Surgical Excision of Invasive Aspergillosis of the Right Ventricle Presenting as Intractable Ventricular Arrhythmia and Right Ventricular Mass

To the Editor:

Aspergillosis can manifest as either noninvasive (allergic disease or fungal ball) or invasive disease. The respiratory tract is the most commonly affected site, usually serving as the location of initial infection, often in immunocompromised hosts.^1-3 Involvement of the heart is rare and, when present, typically manifests as infective endocarditis.^1,2

The diagnosis of cardiac aspergillosis requires a high index of suspicion. Early diagnosis is imperative to ensure successful management, which involves complete resection and extensive surgical debridement to clear margins combined with antifungal medical treatment and lifelong suppressive therapy. We report a case in which complete surgical resection of a myocardial aspergilloma combined with long-term antifungal therapy resulted in excellent recovery.

A 52-year-old man with a clinical history of IgA deficiency, allergic bronchopulmonary aspergillosis, and bronchiectasis who was undergoing long-term cortico- steroid therapy presented with shortness of breath, chest tightness, and paroxysmal palpitations. Recurrent, nonsustained ventricular tachycardia was documented, and cardiac imaging revealed a soft tissue mass, measuring 4.5 × 2.1 cm, on the anterior free wall of the right ventricle extending to the apex. Additional imaging revealed cystic bronchiectasis in both lungs and a probable aspergilloma in the upper lobe of the left lung (Figure 1). Catheterization with echocardiography-guided core needle myocardial biopsy was performed. Histologic sections of the biopsy specimen revealed granulomatous myocarditis. Rare septate branching hyphae were noted on silver stain, morphologically suggestive of Aspergillus species. Before cardiovascular surgery, intravenous lipid amphotericin B treatment had been initiated, but the patient developed acute renal failure after 4 doses, necessitating discontinuation of the drug therapy. Voriconazole and intravenous caspofungin were prescribed instead.

FIGURE 1.

A, Magnetic resonance image showing the right ventricular mass. B, Computed tomographic scan showing cystic bronchiectasis of bilateral lungs (205 × 114 mm; 95 × 76 dpi).

A complete resection of the right ventricular mass, including the involved tricuspid subvalvular apparatus (and subsequently the tricuspid leaflets), was performed. Transmural involvement of the infectious process was noted with well-delineated margins that were more pronounced on the endocardial surface. There was encroachment of the mass onto the base of the anterior papillary muscle. A glutaraldehyde-treated bovine pericardial patch was used to reconstruct the defect in the right ventricular free wall, and a 29-mm Hancock porcine bioprosthetic valve was placed in the tricuspid position. The patient was maintained with low amounts of inotropic support for the first 24-hour postoperative period to support the right ventricle. The postoperative period was uneventful, and the patient was dismissed on the sixth day with a β-blocker and antifungal regimen that included oral voriconazole and intravenous caspofungin. A 6-week course of intravenous antifungal treatment and lifelong suppressive therapy with oral voriconazole were tentatively planned.

Histopathologic examination of the resected mass revealed coalescing, nonnecrotizing granulomas that contained numerous narrow, septate fungal hyphae, morphologically identical to those identified in the biopsy specimen and again compatible with Aspergillus species. Fungal culture of the resected mass yielded Aspergillus fumigatus (Figure 2). On follow-up at 6 months after surgery, the patient was in good health without cardiac symptoms. Stress echocardiography revealed no new wall motion abnormalities or arrhythmias. The bioprosthetic tricuspid valve was well seated with normal function.

FIGURE 2.

Photomicrographs of the initial needle core biopsy sample from the right ventricular mass. A, Prominent granulomatous myocarditis with a small portion of uninvolved myocardium (upper left) (hematoxylin-eosin, original magnification × 100). B, Scattered Grocott methenamine silver–positive hyphal fragments were noted within the granulomas (original magnification × 400) (228 × 125 mm; 150 × 150 dpi).

Aspergillus species are ubiquitous in nature and infection caused by Aspergillus species occurs primarily through inhalation. In immunocompromised hosts, dissemination can occur and involve major organ systems and has been associated with high mortality rates. Cardiac involvement can occur but is often not recognized until postmortem examination. Cardiac aspergillosis is rare and manifests in 1 of 2 ways: as endocarditis or diffuse pancarditis. Endocarditis is most often associated with a cardiovascular device, in particular, a prosthetic valve. Infected vegetations can also develop on damaged nonvalvular endocardial surfaces in individuals with structural heart disease.^1-4 Pancarditis presenting as a granulomatous right ventricular mass has not been reported to date.

Treatment of cardiac aspergillosis by medical treatment alone has a mortality rate of 32% to 56.6%.^1,2 Antifungal medication has limited ability to penetrate into endocardial vegetations.⁵ Moreover, fungal lesions can invade and destroy the myocardium with cardiac rupture as a devastating complication.⁴

Our case reveals that successful treatment of cardiac aspergillosis can be accomplished with a combination of complete surgical resection and antifungal therapy. The surgical procedure must ensure complete excision of infected myocardium and valvular tissue whenever possible and can be done by an experienced cardiac surgeon. Most authors¹ also recommend lifelong antifungal therapy with voriconazole for invasive aspergillosis to avert relapse. Our experience suggests that surgical excision along with medical treatment improves the chance for a full cure of cardiac aspergillosis and should be strongly considered whenever feasible.