In the AASK (African-American Study of Kidney Disease and Hypertension) trial, 1094 non-diabetic, black patients, with hypertension-related nephropathy, have been examined, randomizing them to a standard or intensive anti-hypertension treatment. In spite of the average pressure value obtained through intensive treatment (130/78 vs. 141/86 mmHg), the obtained composed outcome– a reduction of 50% in glomerular filtration, terminal-stage renal disease, death – has been reached with a similar frequency in the two groups. As to drugs, ramipril, metoprolole and amlodipine have been used: the best results have been obtained with the ACE-inhibitor. After the randomization phase, subjects have been followed for about 6 years in a phase of “cohort”, where the objective has been to reduce LHBP below 130/80 mmHg, treating everybody with ramipril (plus other drugs if necessary). During this phase, pressure has remained slightly lower in the group of the starting intensive treatment (about 3 mmHg lower) than in the group treated with the standard treatment. Now, the researchers of that trial have published the final data, at the end of 10 years of follow-up. The frequency of the composed endpoint (doubled creatinine, terminal renal failure, death) has remained similar in the two groups: about 7 events/100 people/year. But in subjects where, at the beginning of the trial, the proteins/creatinine relation went beyond 0.22 (corresponding more or less to 300 mg of proteinuria), the intensive control of pressure was associated with a significant decrease of the endpoint (Hazard Ratio 0.73). On the contrary, in subjects where the relation was ≤ 0.22 there have been no better results than the standard treatment.
In the overall, the AASK trial does not confirm the efficacy of an intensive treatment of hypertension in order to obtain an improvement in renal functions: only in patients with a renal compromising in progress, positive results can be obtained with an intensive pressure control, even if we do not know why.
