Proceedings of UCLA Healthcare -VOLUME 16 (2012)- CLINICAL VIGNETTE Dilemma of Right Atrial Thrombi, to Dissolve or to Extract Lawrence Lazar, M.D., Ravi Dave, M.D., Ramin Tabibiazar, M.D. Case Report A 69-year-old male with hypertension and dyslipidemia presented to the ER with syncope and dyspnea. The patient experienced 2 syncopal episodes during exertion. He also reported 3-weeks of progressive dyspnea on exertion with no improvement with antibiotics, steroids, or inhalers. He reported multiple long flights in the past several weeks. In the ER, his vital signs included BP of 93/65, pulse of 111 bpm, respiratory rate of 18 cycles/min, with 99% oxygen saturation on room air. EKG showed right axis deviation and non- specific ST and T wave changes. His laboratory data were notable for creatinine 1.6, elevated BNP of 607, and troponin of 0.66. The patient underwent urgent echocardiogram, which revealed a borderline hypokinetic left ventricle (LV) with EF 50% and a moderately dilated and hypokinetic right ventricle with mildly elevated pulmonary artery pressures. In addition, there was a large mobile echogenic mass in the right atrium measuring 4 cm x 1.5 cm, protruding into the right ventricle, compatible with right heart thrombus (Figure 1). The patient was started immediately on heparin and underwent urgent radiographic studies including CT angiography of his chest and venous Doppler of his lower extremities. The CT angiography showed multiple filling defects in bilateral pulmonary arteries consistent with acute pulmonary thromboemboli (Figure 1). Venous Doppler showed acute DVT in the right popliteal, posterior tibial and peroneal veins (Figure 1). The patient was admitted to the intensive care unit, and an urgent CT surgery consultation was obtained. Surgical intervention was considered, but deferred due to high operative mortality risk. The patient underwent placement of an IVC filter via femoral approach thrombolysis. He tolerated the procedure well without complications, and he was discharged on oral anticoagulation. Serial documented eventual resolution of right heart thrombi and normalization of pulmonary artery pressures as well as LV and RV function. Discussion Right atrial thrombi have been described in patients with atrial fibrillation/flutter, central venous catheters, or pacemaker leads1. In-situ right atrial thrombi are usually immobile, attached to the atrial wall with occasional calcification. Secondary right atrial thrombi are often mobile as they have propagated from the peripheral veins, and are in transit to embolize into the pulmonary arteries. Thus, these mobile right heart thrombi have often been referred to as “emboli in transit” 2 . Mobile right atrial thrombi have been described as spherical, coiled, grapelike, ovoid, worm-like or serpiginous masses moving within the right atrium, and if large, they may prolapse through the tricuspid valve and into the right ventricle 1. Often, these masses appear free-floating with no attachment site. While nearly all of the detected cases of mobile right heart thrombi echocardiography is performed in patients with suspected PE or proven PE, the true incidence of mobile right heart thrombi may be difficult to ascertain2. In patients with PE, it is not uncommon to detect thrombi in the right atria during echocardiography, and in unselected patients with PE, about 4% of patients have right atrial thrombi3. When compared echocardiography, transthoracic echocardiography may have lower sensitivity to detect right heart thrombi and may underestimate the clot burden2. As a result, the incidence of mobile right heart thrombi may be under-estimated due to the preference of using transthoracic rather than transesophageal echo-cardiography in clinical practice. In an autopsy study which included 23,796 subjects and represented 84% of all in- hospital deaths during a 13-year interval, right intracardiac thrombi were seen in nearly 7% of cases with PE4. However, the postmortem incidence may be lower than the actual antemortem incidence since embolization of right heart thrombi into the pulmonary arteries may have caused death2,4. The detection of mobile right heart thrombi has diagnostic and therapeutic implications. The detection of right heart thrombi may support the diagnosis of PE and may expedite therapy. are diagnosed when to trans-esophageal and catheter-directed echocardiograms
