Effectiveness of statins for secondary prevention in elderly patients after acute myocardial infarction: an evaluation of class effect

A comparison of synthetic data generation and federated analysis for enabling international evaluations of cardiovascular health

Sharing health data for research purposes across international jurisdictions has been a challenge due to privacy concerns. Two privacy enhancing technologies that can enable such sharing are synthetic data generation (SDG) and federated analysis, but their relative strengths and weaknesses have not been evaluated thus far. In this study we compared SDG with federated analysis to enable such international comparative studies. The objective of the analysis was to assess country-level differences in the role of sex on cardiovascular health (CVH) using a pooled dataset of Canadian and Austrian individuals. The Canadian data was synthesized and sent to the Austrian team for analysis. The utility of the pooled (synthetic Canadian + real Austrian) dataset was evaluated by comparing the regression results from the two approaches. The privacy of the Canadian synthetic data was assessed using a membership disclosure test which showed an F1 score of 0.001, indicating low privacy risk. The outcome variable of interest was CVH, calculated through a modified CANHEART index. The main and interaction effect parameter estimates of the federated and pooled analyses were consistent and directionally the same. It took approximately one month to set up the synthetic data generation platform and generate the synthetic data, whereas it took over 1.5 years to set up the federated analysis system. Synthetic data generation can be an efficient and effective tool for enabling multi-jurisdictional studies while addressing privacy concerns.

Statin rosuvastatin inhibits apoptosis of human coronary artery endothelial cells through upregulation of the JAK2/STAT3 signaling pathway

The purpose of the present study was to explore the potential molecular signaling pathway mediated by the statin rosuvastatin in cultured human coronary artery endothelial cells (HCAECs) induced by CoCl2. CoCl2 was used to induce the apoptosis of HCAECs. Myocardial infarction rats were established and received statin or PBS treatment. Reverse transcription‑quantitative PCR, western blotting, ELISA, TUNEL assay and immunohistochemistry were used to analyze the role of statin treatment. The results showed that rosuvastatin treatment decreased apoptosis of HCAECs induced by CoCl2 by increasing anti‑apoptosis Bcl‑xl and Bcl‑2 expression, and decreasing pro‑apoptosis Bax, Bad, caspase‑3 and caspase‑9 expression. The myocardial ischemia rat model demonstrated that rosuvastatin treatment decreased the mitochondrial reactive oxygen species, inflammation, mitochondrial damage, lipid catabolism, heart failure and the myocardial infarction areas, but improved the cardiac function indicators, right and left ventricular ejection fraction and increased expression levels of Janus kinase (JAK) and signal transducer and activator of transcription (STAT)3 in myocardial tissue. In conclusion, the results of the current study revealed that the statin rosuvastatin presents cardioprotective effects by activation of the JAK2/STAT3 signaling pathway.

Statin Treatment and Prognosis of Elderly Patients Discharged after Non-ST Segment Elevation Acute Coronary Syndrome

Background: Statins are recommended for secondary prevention. Our aims were to describe the proportion of very elderly patients receiving statins after non-ST segment elevation acute coronary syndrome (NST-ACS) and to determine the prognostic implications of statins use. Methods: This prospective registry was performed in 44 hospitals that included patients ≥80 years discharged after a NST-ACS from April 2016 to September 2016. Results: We included 523 patients, the mean age was 84.2 ± 4.0 years and 200 patients (38.2%) were women. Previous statin treatment was recorded in 282 patients (53.4%), and 135 (32.5%) had LDL cholesterol levels >2.6 mmol/L. Mean LDL cholesterol levels during admission were 2.3 ± 0.9 mmol/L. Statins were prescribed at discharge to 474 patients (90.6%). Compared with patients discharged on statins, those that did not receive statins were more often frail (22 [47.8%] vs. 114 [24.4%], p < 0.01) and underwent an invasive approach less frequently (30 [61.2%] vs. 374 [78.9%], p = 0.01). During a 6-month follow-up, 50 patients died (9.5%). There was a nonsignificant trend to higher mortality in patients not treated with statins (6 [15%] vs. 44 [9.6%], p = 0.30), but statins were not independently associated with lower mortality (hazard ratio [HR] 0.79; 95% confidence interval [CI] 0.30–2.11, p = 0.65), nor with a reduction in the combined endpoint mortality/hospitalizations (HR 0.89; 95% CI 0.52–1.55, p = 0.69). Conclusions: Although most octogenarians presenting a NST-ACS are already on statins before the episode, their LDL cholesterol is frequently >2.6 mmol/L. Octogenarians who do not receive statins have a high-risk profile, with significant frailty and comorbidity.

Achieving quadruple aim goals through clinical networks: A systematic review

INTRODUCTION

Clinical Networks are complex interventions that enable healthcare professionals from various disciplines to work in a coordinated manner in the context of multiple care settings, to provide a high quality response to a specific disease. The aim of this study was to evaluate if clinical networks are able to improve effectiveness, efficiency, patients' satisfaction and professionals' behavior in the health care settings, namely the "quadruple aim" quality goals.

MATERIALS AND METHODS

A systematic review of documents published until February 28, 2018, in Medline, Embase and CINAHL was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach. A specific research strategy was created to identify studies evaluating effectiveness, efficiency, patient satisfaction and professionals well-being obtained through clinical networks implementation.

RESULTS

14249 studies were identified; 12 of these were eligible to the evaluation of "Quadruple Aim" outcomes. 9 studies focused on patients' outcomes improvement and 4 on network efficiency. Professionals' and patients' experience were not considered in any study.

CONCLUSIONS

There are some evidences that clinical network can improve patients' outcomes and health funds allocation in a small number of moderate-low quality studies. Further rigorous studies are needed to confirm these findings and to evaluate patients' and professionals' experience, taking into account also networks' structural features that could influence outcomes achievement.

