TREATMENT
The treatment of TBCP is aimed at achieving three goals: killing and control of active Mtb; relief of the cardiac compression due to the fibrosed pericardium; and the prevention of complications or adverse reactions. Among these, removing fibrosed pericardium is much more urgent. Four anti-tuberculosis drug regimens (rifampicin, isoniazid, ethambutol, and pyrazinamide) for a minimum of six months, killing and controlling Mtb effectively, has been the standard care of TB for decades. The drugs can easily reach the lesion to take effect through the mouth, due to the abundant blood vessels in the lungs, which is different from the pericardial cavity. A recent study found that the penetration of anti-tuberculosis drugs in the pericardial space is low during the first 24 hours following drug administration. The median peak value of rifampicin concentrations in the pericardial fluid was significantly lower than the minimum inhibitory concentration, and isoniazid was the only drug with sufficient concentration found in pericardial fluid in patients with TBP[55]. This is a study of patients with TBP manifesting as pericardial effusion. However, while it progresses to TBCP with fibrosis gradually forming and blood vessels decreasing, the effect of chemotherapy will become smaller, especially following the formation of calcification. Therefore, the only definite treatment of TBCP is surgical pericardiectomy, but it has a high perioperative mortality of between 5%-14%[53] and optimistic prognosis. Considering that TBCP may not exist alone, and it may be accompanied by tuberculosis lesions in other parts of the body, anti-tuberculosis treatment is still necessary. Some researchers had achieved good results with pure anti-tuberculosis drugs for TBCP, but it seems to be related to the stage of the disease, and there is less research to support such results. It’s helpful for prognosis by taking pericardiectomy timely when the anti-tuberculosis does not work. However, the timing of pericardiectomy is controversial. Some authors suggested that we should use standard anti-TB drugs for 6 months and then pericardiectomy for persistent constriction in the face of drug therapy. Some recommended pericardiectomy should be done if the patient’s condition is static hemodynamically or deteriorates after 4 to 8 weeks of anti-TB therapy. Also some though surgery should be undertaken earlier under anti-TB therapy if the pericardial calcification appears[22]. There is no consensus on the scope of a pericardiectomy for the surgical treatment of chronic constrictive pericarditis. A total pericardiectomy is technically more demanding but has superior results-both early and late compared with partial pericardiectomy [56]. The process of pericardiectomy is difficult, especially with calcification penetrating the myocardium, which may damage myocardial laceration and endanger life during operation[57]. At the same time, diuretic therapy, inotropic support and some device support such as cardiopulmonary bypass (CPB), ultrasonic bone scalpel, and extracorporeal membrane oxygenation (ECMO) may be needed during or after the pericardiectomy. Besides, advanced age, atrial fibrillation, tricuspid insufficiency, need for inotropic support, low cardiac output, high atrial pressure, ascites, low functional status and the duration of constriction have been related to poor outcomes[56].
As for MDR-TB or XDR-TB, chemotherapy drugs need some adjustments, using second-line drugs instead of the four drugs. Using only amikacin in shorter regimens and bedaquiline or linezolid in longer regimens were recommended[58]. Drug susceptibility testing (DST) is necessary for the treatment of patients with Mtb-positive. Since little is known about the use of second-line tuberculosis drugs in pregnancy, the management of MDR/XDR-TB in pregnant women is more complicated. And the use of new and repurposed drugs during pregnancy and breastfeeding is not widely recommended. Given the complexity of treating pregnant women with MDR/XDR-TB, individualized treatment should be done for each one from hospitalizing. Aggressive treatments should be used under safety as the mortality of pregnancy-associated TB can up to 40%.
The infection of HIV of patients with TBCP increases the mortality rate greatly. However, the optimal therapeutic strategy concerning the duration of anti-TB therapy is uncertain. Concern about the potential for the development of toxicities, side effects, immune reconstitution syndrome (IRIS) and complex drug-drug interactions if ART is introduced early during therapy for TB often led to long delays. It is said that the use of corticosteroids may prevent the development of TBCP from TBP in the patient without HIV[59]. However, whether corticosteroid is beneficial for the treatment of TBCP still needs further studies. What is certain is that corticosteroid potentially causes complications, including aggravation of diabetes, Cushingoid features, infection risk, osteoporosis and increasing cancer risk for HIV/AIDS patients[53]. And the role of pericardiectomy still needs further exploration.