Using 15-Minute Serial Blood Pressures as an Alternative to Measuring a Single Blood Pressure

Thirty-minute office blood pressure (OBP-30) is an alternative to ambulatory blood pressure (BP) measurement, yet is impractical to implement. This study aimed to determine whether unattended BP readings over 15 minutes would result in a similar probability of obtaining a BP of <140/90. Sixty-seven adults self-described as having high BP were analyzed. BP was measured at baseline and every 5 minutes for 15 minutes with the initial reading compared to the average of the last three readings (OBP-15). Compared to baseline, there was a decline in both average systolic (4.2 points) and diastolic (2.8 points) BP. The probability of BP control predicted by multivariate model was 71.6% at baseline and 78.0% using OBP-15 (p=0.011). The increase in BP control from initial to OBP-15 measurement was significant for indigenous or persons of color compared to whites, and men compared to women. OBP-15 is convenient and results in lower BP readings and higher probability of BP control compared to the initial reading.

Unattended versus Attended Blood Pressure Measurement: Relationship with Retinal Microcirculation

Though the relationship between both “attended” and “unattended” BP and several forms of target organ damage have been evaluated, data on retinal arteriolar alterations are lacking. The aim of our study was to evaluate the relationship between “attended” or “unattended” BP values and retinal arteriolar changes in consecutive individuals undergoing a clinical evaluation and assessment of retinal fundus at an ESH Excellence Centre. An oscillometric device programmed to perform 3 BP measurements, at 1 min intervals and after 5 min of rest was used on all individuals to measure BP with the patient alone in the room (“unattended”) or in the presence of the physician (“attended”) in the same day in a random order. The retinal arteriole’s wall thickness (WT) was measured automatically by a localization algorithm as the difference between external (ED) and internal diameter (ID) by adaptive optics (RTX-1, Imagine Eyes, Orsay, Francia). Media-to-lumen ratio (WLR) of the retinal arterioles and cross-sectional area (WCSA) of the vascular wall were calculated. Results: One-hundred-forty-two patients were examined (mean age 57 ± 12 yrs, 48% female, mean BMI 26 ± 4). Among them, 60% had hypertension (84% treated) and 11% had type 2 diabetes mellitus. Unattended systolic BP (SBP) was lower as compared to attended SBP (129 ± 14.8. vs. 122.1 ± 13.6 mmHg, p < 0.0001). WLR was similarly correlated with unattended and attended SBP (r = 0.281, p < 0.0001 and r = 0.382, p < 0.0001) and with unattended and attended diastolic BP (r = 0.34, p < 0.001 and r = 0.29, p < 0.0001). The differences between correlations were not statistically significant (Steiger’s Z test). Conclusion: The measurement of “unattended” or “attended” BP provides different values, and unattended BP is lower as compared to attended BP. In this study a similar correlation was observed between attended and unattended BP values and structural changes of retinal arterioles.

Evaluation of 30-Minute Office Blood Pressure in a Diverse Urban Population

BACKGROUND

Previous studies have shown benefits of 30-minute office blood pressure (OBP-30) but did not report on race and gender. The purpose of this study was to determine if similar effects are seen in a diverse urban population.

METHODS

Patients with diabetes and/or cardiovascular disease (age 18-89) were invited to participate. Blood pressure was measured using standard procedure (SOBP). Patients were left alone in an exam room connected to an automated office blood pressure monitor which obtained BP readings every 5 minutes for 30 minutes. The last 5 measurements were averaged for the OBP-30 measurement. Primary outcomes were BPs measured using SOBP and OBP-30. Multivariate logit methods were used to estimate the average probability of having a BP measured <140/90 mm Hg (BPM <140/90) for the 2 measurement methods. Differences were computed across methods, in total and by sex and race, all other factors held constant.

RESULTS

The adjusted probability of having a BPM <140/90 was 47.1% using SOBP and 66.7% using OBP-30 (P < 0.01). Using SOBP, females had a 26.2 PP lower probability of having a BPM <140/90 (P < 0.001) than males. Relative to white patients, Black patients had a 43.9 PP lower (P < 0.001) and other races a 38.5 PP lower (P < 0.001) probability of having a BPM <140/90 using SOBP. Using OBP-30, these differences narrowed and became statistically insignificant.

CONCLUSIONS

OBP-30 may increase the probability of BPM meeting goals, especially in females and patients who are Black, indigenous, or persons of color.