Among patients with obstructive prosthetic valve thrombosis, low-dose and slow/ultraslow infusion of tissue plasminogen activator (tPA) were associated with low rates of complication and mortality, according to findings published in the Journal of the American College of Cardiology.
The treatment options of surgery or thrombolytic therapy (TT) for obstructive prosthetic valve thrombosis lack real-world data and randomized controlled trials. This leaves the optimal treatment for this life-threatening complication of prosthetic heart valve replacement unclear. Some major guidelines recommend reoperation for patients with obstructive left-sided prosthetic valve thrombosis, though mortality rates are as high as 18%. Researchers aimed to compare morbidity and mortality short-term outcomes of TT and surgery as the first-line treatment strategy in patients with obstructive prosthetic valve thrombosis.
To accomplish this, researchers conducted a multicenter observational prospective study of 158 adult patients (65.2% women; median age 49 years [IQR, 39-60 years]) diagnosed with prosthetic valve thrombosis in 8 tertiary centers between December 2013 and December 2020. Heart teams considered guidelines and shared decision making with patients. For centers lacking redo-valve surgery experience, TT was opted unless contraindicated. TT was administered using slow (6 hours) or ultraslow (25 hours) infusion of low-dose tPA 25 mg, mostly in repeated sessions. The primary outcome was 3-month mortality following TT or surgery.
TT was performed in 52.5% of patients and 47.5% of patients received surgery. Major criteria for TT success was measured by Doppler documentation of the complete improvement in valve hemodynamics, reduction in major diameter or area of the thrombus by 75%, and symptomatic improvement. The TT success rate was 90.4%, with a median tPA dose of 59 mg (IQR, 37.5-100 mg). Minor complications occurred in 38.7% of patients who underwent surgery and in 8.4% of patients who received TT. Major complications occurred in 41.3% of patients who received surgery and in 6% of patients who received TT. The 3-month mortality rate was 18.7% for surgery and 2.4% for TT.
Study limitations included the non-randomized observational design, that only short-term follow-up data was included, and surgical skills were not standardized. Additionally, more women were in the TT group than the surgery group, which may have led to bias.
“Slowly administered infusions of tPA are a safe and effective alternative to surgical therapy in selected patients with obstructive mechanical heart valve prostheses,” the researchers wrote. “Surgery has a high mortality rate even in experienced centers; therefore, TT may be considered as a beneficial treatment strategy in patients with obstructive [prosthetic valve thrombosis] in the absence of contraindications.”
Özkan M, Gündüz S, Güner A, et al. Thrombolysis or surgery in patients with obstructive mechanical valve thrombosis. J Am Coll Cardiol. Published online March 7, 2022. doi:10.1016/j.jacc.2021.12.027