Protective effect of arjunolic acid against atorvastatin induced hepatic and renal pathophysiology via MAPK, mitochondria and ER dependent pathways

3-Hydroxy-3-methylglutaryl-CoA reductase inhibitor, atorvastatin (ATO), is a highly effective drug used for the treatment of hypercholesterolemia and hypertriglyceridemia. Its application is restricted now-a-days due to several acute and chronic side effects. ATO induced anti hypercholesterolemia and hepatic tissue toxicity has been reported to follow different mechanisms. The present study has been carried out to investigate the protective role of arjunolic acid (AA) against ATO induced oxidative impairment and cell death in hepatic and renal tissue in mice. Administration of ATO (at a dose 30 mg/kg/day for 8 weeks) enhanced serum markers, increased reactive oxygen species (ROS) production and altered the pro oxidant-antioxidant status of liver and kidney tissues. Our experimental evidence suggests that ATO exposure induces apoptotic cell deathby the activation of caspase-3 and reciprocal regulation of Bcl-2/Bax with the concomitant reduction of mitochondrial membrane potential and increased level of cytosolic cytochrome c, Apaf1, caspase-9. Besides, ATO markedly increased the phosphorylation of MAPKs, enhanced caspase-12 and calpain level. Histological studies and DNA fragmentation analysis also support the toxic effect of ATO in these organs pathophysiology. Post treatment with AA (at a dose of 20 mg/kg body weight for 4 days), however, reduced ATO-induced oxidative stress and suppressed all these apoptotic events. Results suggest that AA could effectively and extensively counteract these adverse effects and might protect liver and kidney from ATO-induced severe tissue toxicity.

Development of reusable logic for determination of statin exposure-time from electronic health records

OBJECTIVE

We aim to quantify HMG-CoA reductase inhibitor (statin) prescriber-intended exposure-time using a generalizable algorithm that interrogates data stored in the electronic health record (EHR).

MATERIALS AND METHODS

This study was conducted using the Marshfield Clinic (MC) Personalized Medicine Research Project (PMRP) a central Wisconsin-based population and biobank with, on average, 30 years of electronic health data available in the independently-developed MC Cattails MD EHR. Individuals with evidence of statin exposure were identified from the electronic records, and manual chart abstraction of all mentions of prescribed statins was completed. We then performed electronic chart abstraction of prescriber-intended exposure time for statins, using previously identified logic to capture pill-splitting events, normalizing dosages to atorvastatin-equivalent dose. Four models using iterative training sets were tested to capture statin end-dates. Calculated cumulative provider-intended exposures were compared to manually abstracted gold-standard measures of ordered statin prescriptions, and aggregate model results (totals) for training and validation populations were compared. The most successful model was the one with the smallest discordance between modeled and manually abstracted Atorvastatin 10mg/year Equivalents (AEs).

RESULTS

Of the approximately 20,000 patients enrolled in the PMRP, 6243 were identified with statin exposure during the study period (1997-2011), 59.8% of whom had been prescribed multiple statins over an average of approximately 11 years. When the best-fit algorithm was implemented and validated by manual chart review for the statin-ordered population, it was found to capture 95.9% of the correlation between calculated and expected statin provider-intended exposure time for a random validation set, and the best-fit model was able to predict intended statin exposure to within a standard deviation of 2.6 AEs, with a standard error of +0.23 AEs.

CONCLUSION

We demonstrate that normalized provider-intended statin exposure time can be estimated using a combination of structured clinical data sources, including a medications ordering system and a clinical appointment coordination system, supplemented with text data from clinical notes.

Comparative effectiveness of rosuvastatin versus simvastatin in primary prevention among new users: a cohort study in the French national health insurance database

Purpose

Using the French claims database (Système National d'Information Inter-Régimes de l'Assurance Maladie) linked to the hospital discharge database (Programme de Médicalisation des Systèmes d'Information), this observational study compared the effectiveness of rosuvastatin and simvastatin prescribed at doses with close LDL-cholesterol-lowering potency on all-cause mortality and cardiovascular and cerebrovascular diseases (CCDs) in primary prevention.

Methods

This historical cohort included patients with no prior CCD, aged 40–79 years, who initiated statin therapy with rosuvastatin 5 mg or simvastatin 20 mg in 2008–2009 in general practice. Follow-up started after a 1-year period used to select patients who regularly received the initial treatment.

In an intention-to-treat analysis, patients were followed up to December 2011. In a per-protocol analysis, they were censored prematurely when they discontinued their initial treatment. Adjustment for baseline covariates (age, deprivation index, comedications, comorbidities, prior hospital admissions) was carried out by a Cox proportional hazards model. In the per-protocol analysis, estimation was done by “inverse probability of censoring weighting” using additional time-dependent covariates. Analyses were gender-specific.

Results

A total of 106 941 patients initiated statin therapy with rosuvastatin 5 mg and 56 860 with simvastatin 20 mg. Mean follow-up was 35.8 months. For both genders and both types of analyses, the difference in incidence rates of mortality and/or CCD between rosuvastatin 5 mg and simvastatin 20 mg users was not statistically significant after adjustment (e.g., for CCD and/or mortality in men, in intention-to-treat analysis HR = 0.94 [95% CI = 0.85–1.04], in per-protocol analysis HR = 0.98 [0.87–1.10]).

Conclusions

The results of this real-life study based on medico-administrative databases do not support preferential prescription of rosuvastatin compared to simvastatin for primary prevention of CCD.

Cardiovascular and economic outcomes after initiation of atorvastatin versus simvastatin in an employed population stratified by cardiovascular risk

The relative effects of atorvastatin and simvastatin among higher- and lower-risk patients are not well characterized. This study compared cardiovascular (CV) risk and direct and indirect costs among higher- and lower-risk employees initiating atorvastatin vs. simvastatin. Using a large employer claims database (1999-2006), employees were stratified as 1) high-risk employees with prior CV events, diabetes, or renal disorders; and 2) low- to intermediate-risk employees without these conditions. Propensity score matching was used, and 2-year outcomes were compared between matched cohorts. Indirect costs included disability payments and medically related absenteeism. Drug costs were imputed with recent prices to account for availability of generic simvastatin. Among 4167 matched pairs of high-risk employees, atorvastatin use was associated with a numerically lower risk of CV events (17.6 versus 18.4%, P = 0.37), higher direct medical costs ($17,590 versus $17,377, P = 0.002), numerically lower indirect costs ($4830 versus $4989, P = 0.29), and higher total costs by $54 ($22,420 versus $22,366, P = 0.034). The majority of high-risk employees (62%) received low initial statin doses (atorvastatin = 10 mg or simvastatin = 20 mg). Among 9326 matched pairs of low- to intermediate-risk employees, atorvastatin use was associated with a lower risk of CV events (3.1% versus 3.7%, P = 0.030), lower direct medical costs ($8400 versus $8436, P < 0.001), numerically lower indirect costs ($2781 versus $2807; P = 0.12), and lower total costs by $61 ($11,181 versus $11,243, P < 0.001). These results suggest that formulary policies reserving atorvastatin for higher-risk patients may not be cost-saving from the employer perspective.

