Withdrawal syndrome following cessation of antihypertensive drug therapy

Management of hypertension in the early postpartum: A randomized controlled trial

OBJECTIVES

To evaluate blood pressure control during the immediate postpartum period in hypertensive women who had used methyldopa during pregnancy, comparing continuation of that drug with switching it for captopril.

STUDY DESIGN

A single-blind, randomized clinical trial involving 172 postpartum women with hypertension who had previously used methyldopa during pregnancy at a minimum dose of 750 mg/day for at least one week prior to delivery. The subtypes of hypertension included were gestational hypertension, chronic hypertension, preeclampsia, superimposed preeclampsia, HELLP syndrome and eclampsia. Following delivery, the patients were randomized either to continue with methyldopa at a minimum dose of 250 mg, three times a day (methyldopa group, n = 88) or to switch to captopril at an initial dose of 25 mg, three times a day (captopril group, n = 84).

MAIN OUTCOME MEASURES

Logistic regression was used to compare the groups regarding the potential to maintain blood pressure below 140/90 mmHg at over 50 % of measurements postpartum.

RESULTS

In the 48 h following delivery, no significant differences were found between the groups regarding blood pressure control (methyldopa 92.0% versus captopril 95.2%), side effects, postpartum depression (Edinburgh Postnatal Depression Scale) or other clinical outcomes (hypertensive peaks, time to blood pressure control, additional medication use, or maternal and neonatal complications).

CONCLUSION

Continuation of antihypertensive treatment with methyldopa in the postpartum period yielded similar results to switching it for captopril, both with regard to the efficacy in controlling blood pressure and the safety of the treatment.

Development and Preliminary Testing of the Withdrawal Assessment Tool-Alpha 2 Agonist: An Assessment Instrument for Monitoring Iatrogenic Withdrawal Symptoms in Children Receiving an Alpha-2 Agonist

OBJECTIVES

To develop and conduct preliminary testing of the Withdrawal Assessment Tool-Alpha 2 Agonist (WAT-A2A) to monitor dexmedetomidine and clonidine withdrawal symptoms in acutely ill children.

DESIGN

Three-phase instrument development study. Phase 1: retrospective chart review of symptoms exhibited by children with documented dexmedetomidine withdrawal; phase 2: WAT-A2A instrument construction based on phase 1 data; and phase 3: prospective testing of the WAT-A2A in children weaning from alpha 2 agonists (A2As).

SETTING

Academic free-standing children's hospital.

PATIENTS

Acutely ill children weaning from at least 5 days of dexmedetomidine. Excluded were children concurrently weaning other sedatives.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Phase 1: In 83 of 303 children weaning from at least 5 days of dexmedetomidine who had clinician documentation and were managed for A2A withdrawal, 88% ( n = 72) exhibited at least a 20% increase in heart rate (HR), 83% ( n = 69) exhibited agitation or change in usual state behavior, 46% ( n = 38) exhibited at least a 20% increase in diastolic blood pressure (DBP), and when documented, 56% (27/48) exhibited tremors during their A2A withdrawal episode. Phase 2: The WAT-A2A was constructed, based on phase 1 data, and includes four items: HR, state behavior, DBP, and tremors. Phase 3: The WAT-A2A was tested and performed well in 82 children weaning from A2A. The total WAT-A2A score correlated with clinician subjective assessment of A2A withdrawal (Spearman correlation = 0.5; p < 0.001). Inter-rater agreement, comparing paired ratings of prospectively collected WAT-A2A data, indicated moderate inter-rater reliability.

CONCLUSIONS

Acutely ill children receiving sedation with an A2A for more than 5 days may develop physiologic dependence, requiring gradual dosing reductions. While further psychometric testing is advised, the WAT-A2A provides an objective instrument to help clinicians quantify dexmedetomidine withdrawal symptoms in acutely ill children may facilitate A2A weaning and limit unnecessary variation in practice.

Posterior reversible encephalopathy syndrome due to nonadherence to antihypertensive treatment: A case report from Nepal

Key Clinical Message

Posterior reversible encephalopathy syndrome may occur secondary to abrupt cessation of antihypertensive therapy. A gradual reduction in blood pressure and counseling regarding medication adherence are crucial to prevent adverse consequences.

