The Importance of 24 Hour Ambulatory Blood Pressure Monitoring After Thoracic Organ Transplantation

Hypertension is a significant complication after thoracic organ transplantation. In the non-transplant population, 24-hour ambulatory blood pressure monitoring (24ABPM) is useful in the diagnosis of white-coat hypertension, the assessment of resistant hypertension, and the monitoring of anti-hypertensive therapy. The loss of nocturnal reductions in blood pressure is associated with hypertensive end-organ damage. This study investigated the role of 24ABPM after orthotopic cardiac transplantation. Thirty-three transplant recipients underwent 24ABPM. Clinical blood pressure (CPB) was measured by using a sphygmomanometer before 24ABPM. Clinical data were collected and analyzed by a single observer with p values of less than 0.05 being taken as significant. The incidence of hypertension (diastolic pressure > 90 mm Hg) in the CPB and 24ABPM groups was 33% and 52% ( p =0.002). Thirty-two percent of recipients who were normotensive by clinical measurement were found to be hypertensive after 24ABPM. The converse was true in 1 case. We identified no specific risk factors for 24ABPM hypertension. One recipient failed to complete the 24-hour monitoring period. This study demonstrates that conventional blood pressure monitoring underestimates the incidence of post-transplantation hypertension. Twenty-four hour ambulatory blood pressure monitoring is well tolerated and may improve the management of post-transplantation hypertension. White-coat hypertension is an uncommon diagnosis after cardiac transplantation, and those recipients who are hypertensive in the clinic setting should be considered true hypertensives.