Prospective study of the circadian pattern of blood pressure after heart transplantation

Background : Previous reports indicate that heart transplant recipients lack a normal nocturnal decline in blood pressure. This prospective study was designed to determine the evolution of circadian blood pressure patterns after heart transplantation. Methods : Twenty-four-hour ambulatory blood pressure and heart rate was measured in eight heart transplant recipients early (47 ± 35 days) and late (740 ± 10 days) after transplantation. Results : Early transplant recordings and the normal control group recordings showed similar daytime systolic blood pressure but had different nighttime systolic blood pressure (138 ± 15 mm Hg versus 112 ± 9 mm Hg, p = 0.0002). The percent nocturnal change in systolic blood pressure showed a nocturnal increase in blood pressure in the early recordings versus a decrease in the healthy subjects (+4 ± 2.7 versus -13 ± 5.4, p < 0.0001). The late recordings showed a significant decrease in the nighttime systolic blood pressure (138 ± 15 mm Hg versus 119 ± 7 mm Hg, p = 0.011). The percent nocturnal change in systolic blood pressure was also significantly different between the early and late recordings (+4 ± 2.7 versus -9 ± 9, p = 0.0082) indicating a return of a nocturnal decline in systolic blood pressure. Similar patterns in diastolic blood pressure were observed. No significant change in the percent nocturnal change in heart rate occurred (-10 ± 4.1 versus -7 ± 5.5). Conclusions : Prospective follow-up of this heart transplant population showed that diurnal blood pressure variation is restored in some patients ; diurnal variation is not related to corticosteroids, cyclosporine, or heart rate.