Wednesday, January 15, 2014

Hypertension guidelines

In 2003 the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure published its seventh guideline on hypertension (JNC7). The committee had published guidelines on hypertension every four or five years since the seventies. The eighth guideline (JNC8), however, was long delayed.
In June 2013 the ESH/ESC (European Society of Hypertension/European Society of Cardiology) published its guideline on hypertension. In Dec 2013 ASH/ISH (American Society of Hypertension/International Society of Hypertension) published a guideline on hypertension. One day after, members of the Joint National Committee published their long delayed JNC8.
Now we also learn that ASH/AHA/ACC (American society of hypertension/American Heart Association/American College of Cardiology) intend to publish a guideline on hypertension during 2014.
This plethora of guidelines appearing within a short period of time may produce some confusion for the practicing doctor as the various documents agree on points and differ on others.

Agreements and differences:
Some of the main points of agreement and difference are:
  1. JNC7 classified blood pressure into: prehypertension, stage 1 and stage 2 hypertension. The new ESH/ECC guideline was more elaborate and classified blood pressure into optimal, normal, grade 1, grade 2 and grade 3 hypertension. JNC8 and the ASH/ISH guidelines did not address the issue.
  2. JNC8 guideline increased the treatment threshold (level at which to treat) and treatment target (level you aim at) of blood pressure in adults over 60y of age to 150/90. The other guidelines kept it at 140/90.
  3. JNC7 advised a threshold and target of 130/80 for people with diabetes and people with CKD (Chronic Kidney Disease). All new guidelines advised the same figure of 140/90 for these patients as it is for other patients (except in certain specified situations).
  4. JNC7 ­­­advised initiation of treatment with a thiazide like diuretic except when there is a compelling reason to choose a drug from one of the other three groups of drugs, namely: ACEI (Angiotensin Converting Enzyme Inhibitors) or ARB (Angiotensin Receptor Blockers), CCB (Calcium Channel Blockers) and Beta Blockers. The new ESH/ESC accepted any of the four groups to start treatment with. JNC8 dropped Beta Blockers from the list and advised to choose any drug from the other three groups. The ASH/ISH advised to start with ACEI or ARB.
  5. All new guidelines advised ACEI or ARB in patients with diabetes or CKD.
  6. All new guidelines advised against combining ACEI and ARB (because of increased possibility of side effects of these drugs).

So, what will a practicing physician treating a specific patient do in the face of different advices?

He has to remember that guidelines are based on studies done on large number of patients with various characteristics in different countries. They depend on averages of these various characteristics and averages of results. They are not talking specifically about your patient and they cannot include in their calculations all his variables. They are a great help in throwing light on the general picture but do not make decisions for the doctor. What you exactly do with each patient in his specific circumstances will ultimately depend on your clinical judgement assisted by these guidelines.