ISCHEMIC HEART DISEASE (D MUKHERJEE, SECTION EDITOR) Relationship Between Outpatient Clinic and Ambulatory Blood Pressure Measurements and Mortality KoKo Aung 1 & Thwe Htay 1 # Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Purpose of Review This review aims to summarize and discuss the relationship between outpatient clinic and ambulatory blood pressure (BP) measurements and cardiovascular morbidity and mortality. Recent Findings Contemporary clinical practice guidelines worldwide recommend ambulatory blood pressure monitoring (ABPM) to confirm the diagnosis of hypertension. Recent epidemiological studies and systematic reviews showed ABPM predicts cardiovascular events and mortality independent of clinic BP. Ambulatory BP appears to be prognostically superior to clinic BP. Summary ABPM characterizes BP phenotypes that would not have otherwise identified with clinic BP measurement only. Identification of white coat hypertension, which carries a prognosis almost similar to normotension, and masked hypertension, which carries a prognosis almost similar to sustained hypertension, can be accomplished only by ABPM. Randomize controlled trials to assess the cardiovascular effects of hypertensive patients managed with ABPM vs. clinic BP measurement and cost- effective studies of ABPM are warranted. Keywords Ambulatory blood pressure monitoring . Hypertension . Cardiovascular diseases . Mortality . White coat hypertension . Masked hypertension Introduction Current clinical practice guidelines in North America [1••, 2••, 3••], Europe [4, 5••], Australia [6••], and Asia [7] recommend using ambulatory blood pressure monitoring (ABPM) to con- firm the diagnosis of hypertension in people with suspected hypertension. The recently published guidelines of the European Society of Cardiology and the European Society of Hypertension for management of arterial hypertension [5••] include specific clinical indications for out-of-office blood pressure measurement. Notably, there are two class I recommendations: (a) The diagnosis of hypertension should be based on repeated clinic blood pressure (BP) measurements on more than one visit, except when hypertension is severe, or out-of-office BP measurement with ABPM and/or home blood pressure monitoring if logistically and economically feasible and (b) ABPM or HBPM is recommended for identi- fying white coat and masked hypertension, quantifying the effects of treatment, and identifying possible causes of side effects such as symptomatic hypotension. ABPM is more accurate than clinic and home monitoring in diagnosing hypertension because of multiple measurements [8]. In addition, absence of digit preference, absence of ob- server bias, and lack of white coat effect all contribute to improved accuracy of ambulatory over clinic BP. Utilization of ABPM is expected to reduce unnecessary treatment in peo- ple who do not have true hypertension. Diagnosis and treatment of hypertension has been both historically and currently based largely upon outpatient clinic BP measurement. Variability of BP throughout the day has been well recognized. The advent of non-invasive ABPM about 40 years ago led to identification of white coat hyper- tension, a phenomenon where individuals have elevated BP during clinic visits yet their ambulatory BP measurements This article is part of the Topical Collection on Ischemic Heart Disease * KoKo Aung koko.aung@ttuhsc.edu Thwe Htay thwe.htay@ttuhsc.edu 1 Texas Tech University Health Sciences Center El Paso, 200 Rick Francis St, MSC 21006, El Paso, TX 79905, USA Current Cardiology Reports (2019) 21:28 https://doi.org/10.1007/s11886-019-1114-z