Animal-Assisted Therapy for Hospitalized Heart Failure Patients

Context: Effects of complementary therapies on heart failure, a leading cause of hospitalization, are unknown. Animal-assisted therapy improves physiological and psychosocial variables in healthy and hypertensive subjects.

Objectives: To determine whether a 12-minute hospital visit with a therapy dog improves hemodynamics, lowers neurohormone levels, and decreases state anxiety in patients hospitalized with heart failure.

Design, Setting, Participants: A 3-group (volunteer-dog team, volunteer only, and control) randomized repeated-measures experimental design was used in 76 adult patients with advanced heart failure hospitalized between November 2001 and July 2004. Longitudinal analysis was used to model differences among the 3 groups at 3 time points.

Interventions: One group received a 12-minute visit from a volunteer with a therapy dog, another group received a 12-minute visit from a volunteer, and the control group received usual care, at rest. Data were collected at baseline, 8 minutes after the intervention started, and 16 minutes (4 minutes after intervention ended).

Main Outcome Measures: Blood pressure, heart rate, pulmonary artery pressure, pulmonary capillary wedge pressure, right atrial pressure, cardiac index, systemic vascular resistance, plasma levels of epinephrine and norepinephrine, and state anxiety.

Results: Compared with the control group, patients visited by a volunteer-dog team showed significantly greater decreases in pulmonary artery pressure during (5.34, P = .003) and after (5.78, P = .001) the intervention, pulmonary capillary wedge pressure during (3.09, P = .02) and after (4.31, P = .002) the intervention, and epinephrine (17.54, P = .04) and norepinephrine (240.14, P = .02) levels during the intervention. After the intervention, patients visited by the volunteer-dog team showed the greatest decrease in state anxiety over patients visited by a volunteer only (6.65, P = .003) and the control group (9.13, P < .0001).

Conclusions: Animal-assisted therapy improves cardiopulmonary pressures, neurohormone levels, and anxiety in patients hospitalized with heart failure.

Inclusion criteria

• diagnosis of heart failure requiring medical management with an indwelling pulmonary artery catheter
• age between 18 and 80 years
• ability to read, write, and speak English
• mental status: alert and oriented to person, place, and time
• SVR greater than 1200 dyne · sec · cm-5 at least once within 12 hours from the start of data collection

Exclusion criteria

• SVR less than 1200 dyne · sec · cm-5
• allergies to dogs
• immunosuppression, defined as a white blood cell count of less than 4500 cells/mm3
• infection as determined by an elevated white blood cell count exceeding 11,000 cells/mm3
• body temperature greater than 38ºC
• decreased level of consciousness