Principles of Blood Pressure Measurement - Current Techniques, Office vs Ambulatory Blood Pressure Measurement

Achieving control of resistant hypertension: Not just the number of blood pressure medications

Resistant hypertension (RH) has a prevalence of around 12% and is associated with an increased risk of cardiovascular disease, progression to end-stage renal disease, and even mortality. In 2017, the American College of Cardiology and American Heart Association released updated guidelines that detail steps to ensure proper diagnosis of RH, including the exclusion of pseudoresistance. Lifestyle modifications, such as low salt diet and physical exercise, remain at the forefront of optimizing blood pressure control. Secondary causes of RH also need to be investigated, including screening for obstructive sleep apnea. Notably, the guidelines demonstrate a major change in medication management recommendations to include mineralocorticoid receptor antagonists. In addition to advances in medication optimization, there are several device-based therapies that have been showing efficacy in the treatment of RH. Renal denervation therapy has struggled to show efficacy for blood pressure control, but with a re-designed catheter device, it is once again being tested in clinical trials. Carotid baroreceptor activation therapy (BAT) via an implantable pulse generator has been shown to be effective in lowering blood pressure both acutely and in long-term follow up data, but there is some concern about the safety profile. Both a second-generation pulse generator and an endovascular implant are being tested in new clinical trials with hopes for improved safety profiles while maintaining therapeutic efficacy. Both renal denervation and carotid BAT need continued study before widespread clinical implementation. Central arteriovenous anastomosis has emerged as another possible therapy and is being actively explored. The ongoing pursuit of blood pressure control is a vital part of minimizing adverse patient outcomes. The future landscape appears hopeful for helping patients achieve blood pressure goals not only through the optimization of antihypertensive medications but also through device-based therapies in select individuals.

Baseline check of blood pressure readings of an automated device in severe pre-eclampsia and healthy normotensive pregnancy

OBJECTIVE

The baseline blood pressure (BP) readings of an automated device that have not been validated in pregnancy require comparison with those from a reference standard before the device is utilized in pregnancy. We aimed to perform a baseline check of BP readings of an automated device, Mindray iMEC12 patient monitor, in severe pre-eclampsia and healthy pregnancy.

STUDY DESIGN

The BP of 50 severe pre-eclamptic and 90 normotensive pregnancies were measured using Mindray iMEC12 patient monitor (test device) and Welch Allyn 767 aneroid sphygmomanometer (reference device). A pass in either the International Organization for Standardization (ISO) or British Hypertension Society (BHS) rating was considered acceptable. The cumulative percentage of absolute BP difference between the test and reference devices within 5, 10 and 15 mmHg were calculated to rate the test device according to the BHS grades (A, B, C or D). The ISO recommends that an accurate device should achieve a mean BP difference ± SD of ≤5 ± 8 mmHg.

RESULTS

The mean BP difference between the test and reference devices were 1.27 ± 7.51 mmHg and 0.05 ± 6.09 mmHg for systolic and diastolic BPs respectively. The test device achieved the BHS grades B and A rating in systolic and diastolic BPs respectively. In each of the 2 groups (pre-eclamptic and normotensive pregnancies), the test device also satisfied the set pass criteria.

CONCLUSIONS

In settings that do not have a validated BP device, Mindray iMEC12 patient monitor may be used for BP measurement in normotensive and severe pre-eclamptic pregnancies.