Free-Floating Right Heart Thrombus with Acute Massive Pulmonary Embolism: A Case Report and Review of the Literature.

Free-floating right heart thrombus (RHT) is an extreme medical emergency in the context of acute massive pulmonary embolism (PE). Despite the advances in early diagnosis, the management is still very debatable due to lack of consensus. We reported the case of a 66-year-old male, with a history of moderate renal dysfunction and dilated cardiomyopathy, who presented to the emergency department for acute dyspnea. His angiographic magnetic resonance imaging revealed bilateral extensive PE. Transthoracic echocardiography showed RHT with moderate right ventricular dysfunction and pulmonary hypertension. Venous Doppler of the lower extremities noted the presence of a floating clot in the right common femoral vein. The patient was managed successfully by thrombolytic therapy with tenecteplase. To the best of our knowledge, this is the first case report of RHT and PE from Lebanon. Published cases from Middle Eastern countries are scarse.

INTRODUCTION

The concomitant presence of right heart thrombus (RHT) and pulmonary embolism (PE) is an extreme emergency.[1] The prevalence of RHT in the setting of PE is 4%–18%.[23] The mortality rate is increased beyond PE alone. Treatment options include surgical thrombectomy of the right atrium or the pulmonary artery and/or medical therapy such as thrombolysis and anticoagulation.[1234] Among these options, thrombolysis is a fast readily available treatment that is showing promising outcomes.[5]

CASE REPORT

We report herein the case of a 66-year-old man with a history of noncomplicated ischemic stroke 2 years ago, and a stable dilated nonischemic cardiomyopathy. He presented to the emergency department of our tertiary care center for acute dyspnea that has been increasing progressively over the past 3 days. On admission, the patient was afebrile and his work up showed a mean arterial pressure of 85 mmHg, sinus tachycardia (110/min) and oxygen saturation on room air of 85%. The rest of the physical examination was unremarkable. Transthoracic echocardiography (TTE) using the commercially available machine (GE, Vivid E9 Vingmed Ultrasound, Horten, Norway) with the M5Sc-D probe showed large highly mobile right atrial thrombus protruding to the right ventricle [Figure 1 and Video 1], with moderate systolic right ventricular dysfunction (RVD) and pulmonary hypertension (pulmonary artery systolic pressure of 55 mmHg). We also noted global left ventricular hypokinesia (ejection fraction of 35%). PE was suspected, so he was given 5000 units bolus of unfractionated heparin, followed by continuous intravenous (IV) heparin infusion. Venous Doppler of the lower extremities showed the presence of a floating clot in the right common femoral vein extending for 5 cm to the right superficial femoral vein and to the sapheno-femoral junction.

Figure 1

Transthoracic echocardiogram subcostal view showing a serpiginous highly mobile right atrial thrombus (black arrowheads)

Blood analysis revealed slightly positive Troponin-T value of 0.074 (n < 0.014 ng/ml) and high creatinine level of 2.1 (n < 1.3 mg/dl). Angiographic computed tomography (CT) of the chest could not be done due to moderate renal dysfunction, chest magnetic resonance imaging (MRI) showed signs of massive PE in proximal bilateral pulmonary arteries with extension to segmental and subsegmental arteries [Figure 2]. The patient was transferred to the cardiac surgical unit for thrombolysis. Weight optimized dose regimen of tenecteplase was given as an IV single bolus, and Vitamin K antagonist was started 24 h later.

Figure 2

Chest magnetic resonance imaging showing embolism in the right and left main pulmonary arteries (white arrows)

Six hours after thrombolysis, repeated TTE revealed complete regression of the right atrial thrombus and improvement of the right systolic dysfunction and of pulmonary hypertension. Repeated Venous Doppler of the lower extremities showed marked resorption of the right common femoral vein thrombus. Chest MRI was performed 24 h postthrombolysis and revealed bilateral disappearance of the PE from the main pulmonary arteries [Figure 3]. Total body CT scan excluded the presence of underlying malignancy. Screening for thrombophilia was negative. The patient was discharged on day 7.

Figure 3

Chest magnetic resonance imaging showing marked resorption of the right and left main pulmonary artery embolism (white arrows)

DISCUSSION

The coexistence of RHT with acute PE is an extreme medical emergency. This combination carries a high mortality rate when compared to acute PE alone. The mortality rate was reported to be 27% and goes up to 100% with the absence of treatment.[1] The prevalence of RHT in the setting of acute PE is 4%–18%.[2] Three types of RHT have been described. Type A thrombi are captured in transit within the right cardiac cavities, morphologically serpiginous, highly mobile, and associated with deep vein thrombosis and PE. Type B thrombi are nonmobile, formed in situ and are associated with underlying cardiac abnormalities. Type C thrombi have intermediate characteristics of both Type A and Type B.

