Identification of thrombus-related mechanical prosthetic valve dysfunction (MPVD)
has important therapeutic implications. We sought to develop an algorithm, combining
clinical and echocardiographic parameters, for prediction of thrombus-related MPVD
in a series of 53 patients (24 men, age 52 +/- 16 years) who had intraoperative diagnosis
of thrombus or pannus from 1992 to 1997. Clinical and echocardiographic parameters
were analyzed to identify predictors of thrombus and pannus. Prevalence of thrombus
and diagnostic yields relative to the number of predictors were determined. There
were 22 patients with thrombus, 19 patients with pannus, and 12 patients with both.
Forty-two of 53 masses were visualized using transesophageal echocardiography (TEE),
including 29 of 34 thrombi or both thrombi and panni and 13 of 19 isolated panni.
Predictors of thrombus or mixed presentation include mobile mass (p = 0.009), attachment
to occluder (p = 0.02), elevated gradients (p = 0.04), and an international normalized
ratio of < or = 2.5 (p = 0.03). All 34 patients with thrombus or mixed presentation
had > or = 1 predictor. The prevalence of thrombus in the presence of < or = 1, 2,
and > or = 3 predictors is 14%, 69%, and 91%, respectively. Thus, TEE is sensitive
in the identification of abnormal mass in the setting of MPVD. An algorithm based
on clinical and transesophageal echocardiographic predictors may be useful to estimate
the likelihood of thrombus in the setting of MPVD. In the presence of > or = 3 predictors,
the probability of thrombus is high.