Advances in the Pathogenesis and Treatment of Resistant Hypertension

Hypertension is a prevalent chronic disease associated with an increased risk of cardiovascular (CV) premature death, and its severe form manifests as resistant hypertension (RH). The accurate prevalence of resistant hypertension is difficult to determine due to the discrepancy in data from various populations, but according to recent publications, it ranges from 6% to 18% in hypertensive patients. However, a comprehensive understanding of the pathogenesis and treatment of RH is essential. This review emphasizes the importance of identifying the causes of treatment resistance in antihypertensive therapy and highlights the utilization of appropriate diagnostic methods. We discussed innovative therapies such as autonomic neuromodulation techniques like renal denervation (RDN) and carotid baroreceptor stimulation, along with invasive interventions such as arteriovenous anastomosis as potential approaches to support patients with inadequate medical treatment and enhance outcomes in RH.

Sustained Activation of CLR/RAMP Receptors by Gel-Forming Agonists

Background: Adrenomedullin (ADM), adrenomedullin 2 (ADM2), and CGRP family peptides are important regulators of vascular vasotone and integrity, neurotransmission, and fetoplacental development. These peptides signal through CLR/RAMP1, 2, and 3 receptors, and protect against endothelial dysfunction in disease models. As such, CLR/RAMP receptor agonists are considered important therapeutic candidates for various diseases. Methods and Results: Based on the screening of a series of palmitoylated chimeric ADM/ADM2 analogs, we demonstrated a combination of lipidation and accommodating motifs at the hinge region of select peptides is important for gaining an enhanced receptor-activation activity and improved stimulatory effects on the proliferation and survival of human lymphatic endothelial cells when compared to wild-type peptides. In addition, by serendipity, we found that select palmitoylated analogs self-assemble to form liquid gels, and subcutaneous administration of an analog gel led to the sustained presence of the peptide in the circulation for >2 days. Consistently, subcutaneous injection of the analog gel significantly reduced the blood pressure in SHR rats and increased vasodilation in the hindlimbs of adult rats for days. Conclusions: Together, these data suggest gel-forming adrenomedullin analogs may represent promising candidates for the treatment of various life-threatening endothelial dysfunction-associated diseases such as treatment-resistant hypertension and preeclampsia, which are in urgent need of an effective drug.

Treatment-resistant hypertension

Treatment-resistant hypertension is one of the most significant causes of poor blood pressure regulation. Patients with resistant hypertension are at a higher risk of developing comorbidities compared to the general hypertensive population. As a result, these patients have an increased incidence of disability and premature death, as well as increased treatment costs. Due to the above-mentioned, in the last decade, there has been an increase in researchers' interest in elucidating the pathogenesis, diagnosis, and treatment of resistant hypertension. However, recent data indicate that 20% of female and 24% of male patients with arterial hypertension still have uncontrolled blood pressure, despite maximum doses of three antihypertensive drugs (including a diuretic) and appropriate lifestyle measures. New treatment modalities (i.e. devicebased interventions - catheter-based renal denervation and baroreceptor stimulation) offer hope for achieving adequate blood pressure regulation in these patients. In this paper, we have summarized previous knowledge about the mechanisms underlying the pathogenesis of resistant hypertension, as well as optimal diagnostic methods to differentiate true from pseudo-resistant hypertension. We have also given an overview of the current therapeutic approach, including optimal medical therapy and new treatment modalities (i.e. device-based interventions) and their role in the treatment of resistant hypertension.

Apparent treatment resistant hypertension and the risk of recurrent cardiovascular events and mortality in patients with established vascular disease

AIM

To quantify the relation between apparent treatment resistant hypertension (aTRH) and the risk of recurrent major adverse cardiovascular events (MACE including stroke, myocardial infarction and vascular death) and mortality in patients with stable vascular disease.

METHODS

7455 hypertensive patients with symptomatic vascular disease were included from the ongoing UCC-SMART cohort between 1996 and 2019. aTRH was defined as an office blood pressure ≥140/90 mmHg despite treatment with ≥3 antihypertensive drugs including a diuretic. Cox proportional hazard models were used to quantify the relation between aTRH and the risk of recurrent MACE and all-cause mortality. In addition, survival for patients with aTRH was assessed, taking competing risk of non-vascular mortality into account.

