Subclinical cardiac and renal damage among treated patients with masked hypertension: the ESTHEN study

Abstract

Aim: To investigate the prevalence of silent cardiac (LVH by ECG criteria) and renal damage - estimated glomerular filtration rate (eGFR) and urinary albumin excretion (UAER) - in patients with masked hypertension (MHT). Patients and methods: Observational, cross-sectional, multicenter study in treated hypertensive patients attended by hypertension units in 31 University and Community hospitals across Spain. After 5 minutes rest, six Blood Pressure (BP) readings were performed at 1 minute intervals. 24-h ambulatory BP monitoring (ABPM) and laboratory investigations were also made. Mild LVH on ECG was defined as R in aVL ≥ 0.6 mV, and moderate LVH as R in aVL ≥ 1.1 mV. Silent renal disease (SRD) was defined as serum Cr >1.3 mg/dl (males) or >1.2 mg/dl (females), or eGFR <60 ml/min/1.73 m2, or albumin/creatinine ratio ≥22 (males) and ≥31 (females) mg/g Cr. Patients were considered controlled (C) when office BP <140/90 mmHg and daytime ABPM <135/85 mmHg; isolated clinical HT (ICH) was defined as office BP ≥ 140/90 mmHg and daytime ABPM <135/85 mmHg; masked HT (MHT) as office BP <140/90 mmHg and daytime ABPM ≥ 135/85 mmHg; and uncontrolled sustained hypertension (U) as either office BP ≥ 140/90 mmHg and daytime ABPM ≥ 135/85 mmHg. Results: 498 treated hypertensives were consecutively included (mean age 60±13 years; 48.6% males), BMI 29.1±4.4 kg/m2, 12.2% smokers, 26% type 2 DM, 29.3% previous CV disease. HT was controlled in 40.2% of patients, 17.5% had ICH, 15.1% MHT and 27.3% sustained uncontrolled HT. Mild LVH was observed in 50.8% of patients, and moderate LVH in 4.5% of patients. Prevalence of mild LVH was 41.0% in controlled HT, 55.6% in ICH, 51.0% in MHT and 57.3% in sustained uncontrolled HT (p= 0.021). Subclinical renal damage was observed in 75 patients (18.3%): 18.2% of controlled HT, 18.9% of ICH, 13.6% of MHT and 20.9% of uncontrolled sustained HT (p=0.70). The eGFR was 87.2 (29.6) ml/min, 87.5 (23.4) ml/min, 86.7 (24.8) ml/min and 89.2 (25.8) ml/min, respectively (p=0.9). Microalbuminuria was 34.3 (148.4) mg/g in controlled HT, 26.1 (68.6) mg/g in ICH, 184.1 (692.8) mg/g in MHT and 156.9 (610.2) mg/g in uncontrolled HT (p=0.02). Conclusions: Controlled hypertensive patients according to both office and ABPM have a lower prevalence of mild LVH compared with uncontrolled patients. No differences in moderate LVH were observed between the four groups. However, patients with masked HT had the highest values of microalbuminuria, which were even higher than those observed in uncontrolled sustained hypertensive patients.