Outcomes Associated With Catheter-Directed Therapies in Chronic Thromboembolic Pulmonary Hypertension: Cautionary Tales From a Single-Center Case Series

BackgroundCatheter-directed therapies (CDTs) for acute pulmonary embolism (PE) are becoming increasingly popular. Although potentially beneficial in acute PE, CDT is ineffective for chronic thromboembolic disease. Herein we present our experience of patients with subsequently confirmed chronic thromboembolic pulmonary hypertension (CTEPH) or pulmonary artery sarcoma who initially received CDT before referral for surgical intervention.Research QuestionHow often is CDT being used in patients with CTEPH or pulmonary artery tumor, and what are the associated outcomes?Study Design and MethodsRetrospective review of all pulmonary thromboendarterectomy surgeries performed at the University of California, San Diego, from January 1, 2020, through December 31, 2021.ResultsThree hundred fifty-four pulmonary thromboendarterectomy surgeries were performed during the study period. Fifty-two patients received CDT before referral (15%). Before CDT attempt, duration of dyspnea ranged from 3 days to 10 years and mean right ventricular systolic pressure measured by echocardiography was 75 ± 23 mm Hg. After CDT, mean right ventricular systolic pressure was 77 ± 23 mm Hg. Three patients reported full recovery of symptoms, 23 patients reported some improvement, and 26 patients reported no change in symptoms. Imaging at time of CDT was available for review for 32 patients; 23 patients showed radiologic evidence of CTEPH and three patients showed evidence suspicious of sarcoma. Complications associated with CDT occurred in seven patients (13%) and included one death.InterpretationRadiologic signs of CTEPH frequently were overlooked at the time of CDT. Most patients (94%) achieved minimal or no improvement in symptoms after CDT, and 13% experienced complications. It is important to assess for clinical and radiologic signs of CTEPH when considering CDT in presumed acute PE to minimize unnecessary risk and instead refer patients for CTEPH evaluation. Catheter-directed therapies (CDTs) for acute pulmonary embolism (PE) are becoming increasingly popular. Although potentially beneficial in acute PE, CDT is ineffective for chronic thromboembolic disease. Herein we present our experience of patients with subsequently confirmed chronic thromboembolic pulmonary hypertension (CTEPH) or pulmonary artery sarcoma who initially received CDT before referral for surgical intervention. How often is CDT being used in patients with CTEPH or pulmonary artery tumor, and what are the associated outcomes? Retrospective review of all pulmonary thromboendarterectomy surgeries performed at the University of California, San Diego, from January 1, 2020, through December 31, 2021. Three hundred fifty-four pulmonary thromboendarterectomy surgeries were performed during the study period. Fifty-two patients received CDT before referral (15%). Before CDT attempt, duration of dyspnea ranged from 3 days to 10 years and mean right ventricular systolic pressure measured by echocardiography was 75 ± 23 mm Hg. After CDT, mean right ventricular systolic pressure was 77 ± 23 mm Hg. Three patients reported full recovery of symptoms, 23 patients reported some improvement, and 26 patients reported no change in symptoms. Imaging at time of CDT was available for review for 32 patients; 23 patients showed radiologic evidence of CTEPH and three patients showed evidence suspicious of sarcoma. Complications associated with CDT occurred in seven patients (13%) and included one death. Radiologic signs of CTEPH frequently were overlooked at the time of CDT. Most patients (94%) achieved minimal or no improvement in symptoms after CDT, and 13% experienced complications. It is important to assess for clinical and radiologic signs of CTEPH when considering CDT in presumed acute PE to minimize unnecessary risk and instead refer patients for CTEPH evaluation. Take-home PointsStudy Question: How often are catheter-directed therapies (CDTs) being used inadvertently in chronic thromboembolic pulmonary hypertension (CTEPH) or pulmonary artery tumors, and what are the associated outcomes?Results: In patients who underwent pulmonary