Feasibility of a Pilot Randomized Hypertension Screening Initiative in the Preoperative Setting

So a Diaz (  so a.diaz@yale.edu ) US Department of Veterans Affairs https://orcid.org/0000-0002-4716-6003 Luying Yan Yale School of Medicine: Yale University School of Medicine Feng Dai Yale University School of Public Health Bin Zhou Yale University School of Public Health Matthew M. Burg Yale School of Medicine: Yale University School of Medicine Robert B. Schonberger Yale School of Medicine: Yale University School of Medicine


Introduction
Poorly controlled hypertension increases risk for cardiovascular disease (CVD) (1)(2)(3) and, other than COVID-19, remains the leading modi able cause of death and disability-adjusted life years worldwide.(4) Despite continued efforts to address undertreated blood pressure elevation, approximately 22% of Americans with high blood pressure are unaware of the condition, and 32% are not taking antihypertensive medications. (5) Several investigations have attempted to address this public health opportunity through hypertension screening outside of the traditional setting of the primary care o ce, including in both the acute care setting(6) and in the general community with notable success. (7) Within the eld of anesthesiology, the Merit Based Incentive Program (MIPS) included hypertension screening in its 2007 anesthesiology speci c quality metrics, and subsequent literature established plausible thresholds at which preoperative blood pressures appeared reasonably predictive of longitudinal blood pressure elevation.(8-10) Nevertheless, while isolated teams have attempted to bring hypertension screening and treatment into perioperative work ows, (11) randomized interventional studies based on these efforts have remained unexplored.
In the effort to assess the feasibility of a randomized blood pressure intervention in the preoperative period and to understand baseline rates of blood pressure follow-up following such intervention, we pursued a pilot randomized trial of blood pressure screening, education, and follow up with vs. without longitudinal home blood pressure measurement in a cohort of 100 patients who presented to our preoperative testing center with blood pressures in the hypertensive range. The endpoints of interest included the observed prevalence of post-operative primary care follow-up, patient perspectives on the study protocol, and the ability to execute the several aspects of the trial effectively including recruitment, randomization, home blood pressure monitoring, and follow-up.

Inclusion and Exclusion:
After approval by the Yale School of Medicine Institutional Review Board and registration on Clinicaltrials.gov (NCT03634813), a sample of 100 patients scheduled for surgery was recruited during their preadmission visit at Yale-New Haven Hospital between November of 2018 to November of 2019.
Inclusion criteria included age > 18 years, the ability to understand English, and a clinic-measured blood pressure of at least 140mmHg systolic or 90mmHg diastolic calculated as the mean of two successive measurements ve minutes apart. These blood pressures were measured using an automated oscillometric blood pressure device rather than manually by clinicians in accordance with literature demonstrating the superior reliability of such measurements for hypertension screening.(12) Participants who were unable or unwilling to independently operate a brachial artery home blood pressure monitor, those who could not give proper consent, or those for whom the date of surgery was within 48 hours of the preoperative visit, were excluded.

Randomization:
After informed consent was obtained, all participants were given a questionnaire that included measures of medication adherence previously validated on hypertensive patients.(13) Participants were then randomly assigned to one of two groups in a 1:1 fashion strati ed by gender. The two groups were de ned as follows: One group received brief counseling regarding their apparent hypertension and the importance of blood pressure follow up. They then received a follow-up letter and an educational pamphlet by mail published by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) entitled "Your guide on lowering blood pressure", (14) which includes advice regarding diet, exercise and lifestyle changes that can be implemented to improve blood pressure control.
The second group received the educational pamphlet at the time of enrollment and was also tted with a validated Omron MX3 model BP742 Home Blood Pressure Monitor (HBPM) (Omron, Shaumberg, IL) (15) and instructed in its use. The HBPM stores timestamped results for up to 50 blood pressure measurements. Participants were sent home with the device and instructed to conduct resting measurements in the morning and evening of each day until the day of surgery and then to bring the device back to the investigators on the day of surgery. Since speci c cut-offs for the interpretation of home blood pressure are controversial,(16) and per the 2017 American Heart Association guidelines, should vary based on cardiovascular disease risk assessment, (17) in the present trial we used mean systolic home BP ≥ 135 mmHg or mean diastolic home BP ≥ 85 mmHg as our HBPM cutoffs. A similar HBPM cutoff of 137/84 mmHg has previously been associated with a 10% increase in the adjusted relative hazard of mortality relative to ideal blood pressure. (18) HBPM participants received a summary report of their mean home blood pressure readings by mail. Unless patients demonstrated sustained normotension on HBPM readings, these letters encouraged follow up to discuss hypertension management with participants' primary care physician (PCP).
Outcome assessment: 60-days post-surgery, investigators attempted to reach participants via follow-up telephone call to a) determine whether the participant had been seen in primary-care follow-up; b) determine whether the participant had received new or adjusted hypertension treatment, and c) assess participants' satisfaction with the study interventions. See Fig. 1 for the list of telephone questions. For those participants who were not reached after three phone call attempts, investigators consulted the Electronic Health Record (EHR) to look for new or adjusted hypertension treatment.

