The effectiveness and cost-effectiveness of biomarkers for the prioritisation of patients awaiting coronary revascularisation: a systematic review and decision model

Renal Biomarkers in Heart Failure: Systematic Review and Meta-Analysis

Background

Cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule (KIM)-1 are renal biomarkers increasingly appreciated for their role in the risk stratification and prognostication of heart failure (HF) patients. However, very few have been adopted clinically, owing to the lack of consistency.

Objectives

The authors aimed to study the association between cystatin C, NGAL, and KIM-1 and outcomes, mortality, hospitalizations, and worsening renal function (WRF) in patients with acute and chronic HF.

Methods

We included peer-reviewed English-language articles from PubMed and EMBASE published up to December 2021. We analyzed the above associations using random-effects meta-analysis. Publication bias was assessed using funnel plots.

Results

Among 2,631 articles, 100 articles, including 45,428 patients, met the inclusion criteria. Top-tertile of serum cystatin C, when compared to the bottom-tertile, carried a higher pooled hazard ratio (pHR) for mortality (pHR: 1.59, 95% CI: 1.42-1.77) and for the composite outcome of mortality and HF hospitalizations (pHR: 1.49, 95% CI: 1.23-1.75). Top-tertile of serum NGAL had a higher hazard for mortality (pHR: 2.91, 95% CI: 1.49-5.67) and composite outcome (HR: 4.11, 95% CI: 2.69-6.30). Serum and urine NGAL were significantly associated with WRF, with pHRs of 2.40 (95% CI: 1.48-3.90) and 2.01 (95% CI: 1.21-3.35). Urine KIM-1 was significantly associated with WRF (pHR: 1.60, 95% CI: 1.24-2.07) but not with other outcomes. High heterogeneity was noted between studies without an obvious explanation based on meta-regression.

Conclusions

Serum cystatin C and serum NGAL are independent predictors of adverse outcomes in HF. Serum and urine NGAL are important predictors of WRF in HF.

C-reactive protein and fracture risk: an updated systematic review and meta-analysis of cohort studies through the use of both frequentist and Bayesian approaches

This systematic review and meta-analysis were conducted on all eligible cohort studies to evaluate the association between high-sensitivity C-reactive protein (hs-CRP) and osteoporotic fracture risk. Both frequentist and Bayesian approaches were employed for the meta-analysis. We found that high tertiles of hs-CRP were significantly associated with increased fracture risk.

INTRODUCTION

The association between the inflammatory marker CRP and osteoporotic fracture has remained uncertain. In this study, we conducted a systematic review and meta-analysis to examine the association of serum hs-CRP and fracture risk.

METHODS

We performed a systematic literature search of relevant databases, including PubMed, Embase, and MEDLINE publications from January 1950 through April 2020. Three reviewers independently performed the study selection, quality assessment, and data abstraction. Frequentist and Bayesian hierarchical random-effects models were used separately for the analysis. Statistical heterogeneity was assessed using Higgin's I² and Cochran's Q statistic, and publication bias was examined using funnel plots and rank correlation tests.

RESULTS

Fourteen cohort studies that reported t fracture outcomes were eligible for the systematic review. Only ten studies (n = 29,741) qualified for meta-analysis. In the frequentist approach, the RR for fracture in a comparison of the top tertile group to the bottom tertile group of hs-CRP was 1.54 (1.18, 2.01). The estimated risk of fracture remained significant in all sensitivity and subgroup analyses. Higgin's I² (30.52%) and Cochran's Q statistic (p < 0.01) suggested there was moderate heterogeneity for the meta-analysis. In the Bayesian approach, the pooled RR was 1.60 (95% CI (1.07-2.49)), and the probabilities that the high level of hs-CRP increased fracture risk by more than 0%, 10%, and 20% were 99%, 98%, and 93%, respectively.

CONCLUSION

A high level of hs-CRP is associated with a significantly increased risk of osteoporotic fracture.

Cohort profile: the Coronary Artery disease Risk Determination In Innsbruck by diaGnostic ANgiography (CARDIIGAN) cohort

PURPOSE

The Coronary Artery disease Risk Determination In Innsbruck by diaGnostic ANgiography (CARDIIGAN) cohort is aimed to gain a better understanding of cardiovascular risk factors and their relation to the diagnosis and severity of coronary artery disease, as well as to the long-term prognosis in consecutive (including revascularised) patients referred for elective coronary angiography.

