blood pressure

Importance: Hypertension, defined as office systolic blood pressure (SBP) 130 mm Hg or greater and/or diastolic blood pressure 80 mm Hg or greater, affects 43.9% of women and 49.5% of men in the US. Approximately 19.7% of patients treated for hypertension have apparent resistant hypertension (blood pressure ≥130/80 mm Hg) despite using 3 or more antihypertensive medications, preferably a renin-angiotensin system blocker, a calcium channel blocker, and a thiazide-type diuretic, at maximally tolerated doses.

Observations: Approximately 10% of patients treated for hypertension have true resistant hypertension confirmed with home or 24-hour ambulatory blood pressure monitoring to exclude white-coat hypertension (approximately 37.5% of apparent resistant hypertension) and after excluding medication nonadherence (approximately 50%) and secondary hypertension such as primary aldosteronism (approximately 5%-25%). Conditions associated with resistant hypertension include obesity, diabetes, chronic kidney disease, and sleep apnea. Resistant hypertension is associated with increased risk of cardiovascular death vs controlled blood pressure at 5 years to 10 years (absolute risk increase, 10.3% [95% CI, 8.7%-12.1%]). Lifestyle modifications for resistant hypertension include a low-sodium diet (<1500 mg/d), reducing or avoiding alcohol, 150 min/wk or more of aerobic exercise, and weight loss. Illicit drugs (eg, cocaine) and medications that increase blood pressure (eg, nonsteroid anti-inflammatory drugs, serotonin-norepinephrine reuptake inhibitors) should be avoided. Sleep apnea should be treated when diagnosis is confirmed. Pharmacologic optimization includes use of combination tablets of antihypertensives; intensifying diuretic therapy by using chlorthalidone; and sequential addition of antihypertensive medications using evidence-based algorithms. In a meta-analysis of 20 studies (9 randomized clinical trials [RCTs] and 11 observational studies [331 participants]), use of antihypertensive therapies that combine 2 to 3 medications into a single formulation reduced SBP by -3.99 mm Hg (95% CI, -7.92 to -0.07) vs equivalent doses given separately. For patients with apparent or true resistant hypertension who have an estimated glomerular filtration rate of 45 mL/min/1.73 m2 or greater and a serum potassium level of 4.5 mmol/L or less, adding spironolactone (25-50 mg/d) compared with placebo lowers office SBP by -13.3 mm Hg (95% CI, -17.89 to -8.72 [4 RCTs]) and 24-hour ambulatory SBP by -8.46 mm Hg (95% CI, -12.54 to -4.38 [2 RCTs]) in a network meta-analysis of 24 RCTs (3485 patients with resistant hypertension). A meta-analysis of 10 RCTs (2478 participants) reported that compared with a sham procedure, catheter-based renal denervation, which disrupts the sympathetic nerves in the renal artery walls, decreased 24-hour ambulatory SBP by -4.4 mm Hg (95% CI, -6.1 to -2.7) and office SBP by -6.6 mm Hg (95% CI, -9.7 to -3.6).

Conclusions and relevance: True resistant hypertension affects 10% of patients treated for hypertension and is diagnosed after excluding white-coat hypertension, medication nonadherence, and secondary hypertension such as primary aldosteronism. First-line treatment includes lifestyle modifications, diuretic therapy with chlorthalidone, and combination tablets of antihypertensives. Spironolactone and renal denervation decrease blood pressure in patients with true resistant hypertension.

Importance: Guidelines for blood pressure (BP) measurement recommend arm support on a desk with the midcuff positioned at heart level. Still, nonstandard positions are used in clinical practice (eg, with arm resting on the lap or unsupported on the side).

Objective: To determine the effect of different arm positions on BP readings.

Design, setting, and participants: This crossover randomized clinical trial recruited adults between the ages of 18 and 80 years in Baltimore, Maryland, from August 9, 2022, to June 1, 2023.

Intervention: Participants were randomly assigned to sets of triplicate BP measurements with the arm positioned in 3 ways: (1) supported on a desk (desk 1; reference), (2) hand supported on lap (lap), and (3) arm unsupported at the side (side). To account for intrinsic BP variability, all participants underwent a fourth set of BP measurements with the arm supported on a desk (desk 2).

