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

Abstract

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.

Keywords

hypertension hemodynamics impedance cardiography medical management therapy

References

Agency for Healthcare Research and Quality ( 2001) Translating Research Into Practice (TRIP) - II. AHRQ Pub. No. 01-P017. In: Services, U.S.D.O.H.A.H. and Service, P.H. (eds), Rockville, MD.

Albert, N.M. , Hail, M.D. , Li, J. and Young, J.B. ( 2004) Equivalence of the bioimpedance and thermodilution methods in measuring cardiac output in hospitalized patients with advanced, decompensated chronic heart failure. Am J Crit Care 13: 469-479.

Aoka, Y. ( 2009) Limitation of monotherapy and benefit of impedance cardiography as a guide for a combination therapy in achieving blood pressure control in essential hypertension. J Clin Hypertens 11: A21.

Bogardus Jr, S.T. , Holmboe, E. and Jekel, J.F. ( 1999) Perils, pitfalls, and possibilities in talking about medical risk. JAMA 281: 1037-1041.

Brookes, L. ( 2006) Prehypertension, the elderly, dementia, and sleep - how to treat the blood pressure? Medscape Cardiology 10.

Bull, S.A. , Hu, X.H. , Hunkeler, E.M. , Lee, J.Y. , Ming, E.E. , Markson, L.E. et al. (2002) Discontinuation of use and switching of antidepressants: influence of patient-physician communication. JAMA 288: 1403-1409.

Calhoun, D.A. , Jones, D. , Textor, S. , Goff, D.C. , Murphy, T.P. , Toto, R.D. et al. (2008) Resistant hypertension: diagnosis, evaluation, and treatment: a scientific statement from the American Heart Association Professional Education Committee of the Council for High Blood Pressure Research . Hypertension 51: 1403-1419.

Chobanian, A.V. , Bakris, G.L. , Black, H.R. , Cushman, W.C. , Green, L.A. , Joseph, L. , Izzo, J. et al. (2003) The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure . JAMA 289: 2560-2572.

Ciechanowski, P.S. , Katon, W.J. , Russo, J.E. and Walker, E.A. ( 2001) The patient-provider relationship: attachment theory and adherence to treatment in diabetes. Am J Psychiatry 158: 29-35.

10.

Connolly, C. ( 2009) Comparison Shopping for Medicine: Obama’s Stimulus Package Funds Research on Cutting Costs. Washington Post March 17: 2009.

11.

Cushman, W.C. , Ford, C.E. , Einhorn, P.T. , Wright, Jr. J.T. , Preston, R.A. , Davis, B.R. et al. (2008) Blood pressure control by drug group in the antihypertensive and lipid-lowering treatment to prevent heart attack trial (ALLHAT). J Clin Hypertens (Greenwich ) 10: 751-760.

12.

Drazner, M.H. , Thompson, B. , Rosenberg, P.B. , Kaiser, P.A. , Boehrer, J.D. , Baldwin, B.J. et al. (2002) Comparison of impedance cardiography with noninvasive hemodynamic measurements in patients with heart failure secondary to ischemic or nonischemic cardiomyopathy. Am J Cardiol 89: 993-995.

13.

Duprez, D.A. ( 2008) Systolic hypertension in the elderly: addressing an unmet need. Am J Med 121: 179-184e173.

14.

Ferrario, C.M. , Basile, J. , Bestermann, W. , Frohlich, E. , Houston, M. , Lackland, D.T. et al. (2007) The role of noninvasive hemodynamic monitoring in the evaluation and treatment of hypertension. Ther Adv Cardiovascr Dis 1: 113-118.

15.

Ferrario, C.M. , Smith, R. , and Investigators (2006) Cost-effectiveness of impedance cardiography testing in uncontrolled hypertension , Am Heart Hospital J 4: 279-289.

16.

Flack, J.M. ( 2006) Noninvasive hemodynamic measurements: an important advance in individualizing drug therapies for hypertensive patients. Hypertension 47: 646-647.

17.

Gu, Q. , Burt, V.L. , Paulose-Ram, R. and Dillon, C.F. ( 2008) Gender differences in hypertension treatment, drug utilization patterns, and blood pressure control among US adults with hypertension: data from the National Health and Nutrition Examination Survey 1999-2004. Am J Hypertens 21: 789-798.

18.

New England Health Care Institute. (2009) Balancing Act: Comparative Effectiveness Research and Innovation in U.S. Health Care: A White Paper, Published by New England Healthcare Institute : Cambridge, MA.

19.

Izzo, J.L. , Sica, D.A. and Black, H.R. ( 2008) Hypertension Primer: The Essentials of High Blood Pressure: Basic Science, Population Science, and Clinical Management, 4th edn, Lippincott Williams & Wilkins : Baltimore.

20.

Jones, D.W. ( 2008) ‘Preventing Cardiovascular Disease: Is the General Public’s Erroneous Perception the Reason We Are Not Doing Better?’ , presented at the 16th World Congress of Cardiology , 18-21 may, Buenos Aires, Argentina.

21.

Lewington, S. , Clarke, R. , Qizilbash, N. , Peto, R. and Collins, R. ( 2002) Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet 360: 1903-1913.

22.