Reduced risk of poststroke pneumonia in thrombolyzed stroke patients with continued statin treatment

BACKGROUND

Pneumonia is a frequent complication after stroke with strong impact on clinical outcome. Statins have pleiotropic immunmodulatory properties and were recently shown to exert beneficial effects on the development and clinical course of pneumonia.

AIMS

We aimed to investigate whether statin use is associated with a reduced risk of poststroke pneumonia in acute ischemic stroke patients treated with tissue plasminogen activator within 4·5hours.

METHODS

Data was extracted from a local register including all consecutive stroke patients who received thrombolysis at our institution. Prior statin use was identified retrospectively from clinical records and had to be continued after hospital admission. Poststroke pneumonia was diagnosed according to standardized criteria of US Centers for Disease Control and Prevention. Mortality and functional outcome at three-months were further assessed.

RESULTS

Overall, 481 ischemic stroke patients were analyzed. Continued statin use was documented in 17% of the patients. Frequency of pneumonia was 11%. Patients with statin use were less likely to develop poststroke pneumonia (5% vs. 13%, P = 0·04). After multivariable adjustment for known risk factors for poststroke pneumonia (age, stroke severity, dysphagia, male sex and diabetes), statin treatment was negatively associated with pneumonia (OR 0·31; 95% CI 0·10-0·94). Occurrence of pneumonia independently predicted three-month mortality and functional outcome.

CONCLUSIONS

Use of statins in acute ischemic stroke patients who receive thrombolysis might reduce the risk of poststroke pneumonia. Further studies are warranted to validate this finding.

Clinical implications of pharmacogenetic variation on the effects of statins

The last decade has seen an increase in the trend of HMG-CoA reductase inhibitor (statin) usage in the Western world, which does not come as a surprise noting that the latest American Heart Association heart and stroke statistics indicate an alarming prevalence of 80  million Americans (one in three) with one or more forms of diagnosed cardiovascular disease (CVD). Meta-analysis of several large-scale, randomized clinical trials has demonstrated statins to be efficacious in significantly reducing CVD-associated mortality in both primary and secondary prevention. Despite their proven efficacy, statins have also gained attention with respect to adverse drug reactions (ADRs) of muscle myopathy, derangements in hepatic function and even ADRs classified as psychiatric in nature. The depletion of cholesterol within the myocyte cell wall and/or the depletion of key intermediates within the cholesterol synthesis pathway are hypothesized as possible mechanisms of statin-associated ADRs. However, pharmacogenetic variability may also be a risk factor for ADRs and can include, for example, enzymes, transporters, cell membrane receptors, intracellular receptors or components of ion channels that contribute to the pharmacokinetics or pharmacodynamics of response to a particular drug. The cytochrome P450 (CYP) enzymatic pathways that comprise the polymorphic genes, CYP2D6, CYP3A4 and CYP3A5, and also a hepatic transporter, solute carrier organic anion transporter (SLCO1B1), which is a single nucleotide polymorphism discovered to be associated with statin-induced myopathy through a genome-wide association study, are discussed with respect to their effect on altering the pharmacokinetic profile of statin metabolism. Variants of the Apolipoprotein E (APO-E) gene, polymorphisms in the cholesteryl ester transfer protein (CETP) gene, the HMG-CoA reductase gene and other proteins are discussed with respect to altering the pharmacodynamic profile of statins. Pharmacogenetics and its application in medicine to individualize drug therapy has been previously shown to be clinically and economically beneficial through quality-adjusted life-year assessment. Therefore, polymorphisms affecting the pharmacokinetic and pharmacodynamic profiles of statins, which are widely used in therapy, with their potential application in the personalized prescribing of statin therapy, need further research. In this review, we update the recent literature with respect to genetic polymorphisms that may influence the pharmacokinetics and pharmacodynamics of statin therapy, and consider the relevance of these findings to the efficacy of treatment, prevention of ADRs and what this may mean for patient tolerance and compliance.

Effectiveness of rosuvastatin compared to other statins for the prevention of cardiovascular events-a cohort study in 395 039 patients from clinical practice

PURPOSE

This study compared the effectiveness of rosuvastatin (RSV) to other statins prescribed in clinical practice in prevention of cardiovascular (CV) events.

METHODS

This longitudinal inception cohort study, using Thomson Healthcare's MarketScan databases, included patients aged > or = 18 starting statin therapy during August 2003-December 2005. Patients were followed until 90 days after index statin monotherapy exposure, start of another lipid-lowering therapy, an event, end of eligibility, or end of study. The primary endpoint was a composite of CV death (in-hospital only), myocardial infarction, unstable angina, coronary revascularization, stroke, and carotid revascularization. Adjusted time-to-event analyses incorporating a propensity score covariate were used, and analyses were stratified by duration of statin exposure.

RESULTS

Among 395 039 patients who met inclusion/exclusion criteria, 12% initiated RSV, and 9622 (2.4%) of the total patient population experienced an outcome event. The median duration of statin treatment and follow-up was 100 days and 180 days, respectively. No statistically significant difference in CV event rates between RSV and other statins was observed after adjustment for demographics and medical/prescription history (HR = 0.99, 95%CI = 0.93-1.06). However, with longer exposure time, there was a suggestion of increased benefit with RSV compared to other statins.

CONCLUSIONS

The primary analysis showed similar incidence rates of CV-related events between the statin cohorts over a median of 180 days of follow-up.

