Clinical situations associated with difficult-to-control hypertension

Development and Validation of a Prognostic Model to Predict High-Risk Patients for Coronary Heart Disease in Snorers With Uncontrolled Hypertension

Purpose

Snoring or obstructive sleep apnea, with or without uncontrolled hypertension, is common and significantly increases the risk of coronary heart disease (CHD). The aim of this study was to develop and validate a prognostic model to predict and identify high-risk patients for CHD among snorers with uncontrolled hypertension.

Methods

Records from 1,822 snorers with uncontrolled hypertension were randomly divided into a training set (n = 1,275, 70%) and validation set (n = 547, 30%). Predictors for CHD were extracted to construct a nomogram model based on multivariate Cox regression analysis. We performed a single-split verification and 1,000 bootstraps resampling internal validation to assess the discrimination and consistency of the prediction model using area under the receiver operating characteristic curve (AUC) and calibration plots. Based on the linear predictors, a risk classifier for CHD could be set.

Results

Age, waist circumference (WC), and high- and low-density lipoprotein cholesterol (HDL-C and LDL-C) were extracted as the predictors to generate this nomogram model. The C-index was 0.720 (95% confidence interval 0.663–0.777) in the derivation cohort and 0.703 (0.630–0.776) in the validation cohort. The AUC was 0.757 (0.626–0.887), 0.739 (0.647–0.831), and 0.732 (0.665–0.799) in the training set and 0.689 (0.542–0.837), 0.701 (0.606–0.796), and 0.712 (0.615–0.808) in the validation set at 3, 5, and 8 years, respectively. The calibration plots showed acceptable consistency between the probability of CHD-free survival and the observed CHD-free survival in the training and validation sets. A total of more than 134 points in the nomogram can be used in the identification of high-risk patients for CHD among snorers with uncontrolled hypertension.

Conclusion

We developed a CHD risk prediction model in snorers with uncontrolled hypertension, which includes age, WC, HDL-C, and LDL-C, and can help clinicians with early and quick identification of patients with a high risk for CHD.

Combination Antihypertensive Therapy Prescribing and Blood Pressure Control in a Real-World Setting

BACKGROUND

Specific combinations of two drug classes are recommended in a variety of clinical situations in the management of hypertension. These preferred combinations are based on complimentary blood pressure (BP) lowering mechanisms or benefit for a concomitant disease.

METHODS

Using electronic health records (EHRs) data from 27,579 ambulatory hypertensive patients, we investigated antihypertensive therapy prescribing patterns and associations of preferred two drug classes with BP control.

RESULTS

Overall, BP control, defined as BP <140/90 mm Hg, was 65% among treated patients. Preferred dual antihypertensive therapy was prescribed in 55% of patients with uncomplicated hypertension, 49% of patients with diabetes, and 47% of patients with a history of myocardial infarction (MI); these prescribing frequencies of preferred combinations were not explained by worse BP control on those combinations. In fact, we found suggestive evidence of association between prescribing of preferred two drug classes and improved BP control among post-MI (OR: 1.21, 95% CI: 0.99-1.48, P = 0.061) and uncomplicated hypertensive (OR: 1.11, 95% CI: 0.98-1.26, P = 0.089) patients.

CONCLUSIONS

Prescribing of guideline-recommended antihypertensive drug classes for concomitant diseases is suboptimal and prescribing of preferred/optimized drug class combinations was moderate. We did not find a clear association between the use of optimized drug class combinations and greater BP control. Overall, using EHR data, we identified potential opportunities for re-examining prescribing practices with implications for clinical decision support and healthcare improvement at the community and health system-wide levels.

Which place of pharmacological approaches beyond continuous positive airway pressure to treat vascular disease related to obstructive sleep apnea?

Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete upper airway obstruction, occurring during sleep, leading to chronic intermittent hypoxia (IH), which harms the cardiovascular system. OSA is associated with both functional and structural vascular alterations that contribute to an increased prevalence of fatal and non-fatal cardiovascular events. OSA is a heterogeneous disease with respect to the severity of hypoxia, the presence of daytime symptoms, obesity, and cardiovascular comorbidities. Various clusters of OSA phenotypes have been described leading to more highly personalized treatment. The aim of this review is to describe the various therapeutic strategies including continuous positive airway pressure (CPAP), oral appliances, surgery, weight loss, and especially pharmacological interventions that have been evaluated to reduce vascular alterations in both OSA patients and preclinical animal models. Conventional therapies, predominantly CPAP, have a limited impact on vascular alterations in the presence of co-morbidities. A better knowledge of pharmacological therapies targeting IH-induced vascular alterations will facilitate the use of combined therapies and is crucial for designing clinical trials in well-defined OSA phenotypes.

