Cardiovascular disease risk stratification by the Framigham score is markedly improved by ambulatory compared with office blood pressure

Clinical trial design for assessing hypertension medications: are critical circadian chronopharmacological principles being taking into account?

INTRODUCTION

Clinical hypertension trials typically rely on homeostatic principles, including single time-of-day office blood pressure (BP) measurements (OBPM), rather than circadian chronopharmacological principles, including ambulatory monitoring (ABPM) done around-the-clock to derive the asleep systolic BP (SBP) mean and sleep-time relative SBP decline - jointly the strongest prognosticators of cardiovascular disease (CVD) risk and true definition of hypertension - to qualify participants and assess outcomes.

AREAS COVERED

Eight chronopharmacological elements are indispensable for design and conduct of hypertension medication trials, mainly those on ingestion-time differences in effects, and also a means of rating quality of investigations. Accordingly, we highlight the findings and shortcomings of: (i) 155 such ingestion-time trials, 83.9% finding at-bedtime/evening treatment more beneficial than conventional upon-awakening/morning treatment; (ii) HOPE and ONTARGET CVD outcomes investigations assessing in the former add-on ramipril at-bedtime and in the latter telmisartan, ramipril, or both in combination in the morning; and (iii) pragmatic TIME CVD outcomes trial.

EXPERT OPINION

Failure to incorporate chronopharmacological principals - including ABPM to derive asleep SBP and SBP dipping to qualify subjects as hypertensive and assess CVD risk - results in deficient study design, dubious findings, and unnecessary medical controversy at the expense of advances in patient care.

Does Patient-Applied Testosterone Replacement Therapy Pose Risk for Blood Pressure Elevation? Circadian Medicine Perspectives

We reviewed medication package inserts, US Food and Drug Administration (FDA) reports, and journal publications concerning the 10 nonbiosimilar patient-applied (PA) testosterone (T) replacement therapies (TRTs) for intraday serum T patterning and blood pressure (BP) effects. Blood T concentration is circadian rhythmic in young adult eugonadal males, being highest around awakening and lowest before bedtime. T level and 24 h variation are blunted in primary and secondary hypogonadism. Utilized as recommended, most PA-TRTs achieve nonphysiologic T 24 h patterning. Only Androderm^® , an evening PA transdermal patch, closely replicates the normal T circadian rhythmicity. Accurate determination of risk for BP elevation and hypertension (HTN) by PA-TRTs is difficult due to limitations of office BP measurements (OBPM) and suboptimal methods and endpoints of ambulatory BP monitoring (ABPM). OBPM is subject to "White Coat" pressor effect resulting in unrepresentative BP values plus masked normotension and masked HTN, causing misclassification of approximately 45% of trial participants, both before and during treatment. Change in guideline-recommended diagnostic thresholds over time causes misclassification of an additional approximately 15% of participants. ABPM is improperly incorporated into TRT safety trials. It is done for 24 h rather than preferred 48 h; BP is oversampled during wakefulness, biasing derived 24 h mean values; 24 h mean systolic and diastolic BP (SBP, DBP) are inappropriate primary outcomes, because of not being best predictors of risk for major acute cardiovascular events (MACE); "daytime" and "nighttime" BP means referenced to clock time are reported rather than biologically relevant wake-time and sleep-time BP means; most importantly, asleep SBP mean and dipping, strongest predictors of MACE, are disregarded. © 2022 American Physiological Society. Compr Physiol 12: 1-20, 2022.

Systematic review and quality evaluation of published human ingestion-time trials of blood pressure-lowering medications and their combinations

