Cardionerds: A Cardiology Podcast

CardioNerds Dr. Joseph Kassab, Dr. Mariana Garcia-Arango, and Dr. Christopher Mason explore the technological revolution of Coronary CT Angiography (CCTA) with expert faculty Dr. Michael Gallagher. The discussion details how CCTA has evolved into a frontline diagnostic and preventive tool, moving beyond simple anatomy to incorporate physiology via CT-FFR and biology through AI-driven plaque quantification. The episode reviews landmark evidence like the SCOT-HEART and PROMISE trials, the nuances of CAD-RADS 2.0 reporting, and the emerging role of AI in monitoring treatment response and personalizing cardiovascular care. Critically, they also discuss some of the assumptions and limitations of these techniques.

Stay tuned for a matching review article to be submitted to US Cardiology Review, the official Journal of CardioNerds.

This episode was supported by an independent medical education grant from HeartFlow. All CardioNerds education is planned, produced, and reviewed solely by CardioNerds. 

Enjoy this Circulation Paths to Discovery article to learn more about the CardioNerds mission and journey.

US Cardiology Review is now the official journal of CardioNerds! Submit your manuscripts here.

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Pearls

Shift in Paradigm: CCTA is no longer just an anatomic test; with some key limitations, it can provide anatomy, physiology (CT-FFR), and plaque biology (AI-CPA) in a single non-invasive scan.

The “Power of Zero” vs. Plaque: While a normal CCTA has a >95% negative predictive value, future MIs often arise from non-obstructive plaque that traditional stress tests might miss.

CAD-RADS 2.0 Utility: The addition of plaque burden modifiers (P1–P4) is a “game changer,” allowing clinicians to identify high-risk patients who need aggressive lipid-lowering despite having only mild stenosis.

CT-FFR as a Virtual Stress Test: CT-FFR uses computational fluid dynamics to simulate blood flow, potentially reducing unnecessary invasive catheterizations by approximately 61% without sacrificing safety.

Seeing the Invisible: AI-based quantitative plaque analysis (QCPA) can identify “subvisual” plaque and low-attenuation (lipid-rich) components that are the primary drivers of acute coronary syndromes.

Show Notes

How has the role of CCTA changed compared to traditional functional testing?

Historically, stress testing answered “is there ischemia today?”, which often reflects late-stage disease.

CCTA identifies disease across the entire spectrum, asking “is there atherosclerosis and how much plaque is present?”.

Landmark evidence: SCOT-HEART showed a 41% relative risk reduction in MI at 5 years attributed to intensified preventive therapies, and PROMISE showed CCTA was better at selecting patients who truly needed invasive angiography.

Diagnostic CCTA imaging depends on the protocol, contrast timing, heart rate, heart rhythm, breathholding, scanner quality, and several patient factors (obesity, prior stents, heavy calcification, complex bypass anatomy, and motion artifact all may limit imaging). “CCTA is exceptional for the right patient, with the right scanner, and the right team.”

What are the key modifiers introduced in CAD-RADS 2.0, and why do they matter?

CAD-RADS 2.0 moved beyond stenosis severity to include plaque burden (P0 to P4), high-risk plaque (HRP) features, and the presence of ischemia based on CT-FFR.

It serves as a clinical decision support tool: a patient with mild (25-49%) stenosis but “extensive” (P4) plaque burden is considered high risk and warrants aggressive risk factor modification.

How is CT-FFR calculated, and when is it most useful in clinical practice?

CT-FFR uses resting CCTA data and computational fluid dynamics to create a 3D model of coronary flow during simulated maximal hyperemia.

It is often used for intermediate lesions (40–90% stenosis) to predict if they are  ischemia-producing, guiding the decision whether to proceed with invasive angiography. 

The assumptions necessary for this computational modeling may not apply well to patients with microvascular dysfunction, significant myocardial scar or prior infarction, or ventricular hypertrophy. Still, data indicate that CT-FFR performs similarly to PET in predicting hemodynamically significant lesions. 

CT-FFR performs well at the extremes (either clearly normal or clearly abnormal). Accuracy dips, however, in the intermediate range (~0.75-0.80), where decision-making is most critical. In this grey zone, additional factors can help guide the approach, including the amount of myocardium supplied, translesional gradient, and plaque features.  

CT-FFR has not been validated in distal segments, stented segments, heavily calcified coronary arteries, or in patients with severe aortic stenosis. Caution with CT-FFR should be utilized in very calcified coronary segments. 

