Clinical implications of white-coat effect among patients attending at a lipid clinic

We evaluated clinical implications of the white-coat effect (WCE) in cardiovascular (CV) risk stratification in the primary prevention setting of a Lipid Clinic. We compared home self blood pressure measurement (SBPM) with office blood pressure (BP) readings and BP measured by a nurse before and after the visit on consecutive subjects, free of previous CV diseases, attending at a Lipid Clinic for a first visit. Additionally, we evaluated whether and to what extent the difference between these measurements affect the 10-year cardiovascular risk calculated according to current guidelines. Mean home self-measured systolic and diastolic BP values were significantly lower than physician's and nurse's readings (p=0.000). A WCE was observed in 60.3% of patients during the physician's visit, and in 33.9% and 36.6% of nurse's measurements before and after visit, respectively. Compared with computation of SBPM, inclusion in risk predictive model of systolic BP values obtained by physician and nurse (before or after visit) resulted in significantly higher calculated CV risk (p=0.000) and in a higher risk-class allocation in 16.5%, 8.5% and 9.4% of patients, respectively (p=0.000). Our findings show that among patients attending at a Lipid Clinic there is a high prevalence of WCE, which is roughly halved when nurse's BP measurements were considered. Nurse's BP measurements before or after the doctor's visit may reduce, but not eliminate at all, the clinic overestimation of BP. The WCE associated with physician's office visit carries a substantial probability of 10-year CV risk overestimation in the primary prevention setting.