Study of nycthemeral variations in blood pressure in patients with heart failure

OBJECTIVE: The objective of this study was to describe and analyse the nycthemeral variations in blood pressure (BP) by ambulatory BP monitoring (ABPM) over 24 h in patients with heart failure (HF). METHODS: The study population included 50 stable HF patients hospitalized in a cardiology department for acute pulmonary oedema. Parameters studied were: New York Heart Association class, clinical resting BP and heart rate in sitting and then standing positions, ABPM parameters, distance covered during a 6-min walking test, echographic left ventricular ejection fraction (LVEF), natremia, kaliemia, creatininemia, plasma haemoglobin and N-terminal fragment of brain-type natriuretic peptide levels. RESULTS: Clinical hypertension was noted in 20% of patients (10/50) and orthostatic hypotension in 16% (8/50). Nine of 50 patients (18%) were hypertensive during the day and 21 (42%) at night. Thirty-nine of the 50 patients (78%) are nondippers. Nondipper patients are more prevalent when the HF has been present for more than 24 months (95 vs. 67%, P=0.04). This prevalence does not differ depending on New York Heart Association class or LVEF. Furthermore, there exists: (i) a significant positive relationship (R=0.46, P=0.02) between the diastolic BP (DBP) over 24 h and the distance covered during the walking test; (ii) a significant negative relationship between the day-night differences (in mmHg) of the systolic BP (SBP) (R=-0.46, P=0.01) and DBP (R=-0.33, P=0.03) and the duration of HF, between the day-night difference of the DBP and the LVEF (R=-0.34, P=0.02) and (iii) between the day-night differences of the SBP (R=-0.48, P=0.001) and the DBP (R=-0.32, P=0.03) and natremia. The day-night difference of the SBP has a positive correlation with plasma haemoglobin level (R=0.32, P=0.03). CONCLUSION: This study confirms the feasibility of carrying out ABPM with an adapted device in HF patients with atrial fibrillation. ABPM allows diagnosis to be more precise than the clinical measuring of BP abnormalities, which have a pejorative prognosis (e.g. hypertension, hypotension, nondipper status).