Therapeutic options include surgical embolectomy, thrombolysis, anticoagulation, or percutaneous retrieval technique [Table 1].[4] Successful surgical embolectomy, by exploration of the right heart and pulmonary arteries under cardiopulmonary bypass, has been widely used, mainly in hemodynamically unstable patients.[5] Good outcomes were reported in published articles on RHT and PE.[6789101112] Lohrmann et al.[6] in their study reported the case of an RHT with bilateral proximal PE that has been treated with RHT thrombectomy and bilateral pulmonary endarterectomy. This type of treatment is not available in many centers; however, it should be considered in patients who have a contraindication for thrombolysis or ineffective thrombolysis.

Table 1

Therapeutic options summary for studies on right heart thrombus-pulmonary embolism

Study	Type of therapy				Outcome
	Surgical embolectomy	Thrombolysis	Anticoagulation alone	Percutaneous retrieval techniques
Akili et al., 2013		+			+
Ando et al., 2011	+				+
Dzudovic et al., 2013		+			+
Burns et al., 2009		+			+
Cuccia et al., 1998	+				+
D’Aloia et al., 2013			+		+
Debney et al., 2011		+			+
Eweda et al., 2011	+				+
Fischer et al., 2013	+				+
Hisatomi et al., 2013	+				+
Huang et al., 2008		+			+
Karabay et al., 2011		+			+
Lampropoulos et al., 2013			+		+
Lohrmann et al., 2014	+				+
Momose et al., 2012				+	+
Naeem et al., 2015		+			+
Nkoke et al., 2015		+			+
Pellegrini et al., 2012		+			+
Puls et al., 2014		+			+
Satirogluo et al., 2014		+			+
Sharma et al., 2012		+			+
Temtanakitpaisan et al., 2013			+		+
Yamuchi et al., 2006	+				+

+=Symbol denotes successful treatment

Thrombolytic therapy is a readily available treatment option associated with the excellent immediate outcome as well.[513141516171819202122] Nkoke et al.[2] described the case of RHT and bilateral massive PE, which was treated successfully with tenecteplase. Moreover, Puls et al.[17] reported three cases of highly mobile right heart mass and PE; two cases were treated successfully with thrombolytic therapy, whereas the third case was treated with surgical removal of the mass that revealed myxoma of the right ventricle. Thrombolytic therapy is highly recommended for high risk and intermediate-high risk patients.

Anticoagulation should be used in all cases of RHT and PE as an adjunctive treatment after thrombolysis or surgical embolectomy. However, the increased mortality rate was reported in patients treated with anticoagulation alone. Athappan et al.[23] reported a higher mortality rate in patients treated with anticoagulation alone compared to those treated with thrombolytic therapy or surgical embolectomy. Nevertheless, anticoagulation alone was successfully used in elderly patients who are considered at high risk for bleeding with thrombolytic therapy.[242526] Temtanakitpaisan et al.[24] described the case of a 92-year-old man who had RHT with PE and was successfully treated with heparin alone. A case of RHT and PE on right atrial pacemaker leads were successfully treated with heparin alone in an another 80-year-old man resulting in a complete disappearance of the RHT after 6 days of treatment.[26]

Percutaneous interventional techniques can also be a good therapeutic option [Table 1].[27] Treatment should be individualized according to the patient's bleeding risk, hemodynamic parameters, and laboratory data.[5] Based on what has been mentioned in the literature review, there is still no consensus regarding the best treatment. The study is clinical evidence of the efficacy of thrombolysis in the case of RHT complicated by PE.

CONCLUSION

This case is the first report from Lebanon describing RHT and acute massive PE with DVT that was successfully treated with thrombolysis. Such extreme medical emergency highlights the importance of urgent TTE in the diagnosis of RHT and RVD. The study findings confirm the effect of thrombolysis on the disappearance of the RHT, the PE and the thrombus of the common femoral vein. Thrombolysis improved the RVD and pulmonary hypertension with no bleeding complications. Randomized clinical trials that compare the various modes of treatment are needed.

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Nil.

Conflicts of interest

There are no conflicts of interest.