Rapid assessment of cardiovascular risk among users of smoking cessation drugs within the US Food and Drug Administration's Mini-Sentinel program

Use of Contrave, Naltrexone with Bupropion, Bupropion, or Naltrexone and Major Adverse Cardiovascular Events: A Systematic Literature Review

Naltrexone/Bupropion extended release (ER; Contrave) is an extended-release, fixed-dose combination medication of naltrexone (8 mg) and bupropion (90 mg) for patients with obesity or overweight with at least one weight-related comorbidity. Obese and overweight patients with or without comorbidities are at increased cardiovascular (CV) risk. Due to the increased CV risk profile in this patient population, this systematic literature review was conducted to assess human studies reporting major adverse CV events (MACE) and other CV events. A priori eligibility criteria included clinical studies (randomized and observational) published from January 1, 2012, to September 30, 2021, with data comparing users of naltrexone/bupropion ER, naltrexone with bupropion, bupropion without naltrexone, or naltrexone without bupropion versus comparator groups (placebo or other treatments), and with sufficient information to determine the frequency of MACE or other CV adverse events by treatment group. Among 2539 English-language articles identified, 70 articles met the eligibility criteria: seven studies of naltrexone/bupropion ER or naltrexone with bupropion, 32 studies of bupropion, and 31 studies of naltrexone. No studies reported an increased risk of MACE among users of naltrexone/bupropion ER, naltrexone with bupropion, or bupropion or naltrexone individually compared with nonusers. One-half of the available studies (n = 35) reported no (zero) CV events and the other half (n = 35) reported that a non-zero frequency of CV events occurred. Four studies reported data on MACE, including three studies of bupropion and one study of naltrexone/bupropion ER. For composite MACE and its components, the difference in proportions between naltrexone/bupropion ER-, bupropion-, or naltrexone-treated patients compared with active comparators or placebo-treated patients did not exceed 2.5%. In conclusion, the available human evidence does not indicate an increased risk of CV events or MACE following use of naltrexone/bupropion ER, naltrexone with bupropion, or the individual components.

Comparison of Cardiovascular Safety for Smoking Cessation Pharmacotherapies in a Population-Based Cohort in Australia

IMPORTANCE

Although concerns exist regarding a potential increased risk of cardiovascular events for smoking cessation pharmacotherapies, there is general consensus that any increased risk associated with their use would be outweighed by the benefits of smoking cessation; thus, clinical guidelines recommend that such pharmacotherapies be offered to everyone who wants to quit smoking. In the interest of minimizing risk to patients, prescribers need evidence indicating how these pharmacotherapies compare with one another in terms of cardiovascular safety.

OBJECTIVE

To compare the risk of major adverse cardiovascular events (MACE) among individuals initiating varenicline, nicotine replacement therapy (NRT) patches, or bupropion.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, population-based cohort study using linked pharmaceutical dispensing, hospital admissions, and death data was conducted in New South Wales, Australia. Participants included adults who were dispensed a prescription smoking cessation pharmacotherapy between 2008 and 2015 or between 2011 and 2015, depending on the availability of the pharmacotherapies being compared. Pairwise comparisons were conducted for risk of MACE among 122 932 varenicline vs 92 148 NRT initiators; 342 064 varenicline vs 10 457 bupropion initiators; and 102 817 NRT vs 6056 bupropion initiators.

EXPOSURE

First course of the smoking cessation pharmacotherapy of interest.

MAIN OUTCOMES AND MEASURES

The primary outcome was MACE, defined as a composite of acute coronary syndrome, stroke, and cardiovascular death. Secondary outcomes were the individual components of MACE. Inverse probability of treatment weighting with high-dimensional propensity scores was used to account for potential confounding. Cox proportional hazards regression models with robust variance were used to estimate hazard ratios (HRs) and 95% CIs. Data were analyzed January 24, 2019, to September 1, 2021.

