Background
Hypertension (HTN) is common following renal transplantation and it is associated with adverse effects on cardiovascular (CV) and graft health. Ambulatory blood pressure monitoring (ABPM) is the preferred method to characterize blood pressure (BP) status, since HTN misclassification by office BP (OBP) is quite common in this population. We performed a systematic review and meta-analysis aimed at determining the clinical utility of 24h ABPM and its potential implications for the management of HTN in this population.
Methods
Ovid-MEDLINE and PubMed databases were searched for interventional or observational studies enrolling adult kidney transplant recipients (KTRs) undergoing 24-hour ABP readings compared with office or home BP. Main outcome was: proportion of KTRs diagnosed with HTN by ABPM, home or office recordings. Additionally, day-night BP variability and dipper/non-dipper status were assessed.
Results
Forty-two eligible studies (4115 participants) were reviewed. A cumulative analysis including 27 studies (3481 participants) revealed a prevalence of uncontrolled HTN detected by ABPM of 56% (95% CI, 46%-65%). The pooled prevalence of uncontrolled HTN according to office BP was 47% (95% CI, 36%-58%) in 25 studies (3261 participants). Very few studies reported on home BP recordings. The average concordance rate between office and ABPM measurements in classifying patients as controlled or uncontrolled hypertensive was 66% (95% CI, 59%-73%). ABPM revealed HTN phenotypes among KTRs. Two pooled analyses of eleven and ten studies, respectively, revealed an average prevalence of 26% (95% CI, 19%-33%) for masked HTN and 10% (95% CI, 6%-17%) for white-coat HTN. The proportion of non-dippers was variable across the 28 studies that analyzed dipping status, with an average prevalence of 54% (95% CI, 45%-63%).
Conclusions
In our systematic review, comparison of office vs. ambulatory BP measurements disclosed a high proportion of masked, uncontrolled HTN and, to a lesser extent, white-coat HTN in KTRs. These results suggest that HTN is not adequately diagnosed and controlled by office recordings in this population. Furthermore, the high prevalence of non-dippers confirmed that circadian rhythm is commonly disturbed in KTRs.