Use of Impedance Cardiography to Guide Blood Pressure Lowering Medication Selection: Systematic Review of Randomized Controlled Trials

BACKGROUND: Blood pressure (BP) control can be difficult to attain due to multiple factors, including choosing and titrating antihypertensive medications. Measurement of hemodynamic parameters using impedance cardiography (ICG) at the point of care may allow better alignment of medication with the mechanism(s) underlying an individual's hypertension. We conducted a systematic review of randomized controlled trials of ICG compared to usual care for attainment of BP control. METHODS: We searched Medline inclusive of the year 1946 to January 31, 2024, using a combination of MeSH terms and keywords. English-language articles were eligible for inclusion if they described results of a randomized controlled trial designed to compare ICG-guided BP-medication selection to usual care (i.e., clinician judgment/guidelines-based alone) among a sample of hypertensive patients. RESULTS: Of 1,952 titles screened, 6 trials met inclusion criteria. The first was published in 2002 from a specialty clinic in the United States, and the most recent in 2021 from a specialty clinic in China. One trial was conducted in a primary care setting. Sample sizes ranged from 102 to 164. Participants randomized to ICG-guided antihypertensive medication had reduced BP in the short-term to a greater extent than those randomized to usual care, with odds ratios for BP control (<140/90 mm Hg) at 3 months ranging from 1.87 to 2.92. This effect was seen in both specialty clinics and in a primary care setting. CONCLUSIONS: Incorporation of ICG in the clinical setting may facilitate medication selection that leads to a greater proportion of patients obtaining BP control in the short term.