Prognostic Significance of Renal Function in Elderly Patients with Isolated Systolic Hypertension: Results from the Syst-Eur Trial

P. W. de Leeuw
2002 Journal of the American Society of Nephrology  
Several reports suggest that markers of renal function such as serum creatinine, serum uric acid, and urinary excretion of protein may be related to cardiovascular complications and mortality. This study analyzed the data from the Syst-Eur trial, which was a randomized, placebo-controlled, double-blind intervention trial in elderly patients with isolated systolic hypertension. The purpose was to evaluate whether serum levels of creatinine and uric acid and urinary protein excretion at entry are
more » ... retion at entry are related to subsequent morbidity and mortality. Incidence rates of total mortality, cardiovascular mortality, stroke (fatal as well as nonfatal), coronary events, and all cardiovascular endpoints were calculated for each quintile of serum creatinine or serum uric acid or for each category of protein excretion (none, trace, and overt). Crude and adjusted relative hazard rates were also determined for each 20 M increase in serum creatinine, each 50 M increase in serum uric acid, and for each protein excretion category. Even when adjusted for age, gender, and various other covariates, serum creatinine was significantly associated with a worse prognosis. There was an U-shaped relationship between serum uric acid and total mortality, but otherwise no obvious relationships were detected between serum uric acid levels and complications when appropriate adjustments were made for confounding variables. Proteinuria at entry was a significant predictor of total mortality and all cardiovascular endpoints. It is concluded that higher levels of serum creatinine and trace or overt proteinuria are associated with an increased number of cardiovascular events and with a higher mortality in patients with isolated systolic hypertension. Cardiovascular prognosis in patients with hypertension depends not only on the level of BP and associated risk factors but also on the presence of target organ damage. For instance, after left ventricular hypertrophy has developed as a result of long-standing hypertension, this complication becomes a risk factor in its own right and a predictor not only of further cardiac abnormalities (1) but also of other atherothrombotic events, such as ischemic stroke (2). Similarly, the presence of cerebrovascular abnormalities may raise cardiovascular risk over and above that conferred by hypertension itself. Although the brain and the heart are the prime targets of the hypertensive process, the kidney is also frequently affected. Evidence is accumulating that renal damage, once present, may also independently contribute to an increased cardiovascular risk (3). Many studies on this issue, however, were either retrospective or did not follow a rigid prospective protocol. Consequently, only limited information is available concerning the extent to which renal damage modifies the risk of future cardiovascular complications. This prompted us to address this question using the Syst-Eur database. The Syst-Eur trial was a large, prospective, double-blind, placebo-controlled trial that examined whether active antihypertensive treatment reduces cardiovascular risk in elderly patients with isolated systolic hypertension. The main results of this trial have already been described
doi:10.1097/01.asn.0000027871.86296.92 pmid:12191965 fatcat:xrr5hkcktzbp7oq5wlwnz5i4va