Mechanical cardiac valve thrombosis. Is thrombectomy justified?

Area of Science:

• Cardiovascular Surgery
• Biomaterials Science
• Clinical Outcomes Research

Background:

• Mechanical heart valve replacements (MVR, AVR, DVR) are common procedures.
• Thrombotic obstruction is a known complication of mechanical heart valves.
• Long-term data on the incidence and management of prosthetic valve thrombosis are crucial.

Purpose of the Study:

• To determine the incidence of acute thrombotic obstructions in mechanical heart valves.
• To evaluate the outcomes of treatments for mechanical prosthetic valve thrombosis.
• To compare reoperation with valve replacement versus debridement for thrombosis.

Main Methods:

• Retrospective review of 3,637 hospital survivors undergoing MVR, AVR, or DVR between 1970 and 1990.
• Analysis of 72 thrombotic obstructions occurring over 22,783 patient-years of follow-up.
• Comparison of outcomes for patients treated with reoperation (valve replacement vs. debridement).

Main Results:

• The actuarial thrombosis-free rates were 96-97% for MVR, AVR, and DVR.
• Overall mortality associated with prosthetic thrombosis was 25%.
• Reoperation with valve replacement had a 16% hospital mortality and a 96% rethrombosis-free rate, significantly better than debridement (41% rethrombosis-free rate, p=0.01).

Conclusions:

• Mechanical prosthetic valve thrombosis occurs at a low but significant rate.
• Valve replacement is the preferred treatment for prosthetic valve thrombosis, offering superior long-term outcomes.
• Surgical intervention, particularly valve replacement, is effective in managing acute thrombotic obstructions of mechanical heart valves.