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.