The global risk approach should be better applied in French hypertensive patients: a comparison between simulation and observation studies

[Does aspirin have a place in primary cardiovascular prevention by the polypill ? Simulation study on a realistic virtual population]

BACKGROUND

The polypill strategy could become widely accepted in cardiovascular prevention due to reduced costs and its simplicity, which promote compliance. Aspirin is often included as a component of the polypill for primary prevention, but three powerful recent trials failed to show any favorable net benefit even in high-risk subgroups. Our objective is to estimate the net benefit associated with aspirin in primary cardiovascular prevention.

METHODS

We simulated the impact of different polypill compositions combining pravastatin, ramipril, hydrochlorothiazide, with or without aspirin, on a realistic French virtual population between 35 and 65 years old. We assessed how this impact on myocardial infarction and stroke varied according to gender, diabetes, and arterial hypertension. We identified the subgroup of individuals whose specific benefit from aspirin was greater than twice the risk of serious bleeding it induced.

RESULTS

The absolute benefit associated with aspirin was reduced by co-prescriptions. No subgroup of women benefited from aspirin, and the subgroup of women with a clear net benefit represented 128 women out of 529,421. Men at high risk of cardiovascular death, or with diabetes and hypertension, had a benefit from aspirin exceeding the risk of bleeding induced, but this risk represented more than half of the benefit. No subgroup analyzed did show a benefit greater than twice the risk of bleeding. The proportion of men whose expected benefit from aspirin was greater than twice the risk of bleeding represented 3% of all men. An optimal polypill strategy in primary prevention between the ages of 35 and 65, combining three drugs but not aspirin, can hope to save two out of three strokes and more than one out of two myocardial infarctions. It would prevent a major cardiovascular accident every 16 to 193 individuals treated according to the subgroups considered.

CONCLUSION

Until proven otherwise, aspirin has only a limited place in individuals between 35 and 65 years without a cardiovascular history. We showed how simulating therapeutic strategies on a realistic virtual population could be used for best applying available evidence.

Estimated Population Health Benefits of Intensive Systolic Blood Pressure Treatment Among SPRINT-Eligible US Adults

BACKGROUND

The Systolic Blood Pressure Intervention Trial (SPRINT) demonstrated an intensive (<120 mm Hg) vs. standard (<140 mm Hg) systolic blood pressure (SBP) goal lowered cardiovascular disease (CVD) risk. Estimating the effect of intensive SBP lowering among SPRINT-eligible adults most likely to benefit can guide implementation efforts.

METHODS

We studied SPRINT participants and SPRINT-eligible participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study and National Health and Nutrition Examination Surveys (NHANES). A published algorithm of predicted CVD benefit with intensive SBP treatment was used to categorize participants into low, medium, or high predicted benefit. CVD event rates were estimated with intensive and standard treatment.

RESULTS

Median age was 67.0, 72.0, and 64.0 years in SPRINT, SPRINT-eligible REGARDS, and SPRINT-eligible NHANES participants, respectively. The proportion with high predicted benefit was 33.0% in SPRINT, 39.0% in SPRINT-eligible REGARDS, and 23.5% in SPRINT-eligible NHANES. The estimated difference in CVD event rate (standard minus intensive) was 7.0 (95% confidence interval [CI] 3.4-10.7), 8.4 (95% CI 8.2-8.5), and 6.1 (95% CI 5.9-6.3) per 1,000 person-years in SPRINT, SPRINT-eligible REGARDS participants, and SPRINT-eligible NHANES participants, respectively (median 3.2-year follow-up). Intensive SBP treatment could prevent 84,300 (95% CI 80,800-87,920) CVD events per year in 14.1 million SPRINT-eligible US adults; 29,400 and 28,600 would be in 7.0 million individuals with medium or high predicted benefit, respectively.

CONCLUSIONS

Most of the population health benefit from intensive SBP goals could be achieved by treating those characterized by a previously published algorithm as having medium or high predicted benefit.

