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Hypertension Canada's 2020 guidelines for the prevention, diagnosis, risk assessment, and treatment of hypertension in adults and children provide comprehensive, evidence-based guidance for health care professionals and patients. Hypertension Canada develops the guidelines using rigourous methodology, carefully mitigating the risk of bias in our process. All draft recommendations undergo critical review by expert methodologists without conflict to ensure quality. Our guideline panel is diverse, including multiple health professional groups (nurses, pharmacy, academics, and physicians), and worked in concert with experts in primary care and implementation to ensure optimal usability. The 2020 guidelines include new guidance on the management of resistant hypertension and the management of hypertension in women planning pregnancy.

Author(s): Sukumar, Smrithi; Gulilat, Markus; Linton, Bradley; Gryn, Steven E; Dresser, George K; Alfonsi, Jeffrey E; Schwarz, Ute I; Kim, Richard B; Schwartz, Janice B | Abstract: ObjectivesLower than recommended doses of direct-acting oral anticoagulants are often prescribed to older adults with nonvalvular atrial fibrillation (NVAF). Our goal was to determine the consequences of lower than recommended dosing on plasma apixaban concentrations during the clinical care of older adults with NVAF.DesignConvenience sample of patients receiving anticoagulation during 2017.SettingAcademic medical center.ParticipantsStable adults older than 65 years with NVAF receiving apixaban on a chronic basis.MeasurementsPatient age, weight, creatinine, co-medications, and apixaban concentrations.ResultsA total of 110 older adults with NVAF (mean age = 80.4 y; range = 66-100 y with 45% women) were studied. Overall, 48 patients received recommended dosing of 5 mg twice/day, and 42 received lower than recommended dosing. One patient in each category had concentrations below the expected 5% to 95% range at time of peak concentrations. Differences in proportion of apixaban concentrations within or outside expected ranges were not significant between patients receiving lower than recommended doses and those dosed as recommended at 5 mg twice/day (P = .35). However, in patients dosed as recommended with 5 mg twice/day, four had concentrations above the 5% to 95% range for peak levels expected at 3 to 4 hours after dosing; in two, this occurred around the midpoint of the dosing interval. Twenty patients received 2.5 mg twice/day as recommended. One-third had apixaban concentrations higher than expected peak concentrations compared with the clinical trials, and more than two-thirds had levels above the reported median for peak concentrations.ConclusionsApixaban concentrations in older adults with NVAF seen clinically were higher than expected based on clinical trial data. The findings raise questions about the optimal dosing of apixaban in older adults with NVAF encountered outside of clinical trials and suggest a role for the monitoring of apixaban concentrations during care of patients that differ from those in randomized trials or when considering dosing outside of published guidelines. J Am Geriatr Soc 67:1902-1906, 2019.

Hypertension Canada provides annually-updated, evidence-based guidelines for the diagnosis, assessment, prevention, and treatment of hypertension in adults and children. This year, the adult and pediatric guidelines are combined in one document. The new 2018 pregnancy-specific hypertension guidelines are published separately. For 2018, 5 new guidelines were introduced, and one existing guideline on the blood pressure thresholds and targets in the setting of thrombolysis for acute ischemic stroke was revised. The use of validated wrist devices for the estimation of blood pressure in individuals with large arm circumference is now included. Guidance is provided for the follow-up measurements of blood pressure, with the use of standardized methods and electronic (oscillometric) upper arm devices in individuals with hypertension, and either ambulatory blood pressure monitoring or home blood pressure monitoring in individuals with white coat effect. We specify that all individuals with hypertension should have an assessment of global cardiovascular risk to promote health behaviours that lower blood pressure. Finally, an angiotensin receptor-neprilysin inhibitor combination should be used in place of either an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in individuals with heart failure (with ejection fraction < 40%) who are symptomatic despite appropriate doses of guideline-directed heart failure therapies. The specific evidence and rationale underlying each of these guidelines are discussed.

Rosuvastatin is commonly prescribed for the treatment of hypercholesterolemia and hepatic transporter-mediated accumulation in the liver enhances its efficacy. Current guidelines indicate no preference for fed or fasted rosuvastatin administration. We investigated the association between food intake and rosuvastatin disposition in healthy subjects and low-density lipoprotein cholesterol (LDL-C)-lowering effects among patients taking rosuvastatin. We demonstrate that administration with food resulted in a near 40% reduction of rosuvastatin exposure in healthy Asian (n = 12) and Caucasian (n = 11) subjects. Higher rosuvastatin concentrations in Asian subjects also correlated with higher allele frequency of ABCG2 c.421C>A. In mice, a greater rosuvastatin liver:plasma ratio was noted when administered with food. Among rosuvastatin patients (n = 156), there was no difference in dose needed to reach target LDL-C, measured LDL-C, or lathosterol concentrations, when administered in a fed or fasting state. Therefore, taking rosuvastatin with food could reduce systemic concentrations, and subsequent myopathy risk, without compromising LDL-C-lowering benefit.