RESULTS

The mean (SD) age of included individuals ranged from 41.9 (14.2) to 49.8 (14.9) years, and the proportion of women ranged from 42.8% (52 702 of 123 128) to 52.2% (53 693 of 102 913). The comparison of 122 932 varenicline initiators and 92 148 NRT patch initiators showed no difference in the risk of MACE (HR, 0.87; 95% CI, 0.72-1.07) nor in the risk of the secondary outcomes of acute coronary syndrome (HR, 0.96; 95% CI, 0.76-1.21) and stroke (HR, 0.72; 95% CI, 0.45-1.14). However, decreased risk of cardiovascular death was found among varenicline initiators (HR, 0.49; 95% CI, 0.30-0.79). The results of comparisons involving bupropion were inconclusive owing to wide confidence intervals (eg, risk of MACE: 342 064 varenicline vs 10 457 bupropion initiators, HR, 0.87 [95% CI, 0.53-1.41]; 102 817 NRT patch vs 6056 bupropion initiators, HR, 0.79 [95% CI, 0.39-1.62]).

CONCLUSIONS AND RELEVANCE

The finding of this cohort study that varenicline and NRT patch use have similar risk of MACE suggests that varenicline, the most efficacious smoking cessation pharmacotherapy, may be prescribed instead of NRT patches without increasing risk of major cardiovascular events. Further large-scale studies of the cardiovascular safety of varenicline and NRT relative to bupropion are needed.

Smoking cessation: strategies and effects in primary and secondary cardiovascular prevention

Although smoking is seen as a major health problem by most clinicians, few are able to provide evidence based smoking cessation interventions to their patients. Most individuals who smoke actually want to quit. Unfortunately, smoking is still seen as a vice or lifestyle choice, when it is actually a chronic disease which often starts in adolescence. Nicotine dependence is complex and must be quantified and treated differently for each patient in order to achieve high quit rates. Smoking has a significant impact on the development and progression of cardiovascular disease. Smoking cessation is a cost effective and often overlooked prevention tool which improves both short- and long-term outcomes. There are both pharmacological and non-pharmacological strategies for smoking cessation that can be applied in clinical practice. Brief advice, specialized counseling including therapeutic education and behavioral support, and first- and second-line pharmacological interventions have been proven to be effective to help smokers quit. Although classically tobacco dependence was seen in relation to smoking, since the early 2000s, new nicotine delivery systems have appeared on the market, which despite being marketed as "healthy" alternatives, can often complicate smoking cessation efforts and act as gateway devices for new generations of smokers. In this article we review the results of several large systematic reviews and meta-analyses, which have shown that many cessation strategies are effective. We also offer practical tips on providing brief cessation advice and how pharmacotherapy can be prescribed and incorporated into clinical practice in both primary and secondary cardiovascular prevention.

The importance and implications of comparator selection in pharmacoepidemiologic research

PURPOSE OF REVIEW

Pharmacoepidemiologic studies employing large databases are critical to evaluating the effectiveness and safety of drug exposures in large and diverse populations. Because treatment is not randomized, researchers must select a relevant comparison group for the treatment of interest. The comparator group can consist of individuals initiating: (1) a similarly indicated treatment (active comparator), (2) a treatment used for a different indication (inactive comparator) or (3) no particular treatment (non-initiators). Herein we review recent literature and describe considerations and implications of comparator selection in pharmacoepidemiologic studies.

RECENT FINDINGS

Comparator selection depends on the scientific question and feasibility constraints. Because pharmacoepidemiologic studies rely on the choice to initiate or not initiate a specific treatment, rather than randomization, they are at-risk for confounding related to the comparator choice including: by indication, disease severity and frailty. We describe forms of confounding specific to pharmacoepidemiologic studies and discuss each comparator along with informative examples and a case study. We provide commentary on potential issues relevant to comparator selection in each study, highlighting the importance of understanding the population in whom the treatment is given and how patient characteristics are associated with the outcome.

SUMMARY

Advanced statistical techniques may be insufficient for reducing confounding in observational studies. Evaluating the extent to which comparator selection may mitigate or induce systematic bias is a critical component of pharmacoepidemiologic studies.

