Adherence to Antihypertensive Treatment and the Blood Pressure–Lowering Effects of Renal Denervation in the Renal Denervation for Hypertension (DENERHTN) Trial

Background:

The DENERHTN trial (Renal Denervation for Hypertension) confirmed the blood pressure–lowering efficacy of renal denervation added to a standardized stepped-care antihypertensive treatment for resistant hypertension at 6 months. We report the influence of adherence to antihypertensive treatment on blood pressure control.

Methods:

One hundred six patients with hypertension resistant to 4 weeks of treatment with indapamide 1.5 mg/d, ramipril 10 mg/d (or irbesartan 300 mg/d), and amlodipine 10 mg/d were randomly assigned to renal denervation plus standardized stepped-care antihypertensive treatment, or the same antihypertensive treatment alone. For standardized stepped-care antihypertensive treatment, spironolactone 25 mg/d, bisoprolol 10 mg/d, prazosin 5 mg/d, and rilmenidine 1 mg/d were sequentially added at monthly visits if home blood pressure was ≥135/85 mm Hg after randomization. We assessed adherence to antihypertensive treatment at 6 months by drug screening in urine/plasma samples from 85 patients.

Results:

The numbers of fully adherent (20/40 versus 21/45), partially nonadherent (13/40 versus 20/45), or completely nonadherent patients (7/40 versus 4/45) to antihypertensive treatment were not different in the renal denervation and the control groups, respectively ( P =0.3605). The difference in the change in daytime ambulatory systolic blood pressure from baseline to 6 months between the 2 groups was –6.7 mm Hg ( P =0.0461) in fully adherent and –7.8 mm Hg ( P =0.0996) in nonadherent (partially nonadherent plus completely nonadherent) patients. The between-patient variability of daytime ambulatory systolic blood pressure was greater for nonadherent than for fully adherent patients.

Conclusions:

In the DENERHTN trial, the prevalence of nonadherence to antihypertensive drugs at 6 months was high (≈50%) but not different in the renal denervation and control groups. Regardless of adherence to treatment, renal denervation plus standardized stepped-care antihypertensive treatment resulted in a greater decrease in blood pressure than standardized stepped-care antihypertensive treatment alone.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01570777.

Optimum and stepped care standardised antihypertensive treatment with or without renal denervation for resistant hypertension (DENERHTN): a multicentre, open-label, randomised controlled trial

BACKGROUND

Conflicting blood pressure-lowering effects of catheter-based renal artery denervation have been reported in patients with resistant hypertension. We compared the ambulatory blood pressure-lowering efficacy and safety of radiofrequency-based renal denervation added to a standardised stepped-care antihypertensive treatment (SSAHT) with the same SSAHT alone in patients with resistant hypertension.

METHODS

The Renal Denervation for Hypertension (DENERHTN) trial was a prospective, open-label randomised controlled trial with blinded endpoint evaluation in patients with resistant hypertension, done in 15 French tertiary care centres specialised in hypertension management. Eligible patients aged 18-75 years received indapamide 1·5 mg, ramipril 10 mg (or irbesartan 300 mg), and amlodipine 10 mg daily for 4 weeks to confirm treatment resistance by ambulatory blood pressure monitoring before randomisation. Patients were then randomly assigned (1:1) to receive either renal denervation plus an SSAHT regimen (renal denervation group) or the same SSAHT alone (control group). The randomisation sequence was generated by computer, and stratified by centres. For SSAHT, after randomisation, spironolactone 25 mg per day, bisoprolol 10 mg per day, prazosin 5 mg per day, and rilmenidine 1 mg per day were sequentially added from months two to five in both groups if home blood pressure was more than or equal to 135/85 mm Hg. The primary endpoint was the mean change in daytime systolic blood pressure from baseline to 6 months as assessed by ambulatory blood pressure monitoring. The primary endpoint was analysed blindly. The safety outcomes were the incidence of acute adverse events of the renal denervation procedure and the change in estimated glomerular filtration rate from baseline to 6 months. This trial is registered with ClinicalTrials.gov, number NCT01570777.

FINDINGS

Between May 22, 2012, and Oct 14, 2013, 1416 patients were screened for eligibility, 106 of those were randomly assigned to treatment (53 patients in each group, intention-to-treat population) and 101 analysed because of patients with missing endpoints (48 in the renal denervation group, 53 in the control group, modified intention-to-treat population). The mean change in daytime ambulatory systolic blood pressure at 6 months was -15·8 mm Hg (95% CI -19·7 to -11·9) in the renal denervation group and -9·9 mm Hg (-13·6 to -6·2) in the group receiving SSAHT alone, a baseline-adjusted difference of -5·9 mm Hg (-11·3 to -0·5; p=0·0329). The number of antihypertensive drugs and drug-adherence at 6 months were similar between the two groups. Three minor renal denervation-related adverse events were noted (lumbar pain in two patients and mild groin haematoma in one patient). A mild and similar decrease in estimated glomerular filtration rate from baseline to 6 months was observed in both groups.

INTERPRETATION

In patients with well defined resistant hypertension, renal denervation plus an SSAHT decreases ambulatory blood pressure more than the same SSAHT alone at 6 months. This additional blood pressure lowering effect may contribute to a reduction in cardiovascular morbidity if maintained in the long term after renal denervation.

FUNDING

French Ministry of Health.

