Proposed Topic (Most preferred): :
Clinical Safety and Quality Service I (Projects aiming to improve efficiency and effectiveness of care delivery to meet international standards)
Proposed Topic (Second preferred): :
Clinical Safety and Quality Service II (Projects aiming to enhance clinical safety and outcomes, clinical governance / risk management)
Authors (including presenting author) :
Wong MK(1), Ng KM(1), Leung LM(1), Lam KF(1), Ng YS(1)
Affiliation :
(1)Department of Family Medicine and Primary Health Care, Tuen Mun Hospital, New Territories West Cluster
Introduction :
Ambulatory blood pressure monitoring (ABPM) has become less popular in primary care since the COVID-19 pandemic, with home blood pressure monitoring (HBPM) often the preferred option. However, HBPM cannot provide night-time blood pressure (BP). Patients whose night-time BP does not dip, or rises, have poorer cardiovascular outcomes.
Objectives :
To identify patients with non-dipper or reverse dipper phenotypes.
To identify patients with nocturnal hypertension.
To improve diagnosis and management of hypertension.
Methodology :
This is a retrospective review study involving cases of ABPM performed in a primary care clinic of Hong Kong from 1/10/2021-30/9/2023.
Using BP data collected, four systolic BP phenotypes (dipper, non-dipper, reverse dipper and extreme dipper) and isolated nocturnal hypertension were studied.
Result & Outcome :
345 patients were referred for ABPM. 67.8% were female and 32.2% were male. The range of age was 20 to 92 years old. 36.5% (126/345) were dippers, indicating a normal BP drop (10-< 20%) during sleep. 38.0% (131/345) were non-dippers, indicating a lack of significant nighttime BP decrease (0-< 10%). 11.0% (38/345) were reverse dippers where BP actually rises during sleep instead of decreasing. This abnormal pattern is associated with a higher incidence of cardiovascular complications. 7.8% (27/345) were extreme-dippers, signifying a substantial reduction in BP (>=20%) during sleep. Managing BP in extreme-dippers is crucial to avoid potential hypotensive episodes.
21.7% (75/345) were noted to have newly diagnosed hypertension, in which 3.8% (13/345) were found having nocturnal hypertension, which refers to elevated BP (night-time BP >=120/70mmHg) specifically during the night, leading to an increased risk of cardiovascular events. Identifying and treating nocturnal hypertension is essential in preventing adverse outcomes.
Recommendations of non-dippers, reverse dippers and nocturnal hypertension included assessment for disordered sleep like obstructive sleep apnoea (OSA), narcolepsy and frequent nocturia, resistant hypertension and secondary causes of hypertension including endocrine disorders, renovascular disease and autonomic nervous systems disorders.
Among the group with nocturnal hypertension, 23% (3/13) were found to have snoring and under investigation for OSA, further supporting the prediction of sleep apnea in nocturnal hypertension.
Measuring nighttime BP provides valuable information that cannot be obtained through conventional office-based or home BP measurements. Nighttime BP readings enable healthcare professionals to identify abnormal BP patterns, improve diagnosis of hypertension, assess the effectiveness of antihypertensives and tailor treatment strategies accordingly.