Comprehensive review of cardiovascular toxicity of drugs and related agents

Cardiovascular diseases are a leading cause of morbidity and mortality in most developed countries of the world. Pharmaceuticals, illicit drugs, and toxins can significantly contribute to the overall cardiovascular burden and thus deserve attention. The present article is a systematic overview of drugs that may induce distinct cardiovascular toxicity. The compounds are classified into agents that have significant effects on the heart, blood vessels, or both. The mechanism(s) of toxic action are discussed and treatment modalities are briefly mentioned in relevant cases. Due to the large number of clinically relevant compounds discussed, this article could be of interest to a broad audience including pharmacologists and toxicologists, pharmacists, physicians, and medicinal chemists. Particular emphasis is given to clinically relevant topics including the cardiovascular toxicity of illicit sympathomimetic drugs (e.g., cocaine, amphetamines, cathinones), drugs that prolong the QT interval, antidysrhythmic drugs, digoxin and other cardioactive steroids, beta-blockers, calcium channel blockers, female hormones, nonsteroidal anti-inflammatory, and anticancer compounds encompassing anthracyclines and novel targeted therapy interfering with the HER2 or the vascular endothelial growth factor pathway.

Design and outcomes of the Patient Centered Outcomes Research Institute coronary heart disease cohort study

Background

The Patient Centered Outcomes Research Institute (PCORI) established Clinical Data Research Networks (CDRNs) to support pragmatic research. The objective was to electronically identify, recruit, and survey coronary heart disease (CHD) patients and describe their characteristics, health status, and willingness to participate in future research.

Methods

We developed a computable phenotype and assembled CHD patients 30 years or older and had visits or hospitalizations between 2009 and 2015. A sample of patients was surveyed between August 2014 and September 2015. Survey administration included the following methods: face-to-face, telephone, paper or web portal. Survey items covered broad domains including: health literacy and numeracy, and socio-demographics, physical and mental health, health behaviors, access to medical care, and willingness to participate in future research.

Results

Of 5517 approached patients, 2605 completed the survey. Participants were mostly white (∼88%), male (68%) and had a median age of 69 years (interquartile range [IQR] 61–76 years). Most respondents' health literacy and numeracy were adequate (83.2% and 84.3%, respectively). Only 4% of respondents reported that their overall health or physical health was excellent. The majority (∼58%) reported that their health was good or very good, while 40% reported that their general and physical health were fair or poor. The majority reported that their quality of life was good to excellent (81%). Limitations in physical health and function were common, including often/always having fatigue (25%), pain (38.7%), or sleep difficulty (19.7%). A patient sample (n = 1936) was provided with a trial summary which would randomize their aspirin dose; and 63% reported that they would consider participating.

Conclusion

Many patients with CHD had limitations in physical health. However, the majority reported a good or excellent quality of life.

Priorities for Cardiovascular Outcomes Research: A Report of the National Heart, Lung, and Blood Institute's Centers for Cardiovascular Outcomes Research Working Group

The Centers for Cardiovascular Outcomes Research (CCORs) held a meeting to review how cardiovascular outcomes research had evolved in the decade since the National Heart, Lung, and Blood Institute 2004 working group report and to consider future directions. The conference involved representatives from governmental agencies, outcomes research thought leaders, and public and private healthcare partners. The main purposes of this meeting were to (1) advance collaborative high-yield, high-impact outcomes research; (2) identify priorities and barriers to important cardiovascular outcomes research; and (3) define future needs for the field. This report highlights the key topics covered during the meeting, including an examination of the recent history of outcomes research, an evaluation of the current academic climate, and a vision for the future of cardiovascular outcomes research.

A proposed approach to accelerate evidence generation for genomic-based technologies in the context of a learning health system

Genomic technologies should demonstrate analytical and clinical validity and clinical utility prior to wider adoption in clinical practice. However, the question of clinical utility remains unanswered for many genomic technologies. In this paper, we propose three building blocks for rapid generation of evidence on clinical utility of promising genomic technologies that underpin clinical and policy decisions. We define promising genomic tests as those that have proven analytical and clinical validity. First, risk-sharing agreements could be implemented between payers and manufacturers to enable temporary coverage that would help incorporate promising technologies into routine clinical care. Second, existing data networks, such as the Sentinel Initiative and the National Patient-Centered Clinical Research Network (PCORnet) could be leveraged, augmented with genomic information to track the use of genomic technologies and monitor clinical outcomes in millions of people. Third, endorsement and engagement from key stakeholders will be needed to establish this collaborative model for rapid evidence generation; all stakeholders will benefit from better information regarding the clinical utility of these technologies. This collaborative model can create a multipurpose and reusable national resource that generates knowledge from data gathered as part of routine care to drive evidence-based clinical practice and health system changes.

