Atrial fibrillation, the most common sustained cardiac arrhythmia, raises the risk of thromboembolic stroke five- to six-fold, with more than 90 percent of those emboli in non-valvular disease originating from the left atrial appendage, a small pouch in the left atrium where blood clots form. For patients who cannot take long-term oral anticoagulants because of bleeding risk or contraindications such as prior hemorrhage or high fall risk, percutaneous left atrial appendage occlusion offers a device-based alternative that mechanically seals the pouch. Now, one of the largest real-world comparisons of the two imaging techniques used to guide that procedure suggests that the newer, less invasive option may be at least as safe as the established gold standard.
The study, published in Cardiovascular Ultrasound, drew on the TriNetX Research Network, a federated database aggregating de-identified electronic health records from 112 healthcare organizations. Researchers identified 10,629 adults with atrial fibrillation who underwent percutaneous left atrial appendage occlusion guided exclusively by either intracardiac echocardiography, known as ICE, or transesophageal echocardiography, or TEE, through September 5, 2024. Of these, 3,930 patients received ICE guidance and 6,699 received TEE guidance. Patients with rheumatic mitral valve disease were excluded to isolate the comparison, and anyone with a prior history of stroke, pericardial effusion, device-related complications, or major bleeding was also removed from the analysis.
Because patients were not randomized, the investigators used 1:1 propensity score matching to balance the two groups on demographics, comorbidities, medications, prior procedures, and laboratory values, using a logistic-regression model with a 0.1 pooled standard deviation caliper and matching without replacement. After matching, 3,442 patients remained in each cohort with well-balanced baseline characteristics: mean age of 75.6 years in both groups, male sex at 61.2 percent in both, and standardized mean differences below 0.10 for the displayed covariates. The primary endpoint was all-cause mortality within 30 days of the procedure, with secondary endpoints including pericardial effusion, stroke or cerebrovascular accident, major bleeding, acute kidney injury, device-related complications, and all-cause hospitalization or emergency department encounters assessed at both 30 and 365 days.
The headline result was reassuring but nuanced. At 30 days, all-cause mortality was numerically lower with ICE, occurring in 15 of 3,428 patients, or 0.4 percent, compared with 26 of 3,431 patients, or 0.8 percent, in the TEE group. That difference, corresponding to a risk ratio of 0.577, did not reach statistical significance, with a p-value of 0.085 and a confidence interval spanning 0.306 to 1.088. In other words, the trend favored the newer technique, but the study was not designed to prove a mortality advantage, and the authors are careful not to claim one.
Where the analysis did find statistically significant differences was in pericardial effusion, the accumulation of fluid around the heart that is one of the most feared complications of the procedure. Among at-risk patients, pericardial effusion occurred in 62 of 3,046 ICE patients, or 2.0 percent, versus 88 of 3,094 TEE patients, or 2.8 percent, a risk ratio of 0.716 with a p-value of 0.040. This finding stands in contrast to several earlier reports. A meta-analysis of more than 5,000 patients concluded that ICE achieved higher procedural success but was associated with increased pericardial effusion and iatrogenic atrial septal defect rates, and an updated 2025 meta-analysis similarly observed an excess of pericardial effusion, residual shunts, and vascular complications with ICE. The largest contemporary comparative study, by Ferro and colleagues, reported higher rates of pericardial effusion requiring intervention with ICE compared with TEE at 45 days, 1.0 percent versus 0.5 percent, in a multicenter United States registry of more than 39,000 left atrial appendage occlusion procedures using the Watchman FLX device.
The authors attribute this discrepancy largely to the learning curve. As ICE adoption has expanded and operator experience has matured, complication rates have demonstrably decreased, a pattern consistent with other complex catheter-based procedures. The Ferro registry included procedures from an earlier adoption period, and its authors likewise noted that pericardial complications declined as operators accrued experience. Institutional volume and dedicated structural heart programs also matter, and the propensity matching in the new analysis controlled for baseline differences that may have influenced complication risk in less-adjusted comparisons. The researchers caution, however, that the absolute difference was modest and that continued vigilance for pericardial complications remains warranted, particularly during ICE adoption phases at new centers.
