Lessons Learned from Recent Hypertension Trials about Kidney Disease

Abstract

This article reviews BP trials with primary or secondary cardiovascular (CV) or renal end points. It focuses on how results of recent trials have influenced guidelines and clinical practice with specific reference to two issues: ( 1 ) Achievement of goal BP in patients with chronic kidney disease and ( 2 ) emerging data on the importance of decreasing proteinuria to prevent CV events and slow kidney disease progression. Each study is evaluated on its strengths and weaknesses as well as extrapolation of findings to the general population. The tenants of this article are that the baseline level of proteinuria and the magnitude of proteinuria reduction are important determinants of renal outcome in addition to lowering BP and should be consider in all future trials. Second, comparing trials of people with different stages of nephropathy and unknown or differing levels of proteinuria is limited in generalizing the CV or renal outcome to a more global population. As a preamble to this article, two observations are noteworthy: First, use of antihypertensive therapy in those with stage 3 nephropathy, i.e. , GFR of <60 ml/min, will not slow the rate of decline in kidney function to the same extent as in patients with normal kidney function (stage 1). Studies to address the aforementioned questions will not be performed, however, because of low event rates, relatively higher numbers of participants, and longer duration of follow-up, hence, higher cost than currently completed studies. Thus, we are faced with extrapolating from studies to clinical practice that may not be very appropriate. Second, observations from a number of clinical studies suggest that both risk for kidney disease progression as well as CV events may be inversely related to the level of kidney function and directly related to the amount of proteinuria (macroalbuminuria), defined as >300 mg/d of protein (1– …