RESULTS

A total of 1557 MACE and 1882 deaths occurred during a median follow-up of 9.0 years (interquartile range 4.8-13.1 years). Compared to patients with non-aTRH, the 614 patients (8%) with aTRH were at increased risk of cardiovascular mortality (HR 1.27; 95% CI 1.03-1.56) and death from any cause (HR 1.25; 95% CI 1.07-1.45) but not recurrent MACE (HR 1.13; 95% CI 0.95-1.34). At the age of 50 years, patients with aTRH after a first cardiovascular event on average had a 6.4 year shorter median life expectancy free of recurrent MACE than patients with non-aTRH.

CONCLUSION

In hypertensive patients with clinically manifest vascular disease, aTRH is related to a higher risk of vascular death and death from any cause. Moreover, patients with aTRH after a first cardiovascular event have a 6.4 year shorter median life expectancy free of recurrent cardiovascular disease.

Efficacy and safety of baroreflex activation therapy for treatment of resistant hypertension: a systematic review and meta-analysis

To provide definite evidence for the anti-hypertensive benefit of Baroreflex Activation Therapy (BAT) for resistant hypertension, we performed a systematic review and meta-analysis to evaluate the efficacy and safety of BAT. Electronic searches were conducted in PubMed, EMBASE, The Cochrane Library and Web of Science. Two reviewers independently determined the eligibility of studies and extracted the data. The quality of all included studies was evaluated by the use of the Newcastle Ottawa Scale (NOS). Disagreements were settled through discussion. Twelve studies, included one randomized clinical trials (RCTs) and eleven prospective studies were eligible for qualitative analysis and five prospective studies were selected for meta-analysis. The data of analysis showed office systolic blood pressure (SBP)(WMD = -24.01, 95% CI = -28.65 to -19.36, P= 0.753I² = 0.0%) and diastolic blood pressure (DBP)(WMD = -12.53, 95% CI = -15.82 to -9.24,P = 0.893,I² = 0.893) decreased by BAT treatment.The effect on SBP was both significant in the Barostim neo TM device (WMD = -22.49, 95% CI = -29.13 to 15.84, P= 0.443; I² = 0.0%) and Rheos System (WMD = 25.46, 95% CI = -31.96 to -18.96, P= 0.703; I² = 0.0%). Our study found office BP were significantly decreased by BAT treatment, but available evidence is limited by risk of bias, small sample size, and few RCTs. Thus, there is presently insufficient evidence to fully evaluate the efficacy and safety of BAT for Patients with Resistant Hypertension. Additional high-quality RCT research with long-term follow-up is required.

Trends in Antihypertensive Medication Use Among US Patients With Resistant Hypertension, 2008 to 2014

Little is known of US trends in antihypertensive drug use for patients with treatment-resistant hypertension (TRH). We analyzed antihypertensive use among patients with TRH (treated with ≥4 antihypertensive drugs concurrently) from July 2008 through December 2014 using Marketscan administrative data. We included adults aged 18 to 65 years, with ≥6 months of continuous enrollment, a hypertension diagnosis, and ≥1 episode of overlapping use of ≥4 antihypertensive drugs; patients with heart failure were excluded. We identified 411 652 unique TRH episodes from 261 652 patients with a mean age of 55.9 years. From 2008 to 2014, we observed an increased prevalence, among TRH episodes, of β-blockers (+6.8% [79% to 85.8%]) and dihydropyridine calcium antagonists (+8.1% [69.1% to 77.2%]), and a decreased prevalence of angiotensin-converting enzyme inhibitors (-12.5% [60.4% to 47.9%]) and nondihydropyridine calcium antagonists (-5.0% [15% to 10%]). The prevalence of most other classes changed by <5% from 2008 to 2014. Thiazide diuretic use was largely unchanged from 2008 to 2014, with hydrochlorothiazide being by far the most prevalent thiazide diuretic; chlorthalidone use increased only modestly (+2.6% [3.8% to 6.4%]). Aldosterone antagonist use increased only modestly (+2.9% [7.3% to 10.2%]). Use of optimal regimens increased steadily (+13.8% [50.8% to 64.6%]) during the study period, whereas combined angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use declined (-11.4% [17.7% to 6.3%]). Our results highlight the persistent infrequent use of recommended therapies in TRH, including spironolactone and chlorthalidone, and suggest a need for better efforts to increase the use of such approaches in light of recent evidence demonstrating their efficacy.

