How to use ambulatory blood pressure monitoring in resistant hypertension

Effects of phosphodiesterase 5 inhibition on cardiovascular function in resistant hypertension: A systematic review

Approximately 12-18% of hypertensive patients are diagnosed with resistant hypertension (RH). The risk of having worse cardiovascular outcomes is twice higher in those patients. The low effectiveness of conventional antihypertensive drugs in RH emphasizes the need to evaluate complementary drug therapies to achieve blood pressure (BP) control. Previous studies have demonstrated that phosphodiesterase 5 (PDE-5) inhibitors improve hemodynamics and reduce BP on essential hypertension. So, the authors aimed to summarize current clinical trials-based evidence published concerning the use of PDE-5 inhibitors on BP, cardiovascular function, and hemodynamics of patients with RH. We searched MEDLINE, EMBASE, LILACS, ClinicalTrials.gov, and WHO International Clinical Trials Registry databases on May 15th, 2020 using pre-defined search terms. Two independent reviewers assessed and extracted data from clinical trials that evaluated the effect of PDE-5 inhibitors on BP. We have included five articles in this systematic review. Four of them developed a single-day protocol, while one has developed a 14-day study. The main findings indicate that PDE-5 inhibitors ameliorate BP, vascular hemodynamics, and diastolic function parameters. Some data demonstrated improvement of endothelial function, but it was not a consensus. The side effects seemed to be limited and well-tolerated. In brief, our systematic review highlights the potential of PDE-5 inhibitors as a therapeutic alternative in addition to the multiple-drug regime for RH. Larger studies are still needed to determine whether the beneficial effects of PDE-5 inhibitors on RH would be maintained with chronic administration.

Assessment of a strategy combining ambulatory blood pressure, adherence monitoring and a standardised triple therapy in resistant hypertension

PURPOSE

Poor adherence to drug therapy and inadequate drug regimens are two frequent factors responsible for the poor blood pressure (BP) control observed in patients with apparent resistant hypertension. We evaluated the efficacy of an antihypertensive management strategy combining a standardised therapy with three long acting drugs and electronic monitoring of drug adherence in patients with apparent resistant hypertension.

MATERIALS AND METHODS

In this multicentric observational study, adult patients with residual hypertension on 24 h ambulatory BP monitoring (ABMP) despite the use of three or more antihypertensive drugs could be included. Olmesartan/amlodipine (40/10 mg, single pill fixed-dose combination) and chlorthalidone (25 mg) were prescribed for 3 months in two separated electronic pills boxes (EPB). The primary outcome was 24 h ambulatory systolic BP (SBP) control at 3 months, defined as mean SBP <130 mmHg.

RESULTS

We enrolled 48 patients (36.0% women) of whom 35 had complete EPB data. After 3 months, 52.1% of patients had 24 h SBP <130 mmHg. 24 h SBP decreased by respectively -9.1 ± 15.5 mmHg, -22.8 ± 30.6 mmHg and -27.7 ± 16.6 mmHg from the tertile with the lowest adherence to the tertile with the highest adherence to the single pill combination (p = 0.024). A similar trend was observed with tertiles of adherence to chlorthalidone. Adherence superior to 90% was associated with 24 h systolic and diastolic blood pressure control in multiple logistic regression analysis (odds ratio = 14.1 (95% confidence interval 1.1-173.3, p = 0.039).

CONCLUSIONS

A simplified standardised antihypertensive therapy combined with electronic monitoring of adherence normalises SBP in about half of patients with apparent resistant hypertension. Such combined management strategy enables identifying patients who need complementary investigations and those who rather need a long-term support of their adherence.

Office blood pressure threshold of 130/80 mmHg better predicts uncontrolled out-of-office blood pressure in apparent treatment-resistant hypertension