Abstract

Posterior reversible encephalopathy syndrome (PRES) is a reversible clinical radiographic syndrome with headache, hypertensive encephalopathy, seizures, and visual disturbances as common modes of presentation. PRES can be attributed to several risk factors. We reported the case of a 66-year-old Asian female with PRES following nonadherence to antihypertensive treatment. Initially, her computed tomography scan of the head was normal. After 48 h, we again ordered a head CT scan, which showed lesions suggestive of hypertensive encephalopathy. We immediately reduced 20%-25% of mean arterial pressure, followed by a gradual blood pressure lowering to avoid adverse consequences. We did a follow-up CT scan of the head at 2 weeks, showing the resolution of early lesions. Hence, we made a diagnosis of PRES. In these patients, it is crucial to ensure medication adherence to avoid complications.

Management of renin-angiotensin-aldosterone inhibitors and other antihypertensives and their clinical effects on pre-anesthesia blood pressure

Background

Blood pressure fluctuations appear more significant in patients with poorly controlled hypertension and are known to be associated with adverse perioperative morbidity. In the present study, we aimed to determine the effects of antihypertensive drug treatment strategies on preanesthetic operating room blood pressure measurements.

Methods

A total of 717 patients participated in our study; 383 patients who were normotensive based on baseline measurements and not under antihypertensive therapy were excluded from the analysis. The remaining 334 patients were divided into six groups according to the antihypertensive drug treatment. These six groups were examined in terms of preoperative baseline and pre-anesthesia blood pressure measurements.

Results

As a result of the study, it was observed that 24% of patients had high blood pressure precluding surgery, and patients using renin-angiotensin-aldosterone system inhibitors (RAASI) had higher pre-anesthesia systolic blood pressure than patients using other antihypertensive drugs. Patients who received beta-blockers were also observed to have the lowest pre-anesthesia systolic blood pressure, diastolic blood pressure, and mean blood pressure, compared to others.

Conclusions

Recently, whether RAASI should be continued preoperatively remains controversial. Our study shows that RAASI cannot provide optimal pre-anesthesia blood pressure and lead to an increase in the number of postponed surgeries, probably due to withdrawal of medication before the operation. Therefore, the preoperative discontinuation of RAASI should be reevaluated in future studies.

Physical Dependence in Patient With Chronic Low Back Pain Treated With Topiramate: A Case Report

In the last decade, prescription of anticonvulsants for treatment of low back pain (LBP) increased 4-fold. Among them, topiramate has frequent side effects and a mechanism of action that is not fully understood. The authors describe a 65-year-old woman with dependence on topiramate prescribed for chronic LBP and discuss how she was successfully weaned off topiramate using duloxetine. A significant agonistic effect by topiramate on α-2 adrenergic receptors in the brain likely accounts for the symptoms of withdrawal that were seen. We attribute the resolution of her topiramate withdrawal symptoms to reduced norepinephrine (NE) release, a known effect of duloxetine administration.

Sarcolemmal α2-adrenoceptors in feedback control of myocardial response to sympathetic challenge

α2-adrenoceptor (α2-AR) isoforms, abundant in sympathetic synapses and noradrenergic neurons of the central nervous system, are integral in the presynaptic feed-back loop mechanism that moderates norepinephrine surges. We recently identified that postsynaptic α2-ARs, found in the myocellular sarcolemma, also contribute to a muscle-delimited feedback control capable of attenuating mobilization of intracellular Ca²⁺ and myocardial contractility. This previously unrecognized α2-AR-dependent rheostat is able to counteract competing adrenergic receptor actions in cardiac muscle. Specifically, in ventricular myocytes, nitric oxide (NO) and cGMP are the intracellular messengers of α2-AR signal transduction pathways that gauge the kinase-phosphatase balance and manage cellular Ca²⁺ handling preventing catecholamine-induced Ca²⁺ overload. Moreover, α2-AR signaling counterbalances phospholipase C - PKC-dependent mechanisms underscoring a broader cardioprotective potential under sympathoadrenergic and angiotensinergic challenge. Recruitment of such tissue-specific features of α2-AR under sustained sympathoadrenergic drive may, in principle, be harnessed to mitigate or prevent cardiac malfunction. However, cardiovascular disease may compromise peripheral α2-AR signaling limiting pharmacological targeting of these receptors. Prospective cardiac-specific gene or cell-based therapeutic approaches aimed at repairing or improving stress-protective α2-AR signaling may offer an alternative towards enhanced preservation of cardiac muscle structure and function.

