CORRELATION BETWEEN CLINIC AND AMBULATORY BLOOD PRESSURE MEASUREMENT

Abstract

Objective: Blood pressure (BP) measurements taken in the clinic provide limited information about the BP load. Ambulatory blood pressure monitoring (ABPM) provide a more comprehensive assessment of blood pressure over the course of a day. This study examined the correlation between clinic and ambulatory BP measurements. Design and method: We collated clinic and 24 hour ambulatory BP data of 100 patients aged > 18 years from the outpatient cardiology clinic of Mohamed Taher Maamouri University hospital in Nabeul (n = 100) over a six months period (July-December 2021). Laying of ABPM was performed using a Bravo Mini validated device from Sun Tech Medical. We used the Pearson correlation coefficient (r) to measure the strength of the relationship between these two measurements methods. Results: The mean age of our population was 59.14±13.12 years (range 21-92 years), composed of 47 women and 53 men. The most frequent reason for carrying out ABPM was the monitoring of hypertensive patients in 84% of cases, 16% were done to confirm the diagnosis of hypertension. ABPM confirmed the diagnosis of hypertension in 62.5% and detected 18.75% isolated nocturnal hypertension in patients with suspected hypertension and 14.3% masked uncontrolled nocturnal hypertension in hypertensive patients. Concordance was found in 66% of cases between clinic measurement and the 24-hour ABPM data. There was a weak correlation between clinic systolic BP and 24-hour ambulatory systolic BP (P <0.001; r = 0.349; Curve A) and moderate correlation between clinic diastolic BP and 24-hour ambulatory diastolic BP (P <0.001; r = 0.566; Curve B). Conclusions: The correlation between these two methods isn’t important mainly explained by variation of BP especially at night detected by ABPM which remains the reference method for diagnosing and monitoring hypertension