Efficacy and Safety of Smoking Cessation Interventions in Patients With Cardiovascular Disease

Background—

Although the efficacy and safety of smoking cessation interventions are well established, their efficacy and safety in patients with cardiovascular disease (CVD) remain unclear. The objective of this study was to evaluate the efficacy and safety of pharmacological and behavioral smoking cessation interventions in CVD patients via a meta-analysis of randomized controlled trials.

Methods and Results—

EMBASE, PsycINFO, MEDLINE, PubMed, and the Cochrane Tobacco Addiction Specialized Register were searched for randomized controlled trials evaluating the efficacy of smoking cessation pharmacotherapies and behavioral therapies in CVD patients. Outcomes of interest were smoking abstinence at 6 and 12 months, defined using the most rigorous criteria reported. Data were pooled across studies for direct comparisons using random-effects models. Network meta-analysis using a graph-theoretical approach was used to generate the indirect comparisons. Seven pharmacotherapy randomized controlled trials (n=2809) and 17 behavioral intervention randomized controlled trials (n=4666) met our inclusion criteria. Our network meta-analysis revealed that varenicline (relative risk [RR]: 2.64; 95% confidence interval [CI], 1.34–5.21) and bupropion (RR: 1.42; 95% CI, 1.01–2.01) were associated with greater abstinence than placebo. The evidence about nicotine replacement therapies was inconclusive (RR: 1.22; 95% CI, 0.72–2.06). Telephone therapy (RR: 1.47; 95% CI: 1.15–1.88) and individual counseling (RR: 1.64, 95% CI: 1.17–2.28) were both more efficacious than usual care, whereas in-hospital behavioral interventions were not (RR: 1.05; 95% CI, 0.78–1.43).

Conclusions—

Our meta-analysis suggests varenicline and bupropion, as well as individual and telephone counseling, are efficacious for smoking cessation in CVD patients.

Transparency and Reproducibility of Observational Cohort Studies Using Large Healthcare Databases

The scientific community and decision-makers are increasingly concerned about transparency and reproducibility of epidemiologic studies using longitudinal healthcare databases. We explored the extent to which published pharmacoepidemiologic studies using commercially available databases could be reproduced by other investigators. We identified a nonsystematic sample of 38 descriptive or comparative safety/effectiveness cohort studies. Seven studies were excluded from reproduction, five because of violation of fundamental design principles, and two because of grossly inadequate reporting. In the remaining studies, >1,000 patient characteristics and measures of association were reproduced with a high degree of accuracy (median differences between original and reproduction <2% and <0.1). An essential component of transparent and reproducible research with healthcare databases is more complete reporting of study implementation. Once reproducibility is achieved, the conversation can be elevated to assess whether suboptimal design choices led to avoidable bias and whether findings are replicable in other data sources.

Clinical phenotyping in selected national networks: demonstrating the need for high-throughput, portable, and computational methods

OBJECTIVE

The combination of phenomic data from electronic health records (EHR) and clinical data repositories with dense biological data has enabled genomic and pharmacogenomic discovery, a first step toward precision medicine. Computational methods for the identification of clinical phenotypes from EHR data will advance our understanding of disease risk and drug response, and support the practice of precision medicine on a national scale.

METHODS

Based on our experience within three national research networks, we summarize the broad approaches to clinical phenotyping and highlight the important role of these networks in the progression of high-throughput phenotyping and precision medicine. We provide supporting literature in the form of a non-systematic review.

RESULTS

The practice of clinical phenotyping is evolving to meet the growing demand for scalable, portable, and data driven methods and tools. The resources required for traditional phenotyping algorithms from expert defined rules are significant. In contrast, machine learning approaches that rely on data patterns will require fewer clinical domain experts and resources.

CONCLUSIONS

Machine learning approaches that generate phenotype definitions from patient features and clinical profiles will result in truly computational phenotypes, derived from data rather than experts. Research networks and phenotype developers should cooperate to develop methods, collaboration platforms, and data standards that will enable computational phenotyping and truly modernize biomedical research and precision medicine.

Varenicline and Adverse Cardiovascular Events: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

Varenicline is an efficacious smoking‐cessation drug. However, previous meta‐analyses provide conflicting results regarding its cardiovascular safety. The publication of several new randomized controlled trials (RCTs) provides an opportunity to reassess this potential adverse drug reaction.