New antihypertensive medications and clinical implications

Hypertension remains a global public health issue and is a leading preventable risk factor for many causes of mortality and morbidity. Although it is generally managed as an outpatient chronic disease, anaesthetists will inevitably encounter patients with hypertension, ranging from undiagnosed asymptomatic to chronic forms with end-organ damage(s). An understanding of perioperative management of anti-hypertensive pharmacotherapy is crucial. Although many drugs are familiar, new drug groups that have relevance for blood pressure control and perioperative care have evolved in recent years. This article also describes new antihypertensive agents currently available or under development that could impact perioperative management.

Hypertensive Emergency

A rapid and severe increase in blood pressure resulting in new or progressive end-organ damage is defined as hypertensive emergency. Clinicians should effectively use the patient interview, physical examination, and additional testing to differentiate hypertensive emergency from nonemergent hypertension. Patients with evidence or high suspicion for end-organ damage should be expediently referred from the outpatient setting to a higher level of care. Knowledge of appropriate hypertensive emergency management and the ability to initiate this care in the clinic could help reduce patient morbidity in certain situations. Patients presenting with nonemergent hypertension can continue to be safely managed in the clinic.

Antihypertensive withdrawal for the prevention of cognitive decline

BACKGROUND

Clinical trials and observational data have variously shown a protective, harmful or neutral effect of antihypertensives on cognitive function. In theory, withdrawal of antihypertensives could improve cerebral perfusion and reduce or delay cognitive decline. However, it is also plausible that withdrawal of antihypertensives may have a detrimental effect on cognition through increased incidence of stroke or other vascular events.

OBJECTIVES

To assess the effects of complete withdrawal of at least one antihypertensive medication on incidence of dementia, cognitive function, blood pressure and other safety outcomes in cognitively intact and cognitive impaired adults.

SEARCH METHODS

We searched ALOIS, the specialised register of the Cochrane Dementia and Cognitive Improvement Group, with additional searches conducted in MEDLINE, Embase, PsycINFO, CINAHL, LILACS, Web of Science Core Collection, ClinicalTrials.gov and the World Health Organization Portal/ICTRP on 12 December 2015. There were no language or date restrictions applied to the electronic searches, and no methodological filters were used to restrict the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and controlled clinical trials (CCTs) provided they compared withdrawal of antihypertensive medications with continuation of the medications and included an outcome measure assessing cognitive function or a clinical diagnosis of dementia. We included studies with healthy participants, but we also included studies with participants with all grades of severity of existing dementia or cognitive impairment.

DATA COLLECTION AND ANALYSIS

Two review authors examined titles and abstracts of citations identified by the search for eligibility, retrieving full texts where needed to identify studies for inclusion, with any disagreement resolved by involvement of a third author. Data were extracted independently on primary and secondary outcomes. We used standard methodological procedures expected by Cochrane.The primary outcome measures of interest were changes in global and specific cognitive function and incidence of dementia; secondary outcomes included change in systolic and diastolic blood pressure, mortality, adverse events (including cardiovascular events, hospitalisation and falls) and adherence to withdrawal. The quality of the evidence was evaluated using the GRADE approach.

