Right heart failure medical therapy: Difference between revisions
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==Overview== | ==Overview== | ||
Currently, the basis of therapy for RHF is most importantly cautious diuresis, sinus rhythm maintenance and management of the underlying cause whenever feasible. Management of RHF, which is largely empiric, can be tailored for etiology specific therapy such as anticoagulation in the case of a pulmonary embolism or antibiotics in the case of endocarditis. Management also comprises of optimizing right ventricular preload, afterload and contractility. Since atrial fibrillation and high grade AV block cause detrimental hemodynamic instability in the setting of a right heart failure in particular, maintaining sinus rhythm and AV synchrony is important <ref> Haddad F. et al. Right Ventricular function in Cardiovascular Disease, Part II: Pathophysiology, Clinical Importance and Management of Right Ventricular failure. Circulation. 2008;117:1717-1731</ref><ref>Skhiri M. et al. Evidence-Based Management of Right Heart Failure: a Systematic Review of an Empiric Fiel. Rev Esp Cardiol. 2010;63(4):451-71</ref>. | |||
==Medical Therapy== | ==Medical Therapy== | ||
Revision as of 03:40, 19 November 2012
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Currently, the basis of therapy for RHF is most importantly cautious diuresis, sinus rhythm maintenance and management of the underlying cause whenever feasible. Management of RHF, which is largely empiric, can be tailored for etiology specific therapy such as anticoagulation in the case of a pulmonary embolism or antibiotics in the case of endocarditis. Management also comprises of optimizing right ventricular preload, afterload and contractility. Since atrial fibrillation and high grade AV block cause detrimental hemodynamic instability in the setting of a right heart failure in particular, maintaining sinus rhythm and AV synchrony is important [1][2].
Medical Therapy
General Measures
Treatment of Specific Underlying Conditions
Pulmonary Embolism
In pulmonary embolism, thrombolysis (enzymatic dissolution of the blood clot) is advocated if there is dysfunction of the right ventricle.
Chronic Obstructive Pulmonary Disease
In Chronic Obstructive Pulmonary Disease (COPD), long-term oxygen therapy may improve cor pulmonale.
Pulmonary Arterial Hypertension
Treatment is determined by whether the PH is arterial, venous, hypoxic, thromboembolic, or miscellaneous. Since pulmonary venous hypertension is synonymous with congestive heart failure, the treatment is to optimize left ventricular function by the use of diuretics, beta blockers, ACE inhibitors, etc., or to repair/replace the mitral valve or aortic valve.
In PAH, lifestyle changes, digoxin, diuretics, oral anticoagulants, and oxygen therapy are considered conventional therapy, but have never been proven to be beneficial in a randomized, prospective manner.
High dose calcium channel blockers are useful in only 5% of IPAH patients who are vasoreactive by Swan-Ganz catheter. Unfortunately, calcium channel blockers have been largely misused, being prescribed to many patients with non-vasoreactive PAH, leading to excess morbidity and mortality.
Vasoactive substances
Three major pathways are involved in the abnormal proliferation and contraction of the smooth-muscle cells of the pulmonary artery in patients with pulmonary arterial hypertension. These pathways correspond to important therapeutic targets in this condition and play a role in determining which of three classes of drugs — endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, and prostacyclin derivatives — will be used.
Prostaglandins
Prostacyclin (prostaglandin I2) is commonly considered the most effective treatment for PAH. Epoprostenol (synthetic prostacyclin, marketed as Flolan®) is given via continuous infusion that requires a semi-permanent central venous catheter. This delivery system can cause sepsis and thrombosis. Flolan® is unstable, and therefore has to be kept on ice during administration. Since it has a half-life of 3 to 5 minutes, the infusion has to be continuous (24/7), and interruption can be fatal. Other prostanoids have therefore been developed. Treprostinil (Remodulin®) can be given intravenously or subcutaneously, but the subcutaneous form can be very painful. Iloprost (Ilomedin®) is also used in Europe intravenously and has a longer half life. Iloprost (marketed as Ventavis®) is the only inhaled form of prostacyclin approved for use in the US and Europe. This form of administration has the advantage of selective deposition in the lungs with less systemic side effects.
Endothelin receptor antagonists
The dual (ET and ET) endothelin receptor antagonist bosentan (marketed as Tracleer®) was approved in 2001. Approved in June 2007, ambrisentan is marketed as Letairis® in U.S. by Gilead Sciences.[3], a selective endothelin receptor antagonist that blocks only the action of ET, has been approved for use in Canada and the European Union, to be marketed under the name Thelin®. Sitaxsentan has not been approved for marketing by the US FDA. A new trial is being planned to address FDA's concerns.
Phosphodiesterase type 5 inhibitors
Sildenafil, a selective inhibitor of cGMP specific phosphodiesterase type 5 (PDE5), was approved for the treatment of PAH in 2005. It is marketed for PAH as Revatio®. Tadalafil (currently marketed as Cialis® for erectile dysfunction) is currently is Phase III clinical trials.
Other agents
Vasoactive intestinal peptide by inhalation should enter clinical trials for PAH in 2007. PRX-08066 is a serotonin antagonist currently being developed for hypoxic pulmonary hypertension.
References
- ↑ Haddad F. et al. Right Ventricular function in Cardiovascular Disease, Part II: Pathophysiology, Clinical Importance and Management of Right Ventricular failure. Circulation. 2008;117:1717-1731
- ↑ Skhiri M. et al. Evidence-Based Management of Right Heart Failure: a Systematic Review of an Empiric Fiel. Rev Esp Cardiol. 2010;63(4):451-71
- ↑ cite press release Sitaxsentan