Comparison of Blood Pressure Control Rates Among Recommended Drug Selection Strategies for Initial Therapy of Hypertension

ACE gene polymorphism and susceptibility to hypertension in a Jordanian adult population

Hypertension is one of the most common and complicated disorders associated with genetic and environmental risk factors. The angiotensin-converting enzyme (ACE) is important in the renin-angiotensin-system pathway. The gene expression of ACE has been investigated as a possible hypertension marker. This study investigates the association between polymorphisms within the ACE1 and ACE2 genes and hypertension susceptibility in a Jordanian population. The study comprised a total of 200 hypertensive patients and 180 healthy controls. A polymerase chain reaction (PCR) was performed to genotype the candidate polymorphism (rs4646994) of the ACE1gene. The Luminex DNA array technique was used for genotyping SNPs (rs4359, rs4344, rs4341, rs4343, and rs2106809) of the ACE1 and ACE2 genes. Our findings suggest no association between SNPs and hypertension regarding allelic and genotypic frequencies. However, rs4359 was significantly associated with diet (pP = 0.049), know HTN (P = 0.042), and number of years DM (P = 0.003). rs4341 was associated with diet (P = 0.032), peripheral vascular disease (P = 0.005), and chronic kidney disease (p = 0.049). While rs4343 was associated with diet (P = 0.031), diabetes mellitus (P = 0.032), and other medication (P = 0.025). Furthermore, the haplotypes of four SNPs of the ACE1 gene showed no significant association with HTN patients and healthy controls. Our findings indicate no association between the polymorphisms in the ACE gene and the risk of hypertension development in the Jordanian adult population.

Integrated metabolomics analysis reveals mechanistic insights into variability in blood pressure response to thiazide diuretics and beta blockers

Hypertensive patients with a higher proportion of genetic West African ancestry (%GWAA) have better blood pressure (BP) response to thiazide diuretics (TDs) and worse response to β-blockers (BBs) than those with lower %GWAA, associated with their lower plasma renin activity (PRA). TDs and BBs are suggested to reduce BP in the long term through vasodilation via incompletely understood mechanisms. This study aimed at identifying pathways underlying ancestral differences in PRA, which might reflect pathways underlying BP-lowering mechanisms of TDs and BBs. Among hypertensive participants enrolled in the Pharmacogenomics Evaluation of Antihypertensive Responses (PEAR) and PEAR-2 trials, we previously identified 8 metabolites associated with baseline PRA and 4 metabolic clusters (including 39 metabolites) that are different between those with GWAA <45% versus ≥45%. In the current study, using Ingenuity Pathway Analysis (IPA), we integrated these signals. Three overlapping metabolic signals within three significantly enriched pathways were identified as associated with both PRA and %GWAA: ceramide signaling, sphingosine 1- phosphate signaling, and endothelial nitric oxide synthase signaling. Literature indicates that the identified pathways are involved in the regulation of the Rho kinase cascade, production of the vasoactive agents nitric oxide, prostacyclin, thromboxane A2, and endothelin 1; the pathways proposed to underlie TD- and BB-induced vasodilatation. These findings may improve our understanding of the BP-lowering mechanisms of TDs and BBs. This might provide a possible step forward in personalizing antihypertensive therapy by identifying patients expected to have robust BP-lowering effects from these drugs.

Metabolomics Signature of Plasma Renin Activity and Linkage with Blood Pressure Response to Beta Blockers and Thiazide Diuretics in Hypertensive European American Patients

Plasma renin activity (PRA) is a predictive biomarker of blood pressure (BP) response to antihypertensives in European–American hypertensive patients. We aimed to identify the metabolic signatures of baseline PRA and the linkages with BP response to β-blockers and thiazides. Using data from the Pharmacogenomic Evaluation of Antihypertensive Responses-2 (PEAR-2) trial, multivariable linear regression adjusting for age, sex and baseline systolic-BP (SBP) was performed on European–American individuals treated with metoprolol (n = 198) and chlorthalidone (n = 181), to test associations between 856 metabolites and baseline PRA. Metabolites with a false discovery rate (FDR) < 0.05 or p < 0.01 were tested for replication in 463 European–American individuals treated with atenolol or hydrochlorothiazide. Replicated metabolites were then tested for validation based on the directionality of association with BP response. Sixty-three metabolites were associated with baseline PRA, of which nine, including six lipids, were replicated. Of those replicated, two metabolites associated with higher baseline PRA were validated: caprate was associated with greater metoprolol SBP response (β = −1.7 ± 0.6, p = 0.006) and sphingosine-1-phosphate was associated with reduced hydrochlorothiazide SBP response (β = 7.6 ± 2.8, p = 0.007). These metabolites are clustered with metabolites involved in sphingolipid, phospholipid, and purine metabolic pathways. The identified metabolic signatures provide insights into the mechanisms underlying BP response.