MAIN RESULTS

We included two RCTs investigating withdrawal of antihypertensives in 2490 participants. There was substantial clinical heterogeneity between the included studies, therefore we did not combine data for our primary outcome. Overall, the quality of included studies was high and the risk of bias was low. Neither study investigated incident dementia.One study assessed withholding previously prescribed antihypertensive drugs for seven days following acute stroke. Cognition was assessed using telephone Mini-Mental State Examination (t-MMSE) and Telephone Interview for Cognitive Status (TICS-M) at 90 days as a secondary outcome. The t-MMSE score was a mean of 1.0 point higher in participants who withdrew antihypertensive medications compared to participants who continued them (95% confidence interval (CI) 0.35 to 1.65; 1784 participants) and the TICS-M was a mean of 2.10 points higher (95% CI 0.69 to 3.51; 1784 participants). However, in both cases the evidence was of very low quality downgraded due to risk of bias, indirectness and evidence from a single study. The other study was community based and included participants with mild cognitive impairment. Drug withdrawal was for 16 weeks. Cognitive performance was assessed using a composite of at least five out of six cognitive tests. There was no evidence of a difference comparing participants who withdrew antihypertensive medications and participants who continued (mean difference 0.02 points, 95% CI -0.19 to 0.21; 351 participants). This evidence was of low quality and was downgraded due to risk of bias and evidence from single study.In one study, the systolic blood pressure after seven days of withdrawal was 9.5 mmHg higher in the intervention compared to the control group (95% CI 7.43 to 11.57; 2095 participants) and diastolic blood pressure was 5.1 mmHg higher (95% CI 3.86 to 6.34; 2095 participants). This evidence was low quality, downgraded due to indirectness, because the data must be interpreted in the context of the wider study looking at glyceryl trinitrate administration or not, and evidence from a single study. In the other study, systolic blood pressure increased by 7.4 mmHg in the withdrawal group compared to the control group (95% CI 7.08 to 7.72; 356 participants) and diastolic blood pressure increased by 2.6 mmHg (95% CI 2.42 to 2.78; 356 participants). This was moderate quality evidence, downgraded as evidence was from a single study. We combined data for mortality and cardiovascular events. There was no clear evidence that antihypertensive medication withdrawal affected adverse events, although there was a possible trend to increased cardiovascular events in the large post-stroke study (pooled mortality risk ratio 0.88, 95% CI 0.72 to 1.08; 2485 participants; and cardiovascular events risk ratio 1.29, 95% CI 0.96 to 1.72). Certain prespecified outcomes of interest (falls, hospitalisation) were not reported.

AUTHORS' CONCLUSIONS

The effects of withdrawing antihypertensive medications on cognition or prevention of dementia are uncertain. There was a signal of a positive effect in one study looking at withdrawal after acute stroke but these results are unlikely to be generalisable to non-stroke settings and were not a primary outcome of the study. Withdrawing antihypertensive drugs was associated with increased blood pressure. It is unlikely to increase mortality at three to four months' follow-up, although there was a signal from one large study looking at withdrawal after stroke that withdrawal was associated an increase in cardiovascular events.

Management of Acute Hypertensive Response in Patients With Ischemic Stroke

High blood pressure (BP) >140/90 mm Hg is seen in 75% of patients with acute ischemic stroke and in 80% of patients with acute intracerebral hemorrhages and is independently associated with poor functional outcome. While BP reduction in patients with chronic hypertension remains one of the most important factors in primary and secondary stroke prevention, the proper management strategy for acute hypertensive response within the first 72 hours of acute ischemic stroke has been a matter of debate. Recent guidelines recommend clinical trials to ascertain whether antihypertensive therapy in the acute phase of stroke is beneficial. This review summarizes the current data on acute hypertensive response or elevated BP management during the first 72 hours after an acute ischemic stroke. Based on the potential deleterious effect of lowering BP observed in some clinical trials in patients with acute ischemic stroke and because of the lack of convincing evidence to support acute BP lowering in those situations, aggressive BP reduction in patients presenting with acute ischemic stroke is currently not recommended. While the early use of angiotensin receptor antagonists may help reduce cardiovascular events, this benefit is not necessarily related to BP reduction.

Approach to Antihypertensive Therapy

Antihypertensive agents are commonly prescribed by physicians to prevent the long-term mortality from chronic hypertension. They are also given to improve survival in a number of conditions (eg, heart failure, coronary artery disease), independent of the effect on blood pressure. Several classes of antihypertensives are available with unique pharmacologic characteristics and adverse effects. Not all agents in the same class have identical effects, and careful selection of drugs based on the comorbid conditions is recommended.

Clonidine withdrawal induced sympathetic surge

A 30-year-old man with a history of epilepsy and substance misuse presented to the hospital with status epilepticus. Difficult seizure control necessitated anaesthetising the patient followed by intubation and ventilation. A clonidine infusion was started as the patient developed withdrawal syndrome and was difficult to wean off mechanical ventilation. Once the withdrawal syndrome was controlled, the clonidine was abruptly stopped. Two hours after stopping the infusion, the patient developed high-grade fever, severe hypertension, tachycardia, profound sweating and lacrimation. The patient then developed respiratory distress syndrome secondary to acute pulmonary oedema. Clonidine withdrawal as a cause of such response was proposed. Reversal of symptoms and successful reweaning was achieved by restarting a low-dose clonidine infusion followed by slow downward titration and use of oral clonidine as a step-down measure. The patient was subsequently discharged from the intensive care unit.

