Letter by Messerli et al Regarding Article, "The Implications of Blood Pressure Measurement Methods on Treatment Targets for Blood Pressure".

e47 Circulation. 2017;135:e47. DOI: 10.1161/CIRCULATIONAHA.116.026534 February 14, 2017 In Response: I very much appreciate the comments of Dr Messerli and colleagues on our report1 on blood pressure measurement in SPRINT (Sytolic Blood Pressure Intervention Trial) and fully concur. If one looks at the manual of operations for SPRINT, there is no specification about whether measurements should be attended. However, there is a cryptic comment about not engaging in conversation during measurement. This could be inferred as perhaps they should be attended. This would make Dr Cushman’s methods slide2 discordant with the trial manual of operations. It is known that some centers had nurses attend the measurement but did not speak to the subjects while pressing the blood pressure machine button. How many centers performed measurements in this way is unknown. The only resolution of this question, as the authors assert, is a site survey. These data then need analysis to be stratified by site and method used to evaluate for variance, if any. Even this discordance further adds to the importance of the methodology precision used to measure blood pressure.