Comparison of Tenecteplase versus Alteplase for Pulmonary Embolism During In-Hospital Cardiac Arrest Authors: Paola Reyes-Serrano, Jason Vilar, Emily To Background: Pulmonary embolism (PE) accounts for approximately 2–5% of in-hospital cardiac arrests (IHCA) and is associated with high mortality despite advanced resuscitative efforts. Current guidelines recommend systemic thrombolysis when PE is suspected or confirmed during cardiac arrest; however, evidence supporting thrombolytic use in this setting remains limited. Alteplase has historically been the most commonly used thrombolytic agent for PE, while tenecteplase offers potential advantages, including greater fibrin specificity, longer half-life, and administration as a single intravenous bolus. This study aimed to compare clinical outcomes and safety of tenecteplase versus alteplase for suspected or confirmed PE during IHCA following a system-wide formulary change.
Methods: A retrospective cohort study was conducted across AdventHealth facilities. Adult patients who experienced IHCA and received systemic thrombolysis with alteplase or tenecteplase for suspected or confirmed PE between January 2024 and January 2026 were included. Suspected PE was defined by provider clinical assessment at the time of arrest. Baseline demographic characteristics, arrest characteristics, laboratory values, and PE risk factors were collected from the electronic health record. The primary outcome was return of spontaneous circulation (ROSC). Secondary outcomes included time from arrest to thrombolytic administration, time from thrombolytic administration to ROSC, cardiopulmonary resuscitation (CPR) duration, ICU and hospital length of stay, in-hospital mortality, and neurologic outcomes at discharge. Sustained ROSC was defined as ROSC maintained for at least 20 minutes. Safety outcomes included major bleeding events and blood transfusion requirements. Continuous variables were compared using Mann–Whitney U tests, and categorical variables using chi-square or Fisher’s exact tests.
Results: A total of 48 patients met inclusion criteria, 26 received alteplase and 22 received tenecteplase. ROSC occurred in 16 patients (33%), 10 patients (38.5%) in the alteplase group and 6 patients (27.3%) in the tenecteplase group. Sustained ROSC occurred in 7 patients (15.4%), 4 patients (15.4%) in alteplase group and 3 patients (13.6%) in tenecteplase group. Median time from thrombolytic administration to ROSC was 9.5 minutes (IQR 1.75–12.75) with alteplase and 13.5 minutes (IQR 5.75–16.25) with tenecteplase. Median total CPR duration was 41.0 minutes (IQR 22.5–54.0) with alteplase and 33.5 minutes (IQR 22.0–48.8) with tenecteplase. CPR duration following thrombolytic administration was similar between groups (16.5 minutes in both groups). Median time from arrest to thrombolytic administration was 18.5 minutes (IQR 11–31.3) with alteplase and 14.5 minutes (IQR 6.75–27.3) with tenecteplase. In-hospital mortality occurred in 24 patients (92.3%) who received alteplase and 22 patients (100%) who received tenecteplase. Neurologic outcomes were similar, with a median modified Rankin Scale (mRS) score of 6 (IQR 6–6) in both groups. Major bleeding occurred in 2 patients (7.7%) in the alteplase group and 2 patients (9.1%) in the tenecteplase group. Blood transfusion requirements were low, occurring in 1 patient (3.8%) in the alteplase group and 2 patients (9.1%) in the tenecteplase group. Baseline characteristics differed between groups in several variables. Patients who received tenecteplase were older (66.5 vs 58.5 years) and had lower median weight (73.9 vs 99.5 kg). Tenecteplase dosing was appropriate based on weight in 19 of 22 patients (86%), while 3 patients (14%) received doses outside of recommended weight-based ranges.
Conclusion: In this multicenter retrospective cohort of patients receiving systemic thrombolysis for suspected pulmonary embolism during in-hospital cardiac arrest, tenecteplase demonstrated clinical and safety outcomes comparable to alteplase. Rates of ROSC, bleeding events, and mortality were similar between treatment groups despite baseline differences in patient characteristics. Given its single intravenous bolus administration and comparable outcomes observed in this cohort, tenecteplase may represent a practical alternative to alteplase for thrombolytic therapy during cardiac arrest when pulmonary embolism is suspected. Larger prospective studies are needed to better define optimal thrombolytic selection in this high-risk population.