Effects of continuous positive airway pressure on blood pressure in patients with resistant hypertension and obstructive sleep apnea: a systematic review and meta-analysis of six randomized controlled trials

OBJECTIVE

To evaluate systematically the effects of continuous positive airway pressure (CPAP) on blood pressure in patients with resistant hypertension and obstructive sleep apnea (OSA).

METHODS

The Cochrane Library, PubMed, ScienceDirect, and the Web of Science were searched for studies investigating the effects of CPAP on blood pressure in patients with resistant hypertension and OSA. The selected studies underwent quality assessment and meta-analysis, as well as being tested for heterogeneity.

RESULTS

Six randomized controlled trials were included in the meta-analysis. The pooled estimates of the changes in mean systolic blood pressure and mean diastolic blood pressure (as assessed by 24-h ambulatory blood pressure monitoring) were -5.40 mmHg (95% CI: -9.17 to -1.64; p = 0.001; I2 = 74%) and -3.86 mmHg (95% CI: -6.41 to -1.30; p = 0.00001; I2 = 79%), respectively.

CONCLUSIONS

CPAP therapy can significantly reduce blood pressure in patients with resistant hypertension and OSA.

Antihypertensive combination therapy in primary care offices: results of a cross-sectional survey in Switzerland

BACKGROUND

Most hypertensive patients need more than one substance to reach their target blood pressure (BP). Several clinical studies indicate the high efficacy of antihypertensive combinations, and recent guidelines recommend them in some situations even as initial therapies. In general practice they seem widespread, but only limited data are available on their effectiveness under the conditions of everyday life. The objectives of this survey among Swiss primary care physicians treating hypertensive patients were: to know the frequency of application of different treatment modalities (monotherapies, free individual combinations, single-pill combinations); to see whether there are relationships between prescribed treatment modalities and patient characteristics, especially age, treatment duration, and comorbidities; and to determine the response rate (percentage of patients reaching target BP) of different treatment modalities under the conditions of daily practice.

METHODS

This cross-sectional, observational survey among 228 randomly chosen Swiss primary care physicians analyzed data for 3,888 consecutive hypertensive patients collected at one single consultation.

RESULTS

In this survey, 31.9% of patients received monotherapy, 41.2% two substances, 20.9% three substances, and 4.7% more than three substances. By combination mode, 34.9% took free individual combinations and 30.0% took fixed-dose single-pill combinations. Combinations were more frequently given to older patients with a long history of hypertension and/or comorbidities. In total, 67.8% of patients achieved their BP target according to their physician's judgment. When compared, single-pill combinations were associated with a higher percentage of patients achieving target BP than free individual combinations and monotherapies for the total sample and for patients with comorbidity.

CONCLUSION

Antihypertensive combination therapy was widely used in Swiss primary care practices. The number of prescribed substances depended on age, treatment duration, and type and number of comorbidities. Although the response rate was generally modest under the conditions of daily practice, it was higher for single-pill combinations than for monotherapies and free individual combinations. Further studies are needed to confirm these observations.

The efficacy of antihypertensive drugs in chronic intermittent hypoxia conditions

Sleep apnea/hypopnea disorders include centrally originated diseases and obstructive sleep apnea (OSA). This last condition is renowned as a frequent secondary cause of hypertension (HT). The mechanisms involved in the pathogenesis of HT can be summarized in relation to two main pathways: sympathetic nervous system stimulation mediated mainly by activation of carotid body (CB) chemoreflexes and/or asphyxia, and, by no means the least important, the systemic effects of chronic intermittent hypoxia (CIH). The use of animal models has revealed that CIH is the critical stimulus underlying sympathetic activity and hypertension, and that this effect requires the presence of functional arterial chemoreceptors, which are hyperactive in CIH. These models of CIH mimic the HT observed in humans and allow the study of CIH independently without the mechanical obstruction component. The effect of continuous positive airway pressure (CPAP), the gold standard treatment for OSA patients, to reduce blood pressure seems to be modest and concomitant antihypertensive therapy is still required. We focus this review on the efficacy of pharmacological interventions to revert HT associated with CIH conditions in both animal models and humans. First, we explore the experimental animal models, developed to mimic HT related to CIH, which have been used to investigate the effect of antihypertensive drugs (AHDs). Second, we review what is known about drug efficacy to reverse HT induced by CIH in animals. Moreover, findings in humans with OSA are cited to demonstrate the lack of strong evidence for the establishment of a first-line antihypertensive regimen for these patients. Indeed, specific therapeutic guidelines for the pharmacological treatment of HT in these patients are still lacking. Finally, we discuss the future perspectives concerning the non-pharmacological and pharmacological management of this particular type of HT.

