20 Aug Treatment of Hypertension Remaining Issues After the Anglo-Scandinavian Cardiac Outcomes Trial
Norman M. Kaplan
At least in hypertension, there has never been a perfect clinical trial. By its nature, hypertension poses several barriers to the performance and interpretation of even the most carefully planned and conducted therapeutic trial. First and perhaps foremost, blood pressure is a constantly moving target so that both the initial recognition of hypertension and its subsequent response to therapy are often difficult to validate.
Certainly, the performance of only a few blood pressure measurements in an office setting usually provides blood pressure levels that are higher than multiple blood pressures taken out of the office.1 Both automatic ambulatory measurements2 and self-recorded home measurements3 have been found to be more predictive of future morbidity and mortality than office readings, but until now, all clinical trials have used a few office readings for identification of hypertension and quantification of therapeutic benefits.
The inclusion of even many thousands of patients in a given trial does not erase the potential errors of the inherent variability in blood pressure that is often accentuated by the alerting reaction to office measurements. Moreover, even carefully selected meta-analyses may not cover the faults of incorrect data.4