Main outcomes and measures: The primary outcomes were the difference in differences in mean systolic BP (SBP) and diastolic BP (DBP) between the reference BP (desk 1) and the 2 arm support positions (lap and side): (lap or side - desk 1) - (desk 2 - desk 1). Results were also stratified by hypertensive status, age, obesity status, and access to health care within the past year.

Results: The trial enrolled 133 participants (mean [SD] age, 57 [17] years; 70 [53%] female); 48 participants (36%) had SBP of 130 mm Hg or higher, and 55 participants (41%) had a body mass index (calculated as weight in kilograms divided by height in meters squared) of 30 or higher. Lap and side positions resulted in statistically significant higher BP readings than desk positions, with the difference in differences as follows: lap, SBP Δ 3.9 (95% CI, 2.5-5.2) mm Hg and DBP Δ 4.0 (95% CI, 3.1-5.0) mm Hg; and side, SBP Δ 6.5 (95% CI, 5.1-7.9) mm Hg and DBP Δ 4.4 (95% CI, 3.4-5.4) mm Hg. The patterns were generally consistent across subgroups.

Conclusion and relevance: This crossover randomized clinical trial showed that commonly used arm positions (lap or side) resulted in substantial overestimation of BP readings and may lead to misdiagnosis and overestimation of hypertension.

Objectives The Salt Substitute and Stroke Study (SSaSS) recently reported blood pressure-mediated benefits of a potassium-enriched salt substitute on cardiovascular outcomes and death. This study assessed the effects of salt substitutes on a breadth of outcomes to quantify the consistency of the findings and understand the likely generalisability of the SSaSS results.

Methods We searched PubMed, Embase and the Cochrane Library up to 31 August 2021. Parallel group, step-wedge or cluster randomised controlled trials reporting the effect of salt substitute on blood pressure or clinical outcomes were included. Meta-analyses and metaregressions were used to define the consistency of findings across trials, geographies and patient groups.

Results There were 21 trials and 31 949 participants included, with 19 reporting effects on blood pressure and 5 reporting effects on clinical outcomes. Overall reduction of systolic blood pressure (SBP) was −4.61 mm Hg (95% CI −6.07 to −3.14) and of diastolic blood pressure (DBP) was −1.61 mm Hg (95% CI −2.42 to −0.79). Reductions in blood pressure appeared to be consistent across geographical regions and population subgroups defined by age, sex, history of hypertension, body mass index, baseline blood pressure, baseline 24-hour urinary sodium and baseline 24-hour urinary potassium (all p homogeneity >0.05). Metaregression showed that each 10% lower proportion of sodium choloride in the salt substitute was associated with a −1.53 mm Hg (95% CI −3.02 to −0.03, p=0.045) greater reduction in SBP and a −0.95 mm Hg (95% CI −1.78 to −0.12, p=0.025) greater reduction in DBP. There were clear protective effects of salt substitute on total mortality (risk ratio (RR) 0.89, 95% CI 0.85 to 0.94), cardiovascular mortality (RR 0.87, 95% CI 0. 81 to 0.94) and cardiovascular events (RR 0.89, 95% CI 0.85 to 0.94).

Conclusions The beneficial effects of salt substitutes on blood pressure across geographies and populations were consistent. Blood pressure-mediated protective effects on clinical outcomes are likely to be generalisable across population subgroups and to countries worldwide.

Heart failure is a clinically complex syndrome that results due to the failure of the ventricles to function as pump and oxygenate end organs. The repercussions of inadequate perfusion are seen in the form of sympathetic overactivation and third spacing, leading to clinical signs of increased blood pressure, dyspnea, fatigue, palpitations, etc. This article provided a brief overview of the clinical syndrome of heart failure; its epidemiology, risk factors, symptoms, and staging; and the mechanisms involved in disease progression. This article also described several landmark trials in heart failure that tested the efficacy of first-line drugs such as beta-blockers, angiotensin receptor blockers, angiotensin-converting enzyme inhibitors, and the latest drugs in the field of heart failure: angiotensin receptor neprilysin inhibitors. Most studies described in this article were guideline-setting trials that revolutionized the practice of medicine and cardiology.