What is AI-based quantitative plaque analysis (QCPA), and what metrics are ready for clinical use?

This is potentially a paradigm shift, moving away from stenosis-centric thinking to a more disease burden and plaque biology focus.

QCPA uses deep learning algorithms to automatically segment the vessel wall and quantify plaque volume in mm³.

Ready for “prime time” metrics include: Total Plaque Volume (TPV), non-calcified plaque volume, and Low-Attenuation Plaque (LAP) burden.

Can serial CCTA be used to monitor the effectiveness of medical therapies like statins?

While not yet a routine guideline-driven practice, trials like PARADIGM and EVAPORATE show that therapies can stabilize plaque; notably, CCTA is better for monitoring than CAC scores, which can be misleading as statins often increase plaque calcification as part of the stabilization process.

There are no randomized trials that serial CCTAs improve outcomes. Cost and radiation exposure will be notable limitations. Serial scan timing, scan acquisition and interpretation standardization would be key.

Dr. Gallagher notes that we are moving toward a world in which plaque burden may become a “treatment biomarker,” similar to tumor burden in oncology. 

References

1. Coronary Computed Tomography Angiography From Clinical Uses to Emerging Technologies: JACC State-of-the-Art Review. Abdelrahman KM, Chen MY, Dey AK, et al. Journal of the American College of Cardiology. 2020;76(10):1226-1243. doi:10.1016/j.jacc.2020.06.076.

2. Non-Invasive Imaging in Coronary Syndromes: Recommendations of the European Association of Cardiovascular Imaging and the American Society of Echocardiography, in Collaboration With the American Society of Nuclear Cardiology, Society of Cardiovascular Computed Tomography, and Society for Cardiovascular Magnetic Resonance. Edvardsen T, Asch FM, Davidson B, et al. Journal of the American Society of Echocardiography : Official Publication of the American Society of Echocardiography. 2022;35(4):329-354. doi:10.1016/j.echo.2021.12.012.

3. 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Gulati M, Levy PD, Mukherjee D, et al. Journal of the American College of Cardiology. 2021;78(22):e187-e285. doi:10.1016/j.jacc.2021.07.053.

4. Contemporary, Non-Invasive Imaging Diagnosis of Chronic Coronary Artery Disease. van der Bijl P, Gulati M, Saraste A, et al. Lancet (London, England). 2025;406(10519):2577-2587. doi:10.1016/S0140-6736(25)01586-7.

5. State of the Art: Evaluation and Medical Management of Nonobstructive Coronary Artery Disease in Patients With Chest Pain: A Scientific Statement From the American Heart Association. Slipczuk L, Blankstein R, Bucciarelli-Ducci C, et al. Circulation. 2025;152(23):e443-e466. doi:10.1161/CIR.0000000000001394.

6. Diagnostic Performance of Fractional Flow Reserve Derived From Coronary CT Angiography: The ACCURATE-CT Study. Li C, Hu Y, Jiang J, et al. JACC. Cardiovascular Interventions. 2024;17(17):1980-1992. doi:10.1016/j.jcin.2024.06.027.

7. Clinical Outcomes Based on Coronary Computed Tomography-Derived Fractional Flow Reserve and Plaque Characterization. Sato Y, Motoyama S, Miyajima K, et al. JACC. Cardiovascular Imaging. 2024;17(3):284-297. doi:10.1016/j.jcmg.2023.07.013.

8. Clinical Use of Coronary Computed Tomography Angiography-Derived Fractional Flow Reserve: Expert Consensus by an International Working Group. Tang CX, Leipsic JA, Nørgaard BL, et al. European Radiology. 2026;:10.1007/s00330-025-12313-6. doi:10.1007/s00330-025-12313-6.

9. Diagnostic accuracy of computed tomography–derived fractional flow reserve: a systematic review. Cook CM, Petraco R, Shun-Shin MJ, et al. JAMA Cardiol. 2017;2(7):803-810. Doi:10.1001/jamacardio.2017.1314

10. Diagnostic performance of noninvasive fractional flow reserve derived from coronary computed tomography angiography in suspected coronary artery disease: the NXT trial (Analysis of Coronary Blood Flow Using CT Angiography: Next Steps). Nørgaard BL, Leipsic J, Gaur S, et al. J Am Coll Cardiol. 2014;63(12):1145-1155. Doi:10.1016/j.jacc.2013.11.043

11. Comparison of coronary computed tomography angiography, fractional flow reserve, and perfusion imaging for ischemia diagnosis. Driessen RS, Danad I, Stuijfzand WJ, et al. J Am Coll Cardiol. 2019;73(2):161-173. Doi:10.1016/j.jacc.2018.10.056.