Proceedings of UCLA Healthcare -VOLUME 16 (2012)- Furthermore, the detection of right heart thrombi on echo may prevent the risks associated with contrast. Transjugular placement of inferior vena cava filter may be avoided in order to not dislodge the right atrial thrombi2, and IVC filters may be placed via femoral vein. Patients with PE and right atrial thrombi have a higher early mortality rate, particularly when the thrombi are mobile2,5. Patients with PE and right atrial thrombi are more hemodynamic compromise, hypotension, and tachycardia3,6,7. The presence of mobile right atrial thrombi should be considered a potentially life- threatening situation with high risk of recurrent PE5. If patients remain untreated, the death rate has been reported at 80-100% as the free-floating thrombi in the right heart embolize into an already severely compromised pulmonary circulation. Thus, it is imperative to start therapy immediately in order to improve survival. Although the presence of right heart thrombi in patients with PE is associated with increased mortality, little is known management of this difficult clinical situation. The treatment of choice remains controversial with limited data to compare the various options. In a meta-analysis that included 177 cases, the overall mortality rate was 27%2. The mortality rate associated with no therapy, anticoagulation therapy, embolectomy, and thrombolysis were 100%, 29%, 24%, and 11%, respectively2. These findings suggest that anticoagulation by itself appears insufficient to treat patients with mobile right heart thrombi. This study thrombolysis is the preferred option in the absence of contraindications over embolectomy2. However, the results of this study need to be interpreted cautiously given the various limitations of a meta- anaylsis. Therefore, there is a need for a well- designed prospective, randomized trial in order to determine the optimal treatment for patients with PE and right heart thrombi. Thrombolytic therapy can be administered quickly. Systemic thrombolytics may dissolve thrombi in various areas including pulmonary arteries, intracardiac chambers, and venous circulation. Three lytic drugs have been approved by the FDA for severe pulmonary urokinase, streptokinase, and rtPA5. Thrombolytic agents may accelerate thrombus lysis and pulmonary reperfusion, hypertension, as well as improve right ventricular function and overall cardiac function5,8. With systemic thrombolysis, there is a theoretical concern for disrupting the attachment site of the thrombi with dislodgment into pulmonary arteries. Catheter-directed thrombolysis has been described as a potential option for treatment of right atrial thrombi and PE, but data are scarce9. Thrombolytic therapy is associated with an increased risk of bleeding, including intracranial hemorrhage and retroperitoneal hemorrhage2,10. Embolectomy is typically limited to large medical centers since it requires an experienced surgeon and cardiopulmonary bypass. contraindications to thrombolysis, embolectomy may become the preferred therapeutic option. A potential advantage of surgical approach is the ability to repair a patent foramen ovale, and reduce the risk of subsequent paradoxical embolism and stroke2. The potential disadvantages with surgical embolectomy include an inherent delay in operation of at least hours, cardiopulmonary bypass, and inability to remove thromboemboli beyond the central pulmonary arteries. Also, the availability of an experienced surgical staff may limit surgical options when considering therapy for patients with mobile right heart thrombi. Percutaneous approach with catheter-directed retrieval of clots has been promising, but data embolectomy is limited 2,11,12. In conclusion, the detection of right heart thromboemboli during echocardiography may have