Selective prescribing of simvastatin and atorvastatin by patient characteristics at treatment initiation over a 7-year period in Finland

PURPOSE

The aim of the study was to investigate preferential initiation with the two most frequently used statins, simvastatin and atorvastatin, by patient characteristics over time.

METHODS

Statin initiators without a statin prescription during the 365 days preceding the initiation from 1 January 1998 through 31 December 2004 were captured from the nation-wide Prescription Register in Finland. Associations of demographic factors and morbidities with atorvastatin versus simvastatin at initiation of statin treatment were analysed by a logistic regression model adjusted for significant covariates separately for each year.

RESULTS

Of all new statin users in 1998, atorvastatin was chosen for 18% and simvastatin for 39%. In 2004, the corresponding figures were 32 and 38%. Atorvastatin was more likely than simvastatin to be initiated in younger age groups than in persons older than 74 years (reference group). Initiation with atorvastatin was less likely for people with than without coronary artery disease; adjusted odds ratios ranged from 0.62 to 0.73 over the years 1998-2003.

CONCLUSION

Channelling of atorvastatin over simvastatin toward the younger and healthier population was found during the first 4 years after its launch in Finland. Channelling may lead to confounding by indication, which must be taken into account when designing pharmacoepidemiology studies on statins.

Statin therapy in the elderly: a review

Cardiovascular morbidity is the leading cause of mortality in the developed nations. Elevated serum cholesterol is a major risk factor for ischemic heart disease, one of the common cardiovascular morbidity in older adults, statins have been shown to be effective in reducing serum cholesterol and improving outcomes. Hypercholesterolemia is common in older adults and is one of the major modifiable risk factors. Yet, these patients have often been excluded from major clinical trials of statins and evidence suggests of their underuse. Data from recent clinical trials of statins indicate that the elderly patients with the highest cardiovascular risk are likely to derive the most benefits from cholesterol lowering. With the aging of the population, the prevalence of hypercholesterolemia and cardiovascular morbidity is likely to increase. In this review we evaluate the evidence for the use of statins in older adults.

Differences in cardiovascular event rates between atorvastatin and simvastatin among new users: managed-care experience

OBJECTIVE

Recent clinical trials and observational studies have suggested that reduction in low-density lipoprotein cholesterol (LDL-C) does not account for all differences among statins' effects on cardiovascular (CV) events, but that these effects may vary with time. Using a large US managed-care claims data set for 2002-2005, we assessed whether a difference in the rate of inpatient CV event rates could be observed between new atorvastatin and simvastatin users taking doses with comparable LDL-C-lowering potency, when prior risk factors are controlled and varying observation periods are employed.

RESEARCH DESIGN AND METHODS

Eligible patients had a 6-month period of no statin use prior to the initial statin prescription, an initial statin dosage of either 20 or 40 mg of simvastatin or 10 or 20 mg of atorvastatin (the most commonly used doses of both drugs), a 0 to 3-month 'qualifying period' after the first prescription to allow for varying minimum lengths of statin use, and no statin switches. In the primary analysis, patients were observed until an event or significant non-adherence occurred, up to 3.5 years; in secondary analyses, maximum 3-month, 6-month and 1-year observation periods were used. The primary endpoint was the first inpatient admission due to a CV event after the end of the qualifying period; multivariate Cox regression analysis controlled for a variety of demographic and CV risk characteristics and statin type.

RESULTS

At baseline, simvastatin users had significantly higher observed risk factors and higher subsequent, unadjusted CV event rates. In the primary Cox regression analyses, the CV event hazard rates for atorvastatin ranged from 0.899 (1-month qualifying period, p = 0.027) to 0.936 (3-month qualifying period, p = 0.33) versus simvastatin. Cox-based hazard rates for atorvastatin during 3-month to 1-year observation periods ranged from 0.908 to 0.915 for the 0-day qualifying period and from 0.851 to 0.884 for the 1-month qualifying period cohort (all p < 0.05); rates for the 3-month qualifying period cohort remained non-significant.

LIMITATIONS

Since this was not a prospective randomized study, there is the potential for unobserved risk factors to be responsible for some or all of the differences observed.

CONCLUSIONS

These results indicate an association between atorvastatin use and lower CV event rates, particularly in the first year of use, when observable risk factor differences are controlled. The implied absolute risk reduction of 2-3 events per 1000 patients per year may be considered clinically significant when viewed relative to major clinical trial results.

Discontinuation of statin therapy following an acute myocardial infarction: a population-based study

AIMS

Randomized clinical trials have shown that statins can reduce mortality after acute myocardial infarction (AMI). However, the impact of changes in patterns of statin use, particularly stopping statins, on survival post-AMI is unknown. Our objective was to estimate the extent to which different patterns of statin use are associated with post-AMI mortality.

METHODS AND RESULTS

Population-based, cohort study, from 2002 through 2004 in the United Kingdom General Practice Research Database (GPRD), involving patients surviving 90 days after their first AMI. Past statin use was defined as any statin prescription within 90 days before AMI; statin use post-AMI as any statin prescription within 90 days after AMI. Cohort entry was at day 90 post-AMI; subjects were followed for 1 year. Four groups were identified: (i) non-users (patients never on statins); (ii) users (on statins before and continued post-AMI); (iii) starters (started statins after the event); and (iv) stoppers (stopped statins after the event). Hazard ratios (HRs) were estimated using Cox proportional hazards model. The main outcome measure was 1-year all-cause mortality. The cohort included 9939 AMI survivors (mean age: 68.4 ± 12.8 years; 60.3% men), 22.7% of whom were not prescribed a statin post-AMI. When the non-user group (n = 2124) was considered as the reference, the adjusted HRs (95% confidence intervals) of death were 0.84 (0.66-1.09) for users (n = 2026), 0.72 (0.57-0.90) for starters (n = 5652), and 1.88 (1.13-3.07) for stoppers (n = 137). Stoppers of control medications (aspirin, β-blockers, and proton pump inhibitors) were not associated with increased mortality.

CONCLUSION

Discontinuation of statins in survivors of a first AMI was relatively rare in this cohort. However, statin discontinuation was associated with higher total mortality and this may represent a biological rebound or/and a risk-treatment mismatch phenomenon, where treatment is withdrawn from very ill patients. While awaiting further research, at present statin use should only be withdrawn under judicious clinical supervision.

