Verdecchia P, Schillaci G, Borgioni C, Ciucci A, Porcellati C
Ospedale Generale Regionale Raffaello Silvestrini, Area Omogenea di Cardiologia e Medicina, Perugia, Italy.
Hypertension. 1997 Jun;29(6):1218-24. doi: 10.1161/01.hyp.29.6.1218.
The difference between clinic and ambulatory blood pressure (BP) has been used to quantify the pressure reactivity to the doctor's visit (white coat effect). We investigated the prognostic significance of the clinic-ambulatory BP difference in the setting of the Progetto Ipertensione Umbria Monitoraggio Ambulatoriale (PIUMA) study. A total of 1522 subjects contributed 6371 person-years of observation. All subjects had an initial off-therapy diagnostic workup including 24-hour noninvasive ambulatory BP monitoring. The predicted values of ambulatory BP progressively diverged from the identity line (white coat effect of 0 mm Hg) with increasing clinic BP, but the predicted values of clinic BP tended toward the identity line with increasing ambulatory BP. Hence, the clinic-ambulatory BP difference showed a direct association with clinic BP and an inverse association with ambulatory BP. Consequently, a high clinic-ambulatory BP difference predicted both a high clinic and a low ambulatory BP, whereas a low clinic-ambulatory BP difference predicted both a low clinic and a high ambulatory BP. The clinic-ambulatory BP difference showed also a direct association with age. During up to 9 years of follow-up (mean, 4.2 years), there were 157 major cardiovascular morbid events (125 nonfatal and 32 fatal). The rate of total cardiovascular morbid events did not differ (log-rank test) among the four quartiles of the distribution of the clinic-ambulatory BP difference (2.13, 2.92, 2.10, and 2.83 events per 100 patient-years for systolic BP and 2.94, 2.14, 2.58, and 2.16 events per 100 patient-years for diastolic BP). Also, the rate of fatal cardiovascular events did not differ among the four quartiles of the distribution of the clinic-ambulatory BP difference. The clinic-ambulatory BP difference, taken as a measure of the white coat effect, does not predict cardiovascular morbidity and mortality in subjects with essential hypertension.
诊所血压与动态血压之间的差异已被用于量化对就诊时的血压反应性（白大衣效应）。我们在翁布里亚高血压动态监测项目（PIUMA）研究中调查了诊所 - 动态血压差异的预后意义。共有1522名受试者，提供了6371人年的观察数据。所有受试者均进行了初始的非治疗诊断检查，包括24小时无创动态血压监测。随着诊所血压升高，动态血压的预测值逐渐偏离恒等线（白大衣效应为0 mmHg），但随着动态血压升高，诊所血压的预测值趋于恒等线。因此，诊所 - 动态血压差异与诊所血压呈正相关，与动态血压呈负相关。因此，高诊所 - 动态血压差异预示着高诊所血压和低动态血压，而低诊所 - 动态血压差异预示着低诊所血压和高动态血压。诊所 - 动态血压差异也与年龄呈正相关。在长达9年的随访期内（平均4.2年），发生了157例主要心血管疾病事件（125例非致命性和32例致命性）。诊所 - 动态血压差异分布的四个四分位数之间，总心血管疾病事件发生率无差异（对数秩检验）（收缩压每100患者年分别为2.13、2.92、2.10和2.83例事件，舒张压每100患者年分别为2.94、2.14、2.58和2.16例事件）。同样，诊所 - 动态血压差异分布的四个四分位数之间，致命性心血管事件发生率也无差异。作为白大衣效应衡量指标的诊所 - 动态血压差异，并不能预测原发性高血压患者的心血管发病率和死亡率。
