Characteristics and treatment of African-American and European-American patients with resistant hypertension identified using the electronic health record in an academic health centre: a case-control study

Predictive Factors of Apparent Treatment Resistant Hypertension Among Patients With Hypertension Identified Using Electronic Health Records

BACKGROUND

Early identification of a patient with resistant hypertension (RH) enables quickly intensified treatment, short-interval follow-up, or perhaps case management to bring his or her blood pressure under control and reduce the risk of complications.

OBJECTIVE

To identify predictors of RH among individuals with newly diagnosed hypertension (HTN), while comparing different prediction models and techniques for managing missing covariates using electronic health records data.

DESIGN

Risk prediction study in a retrospective cohort.

PARTICIPANTS

Adult patients with incident HTN treated in any of the primary care clinics of one health system between April 2013 and December 2016.

MAIN MEASURES

Predicted risk of RH at the time of HTN identification and candidate predictors for variable selection in future model development.

KEY RESULTS

Among 26,953 individuals with incident HTN, 613 (2.3%) met criteria for RH after 4.7 months (interquartile range, 1.2-11.3). Variables selected by the least absolute shrinkage and selection operator (LASSO), included baseline systolic blood pressure (SBP) and its missing indicator (a dummy variable created if baseline SBP is absent), use of antihypertensive medication at the time of cohort entry, body mass index, and atherosclerosis risk. The random forest technique achieved the highest area under the curve (AUC) of 0.893 (95% CI, 0.881-0.904) and the best calibration with a calibration slope of 1.01. Complete case analysis is not a valuable option (AUC = 0.625).

CONCLUSIONS

Machine learning techniques and traditional logistic regression exhibited comparable levels of predictive performance after handling the missingness. We suggest that the variables identified by this study may be good candidates for clinical prediction models to alert clinicians to the need for short-interval follow up and more intensive early therapy for HTN.

Whole genome sequence analysis of apparent treatment resistant hypertension status in participants from the Trans-Omics for Precision Medicine program

Introduction: Apparent treatment-resistant hypertension (aTRH) is characterized by the use of four or more antihypertensive (AHT) classes to achieve blood pressure (BP) control. In the current study, we conducted single-variant and gene-based analyses of aTRH among individuals from 12 Trans-Omics for Precision Medicine cohorts with whole-genome sequencing data. Methods: Cases were defined as individuals treated for hypertension (HTN) taking three different AHT classes, with average systolic BP ≥ 140 or diastolic BP ≥ 90 mmHg, or four or more medications regardless of BP (n = 1,705). A normotensive control group was defined as individuals with BP < 140/90 mmHg (n = 22,079), not on AHT medication. A second control group comprised individuals who were treatment responsive on one AHT medication with BP < 140/ 90 mmHg (n = 5,424). Logistic regression with kinship adjustment using the Scalable and Accurate Implementation of Generalized mixed models (SAIGE) was performed, adjusting for age, sex, and genetic ancestry. We assessed variants using SKAT-O in rare-variant analyses. Single-variant and gene-based tests were conducted in a pooled multi-ethnicity stratum, as well as self-reported ethnic/racial strata (European and African American). Results: One variant in the known HTN locus, KCNK3, was a top finding in the multi-ethnic analysis (p = 8.23E-07) for the normotensive control group [rs12476527, odds ratio (95% confidence interval) = 0.80 (0.74-0.88)]. This variant was replicated in the Vanderbilt University Medical Center's DNA repository data. Aggregate gene-based signals included the genes AGTPBP, MYL4, PDCD4, BBS9, ERG, and IER3. Discussion: Additional work validating these loci in larger, more diverse populations, is warranted to determine whether these regions influence the pathobiology of aTRH.

Treatment Intensity, Prescribing Patterns, and Blood Pressure Control in Rural Black Patients with Uncontrolled Hypertension

BACKGROUND/OBJECTIVE

Because racial disparities in hypertension treatment persist, the objective of the present study was to examine patient vs. practice characteristics that influence antihypertensive selection and treatment intensity for non-Hispanic Black (hereafter "Black") patients with uncontrolled hypertension in the rural southeastern USA.