The pharmacokinetics (PK) - absorption, distribution, metabolism, and elimination - and pharmacodynamics (PD) of hypertension medications can be significantly affected by circadian rhythms. As a consequence, the time when blood pressure (BP) lowering medications are ingested, with reference to the staging of all involved circadian rhythms modulating PK and PD, can affect their duration of action, magnitude of effect on features of the 24 h BP profile, and safety. We conducted a systematic and comprehensive review of published prospective human trials that investigated individual hypertension medications of all classes and their combinations for ingestion-time differences in BP-lowering, safety, patient adherence, and markers of hypertension-associated target organ pathology of the kidney and heart. The systematic review yielded 155 trials published between 1976 and 2020 - totaling 23,972 hypertensive individuals - that evaluated 37 different single and 14 dual-combination therapies. The vast (83.9%) majority of them reported clinically and statistically significant benefits - including enhanced reduction of asleep BP mean without induced sleep-time hypotension, reduced prevalence of the higher cardiovascular risk non-dipper 24 h BP profile, decreased incidence of adverse effects, improved kidney function, and reduced cardiac pathology - when hypertension medications are ingested at-bedtime/evening rather than upon-waking/morning. Nonetheless, the findings and conclusions of some past conducted trials are inconsistent, often due to disparities and deficiencies of the investigative protocols. Accordingly, we developed a quality assessment method based upon the eight items identified as crucial according to the recently published guidelines of the International Society for Chronobiology and the American Association for Medical Chronobiology and Chronotherapeutics for the design and conduct of human clinical trials on ingestion-time differences of hypertension medications. Among the most frequent deficiencies are: absence or miscalculation of minimum required sample size (83.2%), incorrect choice of primary BP endpoint (53.6%), and inappropriate arbitrary and unrepresentative clock hours chosen for tested treatment times (53.6%). The inability of the very small proportion (16.1%) of trials to verify the advantages of the at-bedtime/evening treatment strategy is likely explained by deficiencies of their study design and conduct. Nonetheless, regardless of the quality score of the 155 trials retrieved by our systematic review, it is most noteworthy that no single published prospective randomized trial reported significantly enhanced BP-lowering, safety, compliance, or other benefits of the unjustified by medical evidence, yet still most recommended, upon-waking/morning hypertension treatment-time scheme.

Guidelines for the design and conduct of human clinical trials on ingestion-time differences - chronopharmacology and chronotherapy - of hypertension medications

Current hypertension guidelines fail to provide a recommendation on when-to-treat, thus disregarding relevant circadian rhythms that regulate blood pressure (BP) level and 24 h patterning and medication pharmacokinetics and pharmacodynamics. The ideal purpose of ingestion-time (chronopharmacology, i.e. biological rhythm-dependent effects on the kinetics and dynamics of medications, and chronotherapy, i.e. the timing of pharmaceutical and other treatments to optimize efficacy and safety) trials should be to explore the potential impact of endogenous circadian rhythms on the effects of medications. Such investigations and outcome trials mandate adherence to the basic standards of human chronobiology research. In-depth review of the more than 150 human hypertension pharmacology and therapeutic trials published since 1974 that address the differential impact of upon-waking/morning versus at-bedtime/evening schedule of treatment reveals diverse protocols of sometimes suboptimal or defective design and conduct. Many have been "time-of-day," i.e. morning versus evening, rather than circadian-time-based, and some relied on wake-time office BP rather than around-the-clock ambulatory BP measurements (ABPM). Additionally, most past studies have been of too small sample size and thus statistically underpowered. As of yet, there has been no consensual agreement on the proper design, methods and conduct of such trials. This Position Statement recommends ingestion-time hypertension trials to follow minimum guidelines: (i) Recruitment of participants should be restricted to hypertensive individuals diagnosed according to ABPM diagnostic thresholds and of a comparable activity/sleep routine. (ii) Tested treatment-times should be selected according to internal biological time, expressed by the awakening and bed times of the sleep/wake cycle. (iii) ABPM should be the primary or sole method of BP assessment. (iv) The minimum-required features for analysis of the ABPM-determined 24 h BP pattern ought to be the asleep (not "nighttime") BP mean and sleep-time relative BP decline, calculated in reference to the activity/rest cycle per individual. (v) ABPM-obtained BP means should be derived by the so-called adjusted calculation procedure, not by inaccurate arithmetic averages. (vi) ABPM should be performed with validated and calibrated devices at least hourly throughout two or more consecutive 24 h periods (48 h in total) to achieve the highest reproducibility of mean wake-time, sleep-time and 48 h BP values plus the reliable classification of dipping status. (vii) Calculation of minimum required sample size in adherence with proper statistical methods must be provided. (viii) Hypertension chronopharmacology and chronotherapy trials should preferably be randomized double-blind, randomized open-label with blinded-endpoint, or crossover in design, the latter with sufficient washout period between tested treatment-time regimens.