Case reportIacopo Bertolozzi, Angelo PucciA 61-year-old woman came to the Emergency Departmentof our Hospital for fatigue and breathlessness. She wasdischarged from the surgery ward 2 days before, after asubtotal colectomy for adenocarcinoma had been performed10 days before. While explaining her history, she appearedvery worried because of not hearing since the day before,the usual clicking noise of her mechanical mitral valveprosthesis. The metallic bileaflet-tilting—disk valve (StJude Medical, Inc.) had been implanted 10 years before.Anticoagulant therapy (acenocumarol) was interruptedbefore the colon surgery, and the patient was receiving low-molecular weight heparin (nadroparin 5,700 UI bid).On physical examination, the heart rate was 100 beatsper minute, blood pressure was 90/50 mmHg, and respi-ratory rate was 18 breaths per minute. Auscultation of theheart revealed an absence of a prosthetic closure sound anda grade III holosystolic murmur in the mitral area. Raleswere present at both lung bases. A transthoracic echocar-diogram, immediately performed, revealed severelyrestricted movement of the prosthetic mitral valve leafletswith an increased peak diastolic transmitral pressure gra-dient (Fig. 1a).Unfractioned heparin was commenced immediately. Theidea of arranging a transfer to another hospital for cardiacsurgery was rejected because of the high operative risk andthe presence of co-morbidities. The hemodynamic statusindeed rapidly and dramatically worsened, with the clinicalevidence of cardiogenic shock. Notwithstanding the recentabdominal surgery, systemic thrombolysis was adminis-tered (rt-PA 100 mg over 120 min). The patient’shemodynamic status rapidly improved, and a transthoracicechocardiogram, performed at the end of the rt-PA infu-sion, showed normalization of the transmitral flow pattern(Fig. 1b). The patient was discharged after a 2-week hos-pitalization on anticoagulant treatment.Prosthetic valve thrombosis is an infrequent but poten-tially life-threatening complication with a reportedincidence of 0.5–8% of left-sided valves and up to 20% oftricuspid valves [1–3]. Reoperation, the traditional treat-ment of severe prosthetic thrombosis is associated withsignificant morbidity and mortality particularly in criticalpatients [4, 5]. Evidence is growing that fibrinolysis can beconsidered as the first-line treatment in the absence ofcontraindications [6]. Although recent (less than 2 weeks)major surgical procedures usually exclude the possibility offibrinolysis in myocardial infarction [7], this condition isnot considered a contraindication for treating obstruction ofprosthetic valve in critically ill patients [8] where a totallydifferent balance of risks and benefits exists.CommentPietro Amedeo ModestiThe recent disappearance of the usual clicking noise of thevalve prosthesis referred by the patient immediately led to