Effectiveness of antiresorptive agents in the prevention of recurrent hip fractures

Hip fracture is associated with recurrent fractures and increased mortality. The results of our retrospective cohort study support the use of antiresorptive agents to prevent recurrent hip fractures in this population.

INTRODUCTION

Hip fracture, the most serious consequence of osteoporosis, is associated with recurrent fractures and increased mortality. Antiresorptive therapy has proven efficacy in the prevention of fractures after vertebral fractures. It is unknown if it can prevent recurrent fractures after a hip fracture.

METHODS

We designed a population based, retrospective cohort study, using administrative databases and identified patients hospitalized for a hip fracture between 1996 and 2002. The exposure was defined as being dispensed a prescription for an antiresorptive agent at any time following discharge. Multivariate Cox regression models were used to estimate the hazard ratio of recurrent hip fracture. Subgroup and propensity score analyses were performed.

RESULTS

A total of 20,644 patients were identified; 6,779 filled a prescription for antiresorptive agents. There were 992 recurrent hip fractures. Patients exposed to antiresorptives had a 26% reduction in the rate of recurrent fractures (adjusted hazard ratio 0.74; 95% CI, 0.64-0.86) compared to patients who were not. All subgroups experienced a reduction in recurrent fracture, except the very elderly. Propensity score analyses were consistent with the main analysis.

CONCLUSIONS

Antiresorptive therapy reduces the risk of recurrent hip fractures in elderly patients. These results provide evidence that this therapy should be considered for secondary prevention of hip fractures.

Evaluation of networks of randomized trials

Randomized trials may be designed and interpreted as single experiments or they may be seen in the context of other similar or relevant evidence. The amount and complexity of available randomized evidence vary for different topics. Systematic reviews may be useful in identifying gaps in the existing randomized evidence, pointing to discrepancies between trials, and planning future trials. A new, promising, but also very much debated extension of systematic reviews, mixed treatment comparison (MTC) meta-analysis, has become increasingly popular recently. MTC meta-analysis may have value in interpreting the available randomized evidence from networks of trials and can rank many different treatments, going beyond focusing on simple pairwise-comparisons. Nevertheless, the evaluation of networks also presents special challenges and caveats. In this article, we review the statistical methodology for MTC meta-analysis. We discuss the concept of inconsistency and methods that have been proposed to evaluate it as well as the methodological gaps that remain. We introduce the concepts of network geometry and asymmetry, and propose metrics for the evaluation of the asymmetry. Finally, we discuss the implications of inconsistency, network geometry and asymmetry in informing the planning of future trials.

Angiotensin II Receptor Blockers for the Treatment of Heart Failure: A Class Effect?

STUDY OBJECTIVE

To examine the class effect of angiotensin II receptor blockers (ARBs) on mortality in patients with heart failure who were aged 65 years or older.

DESIGN

Retrospective population-based study.

DATA SOURCE

Administrative database that stores information on hospital discharge summaries for the Canadian provinces of Quebec, Ontario, and British Columbia.

PATIENTS

A total of 6876 patients aged 65 years or older who were discharged with a primary diagnosis of heart failure between January 1, 1998, and March 31, 2003, and who filled at least one prescription for an ARB within 90 days of discharge.

MEASUREMENTS AND MAIN RESULTS

Times to all-cause death in patients receiving individual ARBs were compared. Models were adjusted for demographic, clinical, physician, and hospital characteristics; models were also adjusted for dosage categories, which were represented by time-dependent variables. The cohort of 6876 patients had a mean +/- SD age of 78 +/- 7 years, and most (62%) were women. Losartan was the most frequently prescribed ARB (61%), followed by irbesartan (14%), valsartan (13%), candesartan (10%), and telmisartan (2%). Irbesartan, valsartan, and candesartan were associated with better survival rates than losartan (adjusted hazard ratios [HRs] and 95% confidence intervals [CIs] 0.65 [0.53-0.79], 0.63 [0.51-0.79], and 0.71 [0.57-0.90], respectively). No difference was noted in mortality in patients prescribed telmisartan compared with those receiving losartan (HR 0.92 [95% CI 0.55-1.54]).

CONCLUSIONS

Elderly patients with heart failure who were prescribed losartan had worse survival rates compared with those prescribed other commonly used ARBs. The absence of a class effect for ARBs is consistent with data showing pharmacologic differences among the drugs.

Statins in elderly patients with acute coronary syndrome: an analysis of dose and class effects in typical practice

OBJECTIVE

To compare the effectiveness of statins of different treatment intensity used to treat elderly patients with acute coronary syndrome (ACS) in typical care settings.

DESIGN

Retrospective cohort study using linked hospital and pharmacy claims data.

SETTING

Statewide pharmacy benefits programmes in Pennsylvania and New Jersey.

PARTICIPANTS

18,311 Medicare patients discharged alive after ACS who received a prescription for a statin within 90 days of hospital discharge.

MAIN OUTCOME MEASURES

Using multivariable and propensity-matched Cox proportional hazards regression models, patients who were prescribed high-intensity and moderate-intensity statins were compared based on the drug-dose combination that they initially received. Individual drug-dose combinations were also compared. Our primary outcome was the composite of all-cause death or recurrent ACS.

RESULTS

Patients who received moderate-intensity statins were as likely to experience a primary outcome as patients treated with high-intensity statins (adjusted HR 1.02, 95% CI 0.96 to 1.08). Propensity matching did not change the results. Individually, all moderate-intensity statins were as effective as high-intensity atorvastatin with the exception of lovastatin (adjusted HR 1.22, 95% CI 1.09 to 1.36). Similarly, all high-intensity statins seem as effective as high-intensity atorvastatin but the CIs surrounding these estimates were wide.

CONCLUSIONS

This analysis of elderly patients with ACS treated in typical care settings does not demonstrate the superiority of high-intensity over moderate-intensity statin treatment or significant differences among individual statins.