Healthcare utilization told a striking story. All-cause hospitalization or emergency department encounters within 30 days occurred in 741 of 3,442 ICE patients, or 21.5 percent, compared with 1,014 of 3,442 TEE patients, or 29.5 percent, a highly significant reduction with a risk ratio of 0.731 and a p-value below 0.001. At 365 days the gap narrowed but persisted, with 60.0 percent versus 63.2 percent and a p-value of 0.007. The authors emphasize that this endpoint captures any hospitalization or emergency encounter, potentially including planned admissions and non-cardiovascular events, and should therefore be interpreted as a measure of healthcare utilization rather than a purely procedure-specific rehospitalization metric.
Other outcomes were broadly comparable. Stroke or cerebrovascular accident at 30 days occurred in 0.8 percent of ICE patients versus 1.2 percent of TEE patients, a difference that was not statistically significant. Major bleeding at 30 days was likewise similar, at 1.0 percent versus 1.5 percent, as was acute kidney injury at 2.8 percent versus 3.3 percent. Device-related complications within 30 days could not be reported at all because the TriNetX platform suppresses outcomes when event counts fall below 10 in either cohort, a privacy-preserving small-cell suppression measure. At one year, mortality was similar between groups at 5.5 percent versus 6.0 percent, but major bleeding was significantly lower with ICE, at 4.2 percent versus 5.6 percent. The authors treat that longer-term bleeding finding as hypothesis-generating, because post-procedural antithrombotic regimens and bleeding subtypes are not consistently captured across contributing health systems, and long-term bleeding after the procedure is strongly influenced by antithrombotic strategy and comorbidity burden rather than by the imaging modality itself.
In multivariable Cox models adjusted for the prespecified covariates, ICE use was associated with lower hazards of pericardial effusion, stroke, and major bleeding at 30 days, with hazard ratios of 0.682, 0.828, and 0.774 respectively, all statistically significant, while the mortality hazard ratio of 0.634 was not significant. At 365 days, hazards were similar for mortality, pericardial effusion, and stroke, device complications trended lower without reaching significance, and major bleeding remained significantly lower with a hazard ratio of 0.783. The study has important limitations typical of non-randomized electronic health record research: residual confounding cannot be excluded, variables such as operator experience, sedation type, device generation, and center-level practice patterns were not captured, coding misclassification is possible, follow-up was limited to one year, and the dataset does not distinguish ICE catheter types or record procedural time, anesthesia type, or cost. The authors conclude that ICE represents a safe and effective alternative to TEE in experienced centers, particularly for patients unable to tolerate general anesthesia or those with esophageal pathology precluding TEE, while stressing that prospective studies with adjudicated endpoints and granular procedural data are needed to confirm these observations.
Subject of Research: Comparative safety and effectiveness of intracardiac versus transesophageal echocardiography guidance in percutaneous left atrial appendage occlusion
Article Title: Intracardiac vs. Transesophageal echocardiography in left atrial appendage occlusion: real-world comparative effectiveness from a propensity-matched cohort
Article References: Ahmed, F., Gohar, N., Hamza, M., Shafqat, M., Ahmed, S. M., Masood, A., Khan, T. M., Bhat, R. R., Ahmed, H., Ghaffar, M. T., Affan, M., Faraz, M. A., Khan, A. Q., Taha, A., Bakr, M., Patel, S., Hossain, M. A., & Alenezi, F. (2026). Intracardiac vs. Transesophageal echocardiography in left atrial appendage occlusion: real-world comparative effectiveness from a propensity-matched cohort. Cardiovascular Ultrasound, 24(1), Article 12. https://doi.org/10.1186/s12947-026-00375-5
Image Credits: AI Generated
DOI: 10.1186/s12947-026-00375-5
Keywords: atrial fibrillation, left atrial appendage occlusion, intracardiac echocardiography, transesophageal echocardiography, propensity score matching, pericardial effusion, stroke prevention, TriNetX, real-world evidence, interventional cardiology, healthcare utilization, major bleeding
News Source: Ophelia Keating. (October 29, 2026). Intracardiac echocardiography matches traditional imaging safety in heart procedure, large study finds. Scienmag.
