We thankDrDoganandColleaguesfor their commentonourprevi-ously described case [1] and for their contribution on the therapy ofprosthetic valve thrombosis (PVT) during pregnancy [2–4].Wetreatedwiththrombolysisa21year-oldUgandanfemalepatientwith known rheumatic heart disease for highly suspected acute PVT,who had undergone mitral valve replacement with a bileaflet mechan-icalprosthesis(St.Judeno.29)aboutthreemonthsbefore[1].Diagnosiswas based on clinical evaluation and transthoracic echocardiography(TTE).The occurrence of acute PVT was likely due to poor internationalnormalized ratio (INR) control and limited patient's compliance toanticoagulation therapy (warfarin).ItmustbeunderlinedthattheyoungpatientwasnotpregnantatthetimeofacutePVT.Pregnancyoccurredsubsequently,asdescribedinourcase report [1]. The fact that the patient was not pregnant made PVTmanagement easier, particularly the choice to initiate thrombolysis.Furthermore, at that time (May 2011) no urgent prosthetic valve re-placementcouldbeperformedinUganda[5].Thus,theonlymedicalop-tion was thrombolysis. Of further relevance, the patient with highlysuspected PVT was in cardiogenic shock, with evidence of multi-organfailure as demonstrated by anuria and high INR value (INR 9) likely relat-ed to acute liver failure [6]. For this reason, vitamin K was administeredand emergent thrombolysis was performed (standard intravenous bolusof tenecteplase) [7]. With regard to echocardiographic diagnosis, notransesophageal probe was available in the hospital where the patientwastreatedatthetimeoftheevent.Accordingtothe2014AHA/ACCVal-vularHeartDiseaseGuidelinebothTTEandtransesophagealechocardiog-raphy (TEE) are recommended for the evaluation of a suspected PVT(classI, levelofevidence Bforbothapproaches) [7]. However,webelievethat in the setting of hemodynamic instability TEE is not always essentialand should beused with caution. For instance, this is the case of hemo-dynamicallyunstablepatientswithatrialfibrillation(AF)andhighven-tricular response rate [8], where the benefit of immediate electricalcardioversion overwhelms the thromboembolic risk in the absence ofpreliminary TEE screening. Invasive mechanical ventilation and man-agement of cardiogenic shock with inotropic agents and/or mechanicalcirculatory support could potentially allow hemodynamic stabilizationof the patient, thus permitting further investigations such as TEE orfluoroscopy. It is worth underlining how Biteker and Ozkan were ableto manage a hemodynamically unstable patient (blood pressure atpresentation 65/35 mm Hg) and perform TEE, which allowed the iden-tificationofalargeprostheticthrombus(1.6×1cm)[9].Intheirreport-ed case a 40 mm Hg mean diastolic mitral transvalvular gradient andclinical history were highly suggestive of PVT [9]. Referring to ourcase, at less than three months after valve replacement pannus forma-tion seemed less likely than acute thrombosis; on the other hand, nosystemicsignssuggestiveofendocarditiswerepresent,makingthisdif-ferential diagnosis unlikely too. Micro-emboli can cause distal cerebralischemiceventsafteracutethrombolysis,anditispossiblethataslowerinfusion of thrombolytic treatment can reduce this risk as comparedwith a standard administration protocol, although no evidence canfully support a strategy over the other. Particularly in patients in AF(like our patient was), TEE demonstration of thrombus in the left atrialappendage would add information about a potential risk of embolicevents; nevertheless, thrombus identification in the appendage in thereportedoccasionwould havenot substantiallymodi fiedourtherapeu-tic strategy.Finally, TEE-guided low-dose, slow infusion of tissue-type plas-minogen activator with repeateddoses have been demonstrated asasafeandsuccessfulstrategybyOzkanetal.[2,3]. We personallyhave no direct experience on thrombolysis in PVT in pregnancy. Itappears reasonable that thefinal decision on the best approach–surgery versus thrombolysis– be related to the experience of the
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Aug 23, 2024
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