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.