Efficacy and Safety of Spironolactone in Patients with Resistant Hypertension: A Meta-analysis of Randomised Controlled Trials

BACKGROUND

The treatment of resistant hypertension (RH) is challenging. Several observational studies have suggested that the addition of spironolactone to triple-drug therapy might have a promising anti-hypertensive effect on RH. To provide more definite evidence for the benefit of spironolactone, we performed a meta-analysis of randomised controlled trials (RCTs) to evaluate the efficacy and safety of spironolactone in RH patients.

METHODS

Articles were searched from PubMed, EMBASE and Cochrane Library. Randomised controlled trials investigating the effect of additional spironolactone on office blood pressure (BP), ambulatory BP or adverse events in RH patients were included for analysis. Then quality assessment, subgroup, sensitivity, and publication bias analyses were performed.

RESULTS

Five RCTs involving a total of 553 patients were eligible for inclusion. Compared with control therapies, additional spironolactone treatment in RH patients significantly decreased 24-h ambulatory systolic BP (ASBP, weight mean difference [WMD]= -10.50, 95% confidence interval [CI] = -12.30 to -8.71, P<0.001), 24-h ambulatory diastolic BP (ADBP, WMD = -4.09, 95% CI = -5.28 to -2.91, P<0.001), daytime ASBP (WMD = -10.20, 95% CI = -12.41 to -7.99, P<0.001), daytime ADBP (WMD = -4.14, 95% CI = -5.50 to -2.78, P<0.001), night-time ASBP (WMD = -10.02, 95% CI = -12.63 to -7.41), night-time ADBP (WMD=-3.21, 95% CI=-4.84 to -1.58, P<0.001), office systolic BP (WMD=-16.99, 95% CI=-25.04 to -8.95, P<0.001) and office diastolic BP (WMD=-6.18, 95% CI=-9.30 to -3.05, P<0.001). However, serum potassium might be slightly elevated by additional spironolactone (WMD=0.181, 95% CI=0.042 to 0.319, P=0.011).

CONCLUSION

Spironolactone combined with triple-drug therapy may be an effective and relatively safe strategy for the management of RH patients.

Physician-pharmacist collaboration versus usual care for treatment-resistant hypertension

Team-based care has been recommended for patients with treatment-resistant hypertension (TRH), but its efficacy in this setting is unknown. We compared a physician-pharmacist collaborative model (PPCM) to usual care in patients with TRH participating in the Collaboration Among Pharmacists and Physicians To Improve Outcomes Now study. At baseline, 169 patients (27% of Collaboration Among Pharmacists and Physicians To Improve Outcomes Now patients) had TRH: 111 received the PPCM intervention and 58 received usual care. Baseline characteristics were similar between treatment arms. After 9 months, adjusted mean systolic blood pressure was reduced by 7 mm Hg more with PPCM intervention than usual care (P = .036). Blood pressure control was 34.2% with PPCM versus 25.9% with usual care (adjusted odds ratio, 1.92; 95% confidence interval, 0.33-11.2). These findings suggest that team-based care in the primary care setting may be effective for TRH. Additional research is needed regarding the long-term impact of these models and to identify patients most likely to benefit from team-based interventions.

Quality of Life in Treatment-Resistant Hypertension

Treatment-resistant hypertension (TRH) is an increasingly common and clinically challenging hypertension phenotype associated with adverse impact on cardiovascular events and death. Recent evidence, although limited, suggests that TRH may also adversely affect health-related quality of life (HrQoL) and other patient-reported outcomes. However, the precise mechanisms for this link remain unknown. A number of recent studies focusing on both the general hypertensive population and those with TRH suggest that patient awareness of difficult-to-control blood pressure, chronically elevated blood pressure levels, and the use of aggressive medication regimens with attendant cumulative adverse effects may play significant roles. This review summarizes the existing literature on HrQoL in persons with TRH, highlights literature from the general hypertensive population with relevance to TRH, and discusses important remaining questions regarding HrQoL in persons with TRH.