Implementation of a CKD checklist for primary care providers

BACKGROUND AND OBJECTIVES

CKD is associated with significant morbidity, mortality, and financial burden. Practice guidelines outlining CKD management exist, but there is limited application of these guidelines. Interventions to improve CKD guideline adherence have been limited. This study evaluated a new CKD checklist (a tool outlining management guidelines for CKD) to determine whether implementation in an academic primary care clinic improved adherence to guidelines.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

During a 1-year period (August 2012-August 2013), a prospective study was conducted among 13 primary care providers (PCPs), four of whom were assigned to use a CKD checklist incorporated into the electronic medical record during visits with patients with CKD stages 1-4. All providers received education regarding CKD guidelines. The intervention and control groups consisted of 105 and 263 patients, respectively. Adherence to CKD management guidelines was measured.

RESULTS

A random-effects logistic regression analysis was performed to account for intra-group correlation by PCP assignment and adjusted for age and CKD stage. CKD care improved among patients whose PCPs were assigned to the checklist intervention compared with controls. Patients in the CKD checklist group were more likely than controls to have appropriate annual laboratory testing for albuminuria (odds ratio [OR], 7.9; 95% confidence interval [95% CI], 3.6 to 17.2), phosphate (OR, 3.5; 95% CI, 1.5 to 8.3), and parathyroid hormone (OR, 8.1; 95% CI, 4.8 to 13.7) (P<0.001 in all cases). Patients in the CKD checklist group had higher rates of achieving a hemoglobin A1c target<7% (OR, 2.7; 95% CI, 1.4 to 5.1), use of an angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker (OR, 2.1; 95% CI, 1.0 to 4.2), documentation of avoidance of nonsteroidal anti-inflammatory drugs (OR, 41.7; 95% CI, 17.8 to 100.0), and vaccination for annual influenza (OR, 2.1; 95% CI, 1.1 to 4.0) and pneumococcus (OR, 4.7; 95% CI, 2.6 to 8.6) (P<0.001 in all cases).

CONCLUSIONS

Implementation of a CKD checklist significantly improved adherence to CKD management guidelines and delivery of CKD care.

[Blood pressure control in a population of hypertensive diabetic patients treated in primary care: PRESCAP-Diabetes Study 2010]

OBJECTIVES

To determine the level of blood pressure (BP) control in hypertensive diabetic patients treated in primary care and to determine the factors associated with poor control.

MATERIAL AND METHODS

A cross-sectional, multicentre study that enrolled hypertensive diabetics recruited by consecutive sampling by family doctors in Spain in June 2010. A mean BP of less than 140/90mmHg was considered as good control of arterial hypertension. The percentages of patients with<130/80mmHg PA, 140/80mmHg, and 140/85mmHg, respectively, were also determined. Sociodemographic, clinical, cardiovascular risk factors, and pharmacological treatments were recorded.

RESULTS

A total of 3,993 patients were enrolled (50.1% female) with a mean age (standard deviation) of 68.2 (10.2) years, of whom 73.9% received combination therapy. The figures showed good control of both blood pressure values (<140/90mmHg) in 56.4% (95% CI: 54.3 to 58.4) of the cases, with 58.5% (95% CI: 57.0-60.0) only in systolic BP, and 84.6% (95% CI, 83.2 to 85.8) only in diastolic BP. The variables with strongest association with poor control were the presence of albuminuria, elevated total cholesterol, physical inactivity, and not taking the medication on the day of the interview.

CONCLUSIONS

The PRESCAP-Diabetes 2010 study results indicate that 43.6% of diabetics with hypertension seen in primary care have a poorly controlled BP, in particular, systolic BP.

Predicting changes in hypertension control using electronic health records from a chronic disease management program

OBJECTIVE

Common chronic diseases such as hypertension are costly and difficult to manage. Our ultimate goal is to use data from electronic health records to predict the risk and timing of deterioration in hypertension control. Towards this goal, this work predicts the transition points at which hypertension is brought into, as well as pushed out of, control.

METHOD

In a cohort of 1294 patients with hypertension enrolled in a chronic disease management program at the Vanderbilt University Medical Center, patients are modeled as an array of features derived from the clinical domain over time, which are distilled into a core set using an information gain criteria regarding their predictive performance. A model for transition point prediction was then computed using a random forest classifier.

RESULTS

The most predictive features for transitions in hypertension control status included hypertension assessment patterns, comorbid diagnoses, procedures and medication history. The final random forest model achieved a c-statistic of 0.836 (95% CI 0.830 to 0.842) and an accuracy of 0.773 (95% CI 0.766 to 0.780).

CONCLUSIONS

This study achieved accurate prediction of transition points of hypertension control status, an important first step in the long-term goal of developing personalized hypertension management plans.