Usefulness of hydralazine to withdraw from dobutamine in severe congestive heart failure

Response and tolerance to oral vasodilator up-titration after intravenous vasodilator therapy in advanced decompensated heart failure

AIMS

The aim of this study was to assess the haemodynamic response and tolerance to aggressive oral hydralazine/isosorbide dinitrate (HYD/ISDN) up-titration after intravenous vasodilator therapy in advanced decompensated heart failure (ADHF).

METHODS AND RESULTS

Medical records of 147 consecutive ADHF patients who underwent placement of a pulmonary artery catheter and received intravenous vasodilator therapy were reviewed. Intravenous sodium nitroprusside and sodium nitroglycerin as first-line agent for those with preserved blood pressures were utilized in 143 and 32 patients, respectively. Sixty-one percent of patients were converted to oral HYD/ISDN combination therapy through a standardized conversion protocol. These patients had a significantly higher admission mean pulmonary arterial wedge pressure compared with patients not converted (28 ± 7 vs. 25 ± 8 mmHg, respectively; P-value 0.024). Beneficial haemodynamic response to decongestive therapy, defined as low cardiac filling pressures and cardiac index ≥2.20 L/min/m(2) without emergent hypotension, was achieved in 32% and 29% of patients who did or did not receive oral HYD/ISDN, respectively (P-value 0.762). HYD/ISDN dosing was progressively and consistently decreased up to the moment of hospital discharge and during outpatient follow-up, primarily due to incident hypotension.

CONCLUSION

The use of a standardized haemodynamically guided up-titration protocol for conversion from intravenous to oral vasodilators may warrant subsequent dose reductions upon stabilization.

Sodium nitroprusside for advanced low-output heart failure

OBJECTIVES

This study was designed to examine the safety and efficacy of sodium nitroprusside (SNP) for patients with acute decompensated heart failure (ADHF) and low-output states.

BACKGROUND

Inotropic therapy has been predominantly used in the management of patients with ADHF presenting with low cardiac output.

METHODS

We reviewed all consecutive patients with ADHF admitted between 2000 and 2005 with a cardiac index < or =2 l/min/m(2) for intensive medical therapy including vasoactive drugs. Administration of SNP was chosen by the attending clinician, nonrandomized, and titrated to a target mean arterial pressure of 65 to 70 mm Hg.

RESULTS

Compared with control patients (n = 97), cases treated with SNP (n = 78) had significantly higher mean central venous pressure (15 vs. 13 mm Hg; p = 0.001), pulmonary capillary wedge pressure (29 vs. 24 mm Hg; p = 0.001), but similar demographics, medications, and renal function at baseline. Use of SNP was not associated with higher rates of inotropic support or worsening renal function during hospitalization. Patients treated with SNP achieved greater improvement in hemodynamic measurements during hospitalization, had higher rates of oral vasodilator prescription at discharge, and had lower rates of all-cause mortality (29% vs. 44%; odds ratio: 0.48; p = 0.005; 95% confidence interval: 0.29 to 0.80) without increase in rehospitalization rates (58% vs. 56%; p = NS).

CONCLUSIONS

In patients with advanced, low-output heart failure, vasodilator therapy used in conjunction with optimal current medical therapy during hospitalization might be associated with favorable long-term clinical outcomes irrespective of inotropic support or renal dysfunction and remains an excellent therapeutic choice in hospitalized ADHF patients.