Methods and Results

We searched MEDLINE, EMBASE, and the Cochrane Library for RCTs that compare varenicline with placebo for smoking cessation. RCTs reporting cardiovascular serious adverse events and/or all‐cause mortality during the treatment period or within 30 days of treatment discontinuation were eligible for inclusion. Relative risks (RRs) with 95% CIs were generated by using DerSimonian–Laird random‐effects models. Thirty‐eight RCTs met our inclusion criteria (N=12 706). Events were rare in both varenicline (57/7213) and placebo (43/5493) arms. No difference was observed for cardiovascular serious adverse events when comparing varenicline with placebo (RR 1.03, 95% CI 0.72–1.49). Similar findings were obtained when examining cardiovascular (RR 1.04, 95% CI 0.57–1.89) and noncardiovascular patients (RR 1.03, 95% CI 0.64–1.64). Deaths were rare in both varenicline (11/7213) and placebo (9/5493) arms. Although 95% CIs were wide, pooling of all‐cause mortality found no difference between groups (RR 0.88, 95% CI 0.50–1.52), including when stratified by participants with (RR 1.24, 95% CI 0.40–3.83) and without (RR 0.77, 95% CI 0.40–1.48) cardiovascular disease.

Conclusions

We found no evidence that varenicline increases the rate of cardiovascular serious adverse events. Results were similar among those with and without cardiovascular disease. Given varenicline's efficacy as a smoking cessation drug and the long‐term cardiovascular benefits of cessation, it should continue to be prescribed for smoking cessation.

Evaluation of the cardiovascular effects of varenicline in rats

BACKGROUND

Cardiovascular disease is an important cause of morbidity and mortality among tobacco users. Varenicline is widely used worldwide to help smoking cessation, but some published studies have reported associated cardiovascular events.

OBJECTIVE

To determine the cardiovascular toxicity induced by varenicline in rats.

MATERIALS AND METHODS

We randomly separated 34 rats into two groups: 1) the control group (given only distilled water orally, n=10) and the varenicline group (given 9 μg/kg/day varenicline on days 1-3, 9 μg/kg twice daily on days 4-7, and 18 μg/kg twice daily on days 8-90 [total 83 days], n=24). Each group was then subdivided equally into acute and chronic subgroups, and all rats in these groups were euthanized with anesthesia overdose on days 45 and 90, respectively. Body and heart weights, hemodynamic (mean oxygen saturation, mean blood pressure, and heart rate, electrocardiographic (PR, QRS, and QT intervals) biochemical (oxidants and antioxidants), and histopathological analyses (including immunostaining) were performed.

RESULTS

Acute varenicline exposure resulted in loss of body weight, while chronic varenicline exposure caused heart weight loss and decreased mean blood pressure, induced lipid peroxidation, and reduced antioxidant activity. Both acute and chronic varenicline exposure caused impairment of mean oxygen saturation. QT interval was prolonged in the chronic varenicline group, while PR interval prolongation was statistically significant in both the control and acute varenicline groups. Caspase-9 activity was also significantly increased by chronic exposure. Moreover, histopathological observations revealed severe morphological heart damage in both groups.

CONCLUSION

Adverse effects of chronic varenicline exposure on cardiovascular tissue were confirmed by our electrocardiographic, biochemical, and histopathological analyses. This issue needs to be investigated with new experimental and clinical studies to evaluate the exact mechanism(s) of the detrimental effects of varenicline. Physicians should bear in mind the toxic effects of varenicline on the cardiovascular system when prescribing it for smoking cessation.

Cardiovascular and neuropsychiatric risks of varenicline: a retrospective cohort study

Background

Varenicline is an effective pharmacotherapy to aid smoking cessation. However, its use is limited by continuing concerns about possible associated risks of serious adverse cardiovascular and neuropsychiatric events. The aim of this study was to investigate whether use of varenicline is associated with such events.

Methods

In this retrospective cohort study, we used data from patients included in the validated QResearch database, which holds data from 753 National Health Service general practices across England. We identified patients aged 18–100 years (registered for longer than 12 months before data extraction) who received a prescription of nicotine replacement treatment (NRT; reference group), bupropion, or varenicline. We excluded patients if they had used one of the drugs during the 12 months before the start date of the study, had received a prescription of a combination of these drugs during the follow-up period, or were temporary residents. We followed patients up for 6 months to compare incident cardiovascular (ischaemic heart disease, cerebral infarction, heart failure, peripheral vascular disease, and cardiac arrhythmia) and neuropsychiatric (depression and self-harm) events using Cox proportional hazards models, adjusted for potential confounders (primary outcomes).

