This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ramahi, T. M. Articles by Wackers, F. J. T. Search for Related Content PubMed PubMed Citation Articles by Ramahi, T. M. Articles by Wackers, F. J. T.

CLINICAL STUDY: HEART FAILURE

Left ventricular inotropic reserve and right ventricular function predict increase of left ventricular ejection fraction after beta-blocker therapy in nonischemic cardiomyopathy

Tarik M. Ramahi, MD, FACC^*, Marcella D. Longo, MD, Arina R. Cadariu, MD^*, Kate Rohlfs, RN^*, Stella A. Carolan, RN^*, Kathryn M. Engle, RN^*, Habib Samady, MD^* and Frans J. Th Wackers, MD, PhD, FACC^*

^* Section of Cardiovascular Medicine, Yale School of Medicine, New Haven, Connecticut, USA
Division of Cardiology, University of Turin, Molinette Hospital, Turin, Italy

Manuscript received February 28, 2000; revised manuscript received September 29, 2000, accepted November 3, 2000.

Reprint requests and correspondence: Dr. Tarik M. Ramahi, 135 College Street, Suite 301, New Haven, Connecticut 06510-2483
ramahi{at}aya.yale.edu

OBJECTIVES

The purpose of this study was to determine whether higher left ventricular inotropic reserve, defined as the increase in left ventricular ejection fraction (LVEF) in response to intravenous dobutamine infusion, or other ventriculographic variables predict the increase in LVEF after beta-blocker therapy in patients with nonischemic cardiomyopathy (NICM).

BACKGROUND

Long-term beta-blocker therapy increases LVEF in some patients with NICM. Other than dose, there are no definite predictors of LVEF increase.

METHODS

Thirty patients with LVEF 0.35 and NICM underwent assessment of LVEF at rest and after a 10-min intravenous infusion of dobutamine at 10 µg/kg/min, using equilibrium radionuclide ventriculography. Age was 49 ± 11 years, 33% women, functional class 2.6 ± 0.5, duration of chronic heart failure 3.2 ± 2.9 years, LVEF 0.21 ± 0.07, left ventricular end-diastolic volume index 180 ± 64 ml/m². Right ventricular ejection fraction (RVEF) was abnormal in 37%. Mean dobutamine-induced augmentation of LVEF (DoLVEF) was 0.12 ± 0.08. Patients were started on one of three beta-blockers (carvedilol, bucindolol or metoprolol) and the dose was advanced to the maximum tolerated.

RESULTS

Left ventricular ejection fraction, reassessed 7.4 ± 5.9 months after maximum beta-blocker dose was reached, increased to 0.34 ± 0.13 (p = 0.0006). The following baseline variables correlated with improvement of LVEF: DoLVEF (p = 0.001), RVEF (p = 0.005), systolic blood pressure at end of dobutamine infusion (p = 0.02) and dose of beta-blocker (p = 0.07). In a multivariate analysis, only DoLVEF (p = 0.0003) and RVEF (p = 0.002) were predictive of the increase in LVEF.

CONCLUSIONS

Patients with nonischemic cardiomyopathy who have higher left ventricular inotropic reserve and normal RVEF derive higher increase in LVEF from beta-blocker therapy.

Abbreviations and Acronyms   CHF = chronic heart failure   DBP = diastolic blood pressure   LVEF = change in left ventricular ejection fraction after beta-blocker treatment   DoLVEF = dobutamine-induced increase in left ventricular ejection fraction   ECG = electrocardiogram   HR = heart rate   LVEDVI = left ventricular end-diastolic volume index   LVEF = left ventricular ejection fraction   NICM = nonischemic cardiomyopathy   RVEF = right ventricular ejection fraction   SBP = systolic blood pressure

This article has been cited by other articles:

				M. Gheorghiade, W. S. Colucci, and K. Swedberg {beta}-Blockers in Chronic Heart Failure Circulation, April 1, 2003; 107(12): 1570 - 1575. [Full Text] [PDF]

				M. Vogel, M. R. Schmidt, S. B. Kristiansen, M. Cheung, P. A. White, K. Sorensen, and A. N. Redington Validation of Myocardial Acceleration During Isovolumic Contraction as a Novel Noninvasive Index of Right Ventricular Contractility: Comparison With Ventricular Pressure-Volume Relations in an Animal Model Circulation, April 9, 2002; 105(14): 1693 - 1699. [Abstract] [Full Text] [PDF]