thromboendarterectomy, prior CDT was performed in 15% (52/354); in this cohort, the preprocedural right ventricular systolic pressure was 77 ± 23 mm Hg with CT scan signs of CTEPH already present at the time of CDT in > 70%. Most patients showed minimal to no subjective improvement with CDT, and complications occurred in 13% of the cohort, including one death.Interpretation: Clinical, radiologic, hemodynamic, and echocardiographic clues may suggest CTEPH instead of acute pulmonary embolism (PE), but frequently they are overlooked. This can lead to a misdiagnosis of CTEPH as acute PE, leading to the use of CDT in patients with CTEPH that is ineffective and is associated with high complications. CTEPH should be considered in all patients with presumed acute PE before intervention with catheter-directed therapies (catheter-directed thrombolysis or suction thrombectomy). Study Question: How often are catheter-directed therapies (CDTs) being used inadvertently in chronic thromboembolic pulmonary hypertension (CTEPH) or pulmonary artery tumors, and what are the associated outcomes? Results: In patients who underwent pulmonary thromboendarterectomy, prior CDT was performed in 15% (52/354); in this cohort, the preprocedural right ventricular systolic pressure was 77 ± 23 mm Hg with CT scan signs of CTEPH already present at the time of CDT in > 70%. Most patients showed minimal to no subjective improvement with CDT, and complications occurred in 13% of the cohort, including one death. Interpretation: Clinical, radiologic, hemodynamic, and echocardiographic clues may suggest CTEPH instead of acute pulmonary embolism (PE), but frequently they are overlooked. This can lead to a misdiagnosis of CTEPH as acute PE, leading to the use of CDT in patients with CTEPH that is ineffective and is associated with high complications. CTEPH should be considered in all patients with presumed acute PE before intervention with catheter-directed therapies (catheter-directed thrombolysis or suction thrombectomy). Pulmonary embolism (PE) is the third leading cause of cardiovascular death globally, with estimated PE-related deaths in the United States reaching approximately 300,000 annually.1Raskob G.E. Angchaisuksiri P. Blanco A.N. et al.Thrombosis: a major contributor to global disease burden.Semin Thromb Hemost. 2014; 40: 724-735Crossref PubMed Scopus (87) Google Scholar,2Heit J.A. Cohen A.T. Anderson F.A. Estimated annual number of incident and recurrent, non-fatal and fatal venous thromboembolism (VTE) events in the US.Blood. 2005; 106910-910Crossref Google Scholar Moreover, increasing rates of PE-attributed deaths have occurred in the past decade.3Martin K.A. Molsberry R. Cuttica M.J. Desai K.R. Schimmel D.R. Khan S.S. Time trends in pulmonary embolism mortality rates in the united states, 1999 to 2018.J Am Heart Assoc. 2020; 916784Crossref Scopus (61) Google Scholar In deteriorating patients with PE, the mainstay of treatment remains systemic fibrinolysis, but a significantly higher rate of major hemorrhagic complications occurs, including intracranial or fatal bleeding.4Meyer G. Vicaut E. Danays T. et al.Fibrinolysis for patients with intermediate-risk pulmonary embolism.N Engl J Med. 2014; 370: 1402-1411Crossref PubMed Scopus (1050) Google Scholar, 5Chatterjee S. Chakraborty A. Weinberg I. et al.Thrombolysis for pulmonary embolism and risk of all-cause mortality, major bleeding, and intracranial hemorrhage: a meta-analysis.JAMA. 2014; 311: 2414-2421Crossref PubMed Scopus (542) Google Scholar, 6Marti C. John G. Konstantinides S. et al.Systemic thrombolytic therapy for acute pulmonary embolism: a systematic review and meta-analysis.Eur Heart J. 2015; 36: 605-614Crossref PubMed Scopus (328) Google Scholar Given the potential high morbidity and mortality associated with both PE and the use of systemic thrombolytics, developments in the treatment of high-risk PE without use of systemic thrombolysis have been pursued. Catheter-directed therapies (CDTs), including catheter-directed thrombolytics and catheter suction thrombectomy, have gained popularity in recent years in treating PE because of the reported decreased bleeding risk.7Singh M. Shafi I. Rali P. Panaro J. Lakhter V. Bashir R. Contemporary catheter-based treatment options