PARTICIPANTS

The included patients visited the University Clinic of Cardiology at Innsbruck (Austria), which fulfils a secondary and tertiary hospital function. Inclusion took place in the period between February 2004 and April 2008 and resulted in a total of 8296 patients aged 18-91 years; 65% of them were men.

FINDINGS TO DATE

There was one follow-up round on vital status through record linkage for 84% of the cohort (those with residence in Tyrol), resulting in a follow-up duration of over 5.5 to nearly 10.0 years among survivors. The data contain basic patient characteristics, cardiovascular risk factors, laboratory measurements, medications, detailed information on the extent and severity of coronary artery disease, revascularisation history, treatment strategy and mortality specifics. A few studies have already been published.

FUTURE PLANS

Various diagnostic and prognostic studies are planned, also concerning complications, competing risks and cost-effectiveness. Collaboration with other research groups is welcomed.

Biomarkers: Delivering on the expectation of molecularly driven, quantitative health

Biomarkers are the pillars of precision medicine and are delivering on expectations of molecular, quantitative health. These features have made clinical decisions more precise and personalized, but require a high bar for validation. Biomarkers have improved health outcomes in a few areas such as cancer, pharmacogenetics, and safety. Burgeoning big data research infrastructure, the internet of things, and increased patient participation will accelerate discovery in the many areas that have not yet realized the full potential of biomarkers for precision health. Here we review themes of biomarker discovery, current implementations of biomarkers for precision health, and future opportunities and challenges for biomarker discovery. Impact statement Precision medicine evolved because of the understanding that human disease is molecularly driven and is highly variable across patients. This understanding has made biomarkers, a diverse class of biological measurements, more relevant for disease diagnosis, monitoring, and selection of treatment strategy. Biomarkers' impact on precision medicine can be seen in cancer, pharmacogenomics, and safety. The successes in these cases suggest many more applications for biomarkers and a greater impact for precision medicine across the spectrum of human disease. The authors assess the status of biomarker-guided medical practice by analyzing themes for biomarker discovery, reviewing the impact of these markers in the clinic, and highlight future and ongoing challenges for biomarker discovery. This work is timely and relevant, as the molecular, quantitative approach of precision medicine is spreading to many disease indications.

C-reactive protein and risk of fracture: a systematic review and dose-response meta-analysis of prospective cohort studies

This study systematically reviews prospective cohort studies evaluating the relationship between C-reactive protein (CRP) concentrations and subsequent fracture risk. The positive association cannot completely explain the existing evidence, and further studies are needed to demonstrate the shape of the association.

INTRODUCTION

We aimed to perform a systematic review and dose-response meta-analysis of published prospective studies evaluating associations of high-sensitivity CRP (hs-CRP) levels with fracture risk in general populations.

METHODS

We identified relevant studies by searching MEDLINE and EMBASE databases from their inception to May 20, 2014. We included published prospective studies evaluating the associations of hs-CRP levels with risk of fracture in general populations. Two reviewers working independently abstracted the data.

RESULTS

Eight prospective cohort studies involving 34,840 participants and 3,407 incident fracture events were eligible for the present analyses. A meta-analysis of six prospective studies showed that the overall risk for incident fracture in a comparison of individuals in the top tertile with those in the bottom tertile of baseline hs-CRP levels was 2.14 [95% confidence interval (CI) 1.51-3.05, I(2) = 62.3%]. The moderate heterogeneous disappeared when one study was excluded. However, the remaining two studies reported inconsistent results. One study with the biggest sample size showed a U-shaped association for CRP and fracture risk (the association was positive when CRP > 1 mg/L). Similarly, another study reported that per doubling of CRP was positive only when CRP > 3 mg/L.

CONCLUSION

In summary, the present analysis showed that the relationship between CRP concentrations and subsequent fracture risk is still inconsistent. The positive association cannot completely explain the existing evidence, and further larger prospective cohorts with more power are needed to demonstrate the shape of the association, especially for the relatively low CRP concentrations, such as less than 3 mg/L.

Adiponectin is associated with increased mortality in patients with already established cardiovascular disease: a systematic review and meta-analysis

BACKGROUND

The overall quantitative estimate on the possible association of adiponectin concentrations with mortality in patients with cardiovascular diseases (CVD) has not been reported.

METHODS

We performed a systematic review and meta-analysis of prospective studies to evaluate the overall quantitative estimates on the adiponectin levels for risk of mortality in patients with CVD. MEDLINE, EMBASE, CINAHL, and the Cochrane Library (up to Mar 22, 2014) were used to search for studies evaluating the effect of adiponectin levels on mortality in patients with CVD. Random-effect models were selected to estimate overall effect estimates.

