RISK FACTORS : HIGH ALTITUDE & COMPLICATED NEONATAL HISTORY ( EG. SPONTANEOUS PNEUMOTHORAX ) MAY TRIGGER MAINTENANCE OF HIGH PULMONARY VASCULAR RESISTANCE AFTER BIRTH
Medical Care:
" Fluid balance and climate control
o Avoid sudden fluid shifts or dehydration, which may increase right-to-left shunting.
o Avoid very hot or humid conditions, which may exacerbate vasodilation, causing syncope and increased right-to-left shunting.
" Oxygen therapy
o The use of oxygen supplementation is controversial.
o Oxygen therapy has been shown to have no impact on exercise capacity and survival in adult patients with Eisenmenger syndrome (Bowyer, 1986; Sandoval 2001).
o Some patients might benefit from nocturnal supplementation, although it is most useful as a bridge to heart-lung transplant.
o Air travel appears to be safe as long as the airplanes are adequately pressurized. Supplemental oxygen during commercial air travel is often recommended, but limited data exist regarding this issue (Harinck, 1996).
" Pulmonary vasodilator therapy
o The pathophysiology of pulmonary hypertension in patients with Eisenmenger syndrome is somewhat similar to that of idiopathic pulmonary arterial hypertension (IPAH); both are associated with a neurohormonal imbalance of endogenous pulmonary vasodilators and vasoconstrictors. This imbalance leads to vascular remodeling, intimal fibrosis, and increased pulmonary vascular resistance (PVR). Therefore, in the management of patients with Eisenmenger syndrome, it is conceptually appealing to use pulmonary vasodilating agents that have been shown to be useful in the management of patients with IPAH. Recent data support this use.
o Long-term prostacyclin therapy was shown to improve hemodynamics (decrease in mean PA pressure, improvement in cardiac index, and decrease in PVR) and quality of life in patients with congenital heart disease and PAH (Rosenzweig, 1999). Another study evaluated epoprostenol infusion in adolescents with congenital heart disease and Eisenmenger physiology showing improved oxygenation (from 69% to 85%) and improvement in a 6-minute walk test distance (from 48 yd to 375 yd) (Fernandes, 2003).
o Bosentan, an endothelin receptor antagonist, was the second vasodilator to be evaluated in patients with Eisenmenger syndrome. In a small retrospective study of 9 patients with congenital heart disease and Eisenmenger syndrome, bosentan therapy resulted in improved oxygen saturation (from 79% to 88%) and improved New York Heart Association (NYHA) class (Christensen, 2004). A larger, multicenter, prospective study by Schulze-Neick et al tested the same hypothesis. In this study, bosentan titrated to 125 mg orally twice daily was associated with improvement in 6-minute walk test distance (362 m to 434 m), improvement in NYHA class (3.1 to 2.4), and a decrease in systolic PA pressure (111 mm Hg to 106 mm Hg).
o A recent retrospective study that examined the outcomes of patients with Eisenmenger syndrome who were treated with pulmonary vasodilators versus those who were not showed that treatment with prostacyclin analogues and/or endothelin receptor antagonists delayed the need for transplantation (Adriaenssens, 2006).
o Sildenafil (Viagra) is another vasodilatory agent originally used for erectile dysfunction but recently approved for IPAH. Recent studies suggest that sildenafil is safe and effective in patients with Eisenmenger syndrome. In a randomized placebo-controlled study of 20 patients with PAH (10 patients with Eisenmenger syndrome and 10 with IPAH), sildenafil improved NYHA class, 6-minute walk test distance, and exercise duration (Singh, 2006). Furthermore, sildenafil therapy resulted in a decrease in systolic PA pressure from 98 mm Hg to 78 mm Hg. The effects of the drug were similar for the 2 patient populations in this study. In summary, vasodilator therapy improves symptoms in patients with Eisenmenger syndrome and should be used routinely in the management of this patient population. However, a single medical therapy has not been consistently shown to reduce mortality in patients with Eisenmenger syndrome.
" Anticoagulation: One study by Silversides et al reported that the incidence of proximal pulmonary artery thrombus in this patient population was 21%. This study raised the issue of anticoagulation in Eisenmenger patients. These patients are at increased risk of bleeding; hence, the use of anticoagulation is still not routinely used.
" Contraception, pregnancy, and genetic counseling
o Avoid pregnancy. Tubal ligation is strongly recommended in women with Eisenmenger syndrome.
o If patients refuse tubal ligation, hormone therapy (controlled release levonorgestrel or norethindrone and ethinyl estradiol preparations) is preferred over intrauterine devices, which can cause significant menorrhagia and potentially increase the risk of endocarditis.
o The fetal mortality rate is approximately 25%, and the maternal mortality rate exceeds 50%.
o Therapeutic abortion is recommended for women in the early stages of pregnancy.
o The risk of congenital heart defects in offspring is approximately 10% and sometimes higher, depending on the primary natural cardiac defect.
o Fetal echocardiography is recommended for pregnant patients or siblings.
" For resuscitation in the event of massive acute bleeding, replace losses with fresh frozen plasma, cryoprecipitate, and platelets.