The objective of this study was to compare the diagnostic accuracy of office blood pressure (BP) threshold of 140/90 and 130/80 mmHg for correctly identifying uncontrolled out‐of‐office BP in apparent treatment‐resistant hypertension (aTRH). We analyzed 468 subjects from a prospectively enrolled cohort of patients with resistant hypertension in South Korea (clinicaltrials.gov: NCT03540992). Resistant hypertension was defined as office BP ≥ 130/80 mmHg with three different classes of antihypertensive medications including thiazide‐type/like diuretics, or treated hypertension with four or more different classes of antihypertensive medications. We conducted different types of BP measurements including office BP, automated office BP (AOBP), home BP, and ambulatory BP. We defined uncontrolled out‐of‐office BP as daytime BP ≥ 135/85 mmHg and/or home BP ≥ 135/85 mmHg. Among subjects with office BP < 140/90 mmHg and subjects with office BP < 130/80 mmHg, 66% and 55% had uncontrolled out‐of‐office BP, respectively. The prevalence of controlled and masked uncontrolled hypertension was lower, and the prevalence of white‐coat and sustained uncontrolled hypertension was higher, with a threshold of 130/80 mmHg than of 140/90 mmHg, for both office BP and AOBP. The office BP threshold of 130/80 mmHg was better able to diagnose uncontrolled out‐of‐office BP than 140/90 mmHg, and the net reclassification improvement (NRI) was 0.255. The AOBP threshold of 130/80 mmHg also revealed better diagnostic accuracy than 140/90 mmHg, with NRI of 0.543. The office BP threshold of 130/80 mmHg showed better than 140/90 mmHg in terms of the correspondence to out‐of‐office BP in subjects with aTRH.

Prevalence and clinical profile of refractory hypertension in a large cohort of patients with resistant hypertension

Refractory hypertension (RfHT) is an extreme phenotype of resistant hypertension (RHT) and is considered uncontrolled blood pressure (BP) despite the use of five or more antihypertensives. The objective of this study was to characterize the prevalence and clinical profile of RfHT patients in a historical cohort of patients with RHT at two different times: before and after the introduction of spironolactone. First, this cross-sectional study evaluated 1048 RHT patients (72.3% females, mean [SD] age: 61.2 [11.3] years) referred to a hypertension clinic (prespironolactone period). All patients were submitted to a standard protocol including clinical and complementary exams. Second, the analysis evaluated patients after the introduction of spironolactone (postspironolactone period). Statistical analysis included bivariate comparisons between patients with RHT and patients with RfHT and logistic regressions to assess the independent correlations of RfHT. A total of 146 patients (13.9%) remained refractory despite the use of at least five antihypertensives (prespironolactone period). After the introduction of spironolactone, the prevalence increased to 17.6%. For any criterion, RfHT patients were younger and more obese. In the initial period, current smoking and left ventricular hypertrophy were independently correlated with RfHT. Furthermore, after spironolactone use, RfHT patients had lower aortic stiffness and peripheral artery disease (PAD), pointing to a lower cardiovascular risk despite the lack of BP control. Younger age and lower prevalence of PAD correlated independently with RfHT. In conclusion, there was a high prevalence of RfHT, especially in younger and obese patients, and spironolactone use seemed to reduce cardiovascular risk despite the lack of BP control.

Resistant and refractory hypertension: two sides of the same disease?

Refractory hypertension (RfH) is an extreme phenotype of resistant hypertension (RH), being considered an uncontrolled blood pressure besides the use of 5 or more antihypertensive medications, including a long-acting thiazide diuretic and a mineralocorticoid antagonist. RH is common, with 10-20% of the general hypertensives, and its associated with renin angiotensin aldosterone system hyperactivity and excess fluid retention. RfH comprises 5-8% of the RH and seems to be influenced by increased sympathetic activity. RH patients are older and more obese than general hypertensives. It is strongly associated with diabetes, obstructive sleep apnea, and hyperaldosteronism status. RfH is more frequent in women, younger patients and Afro-americans compared to RFs. Both are associated with increased albuminuria, left ventricular hypertrophy, chronic kidney diseases, stroke, and cardiovascular diseases. The magnitude of the white-coat effect seems to be higher among RH patients. Intensification of diuretic therapy is indicated in RH, while in RfH, therapy failure imposes new treatment alternatives such as the use of sympatholytic therapies. In conclusion, both RH and RfH constitute challenges in clinical practice and should be addressed as distinct clinical entities by trained professionals who are capable to identify comorbidities and provide specific, diversified, and individualized treatment.

The value of ABPM and subclinical target organ damage parameters in diagnosis of resistant hypertension

INTRODUCTION

We aimed to assess the effectiveness of ambulatory blood pressure monitoring (ABPM) and subclinical target organ damage parameters for diagnosis of resistant hypertension (RH).

METHODS

We assessed demographic and anthropometric variables, the incidence of cardiovascular events and subclinical target organ damage (n=112). We also studied the relationship between these variables and the ABPM results.

