(+91) 9810131739

Blogs

15July, 2016

Resistant Hypertension: an Approach to Management in Primary Care

By: | Tags:

Hypertension is widely encountered in primary care and is most common condition managed at primary care level.  Hypertension affects 25% in Urban & 10-15% in rural population of India and almost half are poorly controlled.  Rules of Halves are applicable in Indian Society also whereby:-

  • Only ½ have been diagnosed
  • Only ½ of those diagnosed have been treated
  • Only ½ of those treated are adequately controlled
  • Thus only 12.5% overall are adequately controlled.

What is Resistant Hypertension?
It is defined as blood pressure that remains above goal in spite of concurrent use of three antihypertensive agents of different classes. 
(If tolerated, one of the three agents should be a diuretic, and all agents should be prescribed at optimal doses [i.e. 50% or more of the maximum recommended antihypertensive dose]). 

  • The blood pressure goal in uncomplicated patients is 140/90 mm Hg which could be relaxed to 150/90 in patients greater than 60 years of age.  A more appropriate treatment target in patients with end-organ damage is 130/80 mm Hg.

 

  • Although patients with resistant hypertension may have elevations in both systolic and diastolic pressures, isolated systolic hypertension is common.  Treatment of older patients with isolated systolic hypertension that is resistant to therapy may be more difficult since intensification of the therapeutic regimen may lead to unacceptably low diastolic pressures.

Refractory Hypertension
Some patients with resistant hypertension cannot be controlled, even with maximal medical therapy (five or more drugs including chlorthalidone and a mineralocorticoid receptor antagonist) under the care of a hypertension specialist.  Such patients are referred to as having refractory hypertension.
Define whether it is apparent, true, pseudoresistant hypertension – in patients who appear to have resistant hypertension according to the definition presented above, it should be determined whether the hypertension is truly resistant.

Apparent resistant hypertension– Patients with apparent resistant hypertension have uncontrolled clinical blood pressure (i.e. greater than or equal to 140/90 mm Hg) despite being prescribed three or more antihypertensive medications or require prescriptions of four or more drugs to control their blood pressure.  However, such patients may have pseudoresistant hypertension.

Trueresistanthypertension– Patients with true resistant hypertension are those who have uncontrolled clinic blood pressure despite being compliant with an antihypertensive regimen that includes three or more drugs (including a diuretic, and each at optimal doses) and who have uncontrolled blood pressure confirmed by 24-hour ambulatory blood pressure monitoring.

Pseudoresistant hypertension– Pseudoresistance refers to poorly-controlled hypertension that appears resistant to treatment but is actually attributable to other factors. The five most common causes of pseudoresistance are:-

Step in Management of patients with Resistant Hypertension
Step 1:             Define whether it is apparent, true, pseudoresistant hypertension – in patients who appear to have resistant hypertension according to the definition presented above, it should be determined whether the hypertension is truly resistant.

  • Apparent resistant hypertension – Patients with apparent resistant hypertension have uncontrolled clinical blood pressure (i.e. greater than or equal to 140/90 mm Hg) despite being prescribed three or more antihypertensive medications or require prescriptions of four or more drugs to control their blood pressure.  However, such patients may have pseudoresistant hypertension.

 

  • True resistant hypertension – Patients with true resistant hypertension are those who have uncontrolled clinic blood pressure despite being compliant with an antihypertensive regimen that includes three or more drugs (including a diuretic, and each at optimal doses) and who have uncontrolled blood pressure confirmed by 24-hour ambulatory blood pressure monitoring.
  • Pseudoresistant hypertension – Pseudoresistance refers to poorly-controlled hypertension that appears resistant to treatment but is actually attributable to other factors. The five most common causes of pseudoresistance are:-

 

  • Inaccurate measurement of blood pressure
  • Poor adherence to antihypertensive therapy
  • Suboptimal antihypertensive therapy
  • Poor adherence to lifestyle and dietary approaches to lower blood pressure
  • White coat hypertension

White coat Hypertension – It (also called isolated clinic or office hypertension) refers to patients who have office readings that average more than 140/90 mm Hg and reliable out-of-office readings that average less than 140/90 mm Hg.  Having the blood pressure in the office taken by a nurse or technican, rather than the clinician, may minimize the white coat effect.  It is more common among patients with resistant hypertension, with a reported prevalence of 37 to 44%.  Patient with white coat hypertension have less severe target-organ damage and appear to be at less cardiovascular risk compared with those patients with persistent hypertension during ambulatory monitoring.

Step 2:            Identify Risk Factors
Patient characteristics that predict difficult-to-control hypertension include:-

  • Higher baseline blood pressure
  • Presence of left ventricular hypertrophy
  • Older age
  • Obesity
  • Chronic kidney disease and
  • Diabetes

Potentially reversible factors that contribute to resistant hypertension are:-

  • Suboptimal therapy – It is most often due to the lack of administration or more effective drugs and failure to prevent volume expansion with adequate diuretic therapy
  • Lifestyle and diet – Obesity, a high-salt diet, physical inactivity, and heavy alcohol intake all contribute to hypertension, although not all have been examined specifically among patients with resistant hypertension
  • Medications – Identify medications which can raise the blood pressure and in some cases reduce the response to antihypertensive drugs.  Drugs that interfere with blood pressure control are:-

 

  • Non-steroidal anti-inflammatories
  • Oral contraceptives
  • Corticosteroids
  • Tricyclic antidepressants
  • Monoamine oxidase inhibitors
  • Other substance-caffeine, cocaine, alcohol
  • Extracellular volume expansion – Relative or absolute volume expansion is frequently at least partially responsible for an inability to control hypertension.  Underlying renal insufficiency, sodium retention due to therapy with vasodilators, and / or ingestion of a high-salt diet (which can be assessed by measuring sodium excretion in a 24-hour urine collection) all may play a role.

 

  • Secondary cause of hypertension should be ruled out by appropriate investigations:-

Disorder

Suggested investigation

Primary hyperaldosteronism

Plasma aldosterone: Renin ratio

Thyroid disease

Thyroid function tests

Pheochromocytoma

24-hour urinary catecholamine level
Plasma metanephrines

Cushing’s syndrome

Urinary cortisol

Obstructive sleep apnoea

Polysomnography

Renovascular disease

Renal artery duplex scan

Renal parenchymal disease

Renal ultrasound scan

Coarctation of the aorta

Cardiac ultrasound scan

FOR MORE INFORMATION CALL AT
Dr Vinod Sharma
National Heart Institute
49-50, Community Centre,
East Of Kailash,New Delhi - 110065
For appointments: (+91) 9818020014, 9810131739
Email : drvs1994@gmail.com
Website : www.drvinodsharma.in

 

Renowned Heart Surgeon in Delhi
Best Heart Surgeon in Delhi
Best Heart Surgeon in India
Best Bypass Surgeon in Delhi
Best Heart Surgeon In India
Best Heart Hospital India
Best Open Heart Surgeon in Delhi
Best interventional cardiologist in delhi
Best Heart Surgeon in Delhi,/br>