METHODS

We enrolled 25 Black patients from each of 69 rural practices in Alabama and North Carolina with uncontrolled hypertension (systolic blood pressure (BP) ≥ 140 mm Hg) in a 4-arm cluster randomized trial of BP control interventions. Patients' antihypertensive medications were abstracted from medical records and reconciled at the baseline visit. Treatment intensity was computed using the defined daily dose (DDD) method of the World Health Organization. Correlates of greater antihypertensive medication intensity were assessed by linear regression modeling, and antihypertensive medication classes were compared by baseline systolic BP (SBP) level.

RESULTS

A total of 1431 patients were enrolled and had complete baseline data. Antihypertensive treatment intensity averaged 3.7 ± 2.6 equivalent medications at usual dosages and was significantly related to higher baseline systolic BP, older age, male sex, insurance availability, higher BMI, and concurrent diabetes, but not to practice type or medication barriers in regression models. Renin-angiotensin system inhibitors were the most commonly used medications, followed by diuretics and calcium channel blockers.

CONCLUSION/RELEVANCE

Antihypertensive treatment intensity for Black patients in the rural southeastern USA with a history of uncontrolled hypertension averaged the equivalent of almost four medications at usual dosages and was significantly associated with baseline SBP levels and other patient characteristics, but not clinic type.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02866669.

A flexible symbolic regression method for constructing interpretable clinical prediction models

Machine learning (ML) models trained for triggering clinical decision support (CDS) are typically either accurate or interpretable but not both. Scaling CDS to the panoply of clinical use cases while mitigating risks to patients will require many ML models be intuitively interpretable for clinicians. To this end, we adapted a symbolic regression method, coined the feature engineering automation tool (FEAT), to train concise and accurate models from high-dimensional electronic health record (EHR) data. We first present an in-depth application of FEAT to classify hypertension, hypertension with unexplained hypokalemia, and apparent treatment-resistant hypertension (aTRH) using EHR data for 1200 subjects receiving longitudinal care in a large healthcare system. FEAT models trained to predict phenotypes adjudicated by chart review had equivalent or higher discriminative performance (p < 0.001) and were at least three times smaller (p < 1 × 10-6) than other potentially interpretable models. For aTRH, FEAT generated a six-feature, highly discriminative (positive predictive value = 0.70, sensitivity = 0.62), and clinically intuitive model. To assess the generalizability of the approach, we tested FEAT on 25 benchmark clinical phenotyping tasks using the MIMIC-III critical care database. Under comparable dimensionality constraints, FEAT's models exhibited higher area under the receiver-operating curve scores than penalized linear models across tasks (p < 6 × 10-6). In summary, FEAT can train EHR prediction models that are both intuitively interpretable and accurate, which should facilitate safe and effective scaling of ML-triggered CDS to the panoply of potential clinical use cases and healthcare practices.

Characteristics, management, and blood pressure control in patients with apparent resistant hypertension in the US

Background

Per treatment guidelines, resistant hypertension is defined as uncontrolled blood pressure (BP) while taking 3 concomitant antihypertensives (AHTs) or controlled BP while taking ≥4 AHTs. Characteristics, AHT therapy use, and BP control were analyzed in US patients with hypertension who were prescribed ≥3 classes of AHT medications.

Methods

This retrospective analysis of the Optum® Electronic Health Record Database evaluated patients ≥18 years of age with a diagnosis of hypertension classified based on the number of prescribed AHT medication classes (3, 4, or ≥5). For the primary analysis, uncontrolled hypertension was defined as systolic BP (SBP) ≥140 mmHg or diastolic BP (DBP) ≥90 mmHg. For secondary analyses, uncontrolled hypertension was defined as SBP ≥130 mmHg or DBP ≥80 mmHg.