RESULTS

Of the 112 patients referred from primary care with a diagnosis of RH, 69 (61.6%) were confirmed by ABPM. We found statistically significant differences (P<.001) between patients with RH and pseudo-resistant hypertension in the appearance of subclinical target organ damage. A percentage of 84 of the patients had microalbuminuria: 66.25±30.7mg/dl); 44.9% had stage 3 chronic kidney disease: the average glomerular filtration was 59ml/min/1.73m²; and 56.5% had left ventricular hypertrophy on echocardiography. Fundoscopy revealed that 64% of the patients had hypertensive retinopathy. Three variables were associated with an increased HR risk: microalbuminuria, hypertensive retinopathy and left ventricular hypertrophy (OR 5.7, 6.2 and 11.2, respectively).

CONCLUSIONS

This study shows that the systematic testing for target organ damage, particularly in terms of albuminuria, is a simple and inexpensive tool, with a high predictive value for RH (85%), which could be useful for prioritising patients who need ABPM.

Acute Sildenafil Use Reduces 24-Hour Blood Pressure Levels in Patients With Resistant Hypertension: A Placebo-Controlled, Crossover Trial

The authors previously demonstrated that acute administration of sildenafil-a phosphodiesterase 5 (PDE5) inhibitor-improves hemodynamic parameters in patients with resistant hypertensive (RH), but its effect on ambulatory blood pressure monitoring (ABPM) is unknown. This interventional, nonrandomized, single-blinded, placebo-controlled, crossover trial included 26 patients with RH. A dose of sildenafil (187.5mg) was given, and after a washout period of 14 days the patients received a single oral dose of placebo and the protocol was repeated. The patients underwent 24-hour ABPM recordings the day before and immediately after the protocols. The reduction of systolic (-8.8±1.4 vs 1.3±1.2 mm Hg, P=.02), diastolic (-5.3±3.3 vs 1.8±1.1 mm Hg, P=.03), and mean (-7.9±3.6 vs 0.8±0.9 mm Hg, P=.01) 24-hour BP were found after the use of sildenafil compared with placebo. Improvement in daytime BP levels was also observed (systolic -6.0±4.7 vs 4.4±1.5 mm Hg [P=.02] and mean -4.8±3.9 vs 3.5±1.4 mm Hg [P=.02] for sildenafil vs placebo, respectively). Considering its antihypertensive effect, sildenafil may represent a therapeutic option for RH treatment.

Hypertension in chronic kidney disease: role of ambulatory blood pressure monitoring

Children with chronic kidney disease have a markedly increased risk of cardiovascular morbidity and children with end stage renal disease have an estimated 30 times greater risk of cardiovascular mortality than the general pediatric population. In adults, the link between hypertension and cardiovascular disease is well-documented but that association has not been so readily apparent in children with chronic kidney disease. This may be in part because the early changes in blood pressure that occur in these patients do not necessarily manifest with changes in casual blood pressure measurements. Ambulatory blood pressure monitoring, with its ability to gather multiple readings both during the normal activities of the day and the night, is felt to be a more veritable measure of blood pressure. Its use in children has been hampered by limited data on normative values and difficulties in blood pressure classification, while its use in adults is ever expanding. However, with an increasing number of studies in children with chronic kidney disease, ambulatory blood pressure has revealed a greater prevalence of abnormal findings in this population and has been shown to better predict cardiovascular risk than current standards. Two large multi-center studies in Europe and North America have revealed even greater utility of ambulatory blood pressure measures in this population. It is hoped that continued use of ambulatory monitoring in children will help overcome some of its perceived limitations while also validating its use in those at high risk of cardiovascular morbidity.

Diagnostic accuracy of the Berlin questionnaire in detecting obstructive sleep apnea in patients with resistant hypertension

OBJECTIVES

Obstructive sleep apnea (OSA) is strongly associated with resistant hypertension. The Berlin questionnaire is the most widely used screening tool to identify patients at high risk of having OSA. The objective was to test the diagnostic accuracy of the Berlin questionnaire in detecting OSA in resistant hypertensive patients.

METHODS

A cross-sectional analysis of 422 resistant hypertensive patients [31% men; mean (SD) age 62.4 (9.9) years] submitted to polysomnography (PSG), in whom the Berlin questionnaire was previously applied. OSA was defined by an apnea-hypopnea index of at least 5 per hour and moderate-to-severe OSA by an apnea-hypopnea index of at least 15. Statistical analysis included bivariate comparisons between patients at high and low risk by the Berlin questionnaire, and logistic regression to assess the predictors of agreement between the Berlin questionnaire and PSG. Sensitivity, specificity, positive and negative predictive values and likelihood ratios for the Berlin questionnaire in detecting OSA were calculated.