‘People say it is dangerous’

Introduction: Mild hypertension is a common asymptomatic condition present in people at low risk of future cardiovascular events. These people represent approximately two-thirds of those diagnosed with hypertension. The best available evidence does not support pharmacological treatment for mild hypertension to reduce cardiovascular mortality. Additionally, overdetection of hypertension also occurs, and this practice is supported by public awareness campaigns, screening, easy access to testing, and poor clinical practice, enhancing the overdiagnosis potential. Moreover, sparse qualitative patient-oriented evidence that diagnosing hypertension has harmful consequences is observed. Therefore, evidence regarding the potential for unintended psychosocial effects of diagnosing mild hypertension is required. Objective: The aim of this study was to investigate if diagnosing low-risk people with mild hypertension has unintended psychosocial consequences. Methods: Eleven semi-structured single interviews and four focus groups were conducted in São Paulo, Brazil, among people diagnosed with mild hypertension without comorbidities. Informants were selected among the general population from a list of patients, a primary healthcare clinic, or a social network. The informants had a broad range of characteristics, including sex, age, education level, race/skin colour, and time from diagnosis. Data were subjected to qualitative thematic content analysis by three of the authors independently, followed by discussions, to generate categories and themes. Results: The informants confirmed that the hypertension diagnosis was a label for psychosomatic reactions to stress, medicalised illness experiences, and set a biographical milestone. We observed unintended consequences of the diagnosis in a broad range of psychosocial dimensions, for example, fear of death, disabilities, or ageing; pressure and control from significant others; and guilt, shame, and anxiety regarding work and leisure. Although informants had a broad range of characteristics, they shared similar stories, understandings, and labelling effects of the diagnosis. Conclusion: The diagnosis of hypertension is a significant event and affects daily life. Most of the impact is regarded as negative psychosocial consequences or harm; however, sometimes the impact might be ambiguous. Patients’ explanatory models are key elements in understanding and changing the psychosocial consequences of the diagnosis, and healthcare providers must be aware of explanatory models and psychosocial consequences when evaluating blood pressure elevations.

A methodological framework for drug development in rare diseases. The CRESim program: Epilogue and perspectives

Based on the 'European Child-Rare-Euro-Simulation' (CRESim) project, this article proposes a generalizable strategy utilizing datasets analysis in combination with modeling and simulation, in order to optimize the clinical drug development applied in the field of rare diseases. The global process includes: (i) the simulation of a realistic virtual population of patients (modeled from a real dataset of patients), (ii) the modeling of disease pathophysiological components and of pharmacokinetic-pharmacodynamic relations of the drug(s) of interest, (iii) the modeling of several randomized controlled clinical trials (RCTs) designs and (iv) the analysis of the results (multi-dimensional approach for RCTs durations and precision of the estimation of the treatment effect). However, whereas modeling and numerical simulation may provide supplementary tools for drug development, they cannot be considered as a substitute for RCTs performed in 'real' patients.

High Risk versus Proportional Benefit: Modelling Equitable Strategies in Cardiovascular Prevention

OBJECTIVE

To examine the performances of an alternative strategy to decide initiating BP-lowering drugs called Proportional Benefit (PB). It selects candidates addressing the inequity induced by the high-risk approach since it distributes the gains proportionally to the burden of disease by genders and ages.

STUDY DESIGN AND SETTING

Mild hypertensives from a Realistic Virtual Population by genders and 10-year age classes (range 35-64 years) received simulated treatment over 10 years according to the PB strategy or the 2007 ESH/ESC guidelines (ESH/ESC). Primary outcomes were the relative life-year gain (life-years gained-to-years of potential life lost ratio) and the number needed to treat to gain a life-year. A sensitivity analysis was performed to assess the impact of changes introduced by the ESH/ESC guidelines appeared in 2013 on these outcomes.

RESULTS

The 2007 ESH/ESC relative life-year gains by ages were 2%; 10%; 14% in men, and 0%; 2%; 11% in women, this gradient being abolished by the PB (relative gain in all categories = 10%), while preserving the same overall gain in life-years. The redistribution of benefits improved the profile of residual events in younger individuals compared to the 2007 ESH/ESC guidelines. The PB strategy was more efficient (NNT = 131) than the 2013 ESH/ESC guidelines, whatever the level of evidence of the scenario adopted (NNT = 139 and NNT = 179 with the evidence-based scenario and the opinion-based scenario, respectively), although the 2007 ESH/ESC guidelines remained the most efficient strategy (NNT = 114).

