SIU research is reshaping blood pressure care
At SIU School of Medicine, the story of hypertension research doesn’t begin in a distant lab. It begins in the clinic, often with a patient who has run out of options.
A provider reviews the numbers. Despite multiple medications, lifestyle changes and follow-up visits, blood pressure remains stubbornly high. In that moment, a different path forward is offered: enrollment in a clinical trial conducted by SIU’s Hypertension Clinic.
These trials are not theoretical with no practical outcome. They are active, evidence-based and available right here in central and southern Illinois. One of SIU’s own, Dr. John M. Flack, not only participates in these global trials, but he helps design and formally lead them.
A clinic where research meets real life
Led by John M. Flack, MD, MPH, an internationally recognized hypertension expert and NIH-trained cardiovascular epidemiologist, SIU’s Hypertension Clinic bridges the gap between discovery and care. Flack also chairs the Departments of Internal Medicine and Population Science and Policy and has authored more than 250 peer-reviewed manuscripts, book chapters and editorials. His work has been cited more than 16,500 times by fellow researchers, clinicians and scientists.
He has served in leadership and advisory roles with the National Institutes of Health, the American Heart Association and the American Society of Hypertension. He is currently president of the American Hypertension Specialist Certification Program.
“Our goal is to connect expert, state-of-the-art hypertension care with the discovery of new insights that can improve treatment and understanding of the disease,” Flack said. “The clinical trials testing new drugs and devices at SIU rival those offered anywhere in the world. We also lead SIU-only studies focused on specific challenges, such as primary aldosteronism, hypertension in women with a history of pregnancy-related blood pressure issues, and resistant or refractory hypertension,” he continued.
The clinic is part of a growing research ecosystem at SIU School of Medicine focused on improving outcomes for patients with resistant/refractory hypertension, a form of high blood pressure that remains uncontrolled despite the use of multiple, usually effective, medications. Working with a multidisciplinary team that includes nurse practitioners, pharmacists, nurses and data scientists, Flack’s group is testing therapies that could change the standard of care.
Key research and clinical collaborators include:
- Michael Buhnerkempe, PhD, associate vice chair of research, Department of Internal Medicine, director of data analytics, Department of Population Science and Policy
- Albert Botchway, PhD, deputy director of data analytics, Departments of Population Science and Policy and Internal Medicine, Center for Clinical Research
- Emily Starkey, associate director of research, Department of Internal Medicine
- Ashley Hill, DNP, certified hypertension clinician, Hypertension Specialty Clinic
- Stephanie Bitner, PharmD, Hypertension Specialty Clinic
- Christine Jarmer, RN, Hypertension Specialty Clinic
- Priyank Bhandari, MD, certified hypertension specialist, Department of Family and Community Medicine
- Michael Jakoby, MD, vice chair for research, Chief of Endocrinology, Department of Internal Medicine
- Vanessa Williams, MD, assistant professor of Clinical Internal Medicine, Division of Endocrinology, Department of Internal Medicine
- Vivek Prakash, information technology associate, Center for Clinical Research
- Katy Martz, clinical research coordinator, Department of Internal Medicine and Center for Clinical Research
- Sheridan Houston, clinical research specialist, Center for Clinical Research
Offering major studies close to home
The same advanced hypertension clinical trial research offered at major urban centers is available through SIU School of Medicine. Several trials are currently enrolling participants from central and southern Illinois.
The HyPhen study, for example, examines how body composition, vascular function and pregnancy-related changes in vascular function influence long-term cardiovascular health. This homegrown study reflects SIU’s mission to conduct community-relevant research.
Another milestone: SIU researchers participated in a national clinical trial for the Paradise Renal Denervation System, a sound wave-based device that interrupts nerve signals between the kidneys and the brain. That therapy is now FDA-approved, and SIU Medicine is one of the first centers in Illinois to offer renal denervation as an option for patients whose blood pressure cannot be adequately controlled with medication.
Performed on an outpatient basis, the procedure is minimally invasive and has been shown to safely lower blood pressure for years. Interventional cardiologist Abdul Moiz Hafiz, MD, has led the clinical implementation of renal denervation at Springfield Memorial Hospital.
In a large worldwide trial, Flack was vice chair of the baxdrostat clinical trials executive committee and is the lead author on the manuscript reporting the main results. Baxdrostat is an aldosterone synthase inhibitor, for lowering blood pressure in patients with hypertension uncontrolled by FDA-approved medications. Dr. Flack and his team enrolled SIU patients into this now completed clinical trial. The drug is pending FDA approval.
Behind each trial is a dedicated team of coordinators, nurses and investigators who work to ensure patient safety, transparency and respect. Participation is always voluntary, with no-cost study-related care and a stipend available to offset time and/or travel costs.
From data to insight
Recent research from Flack and his team continues to shed light on real-world challenges in hypertension care.
A 2025 study co-authored with scientists at the Centers for Disease Control and Prevention found a concerning trend: more patients with high blood pressure are also taking medications that can raise it. The result is a reduction in the effectiveness of their blood pressure treatments.
Another publication, co-authored with SIU colleagues including Bhandari, MD, Bitner, PharmD, and Buhnerkempe, PhD, found that individuals with obesity often require more intensive medication than leaner patients. However, despite more intense antihypertensive drug therapy, they do not achieve as low a blood pressure as their leaner counterparts on average. That insight, published in the American Journal of Hypertension, adds clarity to the need for even more intensive drug therapy and/or lifestyle interventions to parity in blood pressure lowering relative to leaner patients.
Joseph Milbrandt, PhD, Director, Center for Clinical Research, said, “Dr. Flack has demonstrated a strong commitment to advancing clinical research within the Department of Internal Medicine. His vision and leadership, combined with a collaborative approach, have driven meaningful change and transformative growth. The Center for Clinical Research is proud to have supported Dr. Flack and his faculty, and remains dedicated to the continued success of our clinical trials enterprise.”
Forward, together
Clinical trials and other related hypertension studies at SIU School of Medicine are about the discovery of new knowledge that will advance the care options available to patients with hypertension and related conditions. This will be of tremendous benefit to the patients we serve here in central and southern Illinois.
For Flack, the work is grounded in a simple belief: research should benefit the communities where it happens. That’s why his team continues to expand clinical trial opportunities that are accessible, affordable and designed around the needs of local patients.
To learn more about current hypertension clinical trials at SIU School of Medicine, visit siumed.org/hypertension-clinical-trials or contact the hypertension research team at 217-545-7511 or bpresearch@siumed.edu.
