The study population was derived from a single-center registry of patients with confirmed massive and submassive PEs who had undergone thrombolytic treatment between January 1995 and January 2005. All patients gave their informed written consent for inclusion in the registry, and the protocol was approved by the local ethics committee.
Patients with proven recent PE (symptom onset, < 15 days) and no contraindication to thrombolytic therapy were included in the registry if they met at least one of the following criteria: (1) cardiogenic shock defined as systolic BP < 90 mm Hg associated with clinical signs of organ hypoperfusion and hypoxia; (2) syncope; (3) pulmonary vascular obstruction of > 50%; and (4) mean pulmonary artery pressure of >20 mm Hg by right heart catheterization, plus at least one echocardiographic finding indicating RV