Impact of miscuffing during home blood pressure measurement on the prevalence of masked hypertension

BACKGROUND

Masked hypertension has been associated with obesity. However, because most studies do not mention the specific cuff size used for home measurements, masked hypertension prevalence may have been overestimated in obese patients because of undersized cuffs. In this prospective, observational study, the effect of miscuffing on hypertension status was evaluated in patients with large arms.

METHODS

Fifty-three patients with an upper-arm circumference >33cm, undergoing treatment for mild-to-moderate hypertension, took 2 sets of home blood pressure (BP) measurements (standard vs. large cuff) using the validated Microlife BP A100 Plus automated device.

RESULTS

Mean BP was 143/85mm Hg at the office using a large cuff, 141/84mm Hg at home using a standard cuff, and 134/80mm Hg at home using a large cuff. Standard vs. large cuff home BP mean differences were 6.9mm Hg (95% confidence interval (CI) = 4.7-9.2; P < 0.0001) for systolic BP and 4.0mm Hg (95% CI = 2.4-5.5; P < 0.0001) for diastolic BP. Hypertension status differed significantly between standard vs. large cuffs: sustained hypertension (56.6% vs. 41.5%, respectively; P = 0.002), controlled hypertension (20.8% vs. 28.3%, respectively; P = 0.04), white coat hypertension (7.5% vs. 22.6%, respectively; P = 0.002), masked hypertension (15.1% vs. 7.5%, respectively; P = 0.04).

CONCLUSIONS

In patients with large arms, use of an appropriately sized large cuff for home BP measurements led to a 2-fold reduction in masked hypertension. Regarding clinical and epidemiological implications, future studies investigating masked hypertension should specify cuff size for home BP measurements. The low market availability and increased cost of large cuffs should also be addressed.

[Assessement of home blood pressure with a monitor including MAM technology: comparison with the standard monitor]

OBJECTIVES

To compare two periods of three days of home blood pressure monitoring (HBPM) using two different monitors with one including MAM (microlife average mode) technology.

METHODS

In 152 hypertensive subjects referred to hypertension specialists, a self-measurement of blood pressure was performed sequentially with an Omron M6 (arm cuff, A/A, BHS validation) or Microlife BP-3AC1 with the MAM technology. Each patient recorded home blood pressure during two periods of 3 days with 3 measures in the morning and 3 in the evening. Order for use of each monitor was randomised. BP values were reported on a standardized document.

RESULTS

In this population, aged 60 +/- 14 years, with 57% of men and a mean blood pressure of 150 +/- 21/84 +/- 21 mmHg, the home blood pressure values were 141.5 +/- 18.7/79.9 +/- 9.6 mmHg with the OMRON monitor and 138.2 +/- 17.1/79.9 +/- 10.1 mmHg with the Microlife monitor. Values between the two monitors differed about 5 mmHg for the mean SBP and about 2.8 mmHg for the mean DBP. The mean HBPM values does not differ between the two methods for more than 2.5 mmHg, 5 mmHg, 10 mmHg and 15 mmHg in 29%, 49%, 80% and 90% for SBP and in 42%, 76%, 94% and 98% for DBP respectively.

CONCLUSIONS

For most of patients, mean SBP/DBP obtained with home blood pressure Measurement during three days are comparable when using monitor operated with MAM technology or not.

[Systolic blood pressures are not comparable when home blood pressure is measured with a wrist or an arm validated monitor]

OBJECTIVES

To compare home blood pressure values obtained with two validated OMRON (wrist or arm) monitors used sequentially in the same subject.

METHODS

In 265 hypertensive subjects referred to hypertension specialists, a self measurement of blood pressure was performed sequentially with an OMRON M4-I (arm cuff, A/A, BHS validation) or OMRON RX-I (wrist cuff, B/B, BHS validation). Each patient recorded home blood pressure during two periods of 4 days with 3 measures in the morning and 3 in the evening. Order for use of each monitor was randomised. With wrist devices, subjects were advised to keep the arm at heart level during measurements. BP values were reported on a standardized document. Patients were asked by a questionnaire about the tolerance and feasibility of the 2 methods.

RESULTS

In this population, aged 59 +/- 14 years, with 60% of men and a mean blood pressure of 152 +/- 21 / 86 +/- 14 mmHg, the home blood pressure values were 143 +/- 20/81 +/- 11 mmHg with the arm monitor and 135 +/- 10 / 80 +/- 11 mmHg with the wrist monitor. Mean SBP adjusted on age, initial blood pressure level and period order was significantly lower when home blood pressure monitoring has been recorded with a wrist monitor as compared to an arm monitor (p < 0.001). Self measurement of blood pressure was felt as easy in 92% with the arm monitor and in 96% with the wrist monitor (p < 0.05). Self measurement of blood pressure was felt as constraining in 14% with the arm monitor and in 7% with the wrist monitor (p < 0.01). The feasibility between the two devices was good with none of the value missing in 86% with the arm monitor and in 85% with the wrist monitor. The missing values were in 56% the fourth day.

CONCLUSION

Despite the use of two validated monitors, mean SBP is significantly lower when home blood pressure monitoring is recorded with a wrist monitor as compared to an arm monitor. Uncertainty in the arm position with the use of wrist device could explain these results. When advising home blood pressure monitoring, care should be taken to recommend only the use of validated devices and to prefer the use of arm devices in order to avoid the uncertainty of an inadequate utilisation.