" Endocarditis
o Patients with Eisenmenger syndrome are at very high risk for endocarditis. Endocarditis prophylaxis should be emphasized and patients should be given repeat instructions about this issue. For standard general prophylaxis for dental, oral, respiratory tract, esophageal, genitourinary, and other gastrointestinal procedures, refer to the American Heart Association recommendations for the prevention of bacterial endocarditis (Dajani, 1997).
o Infective endocarditis prophylaxis (nonchemotherapeutic)
" Encourage good oral hygiene (soft-bristle toothbrushing twice a day, mouthwash or hydrogen peroxide rinses, soft conical rubber gum stimulator, semiannual dental visits).
" Skin care advice should include using a nonabrasive cleanser and avoidance of squeezing skin.
" Nail biting should be avoided.
" Right heart failure is often present in patients with Eisenmenger syndrome, but limited treatment options are available for this complication. Typically, digoxin and diuretics have been used. Diuretics, specifically loop diuretics, are used for symptomatic relief of congestion. However, diuretics should be used cautiously in these patients given their preload-dependent state.
" Erythrocytosis
o Erythrocytosis is almost always present in patients with Eisenmenger syndrome. This could result in symptoms of hyperviscosity that include visual disturbances, fatigue, headache dizziness, and paresthesias. Phlebotomy is not usually recommended for this condition, with exceptions of the presence of hyperviscosity symptoms or if the hematocrit level is above 65%. Before initiating phlebotomy, dehydration must be ruled out since it can falsely increase the hematocrit level. Furthermore, phlebotomy should always be performed with concomitant fluid replacement.
o Repeated phlebotomy can result in iron deficiency anemia. Patients with an iron deficiency have apparent normal hematocrit level and low mean corpuscular volume (MCV). The iron deficient erythrocytes are less deformable than normal erythrocytes, and this lack of deformability can worsen hyperviscosity (Linderkamp, 1979).
o To manage erythrocytosis, first rule out dehydration. Then, if the patient has symptoms of hyperviscosity and the hematocrit level is greater than 65%, venesect 250-500 mL of blood and replace with an equivalent volume of isotonic sodium chloride (or 5% dextrose if in heart failure).
" Thrombotic and bleeding complications
o Eisenmenger syndrome patients are prone to thrombotic events as part of their hyperviscosity. At the same time, they are susceptible to bleeding because their platelets are dysfunctional. Therefore, patients who have a hematocrit level greater than 65% and are undergoing noncardiac surgery should receive phlebotomy and concomitant fluid replacement in order to decrease the risk of thrombotic and bleeding events (Brickner, 2000).
" Central Nervous System (CNS) events can occur secondary to paradoxical embolus, CNS venous thrombosis, intracranial hemorrhage, or brain abscesses in the setting of endocarditis (Brickner, 2000). Endocarditis prophylaxis, the use of air filters with all intravenous catheters during hospital admissions, and adequate management of hyperviscosity might help decrease these potentially fatal complications.
Surgical Care:
" Heart-lung transplantation
o Heart-lung transplantation is the procedure of choice if repair of the underlying cardiac defect is not possible.
o It was performed successfully for the first time in 1981. Since then, the outcome has improved due to better immunosuppressive therapy, new antiviral agents, and improved patient selection.
o Reported actuarial survival rates are 68% at 1 year, 43% at 5 years, and 23% at 10 years.
o The main complications are infection, rejection, and obliterative bronchiolitis.
" Bilateral lung transplantation
o Repair of the underlying cardiac defect is required, but it is considered the preferable procedure if the cardiac defect is simple (such as an ASD).
o Bilateral lung transplantation is better than single-lung transplantation in terms of mortality, New York Heart Association functional class, cardiac output, and postoperative pulmonary edema.
" Advantages over heart-lung grafting include no transplant coronary artery disease or cardiac rejection, and this approach may be considered an option in current times of donor organ shortage, although exact indications have yet to be defined.
" Corrective surgery
o Repair of the primary defect is contraindicated in the context of established severe pulmonary hypertension. However, corrective surgery may be possible in certain cases if a significant degree of left-to-right shunting remains and if responsiveness of the pulmonary circulation to vasodilator therapy can be demonstrated.
o Limitations include a transient dynamic right ventricular outflow tract obstruction, and exact indications for this approach have not yet been defined.
Diet:
" Patients with right-sided congestive heart failure should avoid excessive sodium intake.
" Sodium restriction must be balanced with the need to maintain intravascular volume.
Activity:
" Intense athletic activities carry the risk of sudden death.
" Patients should not participate in competitive sports.
" In certain patients, an exercise prescription can be individualized based on exercise testing that documents a level of activity that meets the following 3 criteria:
1. Oxygen saturations remain greater than 80%.
2. No symptomatic arrhythmias occur.
3. No evidence of symptomatic ventricular dysfunction is present.
DRUG THERAPY :
1. OXYGEN
2. DIGOXIN
3. DIURETICS
4. ANTICOAGULANTS
5. VASODILATOR / ANTIPROLIFERATIVE THERAPY : CHR VASODILATOR THERAPY HAS BEEN SHOWN TO IMPROVE QUALITY IF LIFE, HEMODYNAMICS, EXERCISE CAPACITY & SURVIVAL IN PTS WITH IDIOPATHIC PULMONARY ARTERIAL HYPERTENSION.
- PROSTACYCLINS
- ENDOTHELIN RECEPTOR ANTAGONISTS
- PHOSPHODIESTERASE TYPE 5 INHIBITORS