Pause on Surgery for Prosthetic Valve Thrombosis

Volume 13, Issue 2

Mechanical heart valves are significantly more durable than their bioprosthetic counterparts, which can degrade over time and require replacement (which means another major surgery). One unfortunate disadvantage for mechanical heart valves is the need for lifelong warfarin therapy, as direct acting oral anticoagulants (DOACs) have not proven safe in these patients. Scrupulous attention to maintaining goal international normalized ratio values is paramount to preventing thrombosis of mechanical heart valves, as this condition carries a very high mortality rate.  

When prosthetic valves thrombose, the available treatment options are either surgery or intravenous thrombolytic therapy, with no clear advantage for either according to the current data. In this week’s issue of Talking Therapeutics, we explore a new paper published this week in the Journal of the American College of Cardiology, which may forever tip the scales in favor of drug therapy over surgery.  

Point 1: Spare the Surgery, Save the Patient 

The study included 158 patients with obstructive prosthetic valve thrombosis. Thrombolytic therapy “was performed using slow (6 hours) and/or ultraslow (25 hours) infusion of low-dose tissue plasminogen activator (t-PA) (25 mg) mostly in repeated sessions.” The comparator group received traditional open-heart surgery. Authors measured 3-month mortality after intervention.  

Eighty-three (52.5%) patients received thrombolytic therapy, while 75 (47.5%) patients received surgery. Thrombolytic therapy was associated with a success rate of 90.4%, with a median t-PA dose of 59 mg (IQR: 37.5-100 mg). Both major and minor complications were significantly more common with the surgery arm. Most impressively, the 3-month mortality rate was 14 (18.7%) for patients receiving surgery vs 2 (2.4%) for those receiving thrombolytic therapy.  

Point 2: Guidelines Likely to Change 

While the 2020 American College of Cardiology/American Heart Association guidelines recommend urgent initial treatment with either thrombolytic therapy or emergency surgery for symptomatic left-sided mechanical valve thrombosis, the most recent European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines still prioritize surgery in the management of prosthetic valve thrombosis. 

I would posit that, based on the results of this new trial, both guidelines will eventually harmonize to deprioritize urgent surgery over thrombolytic therapy for prosthetic valve thrombosis.