Resident-led improvement project to screen for primary hyperaldosteronism in patients with resistant hypertension in an outpatient clinic (2024)

WHAT IS ALREADY KNOWN ON THIS TOPIC

• In patients with resistant hypertension, guidelines recommend screening for primary hyperaldosteronism (PH). However, outpatient screening rates for PH are low.

WHAT THIS STUDY ADDS

• A screening programme for PH in patients with resistant hypertension and targeted phone calls to initiate mineralocorticoid receptor antagonist therapy can be successfully implemented in a primary care clinic.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

• This resident-led quality improvement project provides a model for the initiation of a systematic screening and treatment programme in a primary care clinic for patients with resistant hypertension with the ultimate goal of improving blood pressure control.

Measurement

The main outcome measured in this project was the PH screening rate. This was defined as the number of patients screened for PH divided by the total number of patients with resistant hypertension. We measured the screening rate before and after each Plan–Do–Study–Act (PDSA) cycle.

A secondary outcome was blood pressure control after starting an MRA. To measure this, we documented the most recent blood pressure prior to MRA initiation, and the blood pressure at least a week after MRA initiation. Serum potassium levels were measured in this fashion as well to assess for potential hyperkalaemia from MRA initiation.

Design

This programme was performed in a resident outpatient primary care clinic, which includes roughly 24 resident physicians who practise longitudinally in this clinic over their three year Internal Medicine residency, under the supervision of faculty physicians. The project was selected as one of the resident-led quality improvement (QI) goals for the academic year, and the project team included 10 resident physician team members, under the mentorship of the Chief Resident in Quality and Safety, primary care faculty and departmental QI leaders. The overall design was based on panel management, in which clinicians take responsibility to proactively optimise the health of an assigned population of patients.9

In August 2021, the resident physician project leaders identified patients with possible resistant hypertension in our resident primary care panels through a VA Primary Care Almanack Metric query with subsequent medical record review for resistant hypertension criteria. The resident physician team members assessed medication adherence through chart review, including a medication refill review, to rule out pseudoresistant hypertension.

In our initial design, we planned to improve PH screening rates in our patients through communicating with patients and their providers and ordering screening labs. We hypothesised that this direct approach would efficiently achieve our objective and be feasible for our relatively small population. We started with the lowest effort intervention with the goal of reassessing and stepping up efforts as needed to achieve our goals.

Patient and public involvement

This study was primarily formulated and conducted by attending and resident physicians. Patients were not directly involved in the development or conduct of this study. We communicated with patients through phone calls and primary care appointments for counselling regarding resistant hypertension workup and blood pressure control.

Strategy

We implemented three sequential PDSA cycles with internal medicine residents during dedicated clinic QI half-days (figure 1). In the first PDSA cycle, patients with resistant hypertension had screening labs (plasma aldosterone concentration (PAC) and plasma renin activity (PRA)) ordered and were scheduled for clinic visits for hypertension follow-up by residents.

Since this did not reach our goal screening rate, we implemented a second PDSA cycle. Residents called patients without screening labs, used a script to discuss resistant hypertension and confirm adherence to medications and counselled patients on the need for labs to screen for PH with the expectation that they would follow up with their primary care providers during their next routine visit.

In PDSA cycle 3, patients with positive screening labs (PAC>5 ng/dL and PRA<1 ng/mL/hour) were called by residents to discuss MRA initiation and possible endocrinology referral. This cycle was intended to improve blood pressure control.

Lessons and limitations

This resident-led QI project demonstrated that an adaptive intervention process using serial PDSA cycles improved PH screening rates in patients with resistant hypertension from 24% to 84% in an academic VA internal medicine practice.

Compared with the PH screening rates in previous studies (less than 3%), our initial PH screening rate was 24%. This discrepancy could be due to small sample size, and the fact that this project was done in a relatively low-volume clinic that prioritises resident education.

The first PDSA cycle was ineffective in reaching our target, which may have been related to patient hesitance in presenting for preclinic labs without additional counselling. Our second PDSA cycle, thus, aimed to counsel patients on the benefits of obtaining labs as a part of blood pressure control and overall chronic disease management. In PDSA cycle 3, MRA initiation improved blood pressures in three of five patients while referral to endocrinology was unsuccessful as patients either deferred or were unable to schedule appointments. This suggests that specialty referral may not be a viable pathway for improving screening and treatment of usual PH and should prompt consideration of MRA initiation by primary care in patients identified through PH screening.

Of 37 screened patients, 9 (24%) screened positive, which is similar to prior study results.7 This relatively high fraction suggests it is beneficial to screen for PH. Our results also support that MRAs can be effective in normalising blood pressure in resistant hypertension patients and can be started safely in primary care.

The structure of a dedicated QI half-day for resident physicians in our clinics facilitated the opportunity to call and reach out to patients with resistant hypertension. However, in clinics where this may not be feasible, the concepts learnt through this QI effort may be integrated into team-based care—calls could be carried out by practice staff rather than resident physicians.

This project has a few limitations. First, this project had a small sample size. It is unclear if the positive PH screening rate would be as high with a larger sample. With a larger sample size, it may be difficult to screen as large of a fraction of the patients for PH due to logistics. A larger sample size would also provide more precise data on the effectiveness of endocrinology referral and MRA initiation in improving blood pressure. This project was done at one VA resident outpatient clinic using the patient-aligned care team (PACT) team structure, and these QI interventions may be difficult to perform in settings with fewer resources for team-based care.9

The sustainability of these improved PH screening rates can be developed in the future through education and systems modifications. To create a culture of appropriately screening for resistant hypertension, educational sessions could be tailored towards physicians demonstrating the effectiveness of the above-mentioned interventions. Physicians can then discuss the necessity of screening with patients in their routine visits. Systems modifications that would promote sustainability include creating nudges on the electronic medical record (EMR) that alert physicians to patients who may be appropriate candidates for screening and adding a ‘resistant hypertension screening labs’ order set that facilitates screening on the EMR.

In addition to screening for PH, an alternate approach to improve blood pressure in patients with resistant hypertension is empirically initiating an MRA, without testing for PH. Although this may not yield a diagnosis, it may improve a blood pressure and avoid the delays of testing. It is worth comparing the blood pressure-lowering outcomes of this ‘empiric MRA’ approach with the ‘testing-first’ approach.

Patient consent for publication

Not applicable.