Transcatheter Aortic Heart Valve Thrombosis
What are the incidence, potential predictors, and clinical implications of transcatheter aortic valve replacement (TAVR) thrombosis determined by contrast-enhanced multidetector computed tomography (MDCT)?
Among 460 consecutive patients undergoing TAVR with the Edwards Sapien XT or Sapien 3 (Edwards Lifesciences; Irvine, CA) valves, 405 (88%) underwent MDCT in addition to transthoracic and transesophageal echocardiography 1-3 months post-TAVR. MDCT scans were evaluated for hypo-attenuated leaflet thickening indicative of transcatheter heart valve thrombosis.
MDCT found evidence of TAVR thrombosis in 28 of 405 (7%) patients. A total of 23 patients had subclinical thrombosis, while 5 (18%) patients experienced clinically overt obstructive thrombosis. TAVR thrombosis risk did not differ between the Edwards Sapien XT and the Sapien 3 valves (8% [14 of 173] vs. 6% [14 of 232], p = 0.42). The risk of thrombosis in patients not receiving warfarin was higher compared to patients receiving warfarin (10.7% vs. 1.8%; relative risk [RR], 6.09; 95% confidence interval [CI], 1.86-19.84). A larger valve was associated with an increased thrombosis risk (p = 0.03). In multivariable analysis, 29 mm TAVR (RR, 2.89; 95% CI, 1.44-5.80) and no post-TAVR warfarin treatment (RR, 5.46; 95% CI, 1.68-17.7) independently predicted TAVR thrombosis. Treatment with warfarin effectively reverted thrombosis and normalized valve function in 85% of patients, as documented by follow-up transesophageal echocardiography and MDCT.
The incidence of transcatheter heart valve thrombosis in this large study was 7%. Larger TAVR size may predispose to valve thrombosis, whereas treatment with warfarin appears to have a protective effect. Although often subclinical, TAVR thrombosis may have important clinical implications.
There appears to be a risk of thrombosis early after bioprosthetic surgical and transcatheter valve implantation (also see Makkar RR, et al., N Engl J Med 2015;373:2015-24), potentially associated with high transvalvular gradients. This large multicenter study found a 7% prevalence after Sapien XT or Sapien 3 TAVR, with increased risk associated with larger devices and absent therapy with warfarin. Although the current (2014) American Heart Association/American College of Cardiology guideline includes a Class IIb recommendation for therapy with warfarin for 3 months after bioprosthetic AVR, and recommends only dual antiplatelet therapy after TAVR, this and other recently published studies suggest that reconsideration might be warranted, potentially strengthening a recommendation for early postoperative anticoagulation after bioprosthetic (surgical or transcatheter) AVR.
Clinical Topics: Anticoagulation Management, Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Stable Ischemic Heart Disease, Valvular Heart Disease, Aortic Surgery, Cardiac Surgery and SIHD, Cardiac Surgery and VHD, Interventions and Imaging, Interventions and Structural Heart Disease, Computed Tomography, Echocardiography/Ultrasound, Nuclear Imaging
Keywords: Anticoagulants, Aortic Valve Stenosis, Cardiac Surgical Procedures, Causality, Coronary Thrombosis, Echocardiography, Transesophageal, ESC Congress, Heart Valve Diseases, Incidence, Multidetector Computed Tomography, Transcatheter Aortic Valve Replacement, Thrombosis, Warfarin
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