Resolution of Left Atrial Thrombus after 6 Months of Anticoagulation in Candidates for Percutaneous Transvenous Mitral Commissurotomy

20 January 2004 | Volume 140 Issue 2 | Pages 101-105

Background: Resolution of left atrial thrombus after long-term oral anticoagulation enhances safe percutaneous transvenous mitral commissurotomy (PTMC); however, the short-term benefit has not been defined.

Objectives: To estimate the resolution rate of left atrial thrombus among PTMC candidates after 6 months of oral anticoagulation and to determine its main predictors.

Design: Prospective cohort.

Setting: Community-based university medical center.

Patients: 219 PTMC candidates with thrombus demonstrated by multiplane transesophageal echocardiographic studies.

Measurements: The primary outcome was the status of the thrombus at the first 6-month follow-up; secondary measures were bleeding or thromboembolic complications.

Results: Among 219 PTMC candidates with left atrial thrombus (mean age [±SD], 39.6 ± 7.4 years [range, 19 to 62 years]), complete resolution of thrombus, with an overall disappearance rate of 24.2% (95% CI, 18.5% to 29.9%), was demonstrated in 53 patients who subsequently underwent successful PTMC. In another 166 patients, the thrombus size was reduced by 24% (P < 0.001). No thrombus resolution was observed in the 27 patients with a left atrial body thrombus. Eighteen patients had minor bleeding. The significant predictors of thrombus resolution were a New York Heart Association class of 2 or less, a left atrial appendage thrombus size of 1.6 cm² or less, a left atrial spontaneous echocardiographic contrast grade of 1 or less, and an international normalized ratio (INR) of at least 2.5. Patients with all of these predictors had a 94.4% chance of complete thrombus resolution (CI, 84.4% to 98.1%).

Conclusions: After 6 months of oral anticoagulation, the left atrial thrombus disappeared in about a quarter of PTMC candidates so they could safely undergo PTMC. Less clinical severity, lower grading of the left atrial spontaneous echocardiographic contrast, a smaller thrombus, and a higher INR level predict thrombus resolution.

Editors' Notes Context Patients with a left atrial thrombus cannot have percutaneous transvenous mitral commissurotomy for mitral stenosis because of the embolic risk. Contribution This prospective study from a university medical center showed that oral anticoagulation for 6 months resolved the atrial thrombus in 24% of 219 patients with mitral stenosis. These patients subsequently had successful percutaneous transvenous mitral commissurotomy. Eighteen of the 219 patients had minor bleeding during anticoagulation. Implications In patients with atrial thrombus and mitral stenosis who do not need immediate surgery, a 6-month trial of oral anticoagulation might increase the number eligible for percutaneous transvenous mitral commissurotomy. –The Editors

 

Author and Article Information

From Khon Kaen University, Khon Kaen, Thailand.

Acknowledgments: The authors thank Bryan Roderick Hamman for his assistance with the English-language presentation of the manuscript. They also thank the patients for their participation and the colleagues, nurses, and hospital staff who cared for the PTMC patients and the many doctors who referred patients to them.

Potential Financial Conflicts of Interest: None disclosed.

Requests for Single Reprints: Songkwan Silaruks, MD, Department of Medicine, Faculty of Medicine, Khon Kaen University, Mitraparp Road, Khon Kaen 40002, Thailand; e-mail, sonsil{at}kku.ac.th.

Current Author Addresses: Drs. Silaruks, Kiatchoosakun, Wongvipaporn, and Tatsanavivat: Department of Medicine, Faculty of Medicine, Khon Kaen University, Mitraparp Road, Khon Kaen 40002, Thailand.

Dr. Thinkhamrop: Department of Biostatistics and Demography, Faculty of Public Health, Khon Kaen University, Mitraparp Road, Khon Kaen 40002, Thailand.

Author Contributions: Conception and design: S. Silaruks.

Analysis and interpretation of the data: S. Silaruks, B. Thinkhamrop.

Drafting of the article: S. Silaruks, B. Thinkhamrop.

Critical revision of the article for important intellectual content: S. Silaruks, B. Thinkhamrop, S. Kiatchoosakun, C. Wongvipaporn, P. Tatsanavivat.

Final approval of the article: S. Silaruks, B. Thinkhamrop, S. Kiatchoosakun, C. Wongvipaporn, P. Tatsanavivat.

Provision of study materials or patients: S. Silaruks, S. Kiatchoosakun, C. Wongvipaporn, P. Tatsanavivat.

Statistical expertise: B. Thinkhamrop.

Collection and assembly of data: S. Silaruks, S. Kiatchoosakun, C. Wongvipaporn, P. Tatsanavivat.