for management of acute pulmonary embolism.Curr Treat Options Cardiovasc Med. 2021; 23: 44Crossref PubMed Scopus (4) Google Scholar Chronic thromboembolic pulmonary hypertension (CTEPH) represents the ultimate sequelae of ineffective intrinsic thrombolysis after PE. Although the true incidence of CTEPH is unknown, it likely ranges between 1% and 5% after acute PE.8Kim N.H. Delcroix M. Jais X. et al.Chronic thromboembolic pulmonary hypertension.Eur Respir J. 2019; 531801915Crossref Scopus (391) Google Scholar, 9Ende-Verhaar Y.M. Cannegieter S.C. Noordegraaf A.V. et al.Incidence of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism: a contemporary view of the published literature.Eur Respir J. 2017; 491601792Crossref PubMed Google Scholar, 10Pengo V. Lensing A.W.A. Prins M.H. et al.Incidence of chronic thromboembolic pulmonary hypertension after pulmonary embolism.N Engl J Med. 2004; 350: 2257-2264Crossref PubMed Scopus (1518) Google Scholar As the prevalence of CDT to treat acute PE grows, it may be used inadvertently in patients with CTEPH rather than those with acute PE. These catheter-based therapies are ineffective in chronic thromboembolic disease, however, because the thrombus has organized and cannot be removed or dissolved easily. However, chronic thromboembolic pulmonary disease may not be recognized easily on CT imaging, and signs of chronic PE or CTEPH, in situ thrombosis, and tumors can be misinterpreted as acute PE.11Rogberg A.N. Gopalan D. Westerlund E. Lindholm P. Do radiologists detect chronic thromboembolic disease on computed tomography?.Acta Radiol. 2019; 60: 1576-1583Crossref PubMed Scopus (26) Google Scholar A recent study showed that among patients with a diagnosis of acute PE by CT scan findings, 15% already showed signs of CTEPH on the initial CT scan.12Barco S. Mavromanoli A.C. Kreitner K-F et al.Pre-existing chronic thromboembolic pulmonary hypertension in acute pulmonary embolism.Chest. 2023; 163: 923-932Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar The incidence of CDT for nonacute cases of PE is unclear though. We present our experience with patients who initially received CDT for presumed acute PE before undergoing pulmonary thromboendarterectomy (PTE) surgery. A retrospective review of all patients undergoing PTE surgery at the University of California, San Diego, between January 1, 2020, and December 31, 2021, was performed. The University of California, San Diego, maintains an institutional review board-approved quality improvement database on all patients undergoing PTE surgery. All patient information was obtained from this de-identified quality improvement database. Informed consent was waived and data were collected in accordance with institutional standards. All patients who had undergone prior CDT before undergoing PTE during the duration of the study period were identified. CDT included catheter-directed thrombectomy and catheter-directed thrombolytics with or without ultrasound assistance (ie, EKOS EkoSonic Endovascular System). Patients who received only extrapulmonary CDT (ie, for DVT) were excluded. All CDT was performed at outside institutions before referral to the University of California, San Diego. Information regarding data relating to CDT was obtained from chart review of available outside records, including operative reports, progress notes, discharge summaries, and imaging reports. CT images of the chest, if available, obtained either before or at the time of CDT were reviewed. CT scans obtained within 21 days of CDT also were included, given that evidence of chronic thromboembolic disease within 3 weeks of presumed acute PE likely actually represented chronic disease, rather than acute PE. Images were reviewed independently by an experienced fellowship-trained cardiothoracic radiologist (S. K.) and a pulmonary vascular specialist (N. H. K.), both with expertise in CTEPH. Each evaluated for radiologic evidence of acute, subacute, chronic, or nonthromboembolic disease on CT scan. Disputed cases were adjudicated by a second experienced pulmonary vascular medicine specialist (K. M. K.). CT scan findings consistent with chronic disease included intraluminal webs, contracted vessels, eccentric thrombus, right ventricular hypertrophy, and collateral vessels. Supportive findings of chronic disease included lung mosaicism. Findings of acute PE included thrombus in the central portion of the vessel and a normal or expanded pulmonary artery.13Wittram C. Maher M.M. Yoo A.J. Kalra M.K. Shepard J.A.O. McLoud T.C. CT angiography of pulmonary embolism: diagnostic criteria and causes of misdiagnosis.Radiographics. 