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Failure to diagnose and treat thrombosis


A 66-year-old man came to his internist reporting shortness of breath and chest pain that had been present for three to four weeks. His history included a metallic prosthetic aortic valve replacement for aortic stenosis two years prior with subsequent warfarin therapy.

Physician action

The internist ordered a transthoracic echocardiogram (TTE), which showed abnormal valve function and evidence of thrombus formation on the artificial valve. Prosthetic aortic valve thrombosis is a very serious condition with risks of stroke, heart failure, and sudden death. Metallic valves require continuous, lifelong full dose anticoagulation (INR 2.5 to 3.5 range). Lab values suggested that the patient was not taking warfarin at all (INR 1.0).

The internist placed the patient on subcutaneous enoxaparin sodium injection therapy due to the low INR. The patient was referred to his cardiologist for follow up at the hospital where the valve replacement surgery was performed.

Four days later, on a Friday, the patient came to the hospital for follow up with his cardiologist. A transesophageal echocardiogram (TEE) was performed and confirmed the presence of a thrombus on the aortic valve and valve dysfunction. However, the patient was found to be stable, with no heart failure. The cardiologist arranged to perform chemical thrombolysis therapy of the thrombotic valve debris on the following Monday.

In the meantime, the cardiologist recommended the continuation of subcutaneous enoxaparin sodium injection therapy. The patient protested the delay in treatment, expressed concern about his shortness of breath, and asked to be admitted to the hospital. The cardiologist reasoned that the necessary personnel for the procedure were not available before Monday. The patient was not admitted to the hospital.

The patient returned to the ED later that evening with worsening symptoms. He was diagnosed with congestive heart failure by the cardiologist on call. An endotracheal intubation was performed and the patient was placed on a respirator.

Thrombolysis therapy was performed emergently on the patient. The thrombolysis treatment, along with anticoagulation therapy with heparin, successfully eliminated the thrombus. The prosthetic valve function was also normalized. However, the patient experienced complications from treatment including groin hematoma, blood transfusion, acute renal failure, pulmonary edema, and pneumonia. The patient eventually recovered from all complications.



A lawsuit was filed against the cardiologist. The allegations included:

  • failure to listen to the patient’s descriptions of the symptoms;
  • failure to take immediate action to treat the thrombosis;
  • failure to perform an adequate physical examination;
  • failure to diagnose congestive heart failure; and
  • failure to reasonably and prudently diagnose and treat the patient.

It was further alleged that the cardiologist put his own personal schedule before the treatment of the patient.

Legal implications

The main criticism in this case is that the cardiologist did not admit the patient to the hospital after the TEE confirmed thrombotic valve disease with valve dysfunction. Two defense experts agreed that the cardiologist could have admitted the patient after the Friday appointment and started thrombolytic therapy with the on-call surgeon or admitted the patient and waited for the treating surgeon.

One of the experts stated that the cardiologist’s actions in not immediately treating the patient or using on-call personnel to begin treatment was in violation of the standard of care. The expert felt that thrombosis on an aortic valve is a serious, life-threatening condition, and that the standard of care requires that a cardiologist take immediate action to dissolve a clot.

The second expert stated that the cardiologist underestimated patient's condition when he came for treatment. While the cardiologist’s notes documented the patient’s shortness of breath and chest pain with exertion, the notes also report clear lungs and no findings of severe heart failure. It is possible the patient's condition worsened from the cardiologist’s consult to the ED visit that night.


The case was settled on behalf of the cardiologist.

Risk management considerations

Complete documentation includes the rationale for decisions made by the physician. When a physician’s thought processes are documented in the record, it can assist his or her defensibility.  The Texas Medical Board requires that a patient’s medical record should accurately and objectively contain the assessment, findings, procedures, diagnoses, and decisions that support the physician’s care.