Cohort Characteristics:
A total of 100 participants, were successfully enrolled. Forty-nine participants were assigned to the HBPM group vs. 51 in the counseling group. Fifty-four (54%) were female and Forty-six (46%) male. 72 (76%) participants identi ed as white, 16 (17%) as Black or African American and Twenty (20%) as Hispanic. See Table 1 for a complete demographic description of the cohort strati ed by randomized group. Comparing the counseling group vs the HBPM group, 50 (98%) and 47 (96%) participants had an existing primary care doctor, respectively; 43 (84%) and 42 (85%) had seen their PCP in the last 6 months (of which 36 and 29 saw their PCP in the last 3 months), and 44 (86%) vs 40 (82%) were aware of a prior diagnosis of hypertension, respectively. The enrolled cohort in our clinic demonstrated higher baseline treatment as compared to prior literature(5) with 78% and 80% of each group, respectively, reporting that they were prescribed medications to control their blood pressure. Regarding medication adherence, it was similar amongst both groups. Out of 79 patients amongst both groups being treated for elevated blood pressure, a total of 64 (81%) agreed or strongly agreed with the statement that they took all their antihypertensive medications as prescribed. See Table 2 for more information regarding their hypertensive history.

Protocol Completion and Feasibility:
Out of 100 participants enrolled, 31 out of 51 (61%) patients in the counseling group and 30 out of 49 (61%) in the HBPM group were able to be reached for a follow up questionnaire. For the 39 participants who could not be contacted, a chart review in the EHR was performed to identify which patients had seen their PCP and had a change in their medication regime. If no information was found, they were coded as missing information. See Fig. 2.
Of the forty-nine home blood pressure monitors provided, 46 (94%) were returned, consistent with our prior experience of adherence to such monitoring among study participants in the preoperative population. Modi cation of hypertensive treatment took place in 17 out of 36 (47%) patients in the counseling group and 18 out of 31 (58%) in the HBPM group that answered this question. Figure 4. The changes in the counseling group included 4 (24%) patients with an increase in dosing, 7 (41%) patients who had a change in medications prescribed, and 9 (53%) patients that had medications added. In the HBPM group, these number were 6 (33%), 5 (28%) and 8 (44%), respectively. Out of the patients that were not on medications pre-operatively, 3 out of 13 (23%) in the control group and 3 out of 16 (19%) in the intervention group were started on medications.
Secondary Outcomes and Participant Acceptance of the Interventions: Out of the 61 participants who we were able to reach for post-surgical follow-up, 30 belonged to the HBPM group and 31 to the counseling group. They were all asked several questions regarding satisfaction with the protocol participation, as listed in Fig. 1.
When asked if they remembered the NHLBI brochure and had put in practice any recommendations, 43 out of sixty-one (70%) of the participants answered that they did. The most common interventions cited by participants were diet changes, and exercise; endorsed equally by 61% of participants. See Table 3. Multiple answers per patient allowed; therefore, columns do not add to 100%. N equals available answers from patients reached by phone, as well as chart reviews.
Regarding protocol acceptance, participants were asked to rate their satisfaction with the study on several 5-point Likert scales ranging from 1 "not at all" through 5 "very much". Overall, fty-two out of 61 (85%) participants who answered, were moderately to very satis ed with their participation in the study. 49 out of 60 (82%) patients thought the NHLBI brochure was moderately to very helpful; and when asked about the follow up call, 44 out of 55 (80%) patients that answered ranked it as moderately helpful to very helpful. Of the patients in the HBPM group, 28 out of 30 (93%) that were reached found it moderately to very easy to utilize, although total of 7 out of the 46 (15.2%) patients who returned the HBPM, expressed that adding the HBPM peri-operatively was an added stressor. See Fig. 5.

