Background: The goal of this study was to evaluate the relative association of several components of blood pressure (BP), as measured in the office and by ambulatory monitoring (ABPM), with clinically useful indicators of target organ damage and cardiovascular events (CE) in essential hypertensive patients.
Patients and method: We retrospectively included 390 hypertensives (55% men; mean age: 56 years) between 1989 and 1998. All them had a baseline office BP measurement and a valid 24-hour ABPM record, both performed while the patient was free of antihypertensive therapy. Estimates of target organ damage included electrocardiographic indexes of left ventricular hypertrophy (Cornell and Sokolow-Lyon), serum creatinine, 24-hour urine protein excretion and creatinine clearance. Multiple linear regression and logistic regression analyses were used to evaluate the relationship between BP and target organ damage or CE.
Results: Forty-nine patients had CE (26 stroke, 18 myocardial infarction and 5 both). The BP parameter correlating better with cardiovascular events was office pulse pressure (multivariate odds ratio: 1.03; CI 95%: 1.00-1.05; p = 0.0095). Nevertheless, cardiac growth indexes correlated better with ABPM measurements. In fact, Cornell index correlated with night-time systolic BP (standardized regression coefficient beta: 0.260; p < 0.001) and Sokolow-Lyon index correlated with day-time systolic BP ( beta: 0.257; p < 0.001). Creatinine clearance inversely correlated with night-time pulse pressure ( beta: 0.122; p = 0.017) while proteinuria correlated better with 24-hour systolic BP ( beta: 0.390; p < 0.001).
Conclusions: Whereas office BP (especially pulse pressure) is associated with the development of CE, ABPM estimates show a better association with target organ damage, especially systolic and pulse pressures.