Optimizing Precision of Hypertension Care to Maximize Blood Pressure Control: A Pilot Study Utilizing a Smartphone App to Incorporate Plasma Renin Activity Testing

Only half of patients with hypertension (HTN) respond to any given antihypertensive medication. Heterogeneity in pathophysiologic pathways underlying HTN is a major contributor. Personalizing antihypertensive therapy could improve blood pressure (BP) reduction. The objective of this study was to assess the effect of pragmatic implementation of a personalized plasma renin activity (PRA)‐based smartphone app on improving BP reduction. Patients with untreated or treated but uncontrolled HTN were recruited. BP and PRA were measured at baseline with final BP measured at 6 months. Patient’s information was entered into the app and treatment recommendations were returned. Clinicians were at liberty to follow or disregard the app’s recommendations. BP levels and percent BP control among patients whose clinicians did and did not follow the app’s recommendations were compared using independent t‐test and Fisher’s exact test, respectively. Twenty‐nine European American patients were included (38% women) with mean age of 52 ± 9 years and median PRA of 1.3 ng/mL/hr (interquartile range 0.5–3.1 ng/mL/hr). Participants whose clinicians followed the app’s recommendations (n = 16, 55%) as compared with those whose clinicians did not (n = 13, 45%), had a greater reduction in 6‐month systolic BP (−15 ± 21 vs. −3 ± 21 mm Hg; adjusted‐P = 0.1) and diastolic BP (−8 ± 8 vs. −1 ± 8 mm Hg; adjusted‐P = 0.04). BP control at 6 months tended to be greater among patients whose clinicians accepted the app’s recommendations vs. those whose clinicians did not (63% vs. 23%, P = 0.06). This pilot study demonstrates that acceptance of the app’s recommendations was associated with a greater BP reduction. Future studies to confirm these pilot findings are warranted.

Plasma Renin Activity Is a Predictive Biomarker of Blood Pressure Response in European but not in African Americans With Uncomplicated Hypertension

BACKGROUND

Interindividual variability in blood pressure (BP) response to antihypertensives has been reported. Although plasma renin activity (PRA) is a potential biomarker for personalizing antihypertensive therapy in European American (EA) and African American (AA) hypertensives, clinical utility of PRA-guided prescribing is incompletely understood.

METHODS

Using systematic-phased approach, PRA's clinical utility was assessed. After categorizing by baseline PRA, clinic systolic BP (SBP) responses to metoprolol and chlorthalidone were compared in 134 EAs and 102 AAs enrolled in the Pharmacogenomics Evaluation of Antihypertensive Responses-2 (PEAR-2) trial. Receiver operating characteristic (ROC) analysis was conducted in EAs. Data from PEAR-2 AAs were used to estimate an optimal PRA cut point using multivariable linear regression models. The derived cut point in AAs was tested in a meta-analysis of 2 independent AA cohorts, and its sensitivity and specificity were assessed.

RESULTS

EAs with PRA < 0.65 ng/ml/hour had a greater decrease in SBP to chlorthalidone than metoprolol (by -15.9 mm Hg, adjusted P < 0.0001), whereas those with PRA ≥ 0.65 ng/ml/hour had a greater decrease in SBP to metoprolol than chlorthalidone (by 3.3 mm Hg, adjusted P = 0.04). Area under ROC curve (0.69, P = 0.0001) showed that PRA can predict SBP response among EAs. However, we observed no association between PRA and SBP response in PEAR-2 AAs. Among independent AA cohorts, those with PRA ≥ 1.3 ng/ml/hour (PEAR-2-derived cut point) responded better to atenolol/candesartan than hydrochlorothiazide (meta-analysis P = 0.01). However, sensitivity of the derived cut point was 10%.

CONCLUSIONS

PRA at the previously established 0.60-0.65 ng/ml/hour cut point is an effective predictive biomarker of BP response in EAs. However, we were unable to identify PRA cut point that could be used to guide antihypertensive selection in AAs.

TRIAL REGISTRATION

NCT01203852, NCT00246519, NCT00005520.

