The need for evidence in hypertension management: historical perspective.

The Task Force of the National Heart, Lung and Blood institute issued the first standardized, algorithmic approach to treating hypertension in 1973. The concept of a stepped-care approach was born at that time. Their initial recommendation for antihypertensive drug therapy was diuretics. Subsequent Joint National Committee (JNC) Reports on Detection, Evaluation, and Treatment of High Blood Pressure recommended that initial drug therapy be either a diuretic or beta-adrenergic blocker, and then either of these two drugs, and then a calcium channel blocker (CCB) or an angiotensin-converting enzyme inhibitor (ACE-inhibitors). The JNC-V then recommended any of the four classes or an alpha-beta-blocker as initial therapy, but diuretics and b-blockers were preferable. That diuretics or beta-blockers should be the initial drug for noncomplicated hypertensive patient was also the recommendation of the Sixth Joint National committee report. Safety issues that arose after introduction ACE inhibitors and CCBs have since been mostly resolved. Drug treatment thresholds varied among the US, Canadian, British and WHO/ISH recommendations despite the fact that all were based on the same set of data. The concept of "the lower the blood pressure the better without causing symptoms" was the rule until the J-curve hypothesis emerged and generated a long debate. Now the current evidence supports the old concept, at least for some conditions such as hypertension in diabetic patients or in those with nephrotic-range proteinuria. Despite the repeated recommendations that thiazide-diuretics are preferred as the initial agent in hypertension treatment, many clinicians ignore these guidelines. This practice has added a signficant cost to hypertension treatment worldwide.