Blood pressure monitoring in clinical trials in the absence of ambulatory blood pressure recording: where is the stand?

Blood Pressure Monitoring in Clinical Trials in the Absence of Ambulatory Blood Pressure Recording: Where Is the Stand? To the Editor: The American Heart Association position statement on blood pressure (BP) measurements1 will be useful for clinicians and academicians alike in arriving at a consensus. The BP recordings reported in clinical trials have an important bearing on the future clinical practice. Although ambulatory BP monitoring is recommended, it may not be possible in all settings because of many factors like patient discomfort, unavailability, or cost. In this situation, BP measurements in the office will still remain as a method to assess efficacy of antihypertensives. In this context, many clinical trials report the BP lowering at the end of study, which is considered the efficacy endpoint. Can this one-time office reading at endpoint accurately describe the efficacy of an antihypertensive? It is obvious that BP recordings performed at one time point do not offer conclusive evidence of antihypertensive efficacy of a drug. Many factors affect officebased BP measurements. However, the International Conference on Harmonization guideline or American Heart Association position statement does not give adequate importance to this criterion. The International Conferrence on Harmonization guideline for clinical evaluation of antihypertensives2 states, “in general, the effect on blood pressure at the end of the study is the primary endpoint, but the time course of the onset of the effect is also of interest; this can be defined by examining trough response each week or every 2 weeks in some studies.” This statement does not reflect the point that for meaningful evaluation of the efficacy of an antihypertensive drug, in the absence of ambulatory BP monitoring, the reduction from baseline averaged for all visits is important and should be the primary criterion for endpoint. Measurement of BP at just the last visit cannot be justified as a reliable primary endpoint. Clinical trials reporting efficacy of antihypertensive medications should report the average decline in BP at all visits.