Blood Pressure Control in Hypertensive Patients, Cardiovascular Risk Profile and the Prevalence of Masked Uncontrolled Hypertension (MUCH).

INTRODUCTION: The term masked hypertension (MH) should be used for untreated individuals who have normal office blood pressure but elevated ambulatory blood pressure. For treated patients, this condition should be termed masked uncontrolled hypertension (MUCH).

RESEARCH OBJECTIVES: Masked uncontrolled hypertension (MUCH) has gone unrecognized because few studies have used 24-h ABPM to determine the prevalence of suboptimal BP control in seemingly well-treated patients, and there are few such studies in large cohorts of treated patients attending usual clinical practice. This is important because masked hypertension is associated with a high risk of cardiovascular events. This study was conducted to obtain more information about the association between hypertension and other CV risk factors, about office and ambulatory blood pressure (BP) control as well as on cardiovascular (CV) risk profile in treated hypertensive patients, also to define the prevalence and characteristics of masked uncontrolled hypertension (MUCH) among treated hypertensive patients in routine clinical practice.

PATIENTS AND METHODS: In this study 2514 male and female patients were included during a period of 5 years follow up. All patients have ambulatory blood pressure monitoring (ABPM) for at least 24h. We identified patients with treated and controlled BP according to current international guidelines (clinic BP, 140/90mmHg). Cardiovascular risk assessment was based on personal history, clinic BP values, as well as target organ damage evaluation. Masked uncontrolled hypertension (MUCH) was diagnosed in these patients if despite controlled clinic BP, the mean 24-h ABPM average remained elevated (24-h systolic BP ≥130mmHg and/or 24-h diastolic BP ≥80mmHg).

RESULTS: Patients had a mean age of 60.2+10 years, and the majority of them (94.6%) were followed by specialist physicians. Average clinic BP was 150.4+16/89.9+12 mmHg. About 70% of patients displayed a very high-risk profile. Ambulatory blood pressure monitoring (ABPM) was performed in all recruited patients for at least 24h. Despite the combined medical treatment (78% of the patients), clinic control (<140/90 mmHg) was achieved in only 26.2% of patients, the corresponding control rate for ambulatory BP (<130/80 mmHg) being 32.7%. From 2514 patients with treated BP, we identified 803 with treated and controlled office BP control (<140/90 mmHg), of whom 258 patients (32.1%) had MUCH according to 24-h ABPM criteria (mean age 57.2 years, 54.7% men). The prevalence of MUCH was slightly higher in males, patients with borderline clinic and office BP (130-139/80-89 mmHg), and patients at high cardiovascular risk (smokers, diabetes, obesity). Masked uncontrolled hypertension (MUCH) was most often due to poor control of nocturnal BP, with the proportion of patients in whom MUCH was solely attributable to an elevated nocturnal BP almost double that solely attributable to daytime BP elevation (22.3 vs. 10.1%, P 0.001).

CONCLUSION: The prevalence of masked suboptimal BP control in patients with treated and well-controlled clinic BP is high. The characteristics of patients with MUCH (male, longer duration of hypertension, obesity, smoking history, and diabetes) indicate that this is a higher-risk group with most to gain from improved BP.