Health-related quality of life in persons with apparent treatment-resistant hypertension on at least four antihypertensives

Little is known about the impact of treatment-resistant hypertension (TRH) on health-related quality of life (HrQoL). We aimed to compare HrQoL measures in adults with apparent TRH (aTRH) and non-resistant hypertension among nationally representative US Medical Expenditure Panel Survey data pooled from 2000 to 2011. Cohorts compared were adults with aTRH (⩾2 unique fills from ⩾4 antihypertensive classes during a year) versus non-resistant hypertension (those with hypertension not meeting the aTRH definition). Key outcomes were cohort differences in SF-12v2 physical component summary (PCS) and mental component summary (MCS) scores and disease-state utility using the SF-6D. Of 57 150 adults with hypertension, 2501 (4.4%) met criteria for aTRH. Persons with aTRH, compared with non-resistant hypertension, were older (mean, 68 vs 61 years), had a higher BMI (30.9 vs 29.7 kg m(-)(2)) and were more likely to be Black (20% vs 14%), but less likely to be female (46% vs 54%). Persons with aTRH, compared with non-resistant hypertension, had lower mean PCS scores (35.8 vs 43.2; P<0.0001), and utility (0.68 vs 0.74; P<0.0001), but similar MCS scores (49.1 vs 50.4). In multivariable-adjusted analyses, aTRH was associated with a 2.37 (95% CI 1.71 to 3.02) lower PCS score and 0.02 (95% CI 0.01 to 0.03) lower utility, compared with non-resistant hypertension. In conclusion, aTRH was associated with substantially lower HrQoL in physical functioning and health utility, but not in mental functioning, compared with non-resistant hypertension. The multivariable-adjusted reduction in physical functioning was similar in magnitude to previous observations comparing hypertension with no hypertension.

Predictors and outcomes of resistant hypertension among patients with coronary artery disease and hypertension

OBJECTIVE

Resistant hypertension (res-HTN) is a challenging problem, but little is known of res-HTN in patients with coronary artery disease (CAD). In this post-hoc INternational VErapamil SR-Trandolapril STudy (INVEST) analysis, we assessed prevalence, predictors, and impact on outcomes of res-HTN in CAD patients with hypertension.

METHODS

Participants (n=17190) were divided into three groups according to achieved blood pressure (BP): controlled (BP <140/90 mmHg on three or fewer drugs); uncontrolled (BP ≥ 40/90 mmHg on two or fewer drugs); or resistant (BP ≥ 40/90 mmHg on three drugs or any patient on at least four drugs).

RESULTS

The prevalence of res-HTN was 38%: significant predictors of res-HTN included heart failure [odds ratio (OR) 1.73], diabetes (OR 1.63), Black race (OR 1.50), and US residence (OR 1.50). Compared with controlled HTN, res-HTN had multivariate-adjusted association with higher risk of adverse outcomes {first occurrence of all-cause death, nonfatal myocardial infarction, or nonfatal stroke [hazard ratio 1.27, 95% confidence interval (CI) 1.13-1.43], and individual outcomes of all-cause death (hazard ratio 1.29, 95% CI 1.13-1.48), cardiovascular mortality (hazard ratio 1.47, 95% CI 1.21-1.78), and nonfatal stroke (hazard ratio 1.61, 95% CI 1.17-2.22), but not nonfatal myocardial infarction (hazard ratio 0.98, 95% CI 0.72-1.34)}. Adverse outcomes, except nonfatal stroke, did not differ in patients with res-HTN compared to uncontrolled HTN.

CONCLUSIONS

Res-HTN is common in patients with CAD and hypertension, associated with poor prognosis, and linked with a number of conditions. Emphasis should be placed on recognizing those at risk for res-HTN and future studies should examine whether more aggressive treatment of res-HTN improves outcomes.