Abstract: FR-PO578
Impedance Cardiography Informs Hypertensive Management
Session Information
- Hypertension: Clinical and Translational
November 03, 2017 | Location: Hall H, Morial Convention Center
Abstract Time: 10:00 AM - 10:00 AM
Category: Hypertension
- 1106 Hypertension: Clinical and Translational - Secondary Causes
Authors
- Chait, Yossi, University of Massachusetts , Amherst, Massachusetts, United States
- Greco, Barbara A., Renal and Transplant Associates of New England, Springfield, Massachusetts, United States
- Germain, Michael J., Renal and Transplant Assoc of New England, Hampden, Massachusetts, United States
Background
High blood pressure (BP) is a leading cause of death and disability in the US and worldwide. Approximately 1 of 3 U.S. adults (75 million) have high blood pressure, and only about half treated with antihypertensive protocol have their high blood pressure in recommended blood pressure target. Titration of medications involves a trial and error process, especially in resistant hypertension, and is typically guided by office blood pressure, an imprecise, indirect piece of overall hemodynamic status. It has been reported that cardiac power index (CPI) is the best hemodynamic correlate of mortality. Our aim was to follow standard hypertensive management using hemodynamic parameters as hypothesis generating. We measured hemodynamics (NICaS, NI Medical Israel) using a non-invasive, whole-body impedance cardiography technology. NICas reports stroke volume and pulse rate and therefore cardiac index (CI), and together with the measurement of BP it calculates total peripheral resistance index (TPRI).
Methods
We repeated NICaS measurements in 40 hypertensive patients with CKD, kidney transplant, and resistance hypertension over a follow up period up to 6 months (Treatment), andtitration was done after the first measurement (Baseline).
Results
We report results in 2 representative cases. BP was significantly reduced in both patients following medication changes. Hemodynamic changes from Baseline (Table, Figure) reveal that the reduction in TPRI in Patient A was associated with normalization of CI and CPI improving into their normal range after treatment. In Patient B an increase in TPRI was associated with decrease in CI and CPI out of normal range after treatment.
Conclusion
If BP alone was the single most important parameter, then the treatment could be considered a success. However, BP changes do not correlate well with direction of changes in other hemodynamic parameters, and can mask worsening CI and CPI. These results suggest that hemodynamics parameters should be guided using measurements of hemodynamics parameters beyond BP alone. Our hypothesis, to be tested in a large study in the near future, is that using impedance cardiography to guide hypertensive management will result in better BP control and patient experience (symptoms and compliance).
| SDP/DBP (mmHg) | Cardiac Index (L/min/m^2) | Total Peripheral Resistance Index (Dyn*sec/cm^5/m^2) | Cardiac Power Index (W/m^2) | |||||
| Patient | A | B | A | B | A | B | A | B |
| Baseline | 142/70 | 188/88 | 2.2 | 2.2 | 3790 | 4272 | 0.41 | 0.58 |
| Treatment | 112/68 | 147/74 | 2.8 | 1.6 | 2324 | 4949 | 0.51 | 0.34 |