12. 1-year outcomes of FFRCT-guided care in patients with suspected coronary disease: the PLATFORM study. Douglas PS, De Bruyne B, Pontone G, et al. J Am Coll Cardiol. 2016;68(5):435-445. Doi:10.1016/j.jacc.2016.05.057.

13. Comparison of an initial risk-based testing strategy vs usual testing in stable symptomatic patients with suspected coronary artery disease: the PRECISE randomized clinical trial. Douglas PS, Nanna MG, Kelsey MD, et al; PRECISE Investigators. JAMA Cardiol. 2023;8(10):904-914. Doi:10.1001/jamacardio.2023.2595.

14. Diagnostic and clinical value of FFRCT in stable chest pain patients with extensive coronary calcification: the FACC study. Mickley H, Veien KT, Gerke O, et al. JACC Cardiovasc Imaging. 2022;15(6):1046-1058. doi:10.1016/j.jcmg.2021.12.010.

15. Low-Attenuation Noncalcified Plaque on Coronary Computed Tomography Angiography Predicts Myocardial Infarction: Results From the Multicenter SCOT-HEART Trial (Scottish Computed Tomography of the HEART). Williams MC, Kwiecinski J, Doris M, et al. Circulation. 2020;141(18):1452-1462. doi:10.1161/CIRCULATIONAHA.119.044720.

16. AI-Guided Quantitative Plaque Staging Predicts Long-Term Cardiovascular Outcomes in Patients at Risk for Atherosclerotic CVD. Nurmohamed NS, Bom MJ, Jukema RA, et al. JACC. Cardiovascular Imaging. 2024;17(3):269-280. doi:10.1016/j.jcmg.2023.05.020.

17. Interaction of AI-Enabled Quantitative Coronary Plaque Volumes on Coronary CT Angiography, FFRCT, and Clinical Outcomes: A Retrospective Analysis of the ADVANCE Registry. Dundas J, Leipsic J, Fairbairn T, et al. Circulation. Cardiovascular Imaging. 2024;17(3):e016143. doi:10.1161/CIRCIMAGING.123.016143.

18. Prognostic Value of AI-Based Quantitative Coronary CTA vs Human Reader-Based Visual Assessment: Results From the CONFIRM2 Registry. van Rosendael A, Nakanishi R, Bax JJ, et al. JACC. Cardiovascular Imaging. 2026;19(3):345-359. doi:10.1016/j.jcmg.2025.09.021.
13. Pericoronary Adipose Tissue as a Marker of Cardiovascular Risk: JACC Review Topic of the Week. Tan N, Dey D, Marwick TH, Nerlekar N. Journal of the American College of Cardiology. 2023;81(9):913-923. doi:10.1016/j.jacc.2022.12.021.

19. Effect of Icosapent Ethyl on Progression of Coronary Atherosclerosis in Patients With Elevated Triglycerides on Statin Therapy: Final Results of the EVAPORATE Trial. Budoff MJ, Bhatt DL, Kinninger A, et al. European Heart Journal. 2020;41(40):3925-3932. doi:10.1093/eurheartj/ehaa652.

20. Coronary CT Angiography Evaluation With Artificial Intelligence for Individualized Medical Treatment of Atherosclerosis: A Consensus Statement From the QCI Study Group. Schulze K, Stantien AM, Williams MC, et al. Nature Reviews. Cardiology. 2026;23(2):100-115. doi:10.1038/s41569-025-01191-6.

Join CardioNerds EP Council Chair Dr. Naima Maqsood and Episode Lead Dr. Sukriti Banthiya as they discuss the results of the International Collaborative LBBAP Study (I-CLAS) with expert faculty Dr. Theofanie Mela and Dr. Pugazhendhi Vijayraman. Audio editing by CardioNerds academy intern, Grace Qiu.

