Targeted lowering of central blood pressure in patients with hypertension: a randomised controlled trial

Effect on left ventricular mass with targeted lowering of central blood pressure using spironolactone in patients with hypertension: a randomised controlled trial

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12613000053729

Acronym

The LOWCBP Study

Enrollment

307

Registered

2013-01-16

Start date

2013-02-25

Completion date

2016-03-11

Last updated

2020-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

High blood pressure (BP) is the most common modifiable cause of death from cardiovascular disease (CVD). Lowering BP with medication improves patient outcomes, but even in populations with normal upper arm (brachial) BP there remains considerable residual risk for CVD. Our recent pilot work found that much of this risk may be due to persistently elevated central BP. However, there has never been a trial to determine the clinical value of targeted central BP lowering. This remains the most significant question to be answered before central BP can be considered for routine clinical use, and is the aim of this project. The proposed study will be a multi-centre, prospective, randomized, open-label, blinded endpoint (PROBE) trial over two years in 300 patients treated for hypertension who have controlled brachial BP but relatively high central BP. Randomisation to spironolactone (and lowering of central BP) is expected to significantly improve CVD risk, despite no significant change in clinic measured brachial BP.

Interventions

Oral spironolactone, 25 mg/d, over 2 years

Study design

Allocation

Randomised controlled trial

Intervention model

Parallel

Primary purpose

Treatment

Masking

Blinded (masking used) (Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

All

Age

18 Years to 70 Years

Healthy volunteers

Inclusion criteria

*Aged 18 – 70 years on stable antihypertensive therapy (at least one month). *Taking at least one, but no more than three, antihypertensive drugs to lower BP (rationale for no more than 3 drugs is that this will rule out cases of complicated or resistant hypertension which may require special attention beyond this study protocol). *Seated brachial BP <140/90 mmHg (controlled brachial BP). *Seated central SBP greater than or equal to +0.5SD of age- and gender-specific normal values (uncontrolled central BP).

Exclusion criteria

*Seated brachial BP greater than or equal to 140/90 mmHg (uncontrolled brachial BP) *Seated brachial BP <140/90 mmHg but central SBP below +0.5SD of age- and gender-specific normal values *Women who are pregnant, breastfeeding or of child bearing age with intending pregnancy. *Concomitant therapy with both ACEi and ARB (due to risk of hyperkalaemia). *Therapy with digoxin or lithium or nondepolarizing skeletal muscle relaxants (e.g. Tubocurarine). *A clinical history of CVD which may affect estimation of central BP or complicate therapeutic decisions. This includes; established coronary artery disease, coronary artery bypass graft surgery, aortic valve stenosis (gradient >20 mmHg), systolic heart failure or ejection fraction <50% or other serious cardiovascular event within 6 months of enrolment. *Chronic use of sex hormone therapy or non-steroidal anti-inflammatory drugs *Using any aldosterone inhibitor (eplereone, spironolactone) within 30 days of enrolment. *Contraindication to spironolactone including; anuria, acute renal insufficiency, significant impairment of renal excretory function (creatinine clearance less than or equal to 50 mL/min [Cockcroft-Gault formula]) or hyperkalemia (plasma potassium >5.0 mmol/l at initiation). *Using potassium supplements or potassium-sparing diuretics (e.g. amiloride or triamterene).

Outcome results