For tricuspid valve OTPHV, thrombolytic therapy is the optimal initial therapy. For left-sided OTPHV, thrombolytic therapy is easier to administer than is surgery but is associated with complication rates and of recurrence of 14% and 13%, respectively. Complete success of thrombolysis is achieved in 70% but is associated with serious complications and a mortality of 8%. In the 30% who have failure of thrombolytic therapy, surgery is necessary, frequently urgently; their mortality is at least 12%, the outcome in this subgroup may have been much worse, additional studies with complete follow-up information are needed. Surgery is associated with a higher mortality of 15%, but 81% of these patients were in NYHA functional classes III/IV. It was associated with lower complication and recurrence rates of 6%. Complete success of thrombosis can be assumed to be 100% because the thrombosed PHV and residual thrombus were removed.
Suggested Therapeutic Strategies for OTPHV
We have developed suggested strategies for treatment of OTPHV (Table 6). The data related to the strategies were not included or were not complete in the studies that were included in our review. Therefore, the suggestions are partly based on our detailed and critical analysis of the 27 studies cited in this review, also on our clinical experience over many decades and judgment, but they are partly difficult to quantitate at the present time.
Limitations of Suggested Strategies
Thrombus area data are based on 1 study. Moreover, that study did not describe the method for the measurement/calculation of thrombus area;
The "very high" surgical operative mortality is difficult to quantitate because: 1) it is partly related to surgical experience at each medical center; and 2) OTPHV is potentially a lethal disorder, and thus, even a very high operative mortality, say 40% to 50%, may be considered appropriate in selected cases;
Surgery not being a viable option is difficult to define, but examples include patients in remote rural areas and inadequately insured patients who may have difficulty in accessing surgery 24 h, 7 days/week; and
Subvalvular pannus is an important factor that was present in 59% of patients at surgery (Table 1). It would be suspected of contributing to obstruction in patients who underwent valve replacement in the remote past (8 to 10 years) and especially in patients with obstruction who have well-documented adequate anticoagulation. Also, underlying pannus leading to thrombotic obstruction may be preceded by gradual increase in transprosthetic pressure gradients.
Strategy After Successful Thrombolysis
This information was also not uniformly presented in the reviewed studies. However, from the 1960s, patients have received adequate anticoagulation with warfarin and more recently have had additional clopidogrel or aspirin. They have been given intravenous unfractionated heparin during the interim period as a bridging procedure till therapeutic anticoagulation is achieved