RESULTS

Data from 14063 CVD patients enrolled in 15 prospective cohort and 1 nested case control studies were collated. The meta-analyses showed strong positive association of adiponectin with all-cause (n=14 studies, overall pooled effect estimate=1.45 [95% CI, 1.17-1.79]) and cardiovascular (n=11 studies, overall pooled effect estimate=1.69 [1.35-2.10]) mortality, for the highest tertile of adiponectin levels versus the lowest tertile. Subgroup analyses show study characteristics (including effect estimate, mean age, study location, sample sizes, gender, durations of follow-up, types of primary event, and acute or chronic CVD) did not substantially influence these positive associations.

CONCLUSIONS

Our results showed that increased baseline plasma adiponectin levels are significantly associated with elevated risk of all-cause and cardiovascular mortality in subjects with CVD. These positive associations may have been amplified by adjustment for potential intermediates or residual confounding, and their basis requires further investigation.

Cost-effectiveness of pharmacogenetics in anticoagulation: international differences in healthcare systems and costs

Genotyping patients for CYP2C9 and VKORC1 polymorphisms can improve the accuracy of dosing during the initiation of anticoagulation with vitamin K antagonists (coumarin derivatives). The anticipated degree of improvement in the safety of anticoagulation with coumarins through genotyping may vary depending on the quality of patient care, which varies both with and among countries. The management and the cost of anticoagulant care can therefore influence the cost-effectiveness of genotyping within any given country. In this article, we provide an overview of the cost-effectiveness of pharmacogenetics-guided dosing of coumarin derivatives. We describe the organization of anticoagulant care in the UK, Sweden, The Netherlands, Greece, Germany and Austria, where a genotype-guided dosing algorithm is currently being investigated as part of the EU-PACT trial. We also explore the costs of anticoagulant care for the treatment of atrial fibrillation in these countries.

The risky business of studying prognosis

Prognosis studies provide important healthcare information. Clinicians use prognostic factors to predict disease progress, thus allowing individualization of disease management. Prognosis is the issue in many translational studies that aim to identify biomarkers to predict outcomes. In a clinical trial, researchers may use prognostic factors to sort patients into risk groups, to clarify the effects of a new therapeutic agent. Prognosis studies can have significant effects on clinical practice.

A method for the early health technology assessment of novel biomarker measurement in primary prevention programs

Many promising biomarkers for stratifying individuals at risk of developing a chronic disease or subsequent complications have been identified. Research into the potential cost-effectiveness of applying these biomarkers in actual clinical settings has however been lacking. Investors and analysts may improve their venture decision making should they have indicative estimates of the potential costs and effects associated with a new biomarker technology already at the early stages of its development. To assist in obtaining such estimates, this paper presents a general method for the early health technology assessment of a novel biomarker technology. The setting considered is that of primary prevention programs where initial screening to select high-risk individuals eligible for a subsequent intervention occurs, for example, prevention of type 2 diabetes. The method is based on quantifying the health outcomes and downstream healthcare consumption of all individuals who get reclassified as a result of moving from a screening variant based on traditional risk factors to a screening variant based on traditional risk factors plus a novel biomarker. As these individuals form well-defined subpopulations, a combination of disease progression modeling and sensitivity analysis can be used to perform an initial assessment of the maximum increase in screening cost for which the use of the new biomarker technology is still likely to be cost effective.

Dabigatran etexilate versus warfarin in management of non-valvular atrial fibrillation in UK context: quantitative benefit-harm and economic analyses

OBJECTIVES

To determine the incremental net health benefits of dabigatran etexilate 110 mg and 150 mg twice daily and warfarin in patients with non-valvular atrial fibrillation and to estimate the cost effectiveness of dabigatran in the United Kingdom.

DESIGN

Quantitative benefit-harm and economic analyses using a discrete event simulation model to extrapolate the findings of the RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy) study to a lifetime horizon.

SETTING

UK National Health Service. Population Cohorts of 50,000 simulated patients at moderate to high risk of stroke with a mean baseline CHADS(2) (Congestive heart failure, Hypertension, Age ≥ 75 years, Diabetes mellitus, previous Stroke/transient ischaemic attack) score of 2.1.

MAIN OUTCOME MEASURES

Quality adjusted life years (QALYs) gained and incremental cost per QALY of dabigatran compared with warfarin.