Findings

We identified 164 766 patients who received a prescription (106 759 for nicotine replacement treatment; 6557 for bupropion; 51 450 for varenicline) between Jan 1, 2007, and June 30, 2012. Neither bupropion nor varenicline showed an increased risk of any cardiovascular or neuropsychiatric event compared with NRT (all hazard ratios [HRs] less than 1. Varenicline was associated with a significantly reduced risk of ischaemic heart disease (HR 0·80 [95%CI 0·72–0·87]), cerebral infarction (0·62 [0·52–0·73]), heart failure (0·61 [0·45–0·83]), arrhythmia (0·73 [0·60–0·88]), depression (0·66 [0·63–0·69]), and self-harm (0·56 [0·46–0·68]).

Interpretation

Varenicline does not seem to be associated with an increased risk of documented cardiovascular events, depression, or self-harm when compared with NRT. Adverse events that do not come to attention of general practitioners cannot be excluded. These findings suggest an opportunity for physicians to prescribe varenicline more broadly, even for patients with comorbidities, thereby helping more smokers to quit successfully than do at present.

Funding

Egton Medical Information Systems, University of Nottingham, Ministry of Innovation, Science and Research of the German Federal State of North Rhine-Westphalia, Cancer Research UK, Medical Research Council, Commonwealth Fund.

Data management and data analysis techniques in pharmacoepidemiological studies using a pre-planned multi-database approach: a systematic literature review

PURPOSE

To identify pharmacoepidemiological multi-database studies and to describe data management and data analysis techniques used for combining data.

METHODS

Systematic literature searches were conducted in PubMed and Embase complemented by a manual literature search. We included pharmacoepidemiological multi-database studies published from 2007 onwards that combined data for a pre-planned common analysis or quantitative synthesis. Information was retrieved about study characteristics, methods used for individual-level analyses and meta-analyses, data management and motivations for performing the study.

RESULTS

We found 3083 articles by the systematic searches and an additional 176 by the manual search. After full-text screening of 75 articles, 22 were selected for final inclusion. The number of databases used per study ranged from 2 to 17 (median = 4.0). Most studies used a cohort design (82%) instead of a case-control design (18%). Logistic regression was most often used for individual-level analyses (41%), followed by Cox regression (23%) and Poisson regression (14%). As meta-analysis method, a majority of the studies combined individual patient data (73%). Six studies performed an aggregate meta-analysis (27%), while a semi-aggregate approach was applied in three studies (14%). Information on central programming or heterogeneity assessment was missing in approximately half of the publications. Most studies were motivated by improving power (86%).

CONCLUSIONS

Pharmacoepidemiological multi-database studies are a well-powered strategy to address safety issues and have increased in popularity. To be able to correctly interpret the results of these studies, it is important to systematically report on database management and analysis techniques, including central programming and heterogeneity testing.

A system to build distributed multivariate models and manage disparate data sharing policies: implementation in the scalable national network for effectiveness research

Background Centralized and federated models for sharing data in research networks currently exist. To build multivariate data analysis for centralized networks, transfer of patient-level data to a central computation resource is necessary. The authors implemented distributed multivariate models for federated networks in which patient-level data is kept at each site and data exchange policies are managed in a study-centric manner.

Objective The objective was to implement infrastructure that supports the functionality of some existing research networks (e.g., cohort discovery, workflow management, and estimation of multivariate analytic models on centralized data) while adding additional important new features, such as algorithms for distributed iterative multivariate models, a graphical interface for multivariate model specification, synchronous and asynchronous response to network queries, investigator-initiated studies, and study-based control of staff, protocols, and data sharing policies.

Materials and Methods Based on the requirements gathered from statisticians, administrators, and investigators from multiple institutions, the authors developed infrastructure and tools to support multisite comparative effectiveness studies using web services for multivariate statistical estimation in the SCANNER federated network.

Results The authors implemented massively parallel (map-reduce) computation methods and a new policy management system to enable each study initiated by network participants to define the ways in which data may be processed, managed, queried, and shared. The authors illustrated the use of these systems among institutions with highly different policies and operating under different state laws.