Effects of Clonidine on Withdrawal From Long-term Dexmedetomidine in the Pediatric Patient

OBJECTIVE

To compare withdrawal symptoms among pediatric intensive care patients receiving clonidine to those not receiving clonidine while being weaned from long-term dexmedetomidine.

METHODS

This retrospective analysis evaluated Withdrawal Assessment Tool-1 (WAT-1) scores and hemodynamic parameters in pediatric patients on dexmedetomidine for 5 days or longer between January 1, 2009, and December 31, 2012. The primary objective was to compare withdrawal symptoms based on the number of elevated WAT-1 scores among patients on clonidine to those not on clonidine, while being weaned from long-term dexmedetomidine. The secondary objective was to describe withdrawal symptoms associated with long-term dexmedetomidine use.

RESULTS

Nineteen patients (median age, 1.5 years; interquartile range [IQR], 0.67-3.3) received 20 treatment courses of dexmedetomidine for at least 5 days. Clonidine was received by patients during 12 of the treatment courses. The patients in the clonidine group had an average of 0.8 (range, 0-6) elevated WAT-1 scores 24 hours post wean compared to an average of 3.2 (0-8) elevated WAT-1 scores in the no clonidine group (p = 0.49). There were no significant difierences between prewean and postwean systolic or diastolic blood pressures among the 2 groups. The average heart rate during the postwean period was 112 beats per minute (bpm) (range, 88.5-151.5) in the clonidine group compared to 138.4 bpm (range, 117.8-168.3) in the no clonidine group (p = 0.003). In the clonidine group, the mean change in heart rate postwean compared to prewean was an increase of 3.6 bpm (range, -39.6 to 47.5), compared to a mean increase of 29.9 bpm (range, 5.5-74.7) in the no clonidine group (p = 0.042).

CONCLUSIONS

There was no difierence in WAT-1 scores between groups, with the clonidine group displaying a trend towards fewer elevated WAT-1 scores during the 24 hours post dexmedetomidine wean. Patients who received clonidine had significantly lower heart rates than the no clonidine group.

A review of the rationale and clinical utilization of α2-adrenoceptor agonists for the treatment of attention-deficit/hyperactivity and related disorders

OBJECTIVE

Interest in the potential role for the α2-adrenoceptor agonists clonidine and guanfacine as treatments for attention-deficit/hyperactivity disorder (ADHD) has driven additional clinical studies as well as development of new formulations of these agents. This article reviews the published data that supported United States Food and Drug Administration approval and subsequent clinical use of α2-adrenoceptor agonists in the treatment of ADHD, and identifies promising directions for future research.

METHODS

Electronic searches were performed in PubMed through October 2012 using the base terms ADHD or attention deficit hyperactivity disorder and alpha agonists, as well as the following limits: humans, clinical trial, meta-analysis, practice guideline, randomized controlled trial, review, English. The electronic searches were complemented with reference lists from the articles retrieved by informal search of the literature, producing a qualitative review of published, pertinent drug-class preclinical and clinical data. Articles were selected for greater exposition based on hierarchy of evidence (e.g., randomized controlled trials), relevance, and quality of individual studies, as well as generalizability to clinical practice.

RESULTS

Results of clinical studies of immediate-release and extended-release formulations of α2-adrenoceptor agonists and basic science investigations of cognitive effects of these drugs are discussed. Studies of both clonidine and guanfacine extended-release formulations as monotherapy and adjunctive therapy with psychostimulants for the treatment of ADHD are also reviewed.

CONCLUSIONS

Large, randomized, placebo-controlled clinical trials support the efficacy and safety of α2-adrenoceptor agonists as monotherapy and adjunctive therapy with psychostimulants for the symptomatic treatment of ADHD. Future research could reveal whether there are cognitive benefits associated with this drug class and thus further define the role of α2-adrenoceptor agonists in the treatment of ADHD.

Guidelines for the early management of patients with acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The authors present an overview of the current evidence and management recommendations for evaluation and treatment of adults with acute ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators responsible for the care of acute ischemic stroke patients within the first 48 hours from stroke onset. These guidelines supersede the prior 2007 guidelines and 2009 updates.

METHODS

Members of the writing committee were appointed by the American Stroke Association Stroke Council's Scientific Statement Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Panel members were assigned topics relevant to their areas of expertise, reviewed the stroke literature with emphasis on publications since the prior guidelines, and drafted recommendations in accordance with the American Heart Association Stroke Council's Level of Evidence grading algorithm.

