Thursday, September 07, 2006

Target BP in managing hypertension

I wrote earlier that the lower your BP, the longer the life, as long as the low BP does not cause undue lethargy or dizziness. We, as well as the writers of clinical guidelines, have argued long and wide about what is normal BP. The latest guidelines included a category of pre-hypertension. Of course we all know that in diabetes, the BP has to be 10 mmHg lower then the usual non-diabetic BP. In non-diabetics, we were told that a BP of 140/90mmHg is fine.

Is it? The August 15th issue of the Journal of the American College of Cardiology (the white journal), carried a study called the CAMELOT study (Comparison of Amlodipine Vs Enalapril to Limit Occurence of Thrombosis study). This study compared the effectiveness of Norvasc, against Renitec and placebo, in patients with CAD, thereby justifying the need for IVUS. The primary endpoints were the usual MACCE. There was an IVUS arm, as is the custom nowadays, reported as a sub-study. This study again showed that Norvasc was more effective than Renitec and placebo in preventing MACCE events. It does look like norvasc is a very good anti-hypertensive, being more effective than Renitec and equivalent to Valsartan (the VALUE study).

What is even more interesting is in the IVUS sub-study. This arm stdied the IVUS finding of atheroma volume in three subgroups, namely Gp1 : BP 120/80 mmHg or less, Gp 2 BP systolic 120-139 mmHg and diastolic 80-89 mmHg, and Gp 3 BP 140/90 mmHg. Guess which group had atheroma plaque regression after 24 months of treatment. Gp3 had some plaque progression, Gp2 had almost no change in plaque volume (plaque stable - less MACCE) and of course in Gp1 there was plaque regression and less MACCE. This must surely lend weight to the arguement that many of us hold, that the lower the BP in patients with CAD, the less MACCE (longer life) and now we know, less plaque progression, and in fact plaque regression.

We now know two ways to regress your plaque, namely "statins "and normalisation of BP in patients with hypertension and CAD. Our understanding of hypertension is changing all the time, and I am sure that I will be writing more about hypertension in the near future.

1 comment:

Queen Of The House said...

Dr NSC ... I am interested to know more about the prehypertension category, which I assume is what I have with my BP of 130/90 (?) I suppose my BP has been at this level for quite some time. I have been told to practise a healthy diet and for now I do not need any medication. I have read though that it could be beneficial for prehypertensive people to take medication to prevent it developing into full-blown hbp. I would love to get some opinion. I am female, 43, not fat (about 54kg)but very much lacking in exercise.