2004; 24: 1219-1238Crossref PubMed Google Scholar If findings of both acute and chronic disease were observed, the results were labeled as acute on chronic disease. Between January 1, 2020, and December 31, 2021, 354 patients underwent PTE surgery. Of those, 56 patients had received CDT before undergoing PTE. Four patients were excluded because the CDT was only extrapulmonary (lower or upper extremity DVT in three patients, subclavian thrombosis in one patient). The remaining 52 patients who received CDT in the pulmonary arteries for presumed acute PE were included for analysis. Patient characteristics are presented in Table 1. The mean age was 54 ± 17 years and 27 patients (52%) were female. Forty patients underwent catheter-directed thrombolysis and 17 patients underwent catheter suction thrombectomy, including 10 patients who received a combination of catheter-directed thrombolysis, thrombectomy, and systemic thrombolytics.Table 1Patient Characteristics at Time of Pulmonary Thromboendarterectomy Surgery (n = 52)CharacteristicDataAge, y54 ± 17BMI, kg/m230.9 ± 7.9Female sex27 (52)Symptom duration before CDT, wk Mean ± SD34 ± 77 Median (range)12 (0.5-480)Method of catheter directed therapyaFive patients received both catheter-directed thrombolysis and catheter-directed thrombectomy and so were included twice. Catheter-directed thrombolysis40 (77) Catheter-directed suction thrombectomy17 (33) Any catheter-directed therapy with systemic thrombolysis7 (13)Functional class I1 (2) II7 (13) III38 (73) IV6 (12)Pulmonary arterial hypertension therapies28 (54) Monotherapy14 (50) Double combination therapy12 (43) Triple combination therapy2 (7)Inpatient transfer7 (13)Time between CDT and PTE, wk Mean ± SD79 ± 73 Median (range)60 (0.4-313)Data are presented as No. (%), mean ± SD, or median (range). CDT = catheter-directed therapy; PTE = pulmonary thromboendarterectomy.a Five patients received both catheter-directed thrombolysis and catheter-directed thrombectomy and so were included twice. Open table in a new tab Data are presented as No. (%), mean ± SD, or median (range). CDT = catheter-directed therapy; PTE = pulmonary thromboendarterectomy. Duration of symptoms before CDT attempt varied significantly, ranging from 3 days to 10 years, with a mean of 34 ± 77 weeks (median, 12 weeks); 89% of patients reported symptoms lasting > 2 weeks before CDT. Thirty-seven transthoracic echocardiography reports were available before the CDT attempt. The mean right ventricular systolic pressure (RVSP) estimate was 75 ± 23 mm Hg, with 81% of patients having an RVSP before CDT of ≥ 60 mm Hg. Invasive hemodynamics before the CDT attempt were available for 24 patients. The systolic, diastolic, and mean pulmonary artery pressures (PAPs) immediately before the CDT attempt were 73 ± 20 mm Hg, 28 ± 12 mm Hg, and 44 ± 13 mm Hg, respectively (Table 2); 58% of patients showed a mean PAP of > 40 mm Hg. Further subgroup analysis by RVSP and invasive hemodynamics are available in e-Tables 1 and 2.Table 2Hemodynamics Before and After CDT (If Available) and Before and After PTEVariableCDTPTEBeforeAfterBefore (n = 52)After (n = 52)Echocardiographic RVSP, mm Hg75 ± 23 (n = 37)77 ± 23 (n = 10)69 ± 2634 ± 12RA, mm Hg. . .. . .9 ± 58 ± 4PAP, mm Hg Systolic73 ± 20 (n = 21)68 ± 24 (n = 12)67 ± 1734 ± 11 Diastolic28 ± 12 (n = 21)30 ± 14 (n = 12)22 ± 713 ± 4 Mean44 ± 13 (n = 24)42 ± 16 (n = 13)37 ± 1221 ± 6PAOP, mm Hg. . .. . .11 ± 4NACO, L/min. . .. . .4.7 ± 1.65.9 ± 1.3Cardiac index, L/min/m2. . .. . .2.4 ± 0.62.9 ± 0.5PVR, dyn × s/cm5. . .. . .545 ± 353188 ± 106Data are presented as mean ± SD, unless otherwise indicated. CDT = catheter-directed therapy; CO = cardiac output; PAOP = pulmonary artery occlusion pressure; PAP = pulmonary artery pressure; PTE = pulmonary thromboendarterectomy; PVR = pulmonary vascular resistance; RA = right atrial pressure; RVSP = right ventricular systolic