Cardiac papillary fibroelastoma as a cause of acute coronary syndrome

Abstract

Cardiac papillary fibroelastoma (CPF) is a benign primary cardiac neoplasm, commonly found in men and above 40 years old. The clinical presentation of CPF ranges from asymptomatic to embolism-related complications such as stroke, myocardial ischemia, infarction, or ventricular fibrillation. Acute coronary syndrome is a rare complication of CPF, which was reported only in a few cases in medical literature. Hence, we report a case of a 50-year-old female with a CPF on the right coronary cusp of the aortic valve diagnosed with multi-modality imaging with definitive diagnosis through histopathologic confirmation. The patient presented with acute onset of fatigue, diaphoresis, and vomiting. Initial electrocardiogram (ECG) demonstrated T wave inversion in aVL. Repeated ECG two hours later showed persistent T wave inversion in aVL with new T wave inversions in lead I and ST depression in V2-V6. Troponin levels were elevated from 3.6 ng/L to 1503 ng/L but the patient did not report chest pain, abdominal pain, or dyspnea. Computed tomography coronary angiography did not show any significant coronary stenosis but revealed a low attenuation node with 7 × 6 mm in dimension attached to the right coronary cusp of the aortic valve. Treatment was discussed among a multidisciplinary team and the CPF was surgically removed.

Learning objective

Acute coronary syndrome is a rare, but potentially fatal complication of cardiac papillary fibroelastoma (CPF). Multi-modality imaging is valuable in delineating the evaluation of exact position, dimensions, nature of cardiac masses, diagnostic workup, and preliminary assessment before the surgery. There are no clear guidelines for the treatment of CPF.

Introduction

Cardiac papillary fibroelastoma (CPF) is a benign primary cardiac neoplasm but has significant morbidity and mortality [1], [2], [3], [4], [5]. CPF was first described by W. M. Yater in 1931 as a “valvular tumor” and Cheitlin et al. were the first to use the term “papillary fibroelastoma” in a case in 1975 [1], [4]. The prevalence of primary cardiac tumors ranges from 0.0017 to 0.28 % of autopsy cases [2], [3]. While CPF can be rare, it is not uncommon among benign primary cardiac tumors [2]. Cardiac myxomas were believed to be the most common benign cardiac primary neoplasm that were based on large autopsy case studies. However, with the improvement of higher resolution imaging technology and increased knowledge of CPF, recent research shows that CPF may possibly be the most common benign cardiac primary neoplasm [1], [2]. The incidence of CPF is not known [5]. This tumor is usually found incidentally postmortem or during a surgical operation that was indicated for other reasons [4]. The clinical presentation of a patient can vary widely with the patient being asymptomatic, experiencing a variety of unspecific signs and symptoms, to having severe embolic complications [1], [3], [4]. We report a case of CPF initially diagnosed with multi-modality imaging with definitive diagnosis confirmed by pathology samples in a 50-year-old woman presenting with an atypical myocardial infarction.

Case report

A 50-year-old female with unremarkable past medical history presented to the emergency department due to an acute onset of increased fatigue, tachypnea, and diaphoresis while resting at home. When she was being transported to the hospital, she vomited approximately 800 mL of nonbloody, nonbilious fluid. Her vital signs displayed a regular heart rate at 68 bpm, a temperature of 37.0 °C, respiratory rate of 26/min, and an arterial blood pressure of 90/63 mmHg. On arrival, she was awake and oriented to person, place, and time. Jugular venous pressure was approximately 9 cm of water, the liver was not palpable, and no peripheral edema was noted. Intravenous fluids were started with 1 L of normal saline used. She did not report any chest pain, and abdominal pain.

The initial electrocardiogram (ECG) showed T wave inversion in lead aVL without specific findings in other leads. ECG repeated 2 h later showed normal sinus rhythm with persistent T wave inversion in lead aVL, new T wave inversion in lead I and aVR, ST depression >2 mm in lead V₄ to lead V₆, and ST depression >1 mm in lead V₂, V₃. The high-sensitivity troponin T (hs-Trop T) at admission was 32.96 ng/L. These findings suggested an ischemic disease of the region supplied by a dominant right coronary artery. She was transferred to the Cardiovascular Department for monitoring. The hs-Trop T markedly increased to 1219 ng/L on day 3 and 1503 ng/L on day 5.

A computed tomography (CT) coronary angiography was performed, given the atypical clinical presentation of acute coronary syndrome in a young female without any history of cardiovascular risk factors and non-availability of a cardiac catheterization laboratory. The CT coronary angiography did not show any significant coronary stenosis, but it did reveal a low attenuation node with 7 × 6 mm in dimension attached to the right coronary cusp of aortic valve (Fig. 1A). The node was mobilizable along with the aortic valve and short pedicle. When the valve opened in systole (corresponding with phase 10 %, 20 %), this node inserted to the right coronary origin. While in diastole (corresponding with phase 40 % to 100 %), this node was 3 mm distal from the artery origin (Fig. 1B). Transthoracic echocardiogram performed showed a thickened aortic valve and the left ventricular ejection fraction of 70 %. Transesophageal echocardiogram (TEE) showed a mobile pedicled tumor on the right coronary cusp of the aortic valve (Fig. 2). Blood cultures done for the workup of infective endocarditis (IE) were negative. Therefore, IE was not a possible cause for our case given the negative echocardiographic findings for new valvular regurgitation/vegetation and the absence of clinical signs suggesting IE.

Fig. 1.

