To the Editor:
We thank Dr. Spiliopoulos and colleagues for their interest in our management of pump thrombosis. We agree that device exchange is the gold standard of treating pump thrombosis and that systemic thrombolysis (STL) can only be a treatment option in selected patients. One important criterion for STL is timing. Thrombolysis should be performed as soon as possible after the onset of clinical symptoms of pump thrombosis, within 24 hours at the latest. This implies that patients are instructed in recognizing signs of device thrombosis manifestation (low pump flow, increased power consumption, hematuria). Moreover, outpatients should maintain intensive contact with their clinic, and readmission to the hospital should be possible very rapidly after the onset of signs of device thrombosis. Because pump thrombosis needs an intervention as soon as possible, therapy can already be started during transportation to the specialized center.
In our decision of treating device thrombosis, we take into account that thrombotic material, because of its fibrous nature, is only partly susceptible to thrombolytic agents. Besides timing of STL, pump design may also play a role. With respect to HeartMate II, any thrombus that forms within the components of the device may become very solid and firm. Although in the STL group of our study freedom from therapy failure did not differ significantly between patients with HeartMate II implants and HeartWare implants,1 we are very cautious in performing STL in patients with HeartMate II implants. Moreover, device exchange is easier to perform in HeartMate II patients than in HeartWare patients, because of better access to the pump head. Therefore, in our opinion, STL can be a first-line therapy in HeartWare patients, whereas in HeartMate II patients, device exchange should be the first line of therapy.
We are also well aware of the high risk of thrombus recurrence after STL. This risk is illustrated by our finding that compared with device exchange STL is associated with markedly lower freedom from therapy failure.1 However, if necessary, device exchange can already be safely performed 12 hours after STL. It is also noteworthy that in the STL group of our study the relatively high risk of therapy failure was not associated with an increased mortality risk.
Taken together, in our opinion, STL represents an alternative therapeutic option for pump thrombosis with acceptable risks.
Jan F. Gummert
Clinic for Thoracic and Cardiovascular Surgery
Heart and Diabetes Center NRW
Ruhr University Bochum
1. Oezpeker C, Zittermann A, Ensminger S, et al.Systemic thrombolysis versus device exchange for pump thrombosis management: A single-center experience.ASAIO J201662246251