pressure. Open table in a new tab Data are presented as mean ± SD, unless otherwise indicated. CDT = catheter-directed therapy; CO = cardiac output; PAOP = pulmonary artery occlusion pressure; PAP = pulmonary artery pressure; PTE = pulmonary thromboendarterectomy; PVR = pulmonary vascular resistance; RA = right atrial pressure; RVSP = right ventricular systolic pressure. Echocardiography findings obtained after CDT were available for 10 patients and demonstrated mean estimated RVSP by echocardiography was 77 ± 23 mm Hg. Invasive hemodynamics after CDT attempt were obtained for 13 patients that revealed systolic PAP of 68 ± 24 mm Hg and a mean PAP of 42 ± 16 mmHg (Table 2). In seven patients, reports on specimen removal were available, with four reports noting mild to moderate amounts of chronic clot and three reports without any specimens removed. Seven patients underwent repeat angiography or CT imaging within 24 to 48 h of CDT to reassess clot burden; improved clot burden with residual thrombus was noted in three patients and no angiographic improvement was noted in four patients. After the procedure, subjective report of symptoms improved to baseline in three patients (6%). Twenty-three patients (44%) experienced some improvement but not to baseline, whereas 26 patients (50%) showed no improvement in symptoms. Of the three patients who reported complete symptom recovery, two subsequently were unable to comply with anticoagulation and experienced new associated persistent dyspnea, and one patient underwent a postprocedural right heart catheterization with elevated PAP that prompted further evaluation for CTEPH. CT imaging was available for review for 32 patients (62%). Twenty of these patients (63%) showed evidence of pure chronic disease and an additional three patients (9%) showed evidence of both acute and chronic thromboembolic disease. The most common radiologic finding of chronic disease observed was vessel contraction (87%), followed by lung mosaicism (70%), hypertrophied bronchial collateral vessels (52%), eccentric thrombus (52%), right ventricular hypertrophy (43%), and intraluminal webs (39%). Six patients (19%) showed acute or subacute disease and three patients (9%) demonstrated imaging concerning for pulmonary artery sarcoma. Further subgroup analysis by imaging before CDT is available in e-Tables 3-5. Complications resulting from CDT occurred in seven patients (13%). Further breakdown of complications by type of CDT is available in e-Table 6. These complications included acute hypoxemic respiratory failure (n = 3), hemoptysis (n = 2), cardiac arrest (n = 1), hemothorax resulting from vessel wire injury (n = 1), groin hematoma (n = 1), and supraventricular tachycardia (n = 1). Venoarterial extracorporeal membrane oxygenation support was required in two patients. Of the three patients who demonstrated acute hypoxemic respiratory failure, two patients required invasive mechanical ventilation. In total, four patients required prolonged ICU admission (≥ 48 h) for these complications. A wide range of time between CDT and PTE was noted, from 3 days to 6 years, with a mean of 18.2 ± 16.8 months (median, 13.7 months). Furthermore, in the subset of patients who did not achieve full recovery from symptoms after CDT, a lapse of 17.4 months occurred between CDT and eventual PTE. These delays include one of the patients with pulmonary artery sarcoma as well, who experienced a 13-month gap between CDT and pulmonary endarterectomy. At the time of PTE evaluation, most patients were functional class III (73%), and 28 patients (54%) were receiving pulmonary hypertension-targeted therapies (Table 1). Seven patients were emergent inpatient transfers, with five of these occurring during the admission for the attempted CDT. Imaging obtained before CDT was available for all five transfer patients; the imaging of two patients was concerning for pulmonary artery sarcoma and that of three patients was consistent with chronic thromboembolic disease (e-Table 7). Immediate preoperative and post-PTE hemodynamics are shown in Table 2. Intraoperative and postoperative characteristics are shown in Table 3.14Madani M.M. Surgical treatment of chronic thromboembolic pulmonary hypertension: pulmonary thromboendarterectomy.Methodist