Clinic dosing of beta blockers in chronic heart failure

Beta blockers improve survival and reduce morbidity of patients with chronic heart failure. Stringent dosing guidelines calling for a 1-hour observation period after initiation or up-titration of beta-blocker therapy might limit the use of beta blockers and increase the expense involved. This study was conducted to determine the usefulness of this observation period. Data were collected from 130 in-clinic postdosing observation periods for 34 stable chronic heart failure patients started on carvedilol. The mean left ventricular ejection fraction was 0.22±0.09, and the mean functional class was 2.5±0.6. No patient had greater than first-degree heart block. Carvedilol was started at 3.125 or 6.25 mg b.i.d., and the dose was doubled every 1-3 weeks. All patients were observed for 1-2 hours after initiation or dosage increase, and blood pressure and heart rate were measured hourly. The maximal daily dose was 50±31 mg. In none of the observation periods was there a decrease in the dose of beta blockers administered in the clinic. The predosing mean blood pressure was 110±15/71±10 mm Hg, and the mean heart rate was 78±13 bpm; the 1-hour postdosing mean blood pressure was 101±14/67±10 mm Hg (p is less than 0.001), and the heart rate was 78±13 bpm. The dose was decreased in six patients and medication was discontinued in three, all consequent to symptoms reported several days after dosage increase. Beta blockers can be safely initiated and up-titrated at home in properly selected and evaluated stable patients with chronic heart failure and severe left ventricular dysfunction resulting in mild or moderate impairment of functional capacity. (c)2001 by CHF, Inc.

Dobutamine-induced augmentation of left ventricular ejection fraction predicts survival of heart failure patients with severe non-ischaemic cardiomyopathy

AIMS

The prognosis of patients with severe non-ischaemic dilated cardiomyopathy is variable. The predictive value of currently utilized tests is suboptimal. The purpose of this study was to determine the prognostic value of dobutamine-induced augmentation of left ventricular ejection fraction in patients with non-ischaemic dilated cardiomyopathy.

METHODS AND RESULTS

Sixty-two patients with left ventricular ejection fraction < or =0.30 underwent exercise testing with gas exchange analysis and assessment of left ventricular ejection fraction at rest and after a 10-min intravenous infusion of dobutamine at 10 microg x kg(-1) x min(-1), using equilibrium radionuclide ventriculography. Age was 48+/-11 years, 32% females, functional class 2.6+/-0.6, resting left ventricular ejection fraction 0.20+/-0.06, and peak exercise oxygen consumption (mVO2) 19+/-6 ml x kg(-1) x min(-1). Mean dobutamine-induced augmentation of left ventricular ejection fraction (DeltaLVEF) was 0.09+/-0.06 (median 0.08, range -0.03 to 0.26). Follow-up was 25+/-15 months during which there were 12 deaths and five transplantations. Patients were divided into two groups based on median DeltaLVEF. The transplant-free survival was better in the group with higher DeltaLVEF (94% vs 64%, P<0.008). In multivariate analysis incorporating age, gender, duration of chronic heart failure, functional class, right and left ventricular ejection fraction, DeltaLVEF, left ventricular end-diastolic volume index, and mVO2, only DeltaLVEF was predictive of 1-year, 3-year, and overall transplant-free survival (RR 0.09, 0.03, and 0.13;P 0.03, 0.09, and 0.08 respectively). The linear correlation between DeltaLVEF and mVO2(r=0.3) and between DeltaLVEF and left ventricular ejection fraction (r=0.5) was weak.

CONCLUSION

Dobutamine-induced augmentation of left ventricular ejection fraction is a strong prognostic variable, independent of exercise capacity and resting ventriculographic variables, in severe non-ischaemic systolic dysfunctional heart failure.

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

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 < or = 0.35 and NICM underwent assessment of LVEF at rest and after a 10-min intravenous infusion of dobutamine at 10 microg/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 (DoALVEF) 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: DoALVEF (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 DoALVEF (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.

Effect of heart failure program on cardiovascular drug utilization and dosage in patients with chronic heart failure

BACKGROUND

Utilization and dosage of angiotensin-converting enzyme (ACE) inhibitors in patients with chronic heart failure (CHF) remain low. Recent data suggest that care of patients with CHF in specialized heart failure programs is associated with improved clinical outcomes.

HYPOTHESIS

Specialized heart failure care is associated with better utilization and higher dose of cardiovascular drugs.

METHODS

Data from 133 patients with CHF referred to a heart failure program were analyzed. Mean functional class 3.1 +/- 0.5, left ventricular ejection fraction 19 +/- 8. Utilization and doses of cardiovascular drugs were examined at initial evaluation and at last visit, after an average period of 17 +/- 14 months. Hospitalization and survival data were determined.

RESULTS

Utilization of ACE inhibitors and angiotensin-receptor blockers increased from 87 to 100% (p < 0.001). Average daily dose increased by 60%, from the equivalent of captopril 105 +/- 78 mg to 167 +/- 86 mg (p < 0.001). Utilization of the following drugs increased significantly: beta blockers (16-37%, p < 0.001), metolazone (10-23%, p = 0.007), spironolactone (1-36%, p < 0.001), amiodarone (7-15%, p = 0.05), hydralazine (1-9%, p = 0.004), and nitrates (20-33%, p = 0.03). One-year survival was 90%. The 3- and 6-month hospitalization rates for heart failure were 4 and 7%, and for all cardiovascular causes they were 6 and 11%, respectively.

CONCLUSIONS

Care of patients with CHF in a specialized heart failure program was associated with significant increase in the utilization and doses of all beneficial cardiovascular drugs, especially ACE inhibitors. It was also associated with excellent clinical outcomes.