The International Collaborative LBBAP Study (I-CLAS) evaluated clinical outcomes between biventricular pacing (BVP) and left bundle branch area pacing (LBBAP) in patients with left ventricular ejection fraction (LVEF) ≤50% undergoing cardiac resynchronization therapy. Between January 2018 and June 2023, 2,579 patients were enrolled across 18 centers. The primary composite outcome was defined as all-cause mortality or heart failure hospitalization. LBBAP demonstrated a shorter paced QRS duration and was associated with a lower risk of primary composite outcome and heart failure hospitalization. No significant difference was observed in all-cause mortality. Additionally, procedural complications were lower with LBBAP.

This episode was planned in collaboration with  Heart Rhythm TV with mentorship from Dr. Daniel Alyesh and Dr. Mehak Dhande. 

Enjoy this Circulation 2022 Paths to Discovery article to learn about the CardioNerds story, mission, and values.

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In this episode, CardioNerds Dr. Colin Blumenthal, Dr. Kelly Arps, and Dr. Yong Hao Yeo are joined by electrophysiology expert Dr. Bradley Knight to discuss atrial fibrillation (AF) management in challenging clinical scenarios. We explore arrhythmias in patients with pre-excitation syndromes, particularly Wolff-Parkinson-White (WPW) syndrome, and strategies for rhythm control. We also discuss AF management in pregnancy, adult congenital heart disease, and patients with tachycardia-bradycardia (tach-brady) syndrome. This episode provides essential insights into nuanced decision-making for the care of patients with complex arrhythmia profiles. Audio editing by CardioNerds academy intern, Grace Qiu.

Enjoy this Circulation 2022 Paths to Discovery article to learn about the CardioNerds story, mission, and values.

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PEARLS

AF in WPW is a true emergency—AV nodal blocking agents can be deadly. In patients with WPW syndrome, AF can rapidly conduct through the accessory pathway, risking ventricular fibrillation and sudden death. Avoid AV nodal blockers like beta-blockers and calcium channel blockers.

Catheter ablation is the first-line rhythm control strategy in WPW. Catheter ablation carries a Class I recommendation and offers >90% success. If antiarrhythmic drugs are needed, sodium channel blockers like flecainide or propafenone are preferred in patients without structural heart disease.

In pregnancy, protecting the mother is protecting the fetus. An unstable mother means an unstable fetus. Rate control is the first step in AF with rapid ventricular responses and electrical cardioversion is safe when needed. Multidisciplinary care is essential.

AF in congenital heart disease is often outside the pulmonary veins. Surgical scars and chamber remodeling in ACHD patients often lead to AF from non-pulmonary vein foci. Electrogram-based mapping and targeted ablation strategies are essential to increase success rate of durable rhythm control.

Tachy-brady syndrome may require pacing to unlock therapy. AF may cause atrial myopathy and sinus node dysfunction. These patients often require permanent pacing to allow safe use of rate-controlling medications like beta-blockers and to prevent syncope or chronotropic incompetence.

Notes: Notes drafted by Dr. Yong Hao Yeo

Why is atrial tachycardia in patients with WPW syndrome dangerous?

Patients with WPW commonly present with supraventricular tachycardia (SVT) due to atrioventricular reentrant circuits, either orthodromic or antidromic. This SVT can degenerate into AF.

In the absence of AV nodal as the governor between the atrium and ventricles, the accessory pathway may conduct impulses rapidly and frequently. This can lead to dangerously high ventricular rates, predisposing patients to ventricular fibrillation and sudden cardiac arrest.

What are some strategies for rhythm control in patients with WPW and atrial tachycardia?

Catheter ablation is the first-line therapy (Class I recommendation), with a success rate of over 90%.

Ablation reduces the risk of sudden cardiac arrest, though some patients may remain prone to AF.

If ablation is not feasible/ contraindicated, sodium channel blockers such as flecainide and propafenone are good options in patients without ischemia or structural heart disease (Class IIa recommendation).

Amiodarone should be avoided because it has a long half-life, can accumulate in the system, and may delay definitive treatment with catheter ablation.

AV nodal blocking agents like beta blockers and calcium channel blockers should be avoided, as they are less effective at controlling ventricular rate in WPW and can increase conduction over the accessory pathway. These agents can also exacerbate the risk of rapid ventricular rates during AF and worsen left ventricular function.

What are some special considerations in managing AF in pregnant patients?

The primary goal in managing cardiovascular disease during pregnancy is to protect the mother, as fetal outcomes depend on maternal well-being. Therefore, while caution is necessary, we should avoid undertreating pregnant patients with AF.