RESULTS

OSA was diagnosed in 347 patients (82.2%) and moderate-to-severe OSA in 234 patients (55.5%). In patients at high risk, moderate-to-severe OSA was confirmed in 58.3%, whereas in those at low risk, it was excluded in 50.4%. The accuracy of the Berlin questionnaire in detecting OSA was 55.6%. The specificity, sensitivity, positive and negative predictive value of the Berlin questionnaire in detecting moderate-to-severe OSA was 40, 69, 58 and 50%, respectively. The positive and negative likelihood ratios were 1.15 and 0.78, with a very low agreement (kappa = 0.081).

CONCLUSION

In a large cohort of resistant hypertensive patients, the Berlin questionnaire had a low accuracy of identifying patients with OSA and should not be used as a screening method for selecting patients to PSG.

Ambulatory Blood Pressure Monitoring in the Diagnosis, Prognosis, and Management of Resistant Hypertension: Still a Matter of our Resistance?

Resistant hypertension, commonly described as the failure to achieve goal blood pressure (BP) despite an appropriate regimen of three antihypertensive drugs at the maximal tolerated doses, one of which is diuretic, is increasingly recognized as an important problem of public health. Large population studies with office measurements suggest that the prevalence of resistance hypertension is approximately at 6-12 % of the general hypertensive population and 8-28 % of treated hypertensives. However, these estimations do not take into account factors of pseudo-resistance, most importantly, the white-coat effect that can be effectively ruled out with ambulatory blood pressure monitoring (ABPM). Recent studies have clearly shown that when ABPM is used, at least 30-35 % of patients labeled as "resistant hypertensives" turn out to have well-controlled BP on ambulatory basis, a finding changing entirely the estimates of prevalence of resistance hypertension and actual patient handling. Furthermore, current evidence suggests that ABPM is a much more accurate predictor of cardiovascular events in resistant hypertension compared to office BP and thus can offer a better risk stratification for these high-risk individuals. Finally, ABPM offers the potential of a better evaluation of the effect of pharmacologic and non-pharmacologic therapeutic interventions. This review attempts to summarize recent evidence on the advantages of ABPM in the diagnosis, prognosis, and management of resistant hypertension.

Is home blood pressure monitoring useful in the management of patients with resistant hypertension?

BACKGROUND

Ambulatory blood pressure (BP) monitoring (ABPM) is a cornerstone in resistant hypertension (RHT) management. However, it has higher cost and lower patients' acceptance than home BP monitoring (HBPM). Our objective was to evaluate HBPM usefulness in the management of patients with RHT.

METHODS

A total of 240 patients were submitted to 24-hour ABPM and 5-day HBPM (triplicate morning and evening measurements). Patients with uncontrolled office BP (≥140/90mm Hg) were classified as true RHT (daytime or home BP ≥135/85mm Hg) or white-coat RHT (daytime or home BP <135/85mm Hg), and patients with controlled office BP were classified as masked RHT (daytime or home BP ≥135/85mm Hg) or controlled RHT (daytime or home BP <135/85mm Hg). Sensitivity, specificity, predictive values, and likelihood ratios for HBPM were calculated. Agreement between the procedures was evaluated using kappa coefficients and the Bland-Altman method.

RESULTS

Mean office BP was 157±26/84±16mm Hg, mean daytime BP was 134±18/77±13mm Hg, and mean home BP was 143±20/76±14mm Hg. The ABPM and HBPM diagnoses were 35% and 48%, respectively, for true RHT; 36% and 23%, respectively, for white-coat RHT; 7% and 17%, respectively, for masked RHT; and 22% and 13%, respectively, for controlled RHT. HBPM overestimated systolic BP by 8.8 (95% confidence interval (CI) = 6.8-10.7) mm Hg and diastolic BP by 0.2 (95% CI = -1.0 to 1.4) mm Hg. The specificity, sensitivity, and positive and negative predictive values of HBPM in detecting controlled ambulatory BP were 91%, 55%, 89%, and 59%.

CONCLUSIONS

HBPM presented good agreement with ABPM and can be used as a complementary method in the follow-up of resistant hypertensive patients, particularly in those with controlled ambulatory BPs.