Dilated Cardiomyopathy

The management of patients with dilated cardiomyopathy (DCM) heart failure starts with the determination of the underlying diagnosis, definition of the hemodynamic character (eg, systolic, diastolic, valvular, right- and left-sided heart dysfunction), recognition of complicating factors (eg, atrial fibrillation, renal dysfunction), and consideration for any surgically remedial lesions (eg, severe valvular regurgitation, high-grade coronary artery occlusive disease). Angiotensin-converting enzyme inhibitors, beta-blocking agents, digoxin, and judicious diuretic administration make up the therapeutic plan for patients with symptomatic DCM heart failure. Angiotensin-converting enzymes are indicated for patients with DCM who have mild or no detectable symptoms; whether this subgroup would benefit from long-term beta-blockade remains to be established. Spirolactone also has been shown to be effective in patients with more advanced stages of heart failure. Biventricular pacing (cardiac resynchronization therapy) recently has been approved for use in patients with DCM and a left ventricular or intraventricular conduction defect and a QRS duration of longer than 140 msec. More intense pharmacotherapy, mechanical devices, and transplantation are directed at patients with severely symptomatic end-stage DCM. The effectiveness of any heart failure treatment plan is very much dependent on nonpharmacologic approaches, including dietary measures, exercise conditioning, and similar considerations, all of which are best delivered by dedicated heart failure programs.

Parenteral inotropic support for advanced congestive heart failure

Parenterally administered positive inotropic agents remain an important component of the therapeutics of cardiac dysfunction and failure. Dobutamine, a catechol, remains the prototype of this drug group, but recently has been joined by the phosphodiesterase III inhibitor, milrinone. Compared with dobutamine, milrinone has greater vasodilating-unloading properties. The catecholamine, dopamine, is often used as a parenteral positive inotrope; but at moderate to high dose, it evokes considerable systemic vasoconstriction. At lower doses, dopamine appears to augment renal function. Levosimendan and toborinone, new compounds with several mechanisms of action, are under active clinical investigation and review for approval. Parenteral positive inotropic therapy is indicated for short-term (hours to days) treatment of cardiovascular decompensation secondary to ventricular systolic dysfunction, low-output heart failure. More prolonged or continuous infusion of one of these agents may be necessary as a "pharmacologic bridge" to cardiac transplantation, another definitive intervention, or more advanced, intense medical therapy. An occasional patient will require a continuous infusion via indwelling venous catheter and portable pump, simply to be able to be discharged from the hospital setting and function in the home environment. Intermittent parenteral inotropic therapy for chronic heart failure has provoked considerable controversy and passion among cardiologists and heart failure specialists; an attempt is made to present this topic in an objective manner.

Refractory Heart Failure: A Therapeutic Approach

Optimal “triple therapy” for patients with chronic congestive heart failure (CHF) includes diuretics, digoxin, and either angiotensin-converting enzyme inhibitors or hydralazine plus nitrates. Refractory CHF is defined as symptoms of CHF at rest or repeated exacerbations of CHF despite “optimal” triple-drug therapy. Most patients with refractory CHF require hemodynamic monitoring and treatment in the intensive care unit. If easily reversible causes of refractory CHF cannot be identified, then more aggressive medical and surgical interventions are necessary. The primary goal of intervention is to improve hemodynamics to palliate CHF symptoms and signs (i.e., dyspnea, fatigue, edema). Secondary goals include improved vital organ and tissue perfusion, discharge from the intensive care unit, and, in appropriate patients, bridge to cardiac transplantation. Medical interventions include inotropic resuscitation (e.g., adrenergic agents, phosphodiesterase inhibitors, allied nonglycoside inodilators), load resuscitation (e.g., afterload and preload reduction with nitroprusside or nitroglycerin; preload reduction with diuretics and diuretic facilitators, such as dopaminergic agents or ultrafiltration), and electrical resuscitation (e.g., prevention of sudden death, correction of new or rapid atrial fibrillation, or dual chamber pacing in the setting of relative prolongation of the PR interval and diastolic mitral/tricuspid regurgitation). Surgical interventions are temporizing (e.g., intra-aortic balloon pump and other mechanical assist devices) or definitive (e.g., coronary artery revascularization, valvular surgery, and cardiac transplantation). Although these interventions may improve immediate survival in the short term, only coronary artery revascularization and cardiac transplantation have been shown to improve long-term survival.