Results

207,705 patients with hypertension and concurrent use of ≥3 AHT medication classes were included. Diuretics, beta blockers, ACE inhibitors and/or ARBs, and CCBs were the most prescribed classes; thiazides and thiazide-like agents were the most prescribed diuretics. Among patients who were prescribed 3, 4, or ≥5 AHT medication classes, approximately 70% achieved a BP goal of <140/90 mmHg; approximately 40% achieved BP <130/80 mmHg. After ≥1 year of follow-up, the number of concurrent AHT medication classes was unchanged from baseline in the majority of patients and the prevalence of uncontrolled hypertension (≥140/90 mmHg) was similar.

Conclusions

This study illustrates suboptimal BP control in many patients with apparent resistant hypertension despite the use of multidrug regimens and suggests a need for new drug classes and regimens that effectively manage resistant hypertension.

Addressing Hypertension Outcomes Using Telehealth and Population Health Managers: Adaptations and Implementation Considerations

PURPOSE OF REVIEW

There is a growing evidence base describing population health approaches to improve blood pressure control. We reviewed emerging trends in hypertension population health management and present implementation considerations from an intervention called Team-supported, Electronic health record-leveraged, Active Management (TEAM). By doing so, we highlight the role of population health managers, practitioners who use population level data and to proactively engage at-risk patients, in improving blood pressure control.

RECENT FINDINGS

Within a population health paradigm, we discuss telehealth-delivered approaches to equitably improve hypertension care delivery. Additionally, we explore implementation considerations and complementary features of team-based, telehealth-delivered, population health management. By leveraging the unique role and expertise of a population health manager as core member of team-based telehealth, health systems can implement a cost-effective and scalable intervention that addresses multi-level barriers to hypertension care delivery. We describe the literature of telehealth-based population health management for patients with hypertension. Using the TEAM intervention as a case study, we then present implementation considerations and intervention adaptations to integrate a population health manager within the health care team and effectively manage hypertension for a defined patient population. We emphasize practical considerations to inform implementation, scaling, and sustainability. We highlight future research directions to advance the field and support translational efforts in diverse clinical and community contexts.

The Burden of Resistant Hypertension Across the World

PURPOSE OF REVIEW

Resistant hypertension (R-HTN) is related to worse cardiovascular, renal outcomes, and death compared to non R-HTN. We aimed to review the burden of R-HTN across the world, focusing on its prevalence, associated factors and outcomes, and the impact of treatment.

RECENT FINDINGS

R-HTN prevalence among hypertensive individuals varies around 10-20%, depending on the population and definition applied. R-HTN consistently relates to older age, chronic kidney disease, obesity, and obstructive sleep apnea - which are increasing in prevalence with global population aging. As such, R-HTN prevalence is also expected to rise. Infrequent use of ambulatory blood pressure monitoring to identify at higher risk individuals and poor adherence to treatment are still barriers in the approach of R-HTN. Available evidence suggests that 10-20% of patients with hypertension have R-HTN. However, the prevalence of true R-HTN using contemporaneous standardized definitions is still unknown. Novel strategies to address clinicians, patients and health system barriers to treatment inertia and adherence are fundamental to reduce the burden of R-HTN.

Race/Ethnic Differences in Atherosclerotic Cardiovascular Disease Risk Factors Among Patients With Hypertension: Analysis From 143 Primary Care Clinics

BACKGROUND

While it is known that sex and race/ethnic disparities persist for atherosclerotic cardiovascular disease (ASCVD), disparities in risk factor control have not been well-described in primary care where ASCVD can be prevented.

METHODS

Adult patients with a hypertension diagnosis without ASCVD were included in this analysis of electronic health records from a large US healthcare system from 2018. Patients were categorized based on risk factor control defined as blood pressure (BP) <130/80 mm Hg; statin prescription among patients with indications, HbA1c of <7%, and not smoking. Multivariable Poisson regressions were developed to explore associations with race/ethnicity. Results are presented as relative risk (RR), 95% confidence intervals (CIs).