Debakey Cardiovasc J. 2016; 12: 213-218Crossref PubMed Scopus (62) Google Scholar Three patients were confirmed to have pulmonary artery sarcoma on pathologic examination at the time of surgery. Postoperative ventilator days, ICU length of stay, and postoperative length of stay were consistent with institutional averages. Rates of complications after PTE surgery also were similar to institutional averages for all PTE surgeries between 2020 and 2021, but a seemingly higher rate of hemothorax was noted in those with prior CDT (three of 52 [6%] vs one of 299 [0.3%]; P = .001). One patient died who had significant CDT-associated complications (cardiac arrest, hemothorax, respiratory failure, and venoarterial extracorporeal membrane oxygenation support) before emergent PTE surgery.Table 3Operative Characteristics and Postoperative Outcomes in All Patients Who Underwent PTE From 2020 through 2021 (n = 351)aThree patients (no CDT group) who underwent PTE at the children’s hospital were excluded.VariablePrevious CDT (n = 52)No Previous CDT (n = 299)Circulatory arrest time, min45.2 ± 20.044.5 ± 19.6Level of diseasebUniversity of California, San Diego, level of disease is a surgical classification for PTE surgical specimen.14Level 0 indicates no surgical evidence of chronic thromboembolic disease, level I disease starts in the main pulmonary arteries, level II disease starts in the lobar branches, level III disease starts at the segmental branches, and level IV disease starts at the subsegmental branches. No patient had bilateral level 0. Right01 (2)3 (1)118 (35)85 (28)222 (42)97 (32)311 (21)87 (29)40 (0)26 (9) Left03 (6)14 (5)113 (25)40 (13)223 (44)101 (34)312 (23)99 (33)41 (2)44 (15)Pulmonary artery sarcoma3 (6)1 (0.3)Time on ventilator, d Mean ± SD2.0 ± 3.32.1 ± 3.8 Median11ICU length of stay, d Mean ± SD4.0 ± 3.94.4 ± 4.2 Median33Postoperative length of stay, d Mean ± SD11.1 ± 4.811.6 ± 5.8 Median1010ECMO03 (1)cAll cases were venoarterial ECMO.Return to the operating room1 (2)6 (2)Post-op bleeding6 (12)28 (9)Airway hemorrhage4 (8)19 (6)Atrial arrhythmias9 (17)52 (17)Reperfusion lung injury2 (4)33 (11)Pericardial effusion12 (23)66 (22)Hemothorax3 (6)1 (0.3)Discharge with oxygen23 (44)182 (61)Discharge with PH medications03 (1)Death before discharge1 (2)1 (0.3)Data are presented as No. (%) or mean ± SD, unless otherwise indicated. CDT = catheter-directed therapy; ECMO = extracorporeal membrane oxygenation; PH = pulmonary hypertension; PTE = pulmonary thromboendarterectomy.a Three patients (no CDT group) who underwent PTE at the children’s hospital were excluded.b University of California, San Diego, level of disease is a surgical classification for PTE surgical specimen.14Madani M.M. Surgical treatment of chronic thromboembolic pulmonary hypertension: pulmonary thromboendarterectomy.Methodist Debakey Cardiovasc J. 2016; 12: 213-218Crossref PubMed Scopus (62) Google ScholarLevel 0 indicates no surgical evidence of chronic thromboembolic disease, level I disease starts in the main pulmonary arteries, level II disease starts in the lobar branches, level III disease starts at the segmental branches, and level IV disease starts at the subsegmental branches. No patient had bilateral level 0.c All cases were venoarterial ECMO. Open table in a new tab Data are presented as No. (%) or mean ± SD, unless otherwise indicated. CDT = catheter-directed therapy; ECMO = extracorporeal membrane oxygenation; PH = pulmonary hypertension; PTE = pulmonary thromboendarterectomy. Catheter-directed therapies, including catheter-directed thrombolytics and catheter suction thrombectomy, are gaining popularity in the treatment of acute PE. In this cohort of patients, the incidence of CDT doubled from 2020 to 2021 (from 10% to 20%). The rise in CDT use may be reflective of the increasing number of recent studies on various catheter-based therapies.15Piazza G. Hohlfelder B. Jaff M.R. et al.A prospective, single-arm, multicenter trial of ultrasound-facilitated, catheter-directed, low-dose fibrinolysis for acute massive and submassive pulmonary embolism: the SEATTLE II Study.JACC Cardiovasc Interv. 