Discussion
Although LVT can occur both in ischaemic and non-ischaemic
cardiomyopathies, the vast majority of them are diagnosed after
myocardial infarction, especially when an anterior apical scar and
reduction of systolic function are developed 4.
However, although limited data is available on the epidemiology of LVT
in patients affected by non-ischemic heart diseases, within this
subgroup, DCM is the most common underlying cardiomyopathy4, as in our case. Besides, LVT has also been
occasionally described in Takotsubo cardiomyopathy, amyloidosis,
hypereosinophilic syndrome, and Chagas’ disease 4,
being an infrequent manifestation of vasculitis, especially in
ANCA-associated vasculitis 1. In our case, the most
probable diagnosis was MP with negative ANCA serology due to the
presence of DAH, pulmonary capillaritis, DCM, heart failure, and LVT.
The absence of eosinophilia, asthma, chronic rhinosinusitis, or other
manifestations discharges EGPA.
Regarding pulmonary capillaritis, it is a histopathologic diagnosis that
is not pathognomonic of a particular problem; it typically indicates the
presence of a systemic vasculitis or collagen vascular disease, and
hence, treatment should concentrate on the underlying condition that
caused it, as in our case 5.
In relation to heart failure in MP, it has been described with a
prevalence between 6.8% 6 and 17.6%7. Additionally, heart involvement in GP is uncommon,
although pericarditis and cardiomyopathy are the most frequent cardiac
pathologies, whereas arrhythmias, coronary arteritis, cardiac thrombus,
valve lesions, and intracardiac masses are less frequently seen8.
Respecting HIV and cardiomyopathy, prior to the development of ART, the
patients suffered from cardiomyopathy with manifest left ventricular
systolic dysfunction; however, after its development, the onset of
cardiomyopathy had a more incisive course, being more frequently of
ischemic aetiology and with a high prevalence of diastolic left
ventricular dysfunction 9. Our patient was in category
A1 and had been adhering to ART (tenofovir disoproxil fumarate,
emtricitabine, efavirenz) since HIV diagnosis, which made an HIV-related
cardiomyopathy unlikely.
Also, while ART generally appears to help the HIV-related
cardiomyopathic process by reducing viral effects on the myocardium,
some antiretroviral drugs may have long-term negative myocardial
effects, including mitochondrial toxicity 9,10.
However, cardiomyopathy due to mitochondrial toxicity with ART therapy
was described mainly with zidovudine, zalcitabine, and didanosine, in
the group of reverse transcriptase inhibitors 10.
Besides, defects in mitochondrial DNA replication and energetics have
been reported with zidovudine 11,12, clevudine and
lodenosine 13,14. Also, patients receiving ART with
protease inhibitors had increased cardiovascular mortality and
readmission rates at 30 days 15. In our case, the
patient was not receiving any of these reverse transcriptase inhibitors
with potential cardiotoxicity, and he was not receiving protease
inhibitors, so ART cardiotoxicity was very unlikely.
Regarding CMR, it allows the assessment of ventricular function and the
analysis of myocardial tissue, which can help, as in our case, to reveal
or rule out underlying aetiologies of heart failure like ischaemic
cardiomyopathy, myocarditis, hypertrophic and DCM, cardiac amyloidosis,
and sarcoidosis, among others 16,17. In addition, CMR
imaging is the gold standard for LVT 4. In our case,
despite subendocardial LGE in the CMR, these results were not considered
to be related to an ischemic aetiology because the involvement was
biventricular, suggesting two coronary territories in a patient who did
not have a medical history of risk factors for coronary artery disease
in young people such as smoking, dyslipidemia, diabetes mellitus,
arterial hypertension, or obesity, among others 18,
nor angina with moderate or high-intensity physical activity in his
medical history.
These considerations, together with the finding of DAH, guided the
medical team to consider and rule out systemic conditions such as
tuberculosis, fungal, viral, and bacterial infections, as well as
autoimmune conditions such as rheumatoid arthritis, cryoglobulinemia,
anti-glomerular basement membrane disease, and Chagas disease, as
previously mentioned; the finding of pulmonary capillaritis was the one
that finally led us to consider systemic vasculitis, ruling out those
that compromise large and medium vessels due to clinical and laboratory
findings, as well as anti-glomerular basement membrane disease,
cryoglobulinemic vasculitis, IgA vasculitis and urticarial
hypocomplementary vasculitis within those of small vessels. Also, Behçet
and Cogan syndromes were ruled out.
Thus, a negative ANCA vasculitis was diagnosed; of the 3 existing ones
(GP, MP, and EGPA), MP was the most probable diagnosis since it presents
pulmonary capillaritis more frequently than EGPA 5,
and the patient did not present chronic rhinosinusitis, asthma, or
prominent peripheral eosinophilia leading to EGPA 3.
Besides, our patient did not present granulomatous inflammation of the
upper and lower airways or pauci-immune necrotizing glomerulonephritis,
which are typically seen in GP, which, like MP, is one of the most
common disorders associated with pulmonary capillaritis5.
Finally, regarding ANCA vasculitis management, our patient was in a
severe disease state, for which he received an intravenous pulse of
glucocorticoids followed by high-dose oral glucocorticoids plus
cyclophosphamide as remission induction therapy, according to the
American College of Rheumatology guidelines 19. Our
patient also received management of his heart failure in accordance with
current European and American guidelines 20,21. He
presented an improvement in the LVEF with a new value of 25% in the
control echocardiogram. He also presented an improvement in the LVT,
evidencing a decrease in their measurements, and also an improvement in
the lung involvement previously evidenced in a new chest CT.