RESULTS

Among 5,227 patients, 55.8% women and 60.0% men had uncontrolled BP, 47.3% women and 46.4% men with statin therapy indication did not have a prescription, 34.9% women and 40.9% men had uncontrolled HbA1c values, and 9.3% women and 13.7% men were smokers. African Americans were more likely to have uncontrolled BP (women: RR 1.18, 95% CI 1.07-1.30; men: RR 1.20, 95% CI 1.05-1.34) and more likely to lack a statin prescription (women: RR 1.23, 95% CI 1.05-1.45; men: RR 1.25, 95% CI 1.03-1.51) compared to Caucasians. Differences in HbA1c control were not statistically significant among Hispanic/Latino compared to Caucasians (women: RR 1.28, 95% CI 0.86-1.90; men: RR 1.20, 95% CI 0.72-1.97).

CONCLUSIONS

Disparities in controlling ASCVD risk factors in primary care persist and were not fully explained by demographic or clinical characteristics. Monitoring changes in disparities is important to ensure equity as interventions to prevent ASCVD in primary care are developed and implemented.

Insights in the pathophysiology of haemorrhagic strokes in a sub-Sahara African country, an epidemiological and MRI study

OBJECTIVE

Intra-cerebral Haemorrhage (ICH) seems more prevalent in sub-Saharan Africa (SSA) than in High-Income Countries (HIC) with poorer clinical outcome. Higher impact of hypertension and/or amyloid angiopathy could account for this disproportion. Here, we sought to (i) retrospectively compare ICH clinical and imaging patterns in Belgium and Guinea and in a subsequent cohort (ii) prospectively compare brain MRI characteristics to seek evidence for a different proportion of amyloid angiopathy patterns.

METHODS

Ninety one consecutive patients admitted for spontaneous ICH at Brussels Erasme-ULB Hospital and at Conakry Ignace Deen-UGANC were retrospectively compared in terms of ICH volume estimated with the ABC/2 method, clinical characteristics and modified ranking (mRS) score at 30 days. mRS was dichotomised as good outcomes (≤3) and poor outcomes (>3). A prospective cohort of 30 consecutive patients with ICH admitted at CHU Conakry Ignace Deen-UGANC was prospectively included to undergo brain MRI. Results of the Guinean MRI were compared to 30 patients randomly selected from Brussels' initial cohort. Paired Student's t-test and Mann-Whitney u-test were used for group comparisons.

RESULTS

Age of ICH onset was higher in Belgium (68 ± 17 years vs. 56 ± 14 years, P < 0.01) while ICH volume and 30-day mortality rate were higher in Guinea (20 ml vs. 11 ml, P < 0.01 and mortality 33% vs. 10 %, P < 0.01). ICH burden in survivors in Conakry and Brussels showed respectively good outcomes in 56.7% and 60.4% (P = 0.09) and poor outcomes in 10.3% vs. 29.6% (P < 0.001). MRI analysis of the prospective cohort failed to disclose significant differences regarding brain MRI characteristics.

CONCLUSIONS

Intra-cerebral Haemorrhage affected patients 15 years younger in Guinea with larger haematoma volumes and higher mortality than in Belgium. MRI findings did not show more prevalent amyloid angiopathy pathology suggesting that better primary prevention of hypertension could positively impact ICH epidemiology in Guinea.

Retrospective cohort study to characterise the blood pressure response to spironolactone in patients with apparent therapy-resistant hypertension using electronic medical record data

OBJECTIVE

Identify blood pressure (BP) response to spironolactone in patients with apparent therapy-resistant hypertension (aTRH) using electronic medical records (EMRs) in order to estimate response in a real-world clinical setting.

DESIGN

Developed an algorithm to determine BP and electrolyte response to spironolactone for use in a retrospective cohort study.

SETTING

An academic medical centre in Nashville, Tennessee.

POPULATION

Patients with aTRH prescribed spironolactone.