The combination of atorvastatin and ethanol is not more hepatotoxic to rats than the administration of each drug alone

Animal studies and premarketing clinical trials have revealed hepatotoxicity of statins, primarily minor elevations in serum alanine aminotransferase levels. The combined chronic use of medicines and eventual ethanol abuse are common and may present a synergistic action regarding liver injury. Our objective was to study the effect of the chronic use of atorvastatin associated with acute ethanol administration on the liver in a rat model. One group of rats was treated daily for 5 days a week for 2 months with 0.8 mg/kg atorvastatin by gavage. At the end of the treatment the livers were perfused with 72 mM ethanol for 60 min. Control groups (at least 4 animals in each group) consisted of a group of 2-month-old male Wistar EPM-1 rats exposed to 10% ethanol (v/v) ad libitum replacing water for 2 months, followed by perfusion of the liver with 61 nM atorvastatin for 60 min, and a group of animals without chronic ethanol treatment whose livers were perfused with atorvastatin and/or ethanol. The combination of atorvastatin with ethanol did not increase the release of injury marker enzymes (alanine aminotransferase, aspartate aminotransferase, and lactic dehydrogenase) from the liver and no change in liver function markers (bromosulfophthalein clearance, and oxygen consumption) was observed. Our results suggest that the combination of atorvastatin with ethanol is not more hepatotoxic than the separate use of each substance.

Sex differences in the effectiveness of statins after myocardial infarction

BACKGROUND

We sought to investigate the sex differences in the effectiveness of statins in patients with acute myocardial infarction (AMI).

METHODS

Linking hospital discharge and drug claims databases from Quebec, Canada (1998-2004), we identified statin users (n = 14 710) and non-users (n = 23 833) discharged from hospital after an AMI-related hospital stay and followed up for as long as 7 years.

RESULTS

All-cause death rates were 4.1 and 14.6 per 100 person-years among users and non-users, respectively, whereas cardiac death rates were 2.2 and 7.4 per 100 person-years. For death from any cause, the adjusted hazard ratios associated with statin use in women were 0.61 (95% confidence interval [CI], 0.54-0.69) within 1 year of follow-up, 0.55 (0.48-0.63) at 1-3 years and 0.38 (0.31-0.49) at > 3 years; in men, the corresponding estimates were 0.54 (0.48-0.60), 0.48 (0.42-0.55) and 0.34 (0.30-0.39). For cardiac-related death, the adjusted hazard ratios associated with statin use in women were 0.70 (0.60-0.81) within 1 year, 0.56 (0.46-0.68) at 1-3 years and 0.44 (0.31-0.62) at > 3 years of follow-up, whereas in men, the estimates were 0.59 (0.51-0.69), 0.47 (0.39-0.58) and 0.37 (0.30-0.45), respectively.

INTERPRETATION

Statin therapy after an AMI was associated with reduced rates of all-cause and cardiac mortality. The effect increased with time in both sexes, but the degree of risk reduction was less for women than for men.

Dyslipidemia in Older Adults

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have been shown in many large, randomized clinical trials to be safe and highly effective for decreasing low-density lipoprotein cholesterol, thus preventing cardiovascular events and decreasing mortality in patients both with and without prior cardiovascular disease. Statins are also appropriate agents for older adults, although they remain underutilized in this population. This article uses three typical case history presentations to review the most recent clinical trial data and guidelines on statin therapy to provide practical guidance on clinical decision making for lipid-lowering therapy in the geriatric population.

Impact of adherence to statins on coronary artery disease in primary prevention

AIMS

To evaluate the impact of adherence to statins on nonfatal coronary artery disease (CAD). Statins reduce cardiovascular morbidity and mortality after 1-2 years of continuous treatment. Studies have shown that <40% of patients take > or =80% of prescribed doses 1 year after starting therapy and that approximately half discontinue medication within 6 months of starting therapy.

METHODS

A cohort of 20 543 patients was reconstructed using the Régie de l'assurance maladie du Québec databases. Patients aged 50-64 years, without cardiovascular disease, and newly treated with statins between 1998 and 2000 were eligible. A nested case-control design was used to study nonfatal CAD. Every case was matched with 20 randomly selected controls. The adherence level was defined as the percentage of the prescribed medication doses used over a specified period and classified as > or =90% or <90%. Rate ratios (RR) of nonfatal CAD were determined through conditional logistic regression adjusted for age, sex, socioeconomic status, diabetes and hypertension.

RESULTS

The mean patient age was 58 years, 45% had hypertension and 19% had diabetes. Men represented 37% of the cohort. Among patients followed for >1 year, adherence of > or =90% was associated with fewer nonfatal CAD events (RR 0.81; 0.67, 0.97) compared with adherence <90%. In the multivariate model, male gender (RR 1.37; 1.16, 1.63), welfare recipients (RR 1.24; 1.04, 1.48), newly diagnosed hypertension (RR 3.54; 2.62, 4.77) and newly diagnosed diabetes mellitus (RR 1.97; 1.20, 3.24) were risk factors for CAD.

CONCLUSION

The incidence of nonfatal CAD events decreases when >90% of the prescribed medications is used over at least 1 year.

Regression or Reduction in Progression of Atherosclerosis, and Avoidance of Coronary Events, With Lovastatin in Patients With or at High Risk of Cardiovascular Disease