Introduction: Statins are beneficial for both primary and secondary prevention of cardiovascular disease in many patients at elevated risk. However, selection of patients most likely to respond and least likely to have adverse effects can benefit from refinement. While pharmacogenomic aspects of statins have been thoroughly evaluated, as yet there has been no major impact on patient care, although there is great potential that a precision medicine approach might one day enhance patient care.Areas covered: This paper provides a brief overview of genetic variants that influence statin responsiveness, together with newer information on genetic risk scores that combine numerous common DNA variants into a stronger prediction of cardiovascular risk reduction from statins. We also discuss a pharmacokinetic-based approach to aid in prediction and prevention of statin adverse effects.Expert commentary: While individual genetic variants appear to have statistically significant effects on lipid lowering by s...

Sequencing of the human genome led to great hopes and expectations for a 'genomics revolution' where disease diagnosis as well as therapies would be based on an individual's genetic makeup. Although significant progress has been made, a number of challenging hurdles must be overcome prior to the broader adoption and implementation of pharmacogenomics and personalized medicine as a part of standard patient care. One aspect of pharmacogenomics-based personalized medicine that has not garnered as much attention, a key focus of this perspective, is the importance of interpreting pharmacogenomic test results in a patient-specific clinical context, and expert physicians and other allied health care providers with the requisite expertise in clinical pharmacology and genomics who are able to provide such services.

Cardiovascular disease is a major cause of death, and hypercholesterolemia is a major risk factor. Statins, with simvastatin among the most widely used, have ample evidence demonstrating prevention of cardiovascular events and mortality. Ezetimibe is effective at improving serum lipids in combination with statins or alone, but its role has been controversial.Here, we provide an overview of the pharmacokinetics and pharmacodynamics of each component of the combination, as well as pharmacogenetic contributors. Regarding clinical efficacy, our focus will be on the post-marketing clinical trials of ezetimibe-simvastatin combination therapy. We broach the controversy around the role of ezetimibe, particularly in light of the results of the IMProved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT).Ezetimibe in combination with simvastatin or other statins provides an excellent means of incremental lipid-lowering effect, although the clinical benefit has been uncertain. IMPROVE-IT is the first to demonstrate incremental cardiovascular risk reduction with the addition of ezetimibe to simvastatin. What the literature lacks is evidence around the common use of ezetimibe as monotherapy or add-on therapy to lower doses of statins in patients who fail to achieve adequate lipid lowering or do not tolerate high-dose statins.

Statins form the backbone of lipid-lowering therapy in the prevention of cardiovascular disease. Numerous studies have evaluated the effect of genomics on the clinical efficacy and adverse effects of statins. Several gene variants that can be linked to either the pharmacokinetics or pharmacodynamics of statins have been identified as potentially important, although there are some discrepant findings among studies. Effect sizes are modest for lipid-lowering efficacy and perhaps somewhat larger for risk of myopathy, although results are inconsistent. Pharmacogenomics of nonstatin lipid-lowering agents have not been evaluated to the same extent, given their relatively limited use, although there are some promising candidate genes for further study. Finally, with several new classes of lipid-lowering therapies soon becoming available, there may be a potential application for pharmacogenomics to identify patients ideally suited to receive-or those who should avoid-specific medications.

We provide an overview of orally administered lipid-lowering therapies under development.Recent data support statins for intermediate risk primary prevention, and ezetimibe for high-risk secondary prevention. Novel agents in development include bempedoic acid and gemcabene, and work continues on one remaining cholesteryl ester transfer protein inhibitor, anacetrapib, to determine whether this class can reduce cardiovascular risk. Selective peroxisome proliferator-activated receptor modulators such as K-877 are under study to determine whether they have an advantage over older fibrates. Diacylglycerol transferase inhibitors such as pradigastat appear to have potent triglyceride-lowering effects, even for patients with familial chylomicronemia syndrome. Finally, novel ω-3 preparations are available with significant triglyceride lowering, although their role in therapy remains unclear.Statins will remain the backbone of lipid-lowering therapy, although several novel oral agents are promising. The common theme across drugs in development is the demonstration of good lipid-lowering effect, although lacking cardiovascular outcomes data, which will likely be necessary before any of them, can be recommended or approved for widespread use.