CONCLUSION

The Proportional Benefit strategy provides the first response ever proposed against the inequity of resource use when treating highest risk people. It occupies an intermediate position with regards to the efficiency expected from the application of historical and current ESH/ESC hypertension guidelines. Our approach allows adapting recommendations to the risk and resources of a particular country.

Bridging Systems Medicine and Patient Needs

While there is widespread consensus on the need both to change the prevailing research and development (R&D) paradigm and provide the community with an efficient way to personalize medicine, ecosystem stakeholders grapple with divergent conceptions about which quantitative approach should be preferred. The primary purpose of this position paper is to contrast these approaches. The second objective is to introduce a framework to bridge simulation outputs and patient outcomes, thus empowering the implementation of systems medicine.

Comparison of an effect-model-law-based method versus traditional clinical practice guidelines for optimal treatment decision-making: application to statin treatment in the French population

Healthcare authorities make difficult decisions about how to spend limited budgets for interventions that guarantee the best cost-efficacy ratio. We propose a novel approach for treatment decision-making, OMES-in French: Objectif thérapeutique Modèle Effet Seuil (in English: Therapeutic Objective-Threshold-Effect Model; TOTEM). This approach takes into consideration results from clinical trials, adjusted for the patients' characteristics in treatment decision-making. We compared OMES with the French clinical practice guidelines (CPGs) for the management of dyslipidemia with statin in a computer-generated realistic virtual population, representing the adult French population, in terms of the number of all-cause deaths avoided (number of avoided events: NAEs) under treatment and the individual absolute benefit. The total budget was fixed at the annual amount reimbursed by the French social security for statins. With the CPGs, the NAEs was 292 for an annual cost of 122.54 M€ compared with 443 with OMES. For a fixed NAEs, OMES reduced costs by 50% (60.53 M€ yr(-1)). The results demonstrate that OMES is at least as good as, and even better than, the standard CPGs when applied to the same population. Hence the OMES approach is a practical, useful alternative which will help to overcome the limitations of treatment decision-making based uniquely on CPGs.

Assessing the overuse of medicines

The use of medicines has increased markedly in many countries over recent years, providing clear evidence of the increasing 'pharmacaeuticalisation' of society. This paper contributes to the sociological analysis of pharmaceuticalisation by starting to explore how we can begin to make judgements as to when and to what extent some medicines are being overused--an important aspect that, rather surprisingly, has not so far been the focus of attention those analysing the process. It considers the World Health Organisation's criteria for the 'rational' use of medicines, pointing to some of the issues they raise. It then develops a typology of over and underuse derived from these criteria. This provides a framework for the discussion of assessing overuse that focuses in particular on the widespread and increasing use of medicines that are not very effective for the conditions for which they are prescribed, and their use where the issue of clinical need is in doubt. Some of the factors that encourage overuse are also considered.

Are we using blood pressure-lowering drugs appropriately? Perhaps now is the time for a change

This topic seems particularly appropriate since this year is the 20th Anniversary of the Cochrane Collaboration. The Cochrane Collaboration and the Hypertension Review Group have played a leading role in advancing the evidence-based agenda that has challenged many of our ways of thinking and approaches to treating patients.

Contribution of modeling approaches and virtual populations in transposing the results of clinical trials into real life and in enlightening public health decisions

Modeling consists in aggregating separate pieces of knowledge, according to a given structure and rules. It allows studying the behavior of more or less complex systems by simulation techniques. Modeling is used in different state-of-the-art technological domains (meteorology, aeronautics). Its use has grown for the evaluation of medicines and medical devices, from conception to prescription (marketing authorization, reimbursement, price setting and re-registrations). It follows a scientific approach and is the object of good practice recommendations. Coupling models to virtual populations allows obtaining realistic results at the population level, testing diagnostic or therapeutic strategies, as well as estimating the consequences of transposing the results of clinical trials to the population. Through examples, the participants of the Round Table analyzed the contributions of the coupling of models and realistic virtual populations, and proposed guidelines for their judicious and systematic use.