In cases of AF with rapid ventricular response (RVR), rate control is usually the first-line strategy, with beta blockers preferred over digoxin or non-dihydropyridine calcium channel blockers. It is then reasonable to initially observe for spontaneous conversion in stable patients.

Antiarrhythmic drugs (AADs) are generally avoided during the first trimester, but clinical judgment on a case-by-case basis is essential.

Evidence for the safety of AADs in pregnancy is limited, often derived from their use in other conditions such as fetal SVT. Flecainide and sotalol are reasonable options for rhythm control (Class IIa recommendation).

Electrical cardioversion is considered safe in pregnancy and should be utilized when indicated (Do not forget!).

There is no pregnancy-specific thromboembolic risk stratification tool. CHA₂DS₂-VASc scoring and the presence of risk factors like mitral stenosis can help guide anticoagulation decisions, though the magnitude of thromboembolic risk during pregnancy remains unclear.

Rate control agents are typically continued during delivery due to the increased physiologic stress of labor and delivery.

Multidisciplinary care is crucial and should involve obstetrics, maternal-fetal medicine, cardiology, and electrophysiology specialists.

What are some key considerations for AF management in patients with adult congenital heart disease (ACHD)?

Patients with repaired congenital heart disease are at increased risk for arrhythmias due to two main factors: surgical scars that create arrhythmogenic foci and mechanical remodeling of the atria or ventricles resulting from the underlying disease.

In these patients with structural heart disease, sodium channel blockers may not be ideal antiarrhythmic options.

When selecting an antiarrhythmic drug, clinicians must consider the nature of structural or surgical impairments, such as right bundle branch block or prolonged QT interval.

It is also essential to assess renal and hepatic function (often impaired in patients with ACHD) to ensure appropriate metabolism and clearance of antiarrhythmic medications.

Electrogram-based ablation strategies (those leveraging artificial intelligence are developing!) may help identify effective ablation targets, which are often outside the pulmonary veins in patients with ACHD. These individualized approaches can improve ablation success rates in this complex patient population.

What makes tachycardia-bradycardia (tach-brady) syndrome a unique challenge in arrhythmia management?

Patients who present with both AF and bradycardia, especially with syncope, require a thoughtful diagnostic approach to identify the underlying rhythm disturbance.

Extended cardiac monitoring, including event monitors or implantable loop recorders, can help capture intermittent arrhythmias and correlate them with symptoms.

AF may lead to atrial myopathy, and since the sinus node resides within the atrium, this can result in sinus node dysfunction—a hallmark of tachy-brady syndrome.

Following spontaneous conversion from AF to sinus rhythm, sinus node dysfunction may persist, leading to prolonged pauses or chronotropic incompetence.

Management becomes more complex when beta-blockers are needed for AF with RVR, as they can exacerbate bradycardia. Permanent pacemaker implantation is often the next step to consider.

Permanent pacemaker implantation is often considered to facilitate safe rate control in these cases.

In younger patients, aggressive AF burden reduction may prevent atrial remodeling and the development of true atrial myopathy, potentially avoiding pacemaker implantation.

References

Joglar JA, Chung MK, Armbruster AL, et al. 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2023;149(1). doi:https://doi.org/10.1161/CIR.0000000000001193 ‌

Van IC, Rienstra M, Bunting KV, et al. 2024 ESC Guidelines for the management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS). European Heart Journal. 2024;45(36). doi:https://doi.org/10.1093/eurheartj/ehae176 ‌

Joglar JA, Kapa S, Saarel EV, et al. 2023 HRS expert consensus statement on the management of arrhythmias during pregnancy. Heart Rhythm. Published online May 1, 2023. doi:https://doi.org/10.1016/j.hrthm.2023.05.017 ‌

Stout KK, Daniels CJ, Aboulhosn JA, et al. 2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease: Executive Summary. Journal of the American College of Cardiology. 2019;73(12):1494-1563. doi:https://doi.org/10.1016/j.jacc.2018.08.1028 ‌

CardioNerds (Amit Goyal, Daniel Ambinder, Carine Hamo, and Karan Desai) are honored to bring you The Braunwald Chronicles — a special tribute to the life and legacy of Dr. Eugene Braunwald.