Blood pressure response to metoprolol and chlorthalidone in European and African Americans with hypertension

Despite the availability of many antihypertensive drug classes, half of patients with hypertension have uncontrolled blood pressure (BP). The authors sought to assess the effect of age on BP response in European American and African American patients with hypertension. Clinic BP from the PEAR2 (Pharmacogenomics Evaluation of Antihypertensive Responses 2) study was used to estimate BP responses from baseline following sequential treatment with metoprolol 100 mg twice daily and chlorthalidone 25 mg daily for 8 to 9 weeks each, with a minimum 4-week washout between treatments. BP responses to both drugs were compared in 159 European Americans and 119 African Americans by age with adjustment for baseline BP and sex. European Americans younger than 50 years responded better to metoprolol than chlorthalidone (diastolic BP: -9.6 ± 8.0 vs -5.9 ± 6.8 mm Hg, adjusted P = .003), whereas patients 50 years and older responded better to chlorthalidone than metoprolol (systolic BP: -18.7 ± 13.8 vs -13.6 ± 14.8 mm Hg, adjusted P = .008). African Americans younger than 50 years responded similarly to both drugs, whereas those 50 years and older responded better to chlorthalidone than metoprolol (-17.0 ± 13.2/-9.6 ± 7.5 vs -7.0 ± 18.6/-6.7 ± 9.3 mm Hg, adjusted P<.0001/.008). Therefore, age should be considered when selecting antihypertensive therapy in European and African American populations with hypertension.

Unsuccessfully Treated Hypertension: A Major Public Health Problem With a Potential Solution

BACKGROUND

About one-half of all hypertensive adults do not have their blood pressure controlled. They are often prescribed medications that conform to national guidelines but they continue to have elevated blood pressure. This public health problem might be improved by applying plasma renin guided therapy.

RESULTS

A contributor to the public health problem of unsuccessfully treated hypertension is that the circulating renin-angiotensin system (RAS) is not recognized in treatment guidelines as clinically relevant for the treatment of hypertension or as important as the body salt status for determining blood pressure levels. Another contributor to the problem is the lack of specificity in the package inserts for antihypertensive drugs. They do not specifically state under the heading "Indications" that RAS blockers are primarily most effective in hypertensive subjects with medium and high plasma renin levels; by contrast, natriuretic drugs are most effective in those with low plasma renin levels.

METHODS

Literature review.

CONCLUSIONS

To address the problem of unsuccessfully treated hypertension, we recommend that the "Indications" section of package inserts for antihypertensive drugs be more specific. The primary indication for RAS blockers ought to be hypertension with medium and high plasma renin levels, and natriuretic agents for those with low plasma renin levels. Similar language ought to be added to treatment guidelines. Additionally, 3 other reasons for lack of blood pressure control also need to be addressed-failure to prescribe antihypertensive drugs to hypertensive subjects, failure of patients to fill prescriptions, and low drug adherence.

Heterogeneity in Early Responses in ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial)

Randomized trials of hypertension have seldom examined heterogeneity in response to treatments over time and the implications for cardiovascular outcomes. Understanding this heterogeneity, however, is a necessary step toward personalizing antihypertensive therapy. We applied trajectory-based modeling to data on 39 763 study participants of the ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) to identify distinct patterns of systolic blood pressure (SBP) response to randomized medications during the first 6 months of the trial. Two trajectory patterns were identified: immediate responders (85.5%), on average, had a decreasing SBP, whereas nonimmediate responders (14.5%), on average, had an initially increasing SBP followed by a decrease. Compared with those randomized to chlorthalidone, participants randomized to amlodipine (odds ratio, 1.20; 95% confidence interval [CI], 1.10-1.31), lisinopril (odds ratio, 1.88; 95% CI, 1.73-2.03), and doxazosin (odds ratio, 1.65; 95% CI, 1.52-1.78) had higher adjusted odds ratios associated with being a nonimmediate responder (versus immediate responder). After multivariable adjustment, nonimmediate responders had a higher hazard ratio of stroke (hazard ratio, 1.49; 95% CI, 1.21-1.84), combined cardiovascular disease (hazard ratio, 1.21; 95% CI, 1.11-1.31), and heart failure (hazard ratio, 1.48; 95% CI, 1.24-1.78) during follow-up between 6 months and 2 years. The SBP response trajectories provided superior discrimination for predicting downstream adverse cardiovascular events than classification based on difference in SBP between the first 2 measurements, SBP at 6 months, and average SBP during the first 6 months. Our findings demonstrate heterogeneity in response to antihypertensive therapies and show that chlorthalidone is associated with more favorable initial response than the other medications.