Discussion and Conclusion Federated research networks need not limit distributed query functionality to count queries, cohort discovery, or independently estimated analytic models. Multivariate analyses can be efficiently and securely conducted without patient-level data transport, allowing institutions with strict local data storage requirements to participate in sophisticated analyses based on federated research networks.

Methodological issues in observational studies and non-randomized controlled trials in oncology in the era of big data

Non-randomized controlled trials, cohort studies and database studies are appealing study designs when there are urgent needs for safety data, outcomes of interest are rare, generalizability is a matter of concern, or randomization is not feasible. This paper reviews four typical case studies from methodological viewpoints and clarifies how to minimize bias in observational studies in oncology. In summary, researchers planning observational studies should be cautious of selection of appropriate databases, validity of algorithms for identifying outcomes, comparison with incident users or self-control, rigorous collection of information on potential confounders and reporting details of subject selection. Further, a careful study protocol and statistical analysis plan are also necessary.

Cardiovascular adverse events associated with smoking-cessation pharmacotherapies

Smoking continues to be the leading cause of preventable deaths in the USA, accounting for one in every five deaths every year, and cardiovascular (CV) disease remains the leading cause of those deaths. Hence, there is increasing awareness to quit smoking among the public and counseling plays an important role in smoking cessation. There are different pharmacological methods to help quit smoking that includes nicotine replacement products available over the counter, including patch, gum, and lozenges, to prescription medications, such as bupropion and varenicline. There have been reports of both nonserious and serious adverse CV events associated with the use of these different pharmacological methods, especially varenicline, which has been gaining media attention recently. Therefore, we systematically reviewed the various pharmacotherapies used in smoking cessation and analyzed the evidence behind these CV events reported with these therapeutic agents.

A modular, prospective, semi-automated drug safety monitoring system for use in a distributed data environment

PURPOSE

The aim of this study was to develop and test a semi-automated process for conducting routine active safety monitoring for new drugs in a network of electronic healthcare databases.

METHODS

We built a modular program that semi-automatically performs cohort identification, confounding adjustment, diagnostic checks, aggregation and effect estimation across multiple databases, and application of a sequential alerting algorithm. During beta-testing, we applied the system to five databases to evaluate nine examples emulating prospective monitoring with retrospective data (five pairs for which we expected signals, two negative controls, and two examples for which it was uncertain whether a signal would be expected): cerivastatin versus atorvastatin and rhabdomyolysis; paroxetine versus tricyclic antidepressants and gastrointestinal bleed; lisinopril versus angiotensin receptor blockers and angioedema; ciprofloxacin versus macrolide antibiotics and Achilles tendon rupture; rofecoxib versus non-selective non-steroidal anti-inflammatory drugs (ns-NSAIDs) and myocardial infarction; telithromycin versus azithromycin and hepatotoxicity; rosuvastatin versus atorvastatin and diabetes and rhabdomyolysis; and celecoxib versus ns-NSAIDs and myocardial infarction.

RESULTS

We describe the program, the necessary inputs, and the assumed data environment. In beta-testing, the system generated four alerts, all among positive control examples (i.e., lisinopril and angioedema; rofecoxib and myocardial infarction; ciprofloxacin and tendon rupture; and cerivastatin and rhabdomyolysis). Sequential effect estimates for each example were consistent in direction and magnitude with existing literature.

CONCLUSIONS

Beta-testing across nine drug-outcome examples demonstrated the feasibility of the proposed semi-automated prospective monitoring approach. In retrospective assessments, the system identified an increased risk of myocardial infarction with rofecoxib and an increased risk of rhabdomyolysis with cerivastatin years before these drugs were withdrawn from the market.

Postmarketing safety of biologics and biological devices

BACKGROUND CONTEXT

Regardless of study design, the approval process of biologics and biological devices cannot identify every possible safety concern. Postmarketing safety surveillance can provide information based on real-world use of medical products in heterogeneous populations and is critical for identifying potentially serious adverse events, events that are too rare to be detected during premarketing studies, late complications, and events involving individuals or uses that were not evaluated in clinical trials.

PURPOSE

To review why adverse event reporting is important and how the information is used, with emphasis on the points that are most applicable for surgeons and other spine professionals.