HMG-CoA reductase inhibitors (statins) are the drugs of first choice for treating hypercholesterolaemia in order to prevent or slow the progression of coronary heart disease (CHD). Statins generally reduce the risk of CHD morbidity or mortality by about 30%. Lovastatin is effective in lowering plasma total cholesterol and low-density lipoprotein cholesterol levels, and is widely prescribed for both the primary and secondary prevention of CHD. In the major AFCAPS/TexCAPS primary prevention study of 6605 middle-aged or elderly men and women without symptomatic cardiovascular disease and with only moderately elevated serum lipids, treatment with lovastatin 20-40 mg once daily for a mean of 5.2 years significantly (p < 0.001) reduced the incidence of a first acute major cardiac event by 37% compared with placebo. In the smaller ACAPS study of 919 men and women who were asymptomatic for cardiovascular disease, but with evidence of early atherosclerosis, treatment with lovastatin for 3 years significantly (p = 0.001) slowed or reversed atherosclerosis compared with placebo, as measured by changes in the intimal-medial thickness of carotid arteries on B-mode ultrasound. Three randomised, controlled, secondary prevention trials have demonstrated that in patients with coronary artery disease, treatment with lovastatin 20-80 mg/day alone or in combination with colestipol for 2-2.5 years reduced the severity of stenosis and/or slowed or reversed the progression of atherosclerosis, as assessed by angiography. In the FATS study, the severity of stenosis after 2.5 years in recipients of lovastatin plus colestipol was reduced by 2.8% compared with placebo, while the frequency of lesion progression was halved and the frequency of lesion regression was tripled. Treatment with lovastatin for 2.2 years in the MARS study significantly reduced the mean percent diameter stenosis compared with placebo (p = 0.005) in patients with more severe stenosis, and also significantly (p = 0.002) reduced the mean global change score (indicating less progression). In the CCAIT study, lovastatin therapy for 2 years significantly improved coronary change scores (p < 0.01) and significantly reduced the incidence of new lesions (p = 0.001) compared with placebo. Across the primary and secondary prevention studies, lovastatin was shown to be similarly effective in women, the elderly, smokers and in subjects with hypertension, hypercholesterolaemia or type 2 diabetes mellitus. Therefore, the available data demonstrate that lovastatin provides significant lipid-modifying efficacy, slows progression or causes regression of atherosclerosis, and protects against acute cardiac events, in both those with and those without symptomatic CHD.

Effectiveness of bisphosphonates on nonvertebral and hip fractures in the first year of therapy: the risedronate and alendronate (REAL) cohort study

INTRODUCTION

Randomized clinical trials have shown that risedronate and alendronate reduce fractures among women with osteoporosis. The aim of this observational study was to observe, in clinical practice, the incidence of hip and nonvertebral fractures among women in the year following initiation of once-a-week dosing of either risedronate or alendronate.

METHODS

Using records of health service utilization from July 2002 through September 2004, we created two cohorts: women (ages 65 and over) receiving risedronate (n = 12,215) or alendronate (n = 21,615). Cox proportional hazard modeling was used to compare the annual incidence of nonvertebral fractures and of hip fractures between cohorts, adjusting for potential differences in risk factors for fractures.

RESULTS

There were 507 nonvertebral fractures and 109 hip fractures. Through one year of therapy, the incidence of nonvertebral fractures in the risedronate cohort (2.0%) was 18% lower (95% CI 2% - 32%) than in the alendronate cohort (2.3%). The incidence of hip fractures in the risedronate cohort (0.4%) was 43% lower (95% CI 13% - 63%) than in the alendronate cohort (0.6%). These results were consistent across a number of sensitivity analyses.

CONCLUSION

Patients receiving risedronate have lower rates of hip and nonvertebral fractures during their first year of therapy than patients receiving alendronate.

Retrospective review of sex differences in the management of dyslipidemia in coronary heart disease: an analysis of patient data from a Maryland-based health maintenance organization

BACKGROUND

Coronary heart disease (CHD) is the leading cause of death in men and women in the United States, with a higher mortality in women, despite a lower prevalence. Statins effectively treat dyslipidemia and reduce the risk of CHD mortality.

OBJECTIVE

The objective of this study was to evaluate the treatment of dyslipidemia in patients with CHD and determine if sex differences exist.

METHODS

This was a retrospective chart review performed within a multioffice staff model health maintenance organization of approximately 70,000 members. An administrative database, containing inpatient and out-patient medical claims, was used to identify patients with CHD based on diagnostic codes. Charts were randomly selected and the following information was obtained from chart review: age; sex; risk factors for CHD; diagnosis and/or prescription for depression; blood low-density lipoprotein cholesterol (LDL-C) level; and drug, dosage, and duration of prescribed lipid-lowering therapy. Exclusion criteria included missing charts and unavailable LDL-C values. LDL-C values were classified as at target if LDL-C<2.59 mmol/L (<100 mg/dL). Patients receiving statin monotherapy were categorized into 3 potency groups, based on efficacy to lower LDL-C values: high (atorvastatin 20-80 mg, lovastatin 80 mg), medium (atorvastatin 10 mg, pravastatin 40 mg, simvastatin 200 mg), and low (fluvastatin 10-40 mg, lovastatin 10-40 mg, pravastatin 10-20 mg, simvastatin 5-10 mg).

RESULTS

A total of 1487 adult patients (64.4% male with a mean (SD) age of 65.7 (11.8) years were identified, based on diagnostic codes for CHD. Three hundred twenty charts were selected for review. After exclusion, the final study cohort was 290 patients. The cohort was 66.2% male (192/290) with no significant difference in mean (SD) age between men (65.2 [9.2] years) and women (66.9 [10.5] years). Weight of women ranged from 85 to 305 lbs; 134 to 288 lbs for men. Among the study cohort, 46.2% (134/290) of the patients achieved the target LDL-C of <2.59 mmol/L (<100 mg/dL), with significantly more men (51.0% [98/192]) than women (36.7% [36/98]) reaching target (P=0.021). Lipid-lowering therapy was prescribed to 68.6% (199/290) of the patients, with no significant sex differences (men, 71.4% [137/192]; women, 63.3% [62/98]). Of the patients prescribed lipid-lowering therapy (primarily statins), 53.8% (107/199) achieved target LDL-C. There was no significant sex difference in the potency groups prescribed, and the rate of LDL-C target attainment was similar across potency groups. Overall, 70.3% of patients who did not receive lipid-lowering therapy had inadequately controlled LDL-C (women, 31/36 [86.1%]; men, 33/55 [60.0%] [P=0.008]).

CONCLUSIONS

The majority of CHD patients from a Maryland-based health maintenance organization had elevated LDL-C values, despite a lipid-lowering prescription rate of 68.6%. A significant gap in dyslipidemia treatment in these CHD patients remained, particularly for women.

How many "Me-Too" drugs are enough? The case of physician preferences for specific statins

BACKGROUND

The increasing availability of "Me-Too" drugs has provided considerable treatment options for clinicians. However, the number of such drugs within a class that are actually used by clinicians has not been well studied.

