Using impedance cardiography with postural change to stratify patients with hypertension

Background: Early detection of cardiovascular disease in patients with hypertension could initiate appropriate treatment to control blood pressure and prevent the progression of cardiovascular disease.

Objective: The goal of this study was to show how impedance cardiography waveform analysis with postural change can be used to detect subclinical cardiovascular disease in patients with high blood pressure.

Methods: Patients with high blood pressure had impedance cardiography data obtained in two positions, standing upright and supine.

Results: In 50 adults, impedance cardiography indicated that all patients had abnormal data, with 44 (88%) having multiple abnormalities. Impedance cardiography showed 32 (64%) had ventricular dysfunction, 48 (96%) had vascular load abnormalities, 34 (68%) had hemodynamic abnormalities, 2 (4%) had hypovolemia, and 3 (6%) had hypervolemia.

Conclusions: Hypertensive patients have diverse cardiovascular abnormalities that can be quantified by impedance cardiography. By stratifying patients with ventricular, vascular, and hemodynamic abnormalities, treatment could be customized based on the abnormal underlying mechanisms with the potential to rapidly control blood pressure, prevent progression of cardiovascular disease, and possibly reverse remodeling.

Individualizing hypertension treatment with impedance cardiography: a meta-analysis of published trials

Objective: Hypertension affects 73 million Americans and costs the US healthcare system over $73 billion annually. Despite increasing awareness of the consequences of uncontrolled hypertension, numerous antihypertensive pharmacologic clinical studies and consistent updates to hypertension guidelines, control rates are suboptimal and have not met national goals. Among treated hypertensives, only 45% of women and 51% of men have reached blood pressure (BP) levels below 140/90 mmHg. Individualization of antihypertensive regimens with hemodynamic information from impedance cardiography (ICG) has been advocated to further improve hypertension control rates. We therefore undertook a quantitative analysis of the trials evaluating the role of ICG as an adjunct to therapeutic decision-making in the treatment of hypertension and the attainment of BP control.

Methods: Five studies comprising a total population of 759 patients met the inclusion criteria. Two randomized controlled trials (RCTs) involving a total of 268 patients and three single-arm prospective trials with 491 patients were evaluated using ICG data to guide therapeutic decision-making in the treatment of hypertensive patients.

Results: Significant benefit was found in both RCTs for ICG-guided BP treatment. The combined odds ratio for the two trials was 2.41 (95% CI = 1.44-4.05, p = 0.0008), in favor of ICG treatment, meaning that it was more than twice as likely to achieve BP success when using ICG than if ICG was not used. Success attainment of goal BP of <140/90 mmHg was 67% in the ICG-guided arms of the combined randomized trials. Overall success in the single-arm prospective trials of ICG-guided BP treatment was a similar 68%.

Conclusion: The results of this meta-analysis confirm the value of using ICG-derived hemodynamic data as an adjunct to therapeutic decision-making in the treatment of hypertension. The data reviewed here demonstrate that ICG-based approaches are in keeping with previously advocated strategies incorporating patient-individualized drug regimens, evidence-based medicine, and practical, easy to apply, cost-effective principles to further improve hypertension control rates.