Background Direct-acting oral anticoagulants (DOACs) are widely prescribed for stroke prevention in patients with atrial fibrillation (AF). An important advantage of DOACs is that routine monitoring of an anticoagulation response is not necessary. Nevertheless, because of their mechanism of action, a DOAC anticoagulation effect can be inferred based on the observed plasma concentration. However, there is a paucity of data relating to observed interpatient variation in DOAC plasma concentrations in the postmarket clinical setting. Methods We determined rivaroxaban and apixaban plasma concentrations in patients with AF during routine clinic visits. Results Among 243 patients (rivaroxaban, n = 94; apixaban, n = 149) enrolled in this study, a 60- and 50-fold interpatient variation in plasma concentration was observed for rivaroxaban and apixaban, respectively. Approximately 12% of patients receiving rivaroxaban and 13% of patients receiving apixaban exceeded the 95th percentile for predicted maximum plasma concentration observed in clinical trials. Conclusions In this routine-care setting, rivaroxaban and apixaban plasma concentrations tended to be more variable than those observed in clinical trials. Identification of additional clinical and molecular determinants that more fully predict patients at risk for excessively high or low DOAC concentrations may enable a more precise DOAC dosing regimen for the individual patient.

Due to high basal interindividual variation in cytochrome P450 3A (CYP3A) activity and susceptibility to drug interactions, there has been interest in the application of efficient probe drug phenotyping strategies, as well as endogenous biomarkers for assessment of in vivo CYP3A activity. The biomarkers 4β-hydroxycholesterol (4βHC) and 6β-hydroxycortisol (6βHCL) are sensitive to CYP3A induction and inhibition. However, their utility for the assessment of constitutive CYP3A activity remains uncertain. We investigated whether endogenous plasma biomarkers (4βHC and 6βHCL) are associated with basal CYP3A metabolic activity in healthy subjects assessed by a convenient single-time-point oral midazolam (MDZ) phenotyping strategy. Plasma 4βHC and 6βHCL metabolic ratios (MRs) were analysed in 51 healthy adult participants. CYP3A activity was determined after administration of an oral MDZ microdose (100 μg). Simple linear and multiple linear regression analyses were performed to assess relationships between MDZ oral clearance, biomarkers and subject covariates. Among study subjects, basal MDZ oral clearance, 4βHC and 6βHCL MRs ranged 6.5-, 10- and 13-fold, respectively. Participant age and alcohol consumption were negatively associated with MDZ oral clearance (p = 0.03 and p = 0.045, respectively), while weight and female sex were associated with lower plasma 4βHC MR (p = 0.0003 and p = 0.032, respectively). Neither 4βHC nor 6βHCL MRs were associated with MDZ oral clearance. Plasma 4βHC and 6βHCL MRs do not relate to MDZ single-time-point metabolic phenotype in the assessment of constitutive CYP3A activity among healthy individuals.

Lipid-lowering medications, particularly statins, have been a popular target for pharmacogenetic studies. A handful of genes have shown promise for predicting response to therapy from the perspective of lipid lowering, as well as myopathy. A number of genes have been implicated and have biological plausibility based on their involvement with the pharmacokinetics or pharmacodynamics of statins or other lipid-lowering medications. The level of confidence and replication of these findings varies, although several associations are likely true. Novel classes of lipid-lowering therapy have opened up new possibilities in the treatment of severe inherited forms of dyslipidemia, making the identification of such mutations an important pharmacogenetic predictor of failure of standard therapy, with potential response to novel therapy. Advances in next-generation sequencing technology bring the application of pharmacogenetics even closer to routine clinical practice.

Few classes of drugs have had a transformational an effect on cardiovascular disease (CVD) prevention and have saved as many lives as 3-hydroxy-3-methylglutaryl-coenzyme A (HMG CoA) reductase inhibitors (statins). The original statind compactin or mevastatindwas a natural product isolated from the fungus Penicillium citrinum. Subsequent chemical modifications yielded compounds with increased efficacy and reduced adverse effects, ultimately leading to the statins we are familiar with today. First evaluated in the 1980s as a treatment for rare severe dyslipidemias, such as familial hypercholesterolemia, statins hit mainstream cardiology as a result of 27 randomized clinical trials (RCTs) involving > 170,000 patients conducted in the 1990s and early 2000s, which indicated that major cardiovascular events, including death, were reduced by 21% for each statin-related 1 mmol/L reduction in low-density lipoprotein cholesterol. Based on such overwhelming and consistent evidence of benefit, statins justifiably became foundational therapy for primary and secondary prevention of CVD, having likely saved millions of years of life worldwide over the past 2 decades. But time passes. Yesterday’s revolutionary therapy becomes today’s standard of care, and is often taken for granted. Furthermore, because statins are now all available generically, there is no active promotion and no new RCTs on statin efficacy, which, for CVD prevention is so well established and incontrovertible that it might no longer be considered newsworthy. Somewhat incongruously, the widespread acceptance and use of statins now permits a different sort of research to be undertaken. One variety of study involves scouring administrative databases, identifying tens of thousands of real-world statin users and then testing hypotheses using indirect outcome variables. By its nature, this type of study design cannot be controlled in the same way as a prospective RCT and might suffer from unmeasured confounding artifacts. Such studies also tend to focus on adverse outcomes, the documentation of which seems relatively straightforward. The