(A) CT coronary angiography image displaying a low attenuation node with 7 × 6 mm in dimension attached to the right coronary cusp of aortic valve. (B) CT coronary angiography image displaying when the valve opens in systole the node inserted to the right coronary origin and in diastole the node was 3 mm distal from the artery origin.

Abbreviation: AO: Aorta, CT: Computed Tomography, LA: Left Atrium, LM: Left Main Artery, RCA: Right Coronary Artery.

Fig. 2.

Transesophageal echocardiogram displaying a mobile pedicled tumor on the right coronary cusp of the aortic valve.

Further assessment with cardiac magnetic resonance imaging (CMR) demonstrated elevated T1 maps of 1621 ms, T2 maps of 57 ms, and extracellular volume fraction value of 47 % in the inferior basal wall, inferior middle, and apical region. T1 and T2 maps delineated an area of myocardial edema in the right coronary territory with subendocardial myocardial infarct on the late gadolinium enhancement image. Pericardial fluid was also noted in the inferior wall on the CMR, turbo inversion recovery magnitude sequence.

Treatment was discussed among a multidisciplinary team, which resulted in the patient undergoing surgical excision of the lesion. The diagnosis was confirmed by histopathologic examination characterized by multiple branching fronds consisting of paucicellular, avascular, dense connective – fibroelastic tissue lined by a single layer of endocardium (Fig. 3). The patient recovered well post-operatively without any complications. The patient will be followed annually with TEE to monitor for recurrence of the lesion and any abnormal functional issues.

Fig. 3.

Histopathology showed multiple branching fronds consisting of paucicellular, avascular, dense connective – fibroelastic tissue lined by a single layer of endocardium.

Discussion

CPF is predominantly found in men with varying ages between 40 and 80 years but many being diagnosed at approximately 60 years old [1], [2], [4]. The incidence of CPF is not entirely known, but there has been an increase in the diagnosis of CPF due to the growth of advanced imaging and use in the clinical setting [1], [5]. CPF are slow growing benign tumors that range between 2 and 70 mm in size [1], [2]. The characteristic pathology findings of CPF are multiple papillary fronds made of collagen, elastic fibers, and proteoglycans giving the specimen a sea anemone appearance [1], [2], [3], [4]. It is unclear how CPF forms, but the etiological theories include neoplasm, hamartomas, organized thrombi, abnormal endocardial response to an infection or iatrogenic causes (hemodynamic trauma, surgery, post radiation) [1], [2], [3], [4]. The theory that is currently most accepted is the microthrombus theory, where small thrombi will come together at the region of the valve where there is damage to the endothelium [1].

The initial diagnosis of CPF is through multi-modality imaging with echocardiography, which is most often used [1], [2]. Common echocardiographic findings of CPF include a small (<1.5 cm), round and echo-dense mass with a pedicle or stalk attached to endocardium and a variable mobility [1], [2]. CT scan and CMR are second line imaging modalities for CPF evaluation [1], [2], [6], [7]. CMR is the gold standard for preoperative diagnosis of CPF, while definitive diagnosis requires pathological confirmation [1], [2], [7]. CPF is most often found on cardiac valvular surfaces with the aortic valve being the most common, followed by the mitral valve [1], [2]. In addition, CPF can be found on non-valvular surfaces with the left ventricle being the most common site [1]. The clinical symptoms of CPF can vary dramatically where some patients can present asymptomatically or with non-specific symptoms while others can have embolic complications with stroke, myocardial ischemia, infarction, or ventricular fibrillation [1], [2], [3], [4], [8]. Iqbal et al. reported a case of cardiac fibroelastoma on aortic valve causing widespread multiple system infarcts involving brain, kidney, and spleen [9]. Acute coronary syndrome is a rare CPF complication which has been reported in five cases in medical literature. Four out of these five cases presented with angina, while the last case presented with cardiac arrest [6], [10]. In our case, a diagnosis of acute myocardial infarction was made based on abnormal ECG and elevated cardiac enzyme despite the patient having no chest pain.

Due to the rarity of these tumors, there are no definitive guidelines for treatment of CPF [1], [2], [4]. Surgical resection is recommended for symptomatic patients, while antiplatelet or anticoagulation therapy should be started in patients who cannot undergo surgery [1], [2], [3]. Patients that are asymptomatic should have a surgical resection if the tumor is >1 cm or if the tumor's mobility increases [1], [4]. If the tumor is <1 cm, not mobile, and the patient is asymptomatic, then they should be followed with echocardiography until any symptoms develop, the tumor enlarges, or the tumor becomes mobile [4]. Some studies have shown that surgical resection should be performed for all left-sided tumors regardless of the symptoms, mobility, or size due to the cardio-embolic risk [1], [3], [4]. There are not enough data to recommend if surgical resections are needed for a right-sided tumor or the efficacy of medical therapy alone to treat these tumors [1]. Echocardiography should be used to assess the valvular function after the tumor has been removed [3]. Long-term echocardiography follow-up studies are important to assess for regrowth of the tumor.

Conclusion

CPF is a non-neoplastic cardiac valvular tumor and should be on the differential diagnosis for patients with cardiac masses. Even though the tumor is mostly benign, acute coronary syndrome can be a potentially fatal complication of CPF. Multi-modality imaging is valuable in delineating the evaluation of exact position, dimensions, nature of cardiac masses, diagnostic workup, and preliminary assessment before the surgery. There are no clear guidelines for the treatment of CPF, but patients that are symptomatic or asymptomatic with a mobile tumor are recommended to undergo surgical resection. The evidence to use long-term antiplatelet or anticoagulation therapy is still sparse for symptomatic or asymptomatic patients that are not able to undergo surgical resection.

Declaration of competing interest

None.