2015; 8: 1382-1392Crossref PubMed Scopus (579) Google Scholar, 16Tapson V.F. Sterling K. Jones N. et al.A randomized trial of the optimum duration of acoustic pulse thrombolysis procedure in acute intermediate-risk pulmonary embolism: the OPTALYSE PE Trial.JACC Cardiovasc Interv. 2018; 11: 1401-1410Crossref PubMed Scopus (245) Google Scholar, 17Tu T. Toma C. Tapson V.F. et al.A prospective, single-arm, multicenter trial of catheter-directed mechanical thrombectomy for intermediate-risk acute pulmonary embolism: the FLARE Study.JACC Cardiovasc Interv. 2019; 12: 859-869Crossref PubMed Scopus (218) Google Scholar, 18Sista A.K. Horowitz J.M. Tapson V.F. et al.Indigo aspiration system for treatment of pulmonary embolism: results of the EXTRACT-PE Trial.JACC Cardiovasc Interv. 2021; 14: 319-329Crossref PubMed Scopus (101) Google Scholar, 19Kucher N. Boekstegers P. Müller O.J. et al.Randomized, controlled trial of ultrasound-assisted catheter-directed thrombolysis for acute intermediate-risk pulmonary embolism.Circulation. 2014; 129: 479-486Crossref PubMed Scopus (694) Google Scholar, 20Michaud E. Pan M. Aggarwal V. Catheter-based therapies in acute and chronic pulmonary embolism.Curr Opin Cardiol. 2021; 36: 704-710Crossref PubMed Scopus (1) Google Scholar However, these CDT studies are small with primarily surrogate outcomes (eg, right ventricle to left ventricle ratio); thus, it is difficult to draw robust, clinically relevant conclusions on their use in PE. Additionally, the long-term benefits of CDT also are unknown. No evidence is available currently that treatment of acute PE with thrombolysis will reduce the incidence or prevent the development of CTEPH or will prevent perfusion defects at follow-up.21Sanchez O. Helley D. Couchon S. et al.Perfusion defects after pulmonary embolism: risk factors and clinical significance.J Thromb Haemost. 2010; 8: 1248-1255Abstract Full Text Full Text PDF PubMed Scopus (124) Google Scholar,22Fernandes T. Planquette B. Sanchez O. Morris T. From acute to chronic thromboembolic disease.Ann Am Thorac Soc. 2016; 13: S207-S214Crossref PubMed Scopus (21) Google Scholar It remains to be seen if long-term outcomes with CDT will differ from those of systemic thrombolysis. However, even with these limitations, optimism in CDT is growing, given less reported bleeding risk compared with thrombolytics.17Tu T. Toma C. Tapson V.F. et al.A prospective, single-arm, multicenter trial of catheter-directed mechanical thrombectomy for intermediate-risk acute pulmonary embolism: the FLARE Study.JACC Cardiovasc Interv. 2019; 12: 859-869Crossref PubMed Scopus (218) Google Scholar,18Sista A.K. Horowitz J.M. Tapson V.F. et al.Indigo aspiration system for treatment of pulmonary embolism: results of the EXTRACT-PE Trial.JACC Cardiovasc Interv. 2021; 14: 319-329Crossref PubMed Scopus (101) Google Scholar CTEPH, pulmonary artery sarcoma, or both easily may be misinterpreted as acute PE, however, with only the latter likely benefiting from such interventions.11Rogberg A.N. Gopalan D. Westerlund E. Lindholm P. Do radiologists detect chronic thromboembolic disease on computed tomography?.Acta Radiol. 2019; 60: 1576-1583Crossref PubMed Scopus (26) Google Scholar In our series, 89% of patients demonstrated clues in the clinical history, echocardiography findings, imaging, or a combination thereof that were indicative of CTEPH or pulmonary artery tumors before undergoing CDT. The normal right ventricle (RV) cannot readily compensate when faced with elevated afterload in the acute setting. Possible echocardiography findings of acute PE include the McConnell sign (RV free wall akinesis with apical sparing), RV dilation, RV free wall hypokinesis, and interventricular septal flattening.23McConnell M.V. Solomon S.D. Rayan M.E. Come P.C. Goldhaber S.Z. Lee R.T. Regional right ventricular dysfunction detected by echocardiography in acute pulmonary embolism.Am J Cardiol. 1996; 78: 469-473Abstract Full Text Full Text PDF PubMed Scopus (561) Google Scholar RV ischemia and dysfunction also can occur in these patients. However, RV hypertrophy or significant RVSP elevation are more indicative of pre-existing cardiopulmonary disease, rather than an acute event. In a study from 1971, 20 patients without any prior cardiopulmonary disease who received a diagnosis of PE via pulmonary angiography were evaluated for their degree of pulmonary vascular