Tamoxifen is a prodrug, requiring cytochrome P450 enzyme-mediated metabolism to form the active metabolite endoxifen. We identified a case of drug-drug interaction involving tamoxifen and phenytoin, associated with a markedly lower endoxifen level than predicted. The patient is a 49-year-old woman, genotyped as a cytochrome P450 2D6 (CYP2D6) extensive metabolizer, chronically taking phenytoin for a seizure disorder. The plasma endoxifen level 2 months after starting tamoxifen was 4.72 nmol/l, the lowest level we have seen in our clinic among patients with CYP2D6 extensive metabolizer genotypes (n=195). To our knowledge, this is the first report documenting the extent of induction in terms of both tamoxifen and endoxifen levels during concomitant phenytoin therapy, and this effect would likely result in loss of therapeutic benefit from tamoxifen. Phenytoin should therefore not be used concurrently with tamoxifen for extended periods of time unless a therapeutic drug (endoxifen) monitoring strategy is utilized.

We provide an overview of recent advances in the therapy of hypertriglyceridemia, focusing on several new therapies with potential for treating of familial chylomicronemia, other forms of hypertriglyceridemia, and for triglyceride-lowering in patients with other lipid disorders.Newer triglyceride-lowering modalities under evaluation include gene therapy for lipoprotein lipase deficiency (alipogene tiparvovec), and antisense oligonucleotides against mRNA for apolipoproteins B (mipomersen) and C3 (volanesorsen, ISIS 304801). Other potential therapies include small molecule inhibitors of microsomal triglyceride transfer protein (lomitapide) and diacylglycerol acyltransferase-1 (pradigastat), and a monoclonal antibody against angiopoietin-like protein 3 (REGN1500). There is also renewed interest in omega-3 fatty acids, and in developing potent and selective agonists of peroxisome proliferator-activated receptors.Several promising triglyceride-lowering therapies are at various stages of development; a few are even available in some markets. Although existing data suggest good biochemical efficacy, data on long-term clinical outcomes are still limited. For some therapies, cost will be an important consideration, and use will likely be restricted to orphan indications, for example very severe cases of hypertriglyceridemia as seen in familial chylomicronemia syndrome, although some therapies could theoretically be more broadly used one day for cardiovascular disease prevention.

Cardiovascular disease remains a major cause of death of Canadians. Current prevention guidelines involve the use of risk prediction tools to determine the aggressiveness of therapy, particularly with respect to lipidand blood pressure–lowering medication. These guidelines recommend use of the Framingham Risk Score (FRS), the Reynolds Risk Score, or the Systematic Cerebrovascular and Coronary Risk Evaluation for estimation of 10-year risk of cardiovascular disease, although they do acknowledge that long-term (lifetime) risk can be dramatically elevated in those with low or intermediate short-term (10-year) risk. In this issue of the Canadian Journal of Cardiology, Bleakley et al. comment on a variety of issues surrounding the use of cardiovascular risk prediction and the general migration toward the use of lifetime risk prediction models. They examine several limitations of short-term risk models, broach the controversy around early initiation of lifelong pharmacologic treatment in the large group of patients with low shortterm but high lifetime risk, and discuss additional roles for lifetime risk prediction besides decisions to treat. There are several concerns with current cardiovascular risk prediction tools. First, there is evidence that available tools are not used appropriately in the primary care setting. Second, while several risk prediction tools have been validated in different populations, prognostic accuracy remains imperfect. For example, the area under the receiver operating characteristic curve for the FRS is 0.77 in women, and 0.76 in men, and other cardiovascular risk scores perform at a similar level, suggesting that up to a quarter of all patients may be misclassified. Furthermore, a systematic review of studies comparing FRSpredicted risk of coronary heart disease to observed 10-year outcomes demonstrated underprediction in high-risk populations, with a predicted-to-observed ratio of 0.43, as well as overprediction in low-risk populations, with a predicted-toobserved ratio of 2.87.