in the 2 groups during the hospitalization period. All-cause death or hospitalization for heart failure within 1 year after randomization occurred in 8.0% of patients assigned to oxygen and in 7.9% of patients assigned to ambient air (hazard ratio, 0.99; 95% CI, 0.84–1.18; P=0.92). During long-term follow-up (median [range], 2.1 [1.0–3.7] years), the composite end point occurred in 11.2% of patients assigned to oxygen and in 10.8% of patients assigned to ambient air (hazard ratio, 1.02; 95% CI, 0.88–1.17; P=0.84), and cardiovascular death occurred in 5.2% of patients assigned to oxygen and in 4.8% assigned to ambient air (hazard ratio, 1.07; 95% CI, 0.87–1.33; P=0.52). The results were consistent across all predefined subgroups. Routine use of supplemental oxygen in normoxemic patients with suspected myocardial infarction was not found to reduce the composite of all-cause mortality and hospitalization for heart failure, or cardiovascular death within 1 year or during long-term follow-up. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01787110.

Uppsala Clinical Research Center—development of a platform to promote national and international clinical science

Uppsala Clinical Research Center (UCR) is a non-profit organization that provides service for clinical research aiming for development and improvement of health care in Sweden and worldwide. UCR was started in 2001 with the ambition to shift the focus of clinical research from new medications or devices launched by the industry to problem-based research on issues identified in clinical reality, for example through the national quality registries. In order to accomplish these goals, UCR has established services in: 1) clinical trials of new and old methods in health care; 2) quality development of the health care system supported by internet-based national quality registries; 3) biostatistics, epidemiology, and data management; 4) biobanking of biological materials (Uppsala Biobank); 5) high-throughput biochemical analyses (UCR laboratory); and 6) academic leadership by the members of the UCR research faculty. The UCR clinical trials group provides services for investigator-driven projects in all areas of health care, for global mega-trials on new pharmaceutical treatments and devices, for biobanking including biomarker and genetics analyses, and for clinical events adjudication in national as well as global mega-trials. During the last few years, UCR has been a pioneer in establishing the registry-based randomized clinical trial (R-RCT), which today is an international model on how to perform cost-effective pragmatic randomized trials in the real-world environment. In 2002, UCR started the first national competence center for national quality registries, which pioneered the development of the current internet-based technologies for registering, reporting, and supporting continuous systematic improvement of health care. UCR is currently harboring around 20 national quality registries in all areas of health care. Today, UCR is the leading European center for registry-based quality development and evaluation of new medical treatments in cardiovascular care and has started to support other European countries in implementing the UCR registry platform in order to improve quality of care in the European Union.

The Swedish vascular registry Swedvasc 1987–2018

The Swedish vascular registry, Swedvasc, was created in 1987 as a regional registry and achieved national coverage in 1994. This article describes how the registry developed during those 31 years. The aims of the registry were to enhance quality improvement and research within the field of vascular surgery. The registry was validated on several occasions and in 2015 an independent international validation took place, showing both excellent external (no missing cases) and internal validity (comparing the variables in the registry with case records). The Swedvasc was instrumental in the creation of Vascunet in 1997, the international collaboration of vascular registries in Europe, Australia and New Zealand. Enabling international comparisons of indications, techniques and outcomes has proven to be a great force in quality improvement. This collaboration is now turning global, including the North American registry the Society for Vascular Surgery Vascular Quality Initiative (SVS-VQI) and hopefully soon also including the Japanese registry. The Swedvasc is used as an integral part of routine healthcare and over 10,000 procedures are registered annually. This provides clinicians, clinics, health authorities and researchers with real-world data from an unselected nationwide population. Registry data have been used to describe patterns of treatment and outcomes over time and for monitoring quality of care locally, nationally and internationally and for quality improvement projects. The clinical data available in Swedvasc provide an important source not only for assessment and development of healthcare but also for research and over 100 original articles based on Swedvasc data have been published. A randomization module has been included in the registry since 2014 and opens up a new clinical trial paradigm; registry-based randomized clinical trials.

Re-inventing the randomized controlled trial in medical oncology: The registry-based trial.

Substantial progress has recently been made in optimizing the management of cancer patients, resulting in major gains in survival and quality of life. Much of this progress has resulted from the serial testing of promising treatment strategies, typically using prospective randomized controlled trials to compare outcomes achieved with the new approach versus the current standard(s) of care. However, there is an ever-expanding list of important questions that are difficult to investigate, particularly with respect to determining the optimal sequencing and combination of proven active agents. With the rapidly growing list of clinical, pathologic and molecular characteristics that promise to predict treatment benefit and/or risk for defined patient subsets, many new questions regarding how best to personalize our approach to treatment selection are emerging. These questions can be investigated in the context of registry-based randomized clinical trials. Recently, the potential of registry-based randomized clinical trials was demonstrated in cardiology, highlighting the ability to rapidly recruit large numbers of patients to a trial addressing an important clinical question, with minimal cost and high external validity. In this review, we discuss the challenges and limitations of conventional clinical trials in multidisciplinary cancer care, describe the potential advantages of registry-based randomized trials, and highlight several registry-based oncology studies that are already underway to demonstrate the feasibility of this approach.

