Objective: Epidemiological studies have shown that an elevated resting heart rate (HR) is a risk factor for both total and cardiovascular mortality. Our aim was to estimate the night-time HR cut-off point that best predicts cardiovascular risk office tachycardia in hypertensive patients.
Design and method: Untreated hypertensive patients without concomitant cardiovascular diseases were included. Office and ambulatory HRs were measured. Cardiovascular risk office tachycardia was defined by office HR at least 85 beats per minute (bpm). Different night-time HR cut-offs were estimated by receiver operating characteristic curve analyses to predict cardiovascular risk office tachycardia. The best cut-off was selected on the basis of its combined sensitivity and specificity.
Results: A total of 32 569 hypertensive patients were included: 46.5% women, mean age (SD) 52 (14) years, office blood pressure 146 (16)/89 (11) mmHg, diabetes 10.3%, smoking 19.2%, BMI 29 (6.8) kg/m2, office HR 77 (11.2) bpm, and night-time HR 64.9 (9.3) bpm. A total of 7070 (21.7%) patients were found to have cardiovascular risk office tachycardia. The night-time HR value that better predicted cardiovascular risk office tachycardia was more than 66 bpm. In comparison with patients with night HR below this value, those with night-time tachycardia were predominantly women, younger, with higher ambulatory blood pressure, greater BMI, and higher prevalence of diabetes and smoking. All comparisons were statistically significant (P less than 0.001).
Conclusion: A mean night-time HR more than 66 bpm is a good predictor of cardiovascular risk office tachycardia in untreated hypertensive patients and could be considered a variable associated with an increased cardiovascular risk.
aLa Mina Primary Care Center, University of Barcelona
bHypertension Unit, Mútua de Terrassa, University of Barcelona
cJordi Gol Institute for Research in Primary Care, Barcelona
dDepartment of Preventive Medicine and Public Health, Universidad Autónoma de Madrid, CIBER en Epidemiología y Salud Pública, Madrid
eNephrology Service, Hospital Universitario Central de Asturias, Oviedo
fHypertension Unit, Doce de Octubre Hospital
gHypertension Unit, Instituto de Investigación Sanitaria, Hospital Clínico San Carlos, Madrid, Spain
Correspondence to Ernest Vinyoles, CAP La Mina, Carrer Mar s/n, 08930 Sant Adrià de Besòs, Barcelona, Spain. Tel: +34 933811593; fax: +34 933812141; e-mail: firstname.lastname@example.org
Abbreviations: ABPM, ambulatory blood pressure monitoring; BP, blood pressure; bpm, beats per minute; CI, confidence interval; ESH/ESC, European Society of Hypertension/European Society of Cardiology; HR, heart rate; OR, odds ratio; SD, standard deviation
Received 9 August, 2013
Revised 9 January, 2014
Accepted 9 January, 2014