diagnostic and therapeutic implications. The presence of mobile right atrial thrombi in patients with PE portends cardiopulmonary collapse due to PE. Therefore, treatment should be started immediately as any delay in administering therapy may be lethal. The optimal therapy remains controversial given absence of randomized trials. Yet in certain cases, the different approaches may prove to be complementary and not necessarily exclusive. While thrombolysis and embolectomy appear effective, anticoagulation insufficient. REFERENCES: 1. Panduranga P, Mukhaini M, Saleem M, Al- Delamie T, Zachariah S, Al-Taie S. Mobile right heart thrombus with pulmonary embolism in a patient with polycythemia rubra vera and splanchnic vein thrombosis. Heart Views. 2010 Mar;11(1):16-20. PubMed PMID: 21042459; PubMed Central PMCID: PMC2964707. 2. Rose PS, Punjabi NM, Pearse DB. Treatment of right heart thromboemboli. Mar;121(3):806-14. PubMed PMID: 11888964. 3. Torbicki A, Galié N, Covezzoli A, Rossi E, De Rosa M, Goldhaber SZ; ICOPER Study Group. Right heart thrombi in pulmonary embolism: results from the International Cooperative Pulmonary Embolism Registry. J Am Coll 18;41(12):2245-51. PubMed PMID: 12821255. When there are likely to have general anesthesia, about optimal regarding catheter poor prognosis with further suggests that alone appears embolism, including Chest. 2002 reduce pulmonary Cardiol. 2003 Jun
Proceedings of UCLA Healthcare -VOLUME 16 (2012)- 4. Ogren M, Bergqvist D, Eriksson H, Lindblad B, Sternby NH. Prevalence and risk of pulmonary embolism in patients with intracardiac thrombosis: a population-based study of 23 796 consecutive autopsies. Eur Heart J. 2005 Jun;26(11):1108-14. Epub 2005 Feb 4. PubMed PMID: 15695529. Chartier L, Béra J, Delomez M, Asseman P, Beregi JP, Bauchart JJ, Warembourg H, Théry C. Free-floating thrombi in the right heart: diagnosis, management, and prognostic consecutive patients. Circulation. 1;99(21):2779-83. PubMed PMID: 10351972. Torbicki A, Perrier A, Konstantinides S, Agnelli G, Galiè N, Pruszczyk P, Bengel F, Brady AJ, Ferreira D, Janssens U, Klepetko W, Mayer E, Remy-Jardin M, Bassand JP; ESC Committee for Practice Guidelines (CPG). Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC). Eur Heart J. 2008 Sep;29(18):2276-315. Epub 2008 Aug 30. PubMed PMID: 18757870. Ferrari E, Benhamou M, Berthier F, Baudouy M. Mobile thrombi of the right heart in pulmonary embolism: delayed disappearance after thrombolytic treatment. Chest. 2005 Mar;127(3):1051-3. PubMed PMID: 15764793. Goldhaber SZ. Thrombolysis embolism. Prog Cardiovasc Dis. 1991 Sep- Oct;34(2):113-34. Review. PubMed PMID: 1909807. Maron BA, Goldhaber SZ, Sturzu AC, Rhee DK, Ali BS, Shah PB, Kirshenbaum JM. Catheter- directed thrombolysis for giant right atrial thrombus. Circ Cardiovasc Imaging. 2010 Jan;3(1):126-7. PubMed PMID: 20086226. Konstantinides S, Geibel A, Olschewski M, Heinrich F, Grosser K, Rauber K, Iversen S, Redecker M, Kienast J, Just H, Kasper W. Association between thrombolytic treatment and the prognosis of hemodynamically stable patients with major pulmonary embolism: results of a multicenter registry. Circulation. 1997 Aug 5;96(3):882-8. PubMed PMID: 9264496. Davies RP, Harding J, Hassam R. Percutaneous retrieval of a right atrioventricular embolus. Cardiovasc Intervent Oct;21(5):433-5. PubMed PMID: 9853154. Beregi JP, Aumégeat V, Loubeyre C, Coullet JM, Asseman P, Debacker-Steckelorom C, Bauchart JJ, Liu PC, Théry C. Right atrial thrombi: percutaneous mechanical thrombectomy. Cardiovasc Intervent Radiol. 1997 PubMed PMID: 9030507. 5. indexes in 38 Jun 1999 6. 7. 8. for pulmonary 9. 10. 11. Radiol. 1998 Sep- 12. Mar-Apr;20(2):142-5. Submited on December 8, 2011
Proceedings of UCLA Healthcare -VOLUME 16 (2012)- Figure Legend A C B D Figure 1: A) A large right atrial thrombus seen during transthoracic echocardiogram. B) CT angiography showing extensive pulmonary embolism. C) Pulmonary artery angiography demonstrating large clots in the right pulmonary artery. D) Lower extremity compression ultrasound demonstrating non-compressible right popliteal vein.