British Hypertension Society Annual Meeting 19th-21st September,2005 Cambridge, UK.
Treating high blood pressure by device-guided paced breathing in the home setting: evidence-based approach
Schein M1, Grossman E2, Rosenthal T2, Giannattasio C3, Elliott B4,
Viskoper R5, Alter A6, Gavish B6
1 Hadassah University Hospital, Jerusalem, Israel, 2 Sheba Medical Center, Tel-Hashomer, Israel,
3 S. Gerardo Hospital, Monza, Italy, 4 RUSH Medical College, Chicago, United States, 5 Barzilai
Medical Center, Ashkelon, Israel, 6InterCure Ltd., Lod, Israel
Objective: 1) To evaluate the hypothesis that 8-week routine use of a device that guides its user to
slow breathing lowers blood pressure (BP) in uncontrolled hypertensive patients, and 2) to investigate the dose-response
relationship between the device-related exercise measure and the clinical outcome.
Design and Methods: In seven independent studies a device was used that interactively guides the patient
to slow breathing and prolonged expiration by synchronizing breathing with sensor-controlled guiding musical tones
(RESPeRATE, InterCure, Israel). The device was used daily at home for 15 minutes. Office BP change over 8 weeks was
the common primary endpoint. Pooling, applied to data of 159 treatment and 127 control patients, was justified by
showing that covariate-adjusted changes in BP were study-independent. Four studies were double-blinded and randomized,
1 controlled, and 2 open-label. Control interventions were relaxation music (3 studies), BP monitoring with automatic
data logging (2 studies), or both (1 study). The patients were 59% males, age 57±11 years (mean±SD), BMI 28±4 kg/m2,
78% treated with BP medication, unchanged 1 month before and during trial and initial office BP 150±13/90±8 mmHg.
Groups were matched by baseline characteristics. The device records automatically and displays a predetermined
exercise measure equal to the minutes spent during the last week breathing slower than 10 breaths/minute
(45 minutes/week was requested). The device also stores minute-to-minute inspiration- and expiration time during
the whole treatment period.
Results:
Changes in office BP (mmHg, mean±SE): -12.0±1.1/-6.1±0.7 (Device, n=159) vs. -8.2±1.2/-3.3±0.6 (Control, n=127),
p=0.02/p=0.003. Office BP change for patients with initial systolic BP > 140: -13.7±1.3 (Device, n=129) vs. -8.9±1.3
(Control, n=109), p=0.008, and for initial diastolic BP > 90: -8.4±0.9 (Device, n=83) vs. -4.1±1.0 (Control, n=60),
p=0.002. Outcomes were independent of gender and medication status. End BP was lower than 140/90 mmHg in 26% of
treatment patients, initially at stage 2, vs. 4% in the controls (p<0.005) and in 46% of stage 1 treatment patients
vs. 34% in the controls (p<0.05). Dose-response relationship of exponential-decay type was observed between
office systolic BP change and the exercise measure, averaged over the 8-week treatment period (r=0.45), showing
that more time spent in slow breathing resulted in a significantly greater systolic BP reduction. Treatment patients
whose average exercise measure was less than a threshold value (50% of requested) did not display a BP change
different from the control. Treatment reduced significantly uncontrolled home systolic BP (>135) and diastolic BP
(>85). BP changes: -5.1±0.8/-3.3±1.3 vs. -0.8±1.3/-1.4±0.8 (p<0.005/p<0.05). Treatment reduced white coat
effect (positive office to home difference) significantly more than control: 81%/75% vs. 20%/40% (p<0.005/p<0.05).
No side effects were observed in either group. Other results of interest found in individual studies: a follow up
conducted in 13 treatment patients, who continued treatment for 6 months, demonstrated continued response
(p<0.02/p<0.05 for BP trend). Treatment reduced significantly 24 hour ambulatory BP monitoring in the
"awake phase". Treatment was effective in patients resistant to anti-hypertensive drugs.