Lloyd-Jones, D.M. , Evans, J.C. , Larson, M.G. , O’Donnell, C.J. , Roccella, E.J. and Levy, D. ( 2000) Differential control of systolic and diastolic blood pressure: factors associated with lack of blood pressure control in the community. Hypertension 36: 594-599.

23.

Matthews, R.E. , Magenheim, D. and Group, P.P. ( 2008) Improvement in blood pressure control using a quality improvement process with impedance cardiography to guide antihypertensive therapy. J Clin Hypertens 10: A76.

24.

Members, W.G. ( 2009) Heart Disease and Stroke Statistics - 2009 Update: A Report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation 119: e21-e181.

25.

Mokwe, E. , Ohmit, S.E. , Nasser, S.A. , Shafi, T. , Saunders, E. , Crook, E. et al. (2004) Determinants of blood pressure response to quinapril in black and white hypertensive patients: the quinapril titration interval management evaluation trial. Hypertension 43: 1202-1207.

26.

Nasser, S.A. , Lai, Z. , O’connor, S. , Liu, X. and Flack, J.M. ( 2008) Does earlier attainment of blood pressure goal translate into fewer cardiovascular events? Curr Hypertens Rep 10: 398-404.

27.

Okonofua, E.C. , Simpson, K.N. , Jesri, A. , Rehman, S.U. , Durkalski, V.L. and Egan, B.M. ( 2006) Therapeutic inertia is an impediment to achieving the healthy people 2010 blood pressure control goals. Hypertension 47: 345-351.

28.

Peverill, R.E. ( 2005) Hypertension guidelines, meta-analyses and clinical trials: do we assume too much? Med J Aust 182: 82-84.

29.

Sageman, W.S. , Riffenburgh, R.H. and Spiess, B.D. ( 2002) Equivalence of bioimpedance and thermodilution in measuring cardiac index after cardiac surgery. J Cardiothorac Vasc Anesth 16: 8-14.

30.

Sehgal, A.R. ( 2004) Overlap between whites and blacks in response to antihypertensive drugs. Hypertension 43: 566-572.

31.

Services, U.D.O.H.A.H. ( 2000) Healthy People 2010, 2nd edn, US Government Printing Office: Washington, D.C.

32.

Shaneyfelt, T.M. and Centor, R.M. (2009) Reassessment of clinical practice guidelines: go gently into that good night. JAMA 301: 868-870.

33.

Smith, R.D. , Levy, P. and Ferrario, C.M. ( 2006) Value of noninvasive hemodynamics to achieve blood pressure control in hypertensive subjects. Hypertension 47: 771-777.

34.

Smith, R.D. and Levy, P.J. ( 2008) New techniques for assessment of vascular function. Ther Adv Cardiovasc Dis 2: 373-385.

35.

Sramek, B. , Tichy, J.A. , Hojerova, M. and Cervenka, V. ( 1996) Normohemodynamic goal-oriented antihypertensive therapy improves the outcome. Am J Hypertens 9: 141A.

36.

Sramek, B. , Badila, E. , Bartos, D. and Tirziu, C. ( 2008) Treating hypertension as a hemodynamic disorder results in three-fold improvement in outcomes. J Clin Hypertens 10(Suppl. A): A81 (abstract).

37.

Stason, W.B. (2009) Hypertension: a policy perspective, 1976-2008. J Am Soc Hypertens 3: 113-118.

38.

Stason, W.B. and Weinstein, M.C. ( 1977) Public-health rounds at the Harvard School of Public Health. Allocation of resources to manage hypertension. N Engl J Med 296: 732-739.

39.

States, C.O.T.U. ( 2007) Research on the Comparative Effectiveness of Medical Treatments:Issues and Options for an Expanded Federal Role. In: Office, C.B (ed), Washington D.C.

40.

Stewart, M.A. ( 1995) Effective physician-patient communication and health outcomes: a review. CMAJ 152: 1423-1433.

41.

Taler, S.J. , Textor, S.C. and Augustine, J.E. ( 2002) Resistant hypertension: comparing hemodynamic management to specialist care. Hypertension 39: 982-988.

42.

Travaline, J.M. , Ruchinskas, R. , Gilbert, E. and D’Alonzo, J. ( 2005) Patient-physician communication: why and how. JAOA 105: 13-18.

43.

Treister, N. , Wagner, K. and Jansen, P.R. ( 2005) Reproducibility of impedance cardiography parameters in outpatients with clinically stable coronary artery disease. Am J Hypertens 18: 44S-50S.

44.

Van De Water, J. , Miller, T. , Vogel, R.L. , Mount, B.E. and Dalton, M.L. ( 2003) Impedance cardiography: the next vital sign technology? Chest 123: 2028-2033.

45.

Wang, T.J. and Vasan, R.S. ( 2005) Epidemiology of uncontrolled hypertension in the United States. Circulation 112: 1651-1662.

46.

Weinstein, M.C. and Stason, W.B. ( 1976) Hypertension: A Policy Perspective, 1st edn, Harvard University Press: Cambridge, MA.

47.

Yakovlevitch, M. and Black, H.R. ( 1991) Resistant hypertension in a tertiary care clinic. Arch Intern Med 151: 1786-1792.