RESULTS

The goal of these guidelines is to limit the morbidity and mortality associated with stroke. The guidelines support the overarching concept of stroke systems of care and detail aspects of stroke care from patient recognition; emergency medical services activation, transport, and triage; through the initial hours in the emergency department and stroke unit. The guideline discusses early stroke evaluation and general medical care, as well as ischemic stroke, specific interventions such as reperfusion strategies, and general physiological optimization for cerebral resuscitation.

CONCLUSIONS

Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke remains urgently needed.

Dexmedetomidine for opioid and benzodiazepine withdrawal in pediatric patients

PURPOSE

The published literature on the use of dexmedetomidine as an adjunct to sedation and analgesia in the management of pediatric narcotic withdrawal was reviewed.

SUMMARY

Pediatric narcotic withdrawal syndromes are reported to be increasingly frequent in pediatric intensive care units. A number of tools specifically designed for assessment of withdrawal in newborns and infants are in current use, including the widely used Finnegan Scoring System. A limited number of studies and case reports suggest that dexmedetomidine, an α(2)-receptor agonist with a mechanism of action similar to that of clonidine but with greater α(2)-receptor specificity, might have a role in the treatment of pediatric withdrawal (by blunting withdrawal symptoms without causing respiratory depression and by permitting shorter narcotic tapering schedules) and also in the prevention of pediatric narcotic withdrawal (by reducing narcotic requirements). Potential adverse effects associated with dexmedetomidine use in pediatric patients are generally associated with use of bolus doses and mainly involve central nervous system effects (e.g., hypotension, bradycardia), with no hemodynamic manifestations. When bolus doses are used, strategies described in published reports entail a loading dose of 0.5-1.0 μg/kg administered over 5-10 minutes, followed by a continuous infusion at 0.1-1.4 μg/kg/hr for a period of 1-16 days. More research is needed to define the optimal use of dexmedetomidine in the management of pediatric narcotic withdrawal.

CONCLUSION

A limited body of published evidence from retrospective studies and case reports suggests a potential role for dexmedetomidine as an adjunct therapy to provide sedation and analgesia to reduce narcotic withdrawal symptoms in pediatric patients.

β-blocker continuation after noncardiac surgery: a report from the surgical care and outcomes assessment program

BACKGROUND

Despite limited evidence of effect, β-blocker continuation has become a national quality improvement metric.

OBJECTIVE

To determine the effect of β-blocker continuation on outcomes in patients undergoing elective noncardiac surgery.

DESIGN, SETTING, AND PATIENTS

The Surgical Care and Outcomes Assessment Program is a Washington quality improvement benchmarking initiative based on clinical data from more than 55 hospitals. Linking Surgical Care and Outcomes Assessment Program data to Washington's hospital admission and vital status registries, we studied patients undergoing elective colorectal and bariatric surgical procedures at 38 hospitals between January 1, 2008, and December 31, 2009.

MAIN OUTCOME MEASURES

Mortality, cardiac events, and the combined adverse event of cardiac events and/or mortality.

RESULTS

Of 8431 patients, 23.5% were taking β-blockers prior to surgery (mean [SD] age, 61.9 [13.7] years; 63.0% were women). Treatment with β-blockers was continued on the day of surgery and during the postoperative period in 66.0% of patients. Continuation of β-blockers both on the day of surgery and postoperatively improved from 57.2% in the first quarter of 2008 to 71.3% in the fourth quarter of 2009 (P value <.001). After adjusting for risk characteristics, failure to continue β-blocker treatment was associated with a nearly 2-fold risk of 90-day combined adverse event (odds ratio, 1.97; 95% CI, 1.19-3.26). The odds were even greater among patients with higher cardiac risk (odds ratio, 5.91; 95% CI, 1.40- 25.00). The odds of combined adverse events continued to be elevated 1 year postoperatively (odds ratio, 1.66; 95% CI, 1.08-2.55).

CONCLUSIONS

β-Blocker continuation on the day of and after surgery was associated with fewer cardiac events and lower 90-day mortality. A focus on β-blocker continuation is a worthwhile quality improvement target and should improve patient outcomes.