Originally released as a 6-part series, we are now bringing these chapters together as one complete experience. These are stories of discovery, innovation, accidents, perseverance, and more… truly, these are the stories of cardiology itself — told firsthand by the father of modern cardiology. Dr. Braunwald’s life and work form the very foundation of contemporary cardiovascular medicine, and his story is, in many ways, the story of our field. Join us as we journey through the history of cardiology across six extraordinary chapters — from the early days of physiologic discovery, to the development of transseptal access, to defining the natural history of valvular disease, to shaping modern therapies for myocardial infarction, and beyond. Through it all, Dr. Braunwald reflects on the principles that guided his career — curiosity, perseverance, mentorship, and the importance of being in the right place, at the right time, with the right people.We hope this collection serves not only as an educational experience, but as a tribute to one of the greatest minds in the history of medicine.

We thank Dr. Karan Desai, Editorial APD with the CardioNerds Academy and fellow at the University of Maryland, for all the work he put into designing The Braunwald Chronicles. Audio editing by Pace Wetstein.

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CardioNerds Drs. Dinu Balanescu, Billy-Joe Mullinax, and Mariana Garcia discuss systemic thrombolysis in pulmonary embolism with expert Dr. Allison Burnett. Audio editing by CardioNerds Academy intern, student doctor, Pace Wetstein.

Pulmonary embolism is the third leading cause of cardiovascular death in the US, and high-risk PE carries a 30-day mortality risk as high as 30-50%. In this episode, we discuss the indications for systemic thrombolysis, including high-risk PE and cardiac arrest. We addressed how to appropriately select candidates for systemic thrombolysis, balancing the high risk of bleeding. Additionally, we discussed anticoagulation management and timing concurrent with lytic therapy, as well as the importance of multidisciplinary PERT teams. 

The 2026 American multi-society PE guidelines were published after this episode was recorded.

Dr. Dinu Balanescu and Dr. Billy-Joe Mullinax are Co-chairs for the CardioNerds PE Series, developed in collaboration with the PERT Consortium.  

Enjoy this Circulation 2022 Paths to Discovery article to learn about the CardioNerds story, mission, and values.

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Pearls

Risk stratification is crucial in acute pulmonary embolism care. Based on the ESC 2019 guidelines, low-risk PE patients are those who are normotensive with no evidence of right ventricular dysfunction. Intermediate risk includes two categories: intermediate-low, with normotensive patients who have a high PE score with negative biomarkers, and intermediate-high risk, which has elevated biomarkers or signs of RV strain. High-risk PE includes hemodynamically unstable patients (SBP<90) who have end-organ dysfunction, shock, or cardiac arrest.

The 2026 American multi-society PE guidelines presented a new clinical classification scheme is presented, entitled “Acute Pulmonary Embolism Clinical Categories,” with 5 categories (A-E) and subcategories, ranging from low to high risk for adverse outcomes.

Systemic lysis has been studied in patients at high and intermediate risk. Overall, the reduction in mortality has been seen in patients with high-risk PE. 

Systemic thrombolysis is associated with high rates of bleeding, 2% fatal or high-risk intracranial hemorrhage per the PEITHO trial; therefore, selecting the appropriate population is critical to improve outcomes and balance the risks and benefits. 

Multidisciplinary PERT teams are crucial for making high-quality decisions, and stewardship is necessary to optimize the care of patients with PE. 

Notes

Notes: Notes drafted by Dr. Mariana Garcia-Arango

What is the role of systemic thrombolysis in the current era of available catheter-directed therapies?

Thrombolytic therapy reduces mortality, PE recurrence, and PE-related mortality in patients with acute PE. 

The evidence supports use during high-risk PE and cardiac arrest. 

The clinical presentation is often severe, with high stakes and limited time to mobilize to the cath lab on time for catheter therapies, especially in rural populations. 

How to approach the use of systemic thrombolysis during CPR?

Cardiac arrest from PE carries a very poor outlook, with survival rates under 10%. Rapid, targeted interventions to restore circulation are critical.

Systemic thrombolysis may be considered for patients in cardiac arrest due to confirmed or strongly suspected pulmonary embolism, especially when standard ACLS interventions have not been successful. 

What is the best anticoagulation approach while using lytics? 

Most of the time, we should opt for low-molecular-weight heparin over unfractionated heparin, which has been shown to lead to less major bleeding and reduction of recurrent PE. 

Exceptions to the rule include renal dysfunction or if there is consideration of cannulation for ECMO or other invasive procedures. 

There is variation in practice regarding timing and initiation of anticoagulation while using lytics. There are different protocols given the variety of how studies were conducted.