OBJECTIVE

To determine the number of different statins that individual physicians use in practice.

METHODS

The Ontario Drug Benefit database was used to identify physicians who issued at least 10 incident statin prescriptions between October 2001 and May 2003 for patients aged 66 years and older. A preferred statin was defined for each physician, and the proportion of each physician's incident prescriptions written for that agent was determined. We then determined the number of different statins required to fill each physician's incident prescribing needs.

RESULTS

A total of 3426 physicians wrote 73,571 incident statin prescriptions. The mean percentage of prescriptions written for each physician's preferred statin formulation was 73.7%. Repeat analysis to examine the proportion of prescriptions filled using each physician's top 2 statin formulations found that the average physician wrote the vast majority of his or her incident prescriptions (94.9%) for only 1 or 2 statins. Half of all physicians used, at most, 2 different statins for all incident prescribing, while 91.3% of physicians used, at most, 3 different statins for all of their incident prescribing.

CONCLUSIONS

A high proportion of Ontario physicians issued the majority of their incident statin prescriptions for the same statin formulation. Most physicians required, at most, 3 different statins for all incident statin prescribing.

Treating non-ST-segment elevation ACS. Pros and cons of current strategies

NSTE-ACS is a complex clinical event characterized by a variable degree of myocardial ischemia and triggered, in most patients, by a rupture of a vulnerable plaque that leads to acute intraluminal nonocclusive thrombosis. Traditionally, acute management strategies for NSTE-ACS have been aimed at identification of vascular areas with discrete atheroma and revascularization of the affected myocardium. Studies that have evaluated invasive strategies in NSTE-ACS suggest that the rates of hard clinical events are similar for both intensive medical treatment and early invasive management strategies. As shown recently in the Cooperative Cardiovascular Project study, intensive therapy with beta-blockers appears to be a viable management option that has comparable outcomes in most patients with NSTE-ACS. Although several different treatment strategies have been advocated in the management of NSTE-ACS, the available evidence-based information does not fully support some of these traditional approaches. Future prospective, well-controlled trials are needed to fully ascertain the role of invasive and other medical management strategies in patients with NSTE-ACS. Long-term aggressive management of established risk factors for CAD is unquestionably the most prudent and cost-effective therapeutic approach in the long-term management in patients recovering from NSTE-ACS.

Statins Are Associated With Better Outcomes After Carotid Endarterectomy in Symptomatic Patients

BACKGROUND AND PURPOSE

Statins have been associated with a reduction in mortality from noncardiac surgery. This study aimed to determine whether statin use on admission to hospital for carotid endarterectomy was associated with a reduction of in-hospital adverse outcomes.

METHODS

Data describing patient characteristics, surgical indication, statin treatment, and in-hospital outcomes of death, ischemic stroke or death and cardiac outcomes were collected from a chart review of all patients (3360) undergoing carotid endarterectomy in Western Canada from January 2000 to December 2001. Outcomes of patients on statins versus those not on statins were compared using logistic regression to account for differences in patient characteristics, and propensity score methods to account for factors influencing patient allocation to statins.

RESULTS

Eight hundred and fifteen of 2031 symptomatic patients and 665 of 1252 asymptomatic patients were on a statin at the time of hospital admission. Statin use by symptomatic patients was associated with reduced in-hospital mortality and in-hospital ischemic stroke or death, but not in-hospital cardiac outcomes (adjusted odds ratio 0.25 [CI, 0.07 to 0.90], 0.55 [CI, 0.32 to 0.95], 0.87 [CI, 0.49 to 1.54], respectively). The improvement in outcomes was robust when tested using propensity score matching. This association was not seen in asymptomatic patients on statins (adjusted odds ratio, in-hospital mortality 0.54 [CI, 0.13 to 2.24]; in-hospital ischemic stroke or death 1.34 [CI, 0.61 to 2.93]; in-hospital cardiac outcomes 1.37 [CI, 0.73 to 2.58]).

CONCLUSIONS

These findings are suggestive of a protective effect of statin therapy in symptomatic patients pre-treated at the time of carotid endarterectomy, though this needs confirmation in a randomized controlled trial.

Statins research unfinished saga: desirability versus feasibility

Drugs in the same class are generally thought to be therapeutically equivalent because of similar mechanisms of action (the so-called "class effect"). However, statins differ in multiple characteristics, including liver and renal metabolism, half-life, effects on several serum lipid components, bioavailability and potency. Some are fungal derivatives, and others are synthetic compounds. The percentage absorption of an oral dose, amount of protein binding, degree of renal excretion, hydrophilicity, and potency on a weight basis is variable. These differences may be even greater in diabetic patients, who may present diabetes-induced abnormalities in P450 isoforms and altered hepatic metabolic pathways. Thus, it is obvious that head-to-head comparisons between different statins are preferable than trial-to-trial comparisons. Such assessments are of utmost importance, especially in cases in which specific populations with a distinct lipid profile and altered metabolic pathways, like diabetics, are studied. It should be specially pinpointed that patients with metabolic syndrome and diabetes constitute also a special population regarding their atherogenic dyslipidemia, which is usually associated with low HDL-cholesterol, hypertriglyceridemia and predominance of small dense LDL-cholesterol. Therefore, these patients may benefit from fibrates or combined statin/fibrate treatment. This policy is not accomplished since in the real world things are more complex. Trials would require very large sample sizes and long-term follow-up to detect significant differences in myocardial infarction or death between two different statins. Moreover, the fact that new compounds are under several phases of research and development represents an additional drawback for performing the trials. Ideally, head-to-head trials regarding clinically important outcomes should be conducted for all drugs. Nonetheless, the desirability of performing such trials, which epitomize modern evidence-based medicine, is frequently superseded by the feasibility dictated by pragmatic and economic circumstances. In the latter case, in absence of solid systematic documentation of comparable health benefits and long-term safety, both researchers and practicing physicians should allude to the weight of scientific endorsement behind the arguments and seek for the possible strengths and weaknesses intrinsic to each specific study. In any case, conclusions based on surrogate endpoints cannot completely substitute head-to-head comparisons regarding patients' outcome.