Pharmacotherapy for mild hypertension

BACKGROUND

People with no previous cardiovascular events or cardiovascular disease represent a primary prevention population. The benefits and harms of treating mild hypertension in primary prevention patients are not known at present. This review examines the existing randomised controlled trial (RCT) evidence.

PRIMARY OBJECTIVE

To quantify the effects of antihypertensive drug therapy on mortality and morbidity in adults with mild hypertension (systolic blood pressure (BP) 140-159 mmHg and/or diastolic BP 90-99 mmHg) and without cardiovascular disease.

SEARCH METHODS

We searched CENTRAL (2011, Issue 1), MEDLINE (1948 to May 2011), EMBASE (1980 to May 2011) and reference lists of articles. The Cochrane Database of Systematic Reviews and the Database of Abstracts of Reviews of Effectiveness (DARE) were searched for previous reviews and meta-analyses of anti-hypertensive drug treatment compared to placebo or no treatment trials up until the end of 2011.

SELECTION CRITERIA

RCTs of at least 1 year duration.

DATA COLLECTION AND ANALYSIS

The outcomes assessed were mortality, stroke, coronary heart disease (CHD), total cardiovascular events (CVS), and withdrawals due to adverse effects.

MAIN RESULTS

Of 11 RCTs identified 4 were included in this review, with 8,912 participants. Treatment for 4 to 5 years with antihypertensive drugs as compared to placebo did not reduce total mortality (RR 0.85, 95% CI 0.63, 1.15). In 7,080 participants treatment with antihypertensive drugs as compared to placebo did not reduce coronary heart disease (RR 1.12, 95% CI 0.80, 1.57), stroke (RR 0.51, 95% CI 0.24, 1.08), or total cardiovascular events (RR 0.97, 95% CI 0.72, 1.32). Withdrawals due to adverse effects were increased by drug therapy (RR 4.80, 95%CI 4.14, 5.57), ARR 9%.

AUTHORS' CONCLUSIONS

Antihypertensive drugs used in the treatment of adults (primary prevention) with mild hypertension (systolic BP 140-159 mmHg and/or diastolic BP 90-99 mmHg) have not been shown to reduce mortality or morbidity in RCTs. Treatment caused 9% of patients to discontinue treatment due to adverse effects. More RCTs are needed in this prevalent population to know whether the benefits of treatment exceed the harms.

Virtual patients and sensitivity analysis of the Guyton model of blood pressure regulation: towards individualized models of whole-body physiology

Mathematical models that integrate multi-scale physiological data can offer insight into physiological and pathophysiological function, and may eventually assist in individualized predictive medicine. We present a methodology for performing systematic analyses of multi-parameter interactions in such complex, multi-scale models. Human physiology models are often based on or inspired by Arthur Guyton's whole-body circulatory regulation model. Despite the significance of this model, it has not been the subject of a systematic and comprehensive sensitivity study. Therefore, we use this model as a case study for our methodology. Our analysis of the Guyton model reveals how the multitude of model parameters combine to affect the model dynamics, and how interesting combinations of parameters may be identified. It also includes a "virtual population" from which "virtual individuals" can be chosen, on the basis of exhibiting conditions similar to those of a real-world patient. This lays the groundwork for using the Guyton model for in silico exploration of pathophysiological states and treatment strategies. The results presented here illustrate several potential uses for the entire dataset of sensitivity results and the "virtual individuals" that we have generated, which are included in the supplementary material. More generally, the presented methodology is applicable to modern, more complex multi-scale physiological models.

Towards personalized medicine: exploring the consequences of the effect model-based approach

Although personalized medicine has been a subject of research and debate in recent years, it has been underused in medical practice, except in some cancers. We believe that the main reason for the gap between the potential of personalized medicine and its use in daily medical practice can be explained by the lack of an appropriate tool to facilitate the use of biomarker values in a doctor's decision-making process. We propose that the effect model could form the basis of such a tool.