What added value does ambulatory blood pressure monitoring brings to the management of post renal transplantation hypertension?
OBJECTIVE
To evaluate BP control, white coat hypertension (WCH) and abnormal circadian variability in a significant outpatient sample of renal transplant (RTx) subjects, normotensive at the last regular visit.


METHODS
ABPM (Spacelab 90217) was performed every 15 min between 07:00-23:00 h and every 30 min between 23:01-06.59 h. in all patients (N = 68, 39M, S-Cr. = 153 +/- 49 mumol/l) normotensive at their last regular office BP (O-BP) measurement and with available BP records for the 12 months preceding RTx and 6 months preceding ABPM.


RESULTS
BP values were frequently abnormal in this RTx cohort considered to have a satisfactory BP control. O-BP (measured with a Hawksley random-0 sphygmomanometer on the day of ABPM) was 135.5/80.6 mmHg, 47.1% of the patients with abnormal BP values. By comparison, ABPM showed a lower prevalence of uncontrolled BP: 44.1% for 24 h.-BP and only 35.3% for the daytime awake period, with values of 134.5/80.4 and 135.3/81 mmHg respectively (P = NS from O-BP). The prevalence of WCH was 12%. 24-h SBP is related to O-SBP (r = 0.71, P < 0.01) and Bland-Altman analysis demonstrates that > 95.6% of all differences between systolic ABPM and O-BP values are within +/- 2SD of the identity line. However, although 24-h DBP is equally related to O-DBP (r = 0.64, P < 0.01), on Bland-Altman analysis, 8.8% of the differences between diastolic ABPM and O-BP values are outside +/- 2SD of the identity line. Thus, systolic but not diastolic O-BP correlates with, and can be substituted to ABPM derived values. Non-dipping was frequent, regardless of the definition of normal nocturnal BP fall (10 mmHg or 10% of the daytime SBP): 82.4%, 89.7%. Even if normality was strictly defined as a night/day ratio < 0.90 for SBP and < 0.92 for DBP, non-dipping prevalence was high 73.5%, with more than one-third of the RTx patients having nocturnal hypertension (ratio > 1).


CONCLUSIONS
BP control is not optimal in one-third of a typical RTx population. Furthermore, nocturnal hypertension is a frequent and underestimated phenomenon in this population. There is a good agreement between ABPM derived and casual systolic values. Office measurements, due to WCH, are under-evaluating the quality and efficacy of the antihypertensive regimens.
Covic
A
A
Dialysis Center, C. I. Parhon University Hospital, Iaşi.
Goldsmith
D J
DJ
Gusbeth-Tatomir
P
P
Seica
Anca
A
Jayawardene
S
S
Agharazii
M
M
Afzali
B
B
D000328:Adult; D000368:Aged; D000465:Algorithms; D000959:Antihypertensive Agents / Q000627:therapeutic use; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods*; D002940:Circadian Rhythm; D015331:Cohort Studies; D005260:Female; D006085:Graft Survival; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
D000959:Antihypertensive Agents