Adherence to medications: insights arising from studies on the unreliable link between prescribed and actual drug dosing histories

Satisfactory adherence to aptly prescribed medications is essential for good outcomes of patient care and reliable evaluation of competing modes of drug treatment. The measure of satisfactory adherence is a dosing history that includes timely initiation of dosing plus punctual and persistent execution of the dosing regimen throughout the specified duration of treatment. Standardized terminology for initiation, execution, and persistence of drug dosing is essential for clarity of communication and scientific progress. Electronic methods for compiling drug dosing histories are now the recognized standard for quantifying adherence, the parameters of which support model-based, continuous projections of drug actions and concentrations in plasma that are confirmable by intermittent, direct measurements at single time points. The frequency of inadequate adherence is usually underestimated by pre-electronic methods and thus is clinically unrecognized as a frequent cause of failed treatment or underestimated effectiveness. Intermittent lapses in dosing are potential sources of toxicity through hazardous rebound effects or recurrent first-dose effects.

Management of Hypertension in Renal Transplant Patients: A Comprehensive Review of Nonpharmacologic and Pharmacologic Treatment Strategies

Objective:

To review the guidelines and literature for the treatment of hypertension in renal transplant patients and to provide guidance to practitioners in the selection of appropriate nonpharmacologic and pharmacologic treatment options.

Data Sources:

A PubMed search (January 1948–March 2010) was performed using the search terms hypertension, antihypertensive agents, blood pressure, and cardiovascular disease, in combination with renal transplant and kidney transplant. The search was limited to articles published in English. All relevant peer-reviewed original studies, meta-analyses, guidelines, consensus statements, and review articles were examined. In addition, reference citations from publications identified were reviewed.

Study Selection and Data Extraction:

All literature found was evaluated for inclusion. Review articles as well as prospective and retrospective original research articles were reviewed.

Data Synthesis:

Hypertension after solid organ transplantation is a problem commonly encountered in patients during their posttransplantation clinic visits. Effective management of these patients' hypertension is crucial, as hypertension left untreated may lead to increased morbidity and mortality as well as graft loss. The unique, multifactorial etiology of hypertension in this population makes treatment choices more challenging compared to treatment of a nontransplant patient. Therefore, to guide practitioners in this process, we developed a hypertension management protocol, taking into account the unique considerations faced in the adult renal transplant population. The review guides practitioners from the initial assessment of patients' hypertension through the evaluation and selection of nonpharmacologic and pharmacologic treatment options and provides information about the discontinuation of certain antihypertensive medications. It also provides a concise, but comprehensive review of the major antihypertensive drug classes and economic considerations.

Conclusions:

The management of hypertension in posttransplantation patients is challenging and complicated, yet necessary to prevent morbidity, mortality, and graft loss for these patients. Therapy should be individualized based on patient assessment, response to previous therapy, and economic considerations.

Increase of 1-year Mortality After Perioperative Beta-blocker Withdrawal in Endovascular and Vascular Surgery Patients

OBJECTIVES

To assess the relation between beta-blocker use, underlying cardiac risk, and 1-year outcome in vascular surgery patients, including the effect of beta-blocker withdrawal.

DESIGN

Prospective survey.

MATERIALS

711 consecutive peripheral vascular surgery patients from 11 hospitals in the Netherlands between May and December 2004.

METHODS

Patients were evaluated for cardiac risk factors, beta-blocker use and 1-year mortality. Low and high risk was defined according to the Revised Cardiac Risk Index. Propensity scores for the likelihood of beta-blocker use were calculated and regression models were used to study the relation between beta-blocker use and mortality.

RESULTS

285 patients (40%) received beta-blockers throughout the perioperative period (continuous users). Only 52% of the 281 high risk patients received continuous beta-blocker therapy. Beta-blocker therapy was started in 29 and stopped in 21 patients, respectively. One-year mortality was 11%. After adjustment for potential confounders and the propensity of its use, continuous beta-blocker use remained significantly associated with a lower 1-year mortality compared to non-users (HR=0.4; 95%CI=0.2-0.7). In contrast, beta-blocker withdrawal was associated with an increased risk of 1-year mortality compared to non-users (HR=2.7; 95%CI=1.2-5.9).

CONCLUSIONS

We demonstrated an under-use of beta-blockers in vascular surgery patients, even in high-risk patients. Perioperative beta-blocker use was independently associated with a lower risk of 1-year mortality compared to non-use, while perioperative withdrawal of beta-blocker therapy was associated with a higher 1-year mortality.