RESULTS

Compared with warfarin, low dose and high dose dabigatran were associated with positive incremental net benefits of 0.094 (95% central range -0.083 to 0.267) and 0.146 (-0.029 to 0.322) QALYs. Positive incremental net benefits resulted for high dose dabigatran in 94% of simulations versus warfarin and in 76% of those versus low dose dabigatran. In the economic analysis, high dose dabigatran dominated the low dose, had an incremental cost effectiveness ratio of £23,082 (€26,700; $35,800) per QALY gained versus warfarin, and was more cost effective in patients with a baseline CHADS(2) score of 3 or above. However, at centres that achieved good control of international normalised ratio, such as those in the UK, dabigatran 150 mg was not cost effective, at £42,386 per QALY gained.

CONCLUSIONS

This analysis supports regulatory decisions that dabigatran offers a positive benefit to harm ratio when compared with warfarin. However, no subgroup for which dabigatran 110 mg offered any clinical or economic advantage over 150 mg was identified. High dose dabigatran will be cost effective only for patients at increased risk of stroke or for whom international normalised ratio is likely to be less well controlled.

Threshold haemoglobin levels and the prognosis of stable coronary disease: two new cohorts and a systematic review and meta-analysis

BACKGROUND

Low haemoglobin concentration has been associated with adverse prognosis in patients with angina and myocardial infarction (MI), but the strength and shape of the association and the presence of any threshold has not been precisely evaluated.

METHODS AND FINDINGS

A retrospective cohort study was carried out using the UK General Practice Research Database. 20,131 people with a new diagnosis of stable angina and no previous acute coronary syndrome, and 14,171 people with first MI who survived for at least 7 days were followed up for a mean of 3.2 years. Using semi-parametric Cox regression and multiple adjustment, there was evidence of threshold haemoglobin values below which mortality increased in a graded continuous fashion. For men with MI, the threshold value was 13.5 g/dl (95% confidence interval [CI] 13.2-13.9); the 29.5% of patients with haemoglobin below this threshold had an associated hazard ratio for mortality of 2.00 (95% CI 1.76-2.29) compared to those with haemoglobin values in the lowest risk range. Women tended to have lower threshold haemoglobin values (e.g, for MI 12.8 g/dl; 95% CI 12.1-13.5) but the shape and strength of association did not differ between the genders, nor between patients with angina and MI. We did a systematic review and meta-analysis that identified ten previously published studies, reporting a total of only 1,127 endpoints, but none evaluated thresholds of risk.

CONCLUSIONS

There is an association between low haemoglobin concentration and increased mortality. A large proportion of patients with coronary disease have haemoglobin concentrations below the thresholds of risk defined here. Intervention trials would clarify whether increasing the haemoglobin concentration reduces mortality.

[Cardiac biomarkers in perioperative risk stratification]

OBJECTIVES

The field of new cardiac biomarkers has triggered physicians' enthusiasm because of their potential diagnostic and prognostic values for routine clinical practice in the surgical setting. The objective of the present article is to review the role of new cardiac biomarkers and their potential additive clinical value in predicting short- and long-term risk following cardiac and non-cardiac surgery.

DATA SOURCES

A PubMed(®) database research in English and French languages published until June 2010. Keywords were cardiac biomarkers, troponins, cardiac troponin I (cTnI), natriuretic peptides, B-type natriuretic peptide (BNP), C-reactive protein (CRP), multiple markers approach, risk stratification, clinical risk scores.

DATA SYNTHESIS

Numerous publications deal with the diagnostic and prognostic values of new cardiac biomarkers in cardiac and non-cardiac surgical settings and provide an increasing evidence of their interest, validating different hierarchical steps which are mandatory before recommending a wide use of biomarkers for routine practice. Even if the first studies demonstrating an additional prognostic value of serum postoperative cTnI and/or preoperative BNP when compared with clinical predictive models are now available, we still lack data concerning an actual positive impact of new biomarkers measurements on clinical decision making or practice, as well as patient care and outcome.

CONCLUSIONS

While use of new cardiac biomarkers in the perioperative period appears to be a simple and objective tool for risk stratification at the bedside, we still need to remain cautious concerning their additional clinical value on existing predictive models for routine practice.

