Globally, the main goal of treating hypertension is to lower blood pressure. If the patient has a lesion of the target organs, or concomitant diseases, then the class of drugs is important.

As many outcomes as classes... If the goal is only to lower blood pressure, then simple agents are OK, not forgetting their secondary effects (if any) that could disturb patient life. Of course, if there is a cardiac hypertrophy or if you patient suffers from diabetes, then your choice has to be smarter, taking into account additional constraints. Don't also forget that some agents are more "neutral" or "clever" than other ; if you put a beta-blocker to work, it will do something whatever is the pressure, if you choose some calcium channel modulator, most will act only if the pressure is too elevated. 

Reduction of blood pressure by any drug is associated with reduction of stroke and heart failure. Choice of antihypertensive agents depends upon associated Co morbidity. Majority of benefits of antihypertensive drugs are because of simple reduction of blood pressure .Meta-analysis of antihypertensive trials showed that beta blocker after MI with hypertension has got some extra benefit. Similarly calcium channel blockers probably have got some extra role in preventing stroke. Telmesartan and perindropril probably have some pleotrophic benefit. Nevibolol has got some protective action against Endothelial dysfunction.. Thanks  

http://www.bmj.com/content/338/bmj.b1665

https://www.ncbi.nlm.nih.gov/pubmed/18402537

I agree with Biswajit answer. Keeping the pressure low is associated with extra benefit. However not all products in all class are equal in terms of benefits or secondary effects. In the beta blocker class not every product provide the same protection and despite the fact that some studies exhibit benefits in the past, it is clearly nowaday difficult to advocate because of secondary consequences. And doubtful protections some times. Let's be critic.... It is the same for calcium channel modulators. It depends what you could use in your country. The "side" protections (not linked to pressure decrease) are very different even inside the same class. Take for example the dihydropyridines : nifedipine : heart and peripheral vascular, nitrendipine : heart, some kidney, good vascular and some neural, nisoldipine : kidney and vascular, nicardipine, heart, vascular and some peripheral including brain, nimodipine : brain circulation, neural protection, and some peripheral including vascular, etc... So, not simple depending on what you need as pressure control, dealing with secondary effects (negative) and protection and what is available on the market in your country.

I agree with previous opinion.

As you can see on slide simply decrease BP only 2 mm has big benefit.

At ages 40–69 years, each difference of 20 mm Hg usual SBP (or, approximately equivalently, 10 mm Hg usual DBP) is associated with more than a twofold difference in the stroke death rate, and with twofold differences in the death rates from IHD and from other vascular causes. All of these proportional differences in vascular mortality are about half as extreme at ages 80–89 years as at ages 40–49 years, but the annual absolute differences in risk are greater in old age.

http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(02)11911-8/abstract

Simple answer is not always right. Lowering BP, you should pay attention at different psysiological functions . It certainly connected with type of medication. So I prefer use term  "optimal or target BP" than "normal BP".

This is right and I agree. What is normal pressure ? Everybody has his own threshold and regulation system. Optimal is somewhat imprecise (optimal for who ?), but target is not bad...

Dear Renaud, I am author of ZhGS formulas. We use minimal energy consumption principle to check " optimal blood pressure". Certainly, you can use "target", but target for what aim? 

Just a matter of philosophy... ? Not so easy, but I prefer your approach.

In ADVANCE trial perindropril and indepamide combination in diabetic patient had showed marked reduction of CV mortality and some benefit in all cause mortality.. This outcome may be of some pleotrophic property of these drugs in addition to reduction of blood pressure.. 

https://www.ncbi.nlm.nih.gov/pubmed/19791837

2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults

Report From the Panel Members Appointed to the Eighth Joint National Committee (JNC 8)

It is important to follow rules...

There is strong evidence to support treating hypertensive persons aged 60 years or older to a BP goal of less than 150/90 mm Hg and hypertensive persons 30 through 59 years of age to a diastolic goal of less than 90 mm Hg; however, there is insufficient evidence in hypertensive persons younger than 60 years for a systolic goal, or in those younger than 30 years for a diastolic goal, so the panel recommends a BP of less than 140/90 mm Hg for those groups based on expert opinion.

If it OK to use - goal BP...