Discussion
Elevated blood pressure is a common, deadly, and modi able cardiovascular disease (CVD) risk factor in patients presenting for surgery. Programs such as the Perioperative Enhancement Team (POET) at Duke University, have created multidisciplinary teams with the intention of reducing perioperative risk factors by sending their patients to subspecialized clinics for optimization with good results. (19)(20)(21) However, interventions focused on care coordination for newly diagnosed or uncontrolled hypertension have been more limited. (11) The present pilot study demonstrates that preoperative clinic blood pressure interventions are feasible and accepted by most participants, but their impact on blood pressure management is not established.
Several important results of the pilot deserve highlighting. First, while HBPM monitoring was successfully implemented in 94% of participants, it is not clear whether the marginal value gained from the relatively time-intensive process of instructing patients on HBPM use and tracking HBPM return carries su cient pay-off over and above the simple intervention of a brief counseling session at the time of preoperative evaluation. Although HBPM has been shown to have a higher sensitivity and speci city for truly elevated blood pressure as compared to o ce measurements, (22)(23)(24) it is notable that almost 4 in 5 participants who were deemed to be hypertensive in the preoperative clinic indeed had the diagnosis con rmed in their home blood pressure readings. It is not clear whether the marginal improvement in diagnostic delity found in HBPM outweighs the practical bene ts of a more widely acceptable brief counseling intervention for hypertensive presurgical patients.
Second, it is notable that the study cohort demonstrated signi cant changes in hypertension treatment at 60 days follow-up regardless of group assignment. The fact that 35 out of 100 patients in the trial had a change in hypertensive medication treatment at 60-days of follow-up may lend credence to the potential importance of preoperative counseling to encourage such follow-up.
Finally, given the nding that a large percentage of the overall cohort were not able to be reached by telephone at 60 days suggests that future pragmatic trials of larger scale blood pressure screening interventions in the perioperative period may bene t from greater reliance on EHR follow up to ascertain blood pressure treatment changes. While this would, of course, limit potential follow-up to patients within integrated EHR systems, the alternative of telephone follow-up itself carried with it a 39% failure to followup. As integrated electronic health records gain market penetrance, we suggest that the bene ts of EHR follow-up are likely to increase.
In conclusion, our pilot study suggests that preoperative clinic blood pressure screening and intervention is feasible and accepted by patients. Given the accuracy of preoperative clinic blood pressure measurement for predicting longitudinally elevated blood pressures, it remains unestablished whether additional diagnostic accuracy obtained from home blood pressure monitoring in the preoperative period The Yale School of Medicine Institutional Review Board approved the study, and all participants provided written informed consent.

Consent for publication
The Yale School of Medicine Institutional Review Board approved the study, and all participants provided written informed consent.

Availability of data and materials
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Competing interests
Dr. Schonberger reports owning stock in Johnson & Johnson. Dr. Schonberger reports that his institution receives funding from Merck, Inc. on a study with which he is involved.

Funding
This work was supported in part by CTSA Grant UL1 RR024139 from the National Center for Advancing Translational Sciences (NCATS). The content is solely the responsibility of the authors and does not necessarily represent the policy or views of the NIH, NCATS, or the United States Government.
Authors' contributions RS, SD and MB performed the study conception and design. SD and LY recruited and followed up with participants and acquired data. FD and BZ analyzed and interpreted the data collected. RS, SD, LY, and FD participated in the drafting of the manuscript. All authors read, performed critical revision and approved the nal manuscript.