MAIN OUTCOME MEASURES

Baseline BP and BP response, determined as the change in mean systolic BP (SBP) and diastolic BP (DBP) following spironolactone initiation. Additional response measures were serum sodium, potassium and creatinine, estimated glomerular filtration rate, haemoglobin A1c (HbA1c), glucose, high-density lipoprotein, low-density lipoprotein and triglycerides. Demographic characteristics included race, age, gender, body mass index (BMI), diabetes mellitus, chronic kidney disease stage 3, ischaemic heart disease and smoking.

RESULTS

The mean decreases in SBP and DBP were 8.1 and 3.4 mm Hg, consistent with clinical trial data. Using a mean decrease in SBP of 5 mm Hg or in DBP of 2 mm Hg to define 'responders', 30.3% of patients did not respond. In univariable analyses, responders had higher BMI, baseline SBP, DBP, sodium and HbA1c, and lower creatinine. In multivariable analysis, responders were older and had significantly higher BMI and baseline SBP and DBP, and lower potassium. Increases in potassium and creatinine following spironolactone were larger in responders. When BP was evaluated as a continuous variable, decreases in SBP and DBP correlated with baseline BP, decrease in sodium and increases in potassium and creatinine following spironolactone. The decrease in SBP was associated with decreasing glucose in European Americans.

CONCLUSIONS

We developed an algorithm to assess BP response to a commonly prescribed medication for aTRH using EMRs. Electrolyte changes associated with the BP response to spironolactone are consistent with its mechanism of action of blocking the mineralocorticoid receptor and decreasing epithelial sodium channel activity.

Increased Incidence of Resistant Hypertension in Patients With Systemic Lupus Erythematosus: A Retrospective Cohort Study

OBJECTIVE

To compare the risk of resistant hypertension (RHTN) in patients with systemic lupus erythematosus (SLE) and in controls without SLE, and to define factors associated with RHTN in patients with SLE.

METHODS

We studied 1,044 patients with SLE and 5,241 control subjects using de-identified electronic health records from a tertiary care center. SLE was defined as ≥4 International Classification of Diseases, Ninth Revision codes for SLE and antinuclear antibody titer ≥1:160. RHTN was defined as uncontrolled blood pressure on 3 antihypertensive medications or requiring 4 or more antihypertensives to attain control. First, we compared the risk of RHTN between groups. Second, we examined the association between RHTN and all-cause mortality in patients with SLE.

RESULTS

RHTN was nearly twice as prevalent in patients with SLE compared to control subjects (10.2% and 5.3%, respectively), with an incidence rate of 10.2 versus 6.1 cases per 1,000 person-years of observation (hazard ratio [HR] 1.72 [95% confidence interval 1.28-2.30]; P < 0.001, adjusted for age, sex, race, baseline end-stage renal disease [ESRD], creatinine, and calendar year). In patients with SLE, we found associations between RHTN and black race, lower renal function, hypercholesterolemia, and increased inflammatory markers. RHTN was associated with a significantly higher mortality risk (HR 2.91, P = 0.0005) after adjustment for age, sex, race, calendar year, creatinine, baseline ESRD, and number of visits.

CONCLUSION

Patients with SLE have a higher risk of RHTN compared to frequency-matched controls, independent of multiple covariates. RHTN is an important comorbidity for clinicians to recognize in SLE, because it is associated with a higher risk of mortality.

Leveraging the Electronic Health Records for Population Health: A Case Study of Patients With Markedly Elevated Blood Pressure

Background

The digital transformation of medical data provides opportunities to perform digital population health surveillance and identify people inadequately managed in usual care. We leveraged the electronic health records of a large health system to identify patients with markedly elevated blood pressure and characterize their follow‐up care pattern.