Evaluating the quality of research into a single prognostic biomarker: a systematic review and meta-analysis of 83 studies of C-reactive protein in stable coronary artery disease

BACKGROUND

Systematic evaluations of the quality of research on a single prognostic biomarker are rare. We sought to evaluate the quality of prognostic research evidence for the association of C-reactive protein (CRP) with fatal and nonfatal events among patients with stable coronary disease.

METHODS AND FINDINGS

We searched MEDLINE (1966 to 2009) and EMBASE (1980 to 2009) and selected prospective studies of patients with stable coronary disease, reporting a relative risk for the association of CRP with death and nonfatal cardiovascular events. We included 83 studies, reporting 61,684 patients and 6,485 outcome events. No study reported a prespecified statistical analysis protocol; only two studies reported the time elapsed (in months or years) between initial presentation of symptomatic coronary disease and inclusion in the study. Studies reported a median of seven items (of 17) from the REMARK reporting guidelines, with no evidence of change over time. The pooled relative risk for the top versus bottom third of CRP distribution was 1.97 (95% confidence interval [CI] 1.78-2.17), with substantial heterogeneity (I(2) = 79.5). Only 13 studies adjusted for conventional risk factors (age, sex, smoking, obesity, diabetes, and low-density lipoprotein [LDL] cholesterol) and these had a relative risk of 1.65 (95% CI 1.39-1.96), I(2) = 33.7. Studies reported ten different ways of comparing CRP values, with weaker relative risks for those based on continuous measures. Adjusting for publication bias (for which there was strong evidence, Egger's p<0.001) using a validated method reduced the relative risk to 1.19 (95% CI 1.13-1.25). Only two studies reported a measure of discrimination (c-statistic). In 20 studies the detection rate for subsequent events could be calculated and was 31% for a 10% false positive rate, and the calculated pooled c-statistic was 0.61 (0.57-0.66).

CONCLUSION

Multiple types of reporting bias, and publication bias, make the magnitude of any independent association between CRP and prognosis among patients with stable coronary disease sufficiently uncertain that no clinical practice recommendations can be made. Publication of prespecified statistical analytic protocols and prospective registration of studies, among other measures, might help improve the quality of prognostic biomarker research.

Assessing the cost effectiveness of using prognostic biomarkers with decision models: case study in prioritising patients waiting for coronary artery surgery

OBJECTIVE

To determine the effectiveness and cost effectiveness of using information from circulating biomarkers to inform the prioritisation process of patients with stable angina awaiting coronary artery bypass graft surgery.

DESIGN

Decision analytical model comparing four prioritisation strategies without biomarkers (no formal prioritisation, two urgency scores, and a risk score) and three strategies based on a risk score using biomarkers: a routinely assessed biomarker (estimated glomerular filtration rate), a novel biomarker (C reactive protein), or both. The order in which to perform coronary artery bypass grafting in a cohort of patients was determined by each prioritisation strategy, and mean lifetime costs and quality adjusted life years (QALYs) were compared.

DATA SOURCES

Swedish Coronary Angiography and Angioplasty Registry (9935 patients with stable angina awaiting coronary artery bypass grafting and then followed up for cardiovascular events after the procedure for 3.8 years), and meta-analyses of prognostic effects (relative risks) of biomarkers.

RESULTS

The observed risk of cardiovascular events while on the waiting list for coronary artery bypass grafting was 3 per 10,000 patients per day within the first 90 days (184 events in 9935 patients). Using a cost effectiveness threshold of pound20,000- pound30,000 (euro22,000-euro33,000; $32,000-$48,000) per additional QALY, a prioritisation strategy using a risk score with estimated glomerular filtration rate was the most cost effective strategy (cost per additional QALY was < pound410 compared with the Ontario urgency score). The impact on population health of implementing this strategy was 800 QALYs per 100,000 patients at an additional cost of pound 245,000 to the National Health Service. The prioritisation strategy using a risk score with C reactive protein was associated with lower QALYs and higher costs compared with a risk score using estimated glomerular filtration rate.

CONCLUSION

Evaluating the cost effectiveness of prognostic biomarkers is important even when effects at an individual level are small. Formal prioritisation of patients awaiting coronary artery bypass grafting using a routinely assessed biomarker (estimated glomerular filtration rate) along with simple, routinely collected clinical information was cost effective. Prioritisation strategies based on the prognostic information conferred by C reactive protein, which is not currently measured in this context, or a combination of C reactive protein and estimated glomerular filtration rate, is unlikely to be cost effective. The widespread practice of using only implicit or informal means of clinically ordering the waiting list may be harmful and should be replaced with formal prioritisation approaches.