METHODS

This is an overview of postmarketing safety surveillance.

RESULTS

Review of adverse event reports has resulted in safety notifications, label changes, and publications regarding the safety of biologics and biological devices, such as the risk of airway compromise after the use of recombinant human bone morphogenetic protein in cervical spine fusion, the occurrence of a fatal air embolism after the use of a fibrin sealant that had been applied with a spray device, and infections after allograft transplantation of human tissues.

CONCLUSIONS

In light of the rapid development of new biologics, postmarketing surveillance is imperative for ensuring that these products are as safe as possible. By reporting adverse events, surgeons and other health care professionals play a key role in improving and refining our understanding of the safety of biologics.

Functional interactions of varenicline and nicotine with nAChR subtypes implicated in cardiovascular control

INTRODUCTION

It has been suggested that varenicline-induced activation of nicotinic acetylcholine receptors (nAChRs) could play a role in the cardiovascular (CV) safety of varenicline. However, since preclinical studies showed that therapeutic varenicline concentrations have no effect in models of CV function, this study examined in vitro profiles of varenicline and nicotine at nAChR subtypes possibly involved in CV control.

METHODS

Concentration-dependent functional effects of varenicline and nicotine at human α3β4, α3α5β4, α7, and α4β2 nAChRs expressed in oocytes were determined by electrophysiology. The proportion of nAChRs predicted to be activated and inhibited by concentrations of varenicline (1mg b.i.d.) and of nicotine in smokers was derived from activation-inhibition curves for each nAChR subtype.

RESULTS

Human varenicline and nicotine concentrations can desensitize and inhibit nAChRs but cause only low-level activation of α3β4, α4β2 (<2%), α7 (<0.05%), and α3α5β4 (<0.01%) nAChRs, which is consistent with literature data. Nicotine concentrations in smokers are predicted to inhibit larger fractions of α3β4 (48%) and α3α5β4 (10%) nAChRs than therapeutic varenicline concentrations (11% and 0.6%, respectively) and to inhibit comparable fractions of α4β2 nAChRs (42%-56%) and α7 nAChRs (16%) as varenicline.

CONCLUSIONS

Nicotine and varenicline concentrations in patients and smokers are predicted to cause minimal activation of ganglionic α3β4* nAChRs, while their functional profiles at α3β4, α3α5β4, α7, and α4β2 nAChRs cannot explain that substituting nicotine from tobacco with varenicline would cause CV adverse events in smokers who try to quit. Other pharmacological properties that could mediate varenicline-induced CV effects have not been identified.

Cardiovascular events associated with smoking cessation pharmacotherapies: a network meta-analysis

BACKGROUND

Stopping smoking is associated with many important improvements in health and quality of life. The use of cessation medications is recommended to increase the likelihood of quitting. However, there is historical and renewed concern that smoking cessation therapies may increase the risk of cardiovascular disease events associated within the quitting period. We aimed to examine whether the 3 licensed smoking cessation therapies-nicotine replacement therapy, bupropion, and varenicline-were associated with an increased risk of cardiovascular disease events using a network meta-analysis.

METHODS AND RESULTS

We searched 10 electronic databases, were in communication with authors of published randomized, clinical trials (RCTs), and accessed internal US Food and Drug Administration reports. We included any RCT of the 3 treatments that reported cardiovascular disease outcomes. Among 63 eligible RCTs involving 21 nicotine replacement therapy RCTs, 28 bupropion RCTs, and 18 varenicline RCTs, we found no increase in the risk of all cardiovascular disease events with bupropion (relative risk [RR], 0.98; 95% confidence interval [CI], 0.54-1.73) or varenicline (RR, 1.30; 95% CI, 0.79-2.23). There was an elevated risk associated with nicotine replacement therapy that was driven predominantly by less serious events (RR, 2.29; 95% CI, 1.39-3.82). When we examined major adverse cardiovascular events, we found a protective effect with bupropion (RR, 0.45; 95% CI, 0.21-0.85) and no clear evidence of harm with varenicline (RR, 1.34; 95% CI, 0.66-2.66) or nicotine replacement therapy (RR, 1.95; 95% CI, 0.26-4.30).

CONCLUSION

Smoking cessation therapies do not appear to raise the risk of serious cardiovascular disease events.