If they are going to get mechanical catheter-based therapy, the trend is to prefer LMWH.

When lytics are included, either systemic or catheter-directed lytics, there is flexibility and room to discuss with the multidisciplinary PERT team which strategy to use.

Future studies and trials are needed to standardize the best therapies. 

What are the pharmacologic properties of available thrombolytics?

Thrombolytics catalyze the conversion of plasminogen to plasmin, leading to fibrin degradation and thrombus dissolution.

Alteplase is a recombinant tissue plasminogen activator, administered intravenously at a dose of IV 100 mg infusion over 2 hours. In cardiac arrest, the initial: 50 mg bolus over 2 minutes and continue CPR; after 15 minutes, if return of spontaneous circulation is not achieved and the medical team decides to continue CPR, repeat 50 mg bolus.

Tenecteplase is a modified variant of alteplase with increased fibrin specificity. The usual dose is weight-based and delivered via IV bolus, which facilitates rapid delivery in emergency settings. Dose per weight: ≥60 to <70 kg: 35 mg, ≥70 to <80 kg: 40 mg, ≥80 to <90 kg: 45 mg, ≥90 kg: 50 mg

Are there any ongoing clinical trials and emerging therapies investigating novel thrombolytics and strategies to optimize efficacy while minimizing bleeding risk?

PEITHO-3 is a large, randomized, double-blind, multinational study comparing reduced-dose intravenous alteplase with standard heparin in patients with intermediate-high-risk PE. 

References

Sedhom R, Megaly M, Elbadawi A, et al. Contemporary national trends and outcomes of pulmonary embolism in the United States. Am J Cardiol. 2022;176:132-138. doi:10.1016/j.amjcard.2022.03.060

Marti C, John G, Konstantinides S, Combescure C, Sanchez O, Lankeit M, Meyer G, Perrier A. Systemic thrombolytic therapy for acute pulmonary embolism: a systematic review and meta-analysis. Eur Heart J. 2015 Mar 7;36(10):605-14. Epub 2014 Jun 10.

Zuo Z, Yue J, Dong BR, Wu T, Liu GJ, Hao Q. Thrombolytic therapy for pulmonary embolism. Cochrane Database Syst Rev. 2021;CD004437.

Feltes J, Popova M, Hussein Y, Pierce A, Yamane D. Thrombolytics in cardiac arrest from pulmonary embolism: a systematic review and meta-analysis. J Intensive Care Med. 2023;39(5):477-483.

Javaudin F, Lascarrou JB, Le Bastard Q, Bourry Q, Latour C, De Carvalho H, Le Conte P, Escutnaire J, Hubert H, Montassier E, Leclère B; Research Group of the French National Out-of-Hospital Cardiac Arrest Registry (GR-RéAC). Thrombolysis during resuscitation for out-of-hospital cardiac arrest caused by pulmonary embolism increases 30-day survival: findings from the French National Cardiac Arrest Registry. Chest. 2019 Dec;156(6):1167-1175. Epub 2019 Aug 2.

Bonnard T, Tennant Z, Niego B, Kanojia R, Alt K, Jagdale S, Law LS, Rigby S, Medcalf RL, Peter K, Hagemeyer CE. Novel thrombolytic drug based on thrombin cleavable microplasminogen coupled to a single-chain antibody specific for activated GPIIb/IIIa. J Am Heart Assoc. 2017 Feb 3;6(2):e004535.

Kearon C, Akl EA, Comerota AJ, Prandoni P, Bounameaux H, Goldhaber SZ, Nelson ME, Wells PS, Gould MK, Dentali F, Crowther M, Kahn SR. Antithrombotic therapy for VTE disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012 Feb;141(2 Suppl):e419S-e496S. Erratum in: Chest. 2012 Dec;142(6):1698-1704.

Levine M, Hirsh J, Weitz J, Cruickshank M, Neemeh J, Turpie AG, Gent M. A randomized trial of a single bolus dosage regimen of recombinant tissue plasminogen activator in patients with acute pulmonary embolism. Chest. 1990 Dec;98(6):1473-1479.

Rivera-Lebron B, Weinberg AS. Acute pulmonary embolism in adults: Reperfusion therapy in intermediate- and high-risk patients. In: Connor RF, ed. UpToDate. Waltham, MA: UpToDate Inc. Accessed August 28, 2025.