Use of Thiazides to Treat Hypertension and Advanced CKD.

PURPOSE OF REVIEW: Hypertension is often difficult to control in patients with CKD as manifested by suboptimal control rates in this population. Use of thiazides in CKD patients has been limited as these agents are thought to be ineffective in reducing blood pressure in people with advanced CKD. This review summarizes recent studies impacting indications and safety of use of thiazide in patients with CKD and discusses the mechanism of how thiazides reduce blood pressure. RECENT FINDINGS: Chlorthalidone reduces blood pressure compared to placebo in patients with advanced CKD, challenging the belief that thiazide diuretics lose efficacy at lower levels of GFR. Recent clinical trial data indicate that thiazides are effective in patients with advanced kidney disease for blood pressure lowering. However, monitoring of electrolytes and kidney function is important to ensure patient safety when prescribing these agents in patients with CKD.

Modulation of Sympathetic Overactivity to Treat Resistant Hypertension.

PURPOSE OF REVIEW: To review the role and evidence for sympathetic overactivity in resistant hypertension and review the therapies that have been studied to modulate the sympathetic nervous system to treat resistant hypertension, with a focus on non-pharmacologic therapies such as renal denervation, baroreflex activation therapy, and carotid body ablation. RECENT FINDINGS: Based on the two best current techniques available for assessing sympathetic nerve activity, resistant hypertension is characterized by increased sympathetic nerve activity. Several device therapies, including renal denervation baroreflex activation therapy and carotid body ablation, have been developed as non-pharmacologic means of reducing blood pressure in resistant hypertension. With respect to renal denervation, the technologies for renal denervation have evolved since the unfavorable results from the HTN-3 study, and the revised technologies are being actively studied. Data from the first phase of the SPYRAL HTN Clinical Trial Program have been published. Results from the SPYRAL HTN-OFF MED trial suggest that ablating renal nerves can reduce blood pressure in patients with untreated mild-to-moderate hypertension. The SPYRAL HTN-ON MED trial demonstrated the safety and efficacy of catheter-based renal denervation in patients with uncontrolled hypertension on antihypertensive treatment. Interestingly, there was a high rate of medication non-adherence among patients with hypertension in this study. One attractive alternative to radiofrequency ablation is the use of ultrasound for renal denervation. Proof of concept data for the Paradise endovascular ultrasound renal denervation system was recently published in the RADIANCE-HTN SOLO trial. The results of this trial indicate that, among patients with mild to moderate hypertension on no medications, renal denervation with the Paradise system results in a greater reduction in both SBP and DBP at 2months compared with a sham procedure. Overall reductions were similar in magnitude to those noted in the SPYRAL HTN-OFF MED study. With respect to carotid body ablation, there is an ongoing proof of concept study that is investigating the safety and feasibility of ultrasound-based endovascular carotid body ablation in 30 subjects with treatment-resistant hypertension outside of the USA. The sympathetic nervous system is an important contributor to resistant hypertension. Modulation of sympathetic overactivity should be an important goal of treatment. Innovative therapies using non-pharmacologic means to suppress the sympathetic nervous system are actively being studied to treat resistant hypertension.

Implementing ABPM into Clinical Practice.

PURPOSE OF REVIEW: To review the data supporting the use of ambulatory blood pressure monitoring (ABPM), and to provide practical guidance for practitioners who are establishing an ambulatory monitoring service. RECENT FINDINGS: ABPM results more accurately reflect the risk of cardiovascular events than do office measurements of blood pressure. Moreover, many patients with high blood pressure in the office have normal blood pressure on ABPM-a pattern known as white coat hypertension-and have a prognosis similar to individuals who are normotensive in both settings. For these reasons, ABPM is recommended by the US Preventive Services Task Force to confirm the diagnosis of hypertension in patients with high office blood pressure before medical therapy is initiated. Similarly, the 2017 ACC/AHA High Blood Pressure Clinical Practice Guideline advocates the use of out-of-office blood pressure measurements to confirm hypertension and evaluate the efficacy of blood pressure-lowering medications. In addition to white coat hypertension, blood pressure phenotypes that are associated with increased cardiovascular risk and that can be recognized by ABPM include masked hypertension-characterized by normal office blood pressure but high values on ABPM-and high nocturnal blood pressure. In this review, best practices for starting a clinical ABPM service, performing an ABPM monitoring session, and interpreting and reporting ABPM data are described. ABPM is a valuable adjunct to careful office blood pressure measurement in diagnosing hypertension and in guiding antihypertensive therapy. Following recommended best practices can facilitate implementation of ABPM into clinical practice.

The utility of home blood pressure load in predicting average self-measured blood pressure.

OBJECTIVES: Average values for self-measured blood pressure (SMBP) more accurately reflect a patient's risk of cardiovascular disease than do office measurements. Oftentimes, however, patients provide lists of individual home blood pressure (BP) measurements, and average values cannot be computed within the time constraints of a clinic visit. In contrast, the home BP load - defined as the proportion of BP values greater than a partition value (e.g., 130 mmHg) - can be easily calculated. We examined the utility of the BP load in predicting the mean SMBP and confirming elevated SMBP. METHODS: Four hundred twenty untreated adults at least 30 years of age acquired SMBP data twice in the morning and twice in the evening over 10 days. The 'true' SMBP was defined as the mean of these 40 determinations. RESULTS: Using all 10 days of BP data and a systolic BP threshold of 130 mmHg, the average SMBP associated with a home BP load of 0.50 was 130 mmHg, with a 95% prediction interval of 126-133 mmHg. True systolic SMBP was approximately 6 mmHg lower and higher at home BP loads of 0.25 and 0.75, respectively. There was a 90% probability that the true systolic SMBP was greater than 130 mmHg if the systolic home BP load was at least 0.60. Corresponding values for 3 days and 1 day of SMBP were at least 0.68 and at least 0.84, respectively. CONCLUSION: Our analysis demonstrates that the home BP load can be used to estimate the average BP acquired on home monitoring and confirm elevated SMBP.

Comparison of patients' confidence in office, ambulatory, and home blood pressure measurements as methods of assessing for hypertension.

OBJECTIVE: Uncertainty exists when relying on office (clinic) blood pressure (BP) measurements to diagnose hypertension. Home BP monitoring and ambulatory BP monitoring (ABPM) provide measurements that are more strongly associated with cardiovascular disease. The degree to which patients exhibit uncertainty about office BP measurements is unknown, as is whether they would have less uncertainty about other BP measurement methods. We therefore assessed people's confidence in methods of BP measurement, comparing perceptions about office BP monitoring, home BP monitoring, and ABPM techniques. METHODS: We surveyed adults who were 30 years or older (n=193), all whom had undergone office BP measurements, two sessions of 24-h ABPM, and two 5-day periods of home BP monitoring. Respondents were asked to indicate their level of confidence on a 1 to 9 scale that BP measurements represented their 'usual' BP. RESULTS: Respondents had least confidence that assessments of BP made by office measurements (median 6) represented usual BP and greater confidence that assessments made by home BP monitoring (median 7, P<0.0001 vs. office) and ABPM (median 8, P<0.0001 vs. office) did so. Confidence levels did not vary significantly by BP levels, age, sex, race, or education level. CONCLUSION: The finding that patients do not have a great deal of confidence in office BP measurements, but have a higher degree of confidence in home BP and ambulatory BP assessment methods may be helpful in guiding strategies to diagnose hypertension and improve antihypertensive medication adherence.