Randomized clinical comparison of the dual-therapy CD34 antibody-covered sirolimus-eluting Combo stent with the sirolimus-eluting Orsiro stent in patients treated with percutaneous coronary intervention: Rationale and study design of the Scandinavian Organization for Randomized Trials with Clinical Outcome (SORT OUT) X trial

BackgroundThe Combo stent (OrbusNeich, Hoevelaken, the Netherlands) combining an abluminal, bioabsorbable polymer eluting sirolimus with a luminal CD34+ antibody to capture endothelial progenitor cells has been developed to further improve safety and efficacy of coronary interventions. We have designed a large-scale registry-based randomized clinical trial to compare the Combo stent to the Orsiro stent (Biotronik, Bülach, Switzerland) in patients undergoing percutaneous coronary intervention. MethodsThe SORT OUT X study will randomly assign 3,140 patients to treatment with Combo or Orsiro stents at 3 sites in Western Denmark. Patients are eligible if they are ≥18 years old, have chronic stable coronary artery disease or acute coronary syndromes, and have ≥1 coronary lesion with >50% diameter stenosis requiring treatment with a drug-eluting stent. The primary end point target lesion failure is a composite of cardiac death, myocardial infarction (not related to other than index lesion), or target lesion revascularization within 12 months. Clinically driven event detection will be derived from validated Danish registries. An event rate of 4.2% is assumed in each stent group. With a sample size of 1,570 patients in each treatment arm, a 2-group large-sample normal approximation test of proportions with a 1-sided 5% significance level will have 90% power to detect noninferiority of the Combo stent compared with the Orsiro stent with a predetermined noninferiority margin of 2.1%. ConclusionThe SORT OUT X trial will determine whether the dual-therapy Combo stent is noninferior to the Orsiro stent with respect to clinically driven events (ClinicalTrials.govNCT03216733).

Oxygen Therapy in Suspected Acute Myocardial Infarction

BackgroundThe clinical effect of routine oxygen therapy in patients with suspected acute myocardial infarction who do not have hypoxemia at baseline is uncertain.MethodsIn this registry-based randomized clinical trial, we used nationwide Swedish registries for patient enrollment and data collection. Patients with suspected myocardial infarction and an oxygen saturation of 90% or higher were randomly assigned to receive either supplemental oxygen (6 liters per minute for 6 to 12 hours, delivered through an open face mask) or ambient air.ResultsA total of 6629 patients were enrolled. The median duration of oxygen therapy was 11.6 hours, and the median oxygen saturation at the end of the treatment period was 99% among patients assigned to oxygen and 97% among patients assigned to ambient air. Hypoxemia developed in 62 patients (1.9%) in the oxygen group, as compared with 254 patients (7.7%) in the ambient-air group. The median of the highest troponin level during hospitalization was 946.5 ng per liter in the oxygen group and 983.0 ng per liter in the ambient-air group. The primary end point of death from any cause within 1 year after randomization occurred in 5.0% of patients (166 of 3311) assigned to oxygen and in 5.1% of patients (168 of 3318) assigned to ambient air (hazard ratio, 0.97; 95% confidence interval [CI], 0.79 to 1.21; P=0.80). Rehospitalization with myocardial infarction within 1 year occurred in 126 patients (3.8%) assigned to oxygen and in 111 patients (3.3%) assigned to ambient air (hazard ratio, 1.13; 95% CI, 0.88 to 1.46; P=0.33). The results were consistent across all predefined subgroups.ConclusionsRoutine use of supplemental oxygen in patients with suspected myocardial infarction who did not have hypoxemia was not found to reduce 1-year all-cause mortality. (Funded by the Swedish Heart–Lung Foundation and others; DETO2X-AMI ClinicalTrials.gov number, NCT01787110.)

Design and rationale for the Influenza vaccination After Myocardial Infarction (IAMI) trial. A registry-based randomized clinical trial

Registry studies and case-control studies have demonstrated that the risk of acute myocardial infarction (AMI) is increased following influenza infection. Small randomized trials, underpowered for clinical end points, indicate that future cardiovascular events can be reduced following influenza vaccination in patients with established cardiovascular disease. Influenza vaccination is recommended by international guidelines for patients with cardiovascular disease, but uptake is varying and vaccination is rarely prioritized during hospitalization for AMI. The Influenza vaccination After Myocardial Infarction (IAMI) trial is a double-blind, multicenter, prospective, registry-based, randomized, placebo-controlled, clinical trial. A total of 4,400 patients with ST-segment elevation myocardial infarction (STEMI) or non-STEMI undergoing coronary angiography will randomly be assigned either to in-hospital influenza vaccination or to placebo. Baseline information is collected from national heart disease registries, and follow-up will be performed using both registries and a structured telephone interview. The primary end point is a composite of time to all-cause death, a new AMI, or stent thrombosis at 1 year. The IAMI trial is the largest randomized trial to date to evaluate the effect of in-hospital influenza vaccination on death and cardiovascular outcomes in patients with STEMI or non-STEMI. The trial is expected to provide highly relevant clinical data on the efficacy of influenza vaccine as secondary prevention after AMI.