[Therapy-resistant hypertension]

BACKGROUND

Therapy-resistant hypertension is commonly encountered in daily practice. It is present when the therapeutic goal is not achieved after trying at least three antihypertensives from different groups with adequate doses and including a diuretic. Between 10 and 20% of patients are affected and their prognosis is poor. Thus, intensive strategies are required to achieve normotension.

DIAGNOSIS

An exact diagnosis is essential. Pseudoresistance needs to be excluded in addition to secondary hypertension and sleep apnea syndrome. The most common cause of pseudoresistance is incorrect blood pressure measurement, false estimation of the real blood pressure level, lack of compliance, unhealthy lifestyle, and drug interactions. Therapeutic resistance should not be diagnosed without 24 h ambulatory blood pressure measurement. This significantly reduces the total number of "resistant" patients.

THERAPY

Successful control of blood pressure is achieved in the majority of patients by taking advantage of all possible therapy options. Treatment with 4-6 antihypertensive drugs is justified because of the improvement of cardiovascular prognosis. However, prerequisite is the absence of undesirable side effects which is the most important condition for adequate and reliable patient compliance. Only in the case of failure of the above therapy options can invasive procedures--renal denervation and baroreflex activation therapy--be applied as they are still experimental. Successful management of patients with resistant hypertension is only possible with intensive and time-consuming physician-patient relationships.

Prevalence and associated factors of obstructive sleep apnea in patients with resistant hypertension

BACKGROUND

Obstructive sleep apnea (OSA) syndromes are strongly associated with resistant hypertension, although this has not been systematically examined. The aim of our study was to investigate the prevalence of OSA and its associated factors in a large cohort of resistant hypertensive patients.

METHODS

A cross-sectional analysis with 422 resistant hypertensive patients (31.3% men; mean age = 62.4±9.9 years) submitted to a full-night polysomnography. The presence of OSA was defined by an apnea-hypopnea index (AHI) >5 per hour and moderate/severe OSA was defined by an AHI >15. Statistical analysis included bivariable comparisons between patients with and without moderate/severe OSA and logistic regressions to assess the independent correlates of OSA severity.

RESULTS

Three-hundred forty-seven patients (82.2%) had OSA, and 234 patients (55.5%) had moderate/severe OSA. Patients with moderate/severe OSA were more frequently elderly and obese men with larger waist and neck circumferences, had higher prevalences of diabetes and left ventricular hypertrophy, and had higher proteinuria than patients with no/mild OSA. No difference was found in plasma aldosterone and renin activity. Nighttime systolic blood pressures and pulse pressures were higher in moderate/severe OSA, with lower nocturnal blood pressure fall. In multivariable logistic regression, male sex, older age, diabetes, obesity, increased waist and neck circumferences, and nighttime systolic blood pressure were the independent correlates of moderate/severe OSA.

CONCLUSIONS

Resistant hypertensive patients had a very high prevalence of OSA, and patients with moderate/severe OSA had an adverse ambulatory BP profile, with higher nighttime systolic blood pressures and pulse pressures and higher prevalence of nondipping patterns. Other correlates of OSA severity were mainly demographic-anthropometric variables.

Resistant hypertension: patient characteristics, risk factors, co-morbidities and outcomes

Among the vast population of hypertensive subjects, between 10 and 15% do not achieve an adequate blood pressure (BP) control despite the use of at least three antihypertensive agents. This group, designated as having resistant hypertension (RH), represents one of the most important clinical challenges in hypertension evaluation and management. Resistant hypertensives are characterized by several clinical particularities, such as a longer history of hypertension, obesity and other accompanying factors, such as diabetes, left ventricular hypertrophy, albuminuria and renal dysfunction. In addition to other diagnostic and therapeutic maneuvers, such as excluding secondary hypertension, ensuring treatment adherence and optimizing therapeutic schemes, ambulatory BP monitoring (ABPM) is crucial in the clinical evaluation of patients with RH. ABPM distinguish between those with out-of-office BP elevation (true resistant hypertensives) and those having white-coat RH (WCRH; normalcy of 24-h BPs), the prevalence of the latter estimated in about one-third of the population with RH. True resistant hypertensives also exhibit more frequently other co-morbidities, more severe target organ damage and a worse cardiovascular prognosis, in comparison to those with WCRH. Some device-based therapies have recently been developed for treatment of RH. This requires a better characterization of a potential candidate population. A better knowledge of the clinical features of resistant hypertensive subjects, the confirmation of elevated BP values out of the doctor's office, and improvements in the search for secondary causes would help to select those candidates for newer therapies, once the pharmacological possibilities have been exhausted.