Methods and Results

We included 373 861 patients aged 18 to 85 years, who had at least 1 outpatient encounter in the Yale New Haven Health System between January 2013 and December 2017. We described the prevalence and follow‐up pattern of patients with at least 1 systolic blood pressure (SBP) ≥160 mm Hg or diastolic blood pressure (DBP) ≥100 mm Hg and patients with at least 1 SBP ≥180 mm Hg or DBP ≥120 mm Hg. Of 373 861 patients included, 56 909 (15.2%) had at least 1 SBP ≥160 mm Hg or DBP ≥100 mm Hg, and 10 476 (2.8%) had at least 1 SBP ≥180 mm Hg or DBP ≥120 mm Hg. Among patients with SBP ≥160 mm Hg or DBP ≥100 mm Hg, only 28.3% had a follow visit within 1 month (time window of follow‐up recommended by the guideline) and 19.9% subsequently achieved control targets (SBP <130 mm Hg and DBP <80 mm Hg) within 6 months. Follow‐up rate at 1 month and control rate at 6 months for patients with SBP ≥180 mm Hg or DBP ≥120 mm Hg was 31.9% and 17.2%.

Conclusions

Digital population health surveillance with an electronic health record identified a large number of patients with markedly elevated blood pressure and inadequate follow‐up. Many of these patients subsequently failed to achieve control targets.

Association of the genetic ancestry with resistant hypertension in the ReHOT (Resistant Hypertension Optimal Treatment) randomized study

Resistant hypertension (RH) is defined as uncontrolled blood pressure despite treatment with three or more antihypertensive medications, including, if tolerated, a diuretic in adequate doses. It has been widely known that race is associated with blood pressure control. However, intense debate persists as to whether this is solely explained by unadjusted socioeconomical variables or genetic variation. In this scenario, the main aim was to evaluate the association between genetic ancestry and resistant hypertension in a large sample from a multicenter trial of stage II hypertension, the ReHOT study. Samples from 1,358 patients were analyzed, of which 167 were defined as resistant hypertensive. Genetic ancestry was defined using a panel of 192 polymorphic markers. The genetic ancestry was similar in resistant (52.0% European, 36.7% African and 11.3% Amerindian) and nonresistant hypertensive patients (54.0% European, 34.4% African and 11.6% Amerindian) (p > 0.05). However, we observed a statistically suggestive association of African ancestry with resistant hypertension in brown patient group. In conclusion, increased African genetic ancestry was not associated with RH in Brazilian patients from a prospective randomized hypertension clinical trial.

Renin-Angiotensin-Aldosterone System Modulates Blood Pressure Response During Vascular Endothelial Growth Factor Receptor Inhibition

Objectives

This study postulated that antihypertensive therapy with renin-angiotensin-aldosterone system (RAAS) inhibition may mitigate vascular endothelial growth factor inhibitor (VEGFi)–mediated increases in blood pressure more effectively than other antihypertensive medications in patients receiving VEGFi therapy.

Background

VEGFi therapy is commonly used in the treatment of cancer. One common side effect of VEGFi therapy is elevated blood pressure. Evidence suggests that the RAAS may be involved in VEGFi-mediated increases in blood pressure.

Methods

This retrospective cohort analysis was performed using a de-identified version of the electronic health record at Vanderbilt University Medical Center in Nashville, Tennessee. Subjects with cancer who were exposed to VEGFi therapy were identified, and blood pressure and medication data were extracted. Changes in mean systolic and diastolic blood pressure in response to VEGFi therapy in patients receiving RAAS inhibitor (RAASi) therapy before VEGFi initiation were compared with changes in mean systolic and diastolic blood pressure in patients not receiving RAASi therapy before VEGFi initiation.

Results

Mean systolic and diastolic blood pressure rose in both groups after VEGFi use; however, patients who had RAASi therapy before VEGFi initiation had a significantly lower increase in systolic blood pressure as compared with patients with no RAASi therapy (2.46 mm Hg [95% confidence interval: 0.7 to 4.2] compared with 4.56 mm Hg [95% confidence interval: 3.5 to 5.6], respectively; p = 0.034).

Conclusions

In a real-world clinical population, RAASi therapy before VEGFi initiation may ameliorate VEGFi-mediated increases in blood pressure. Randomized clinical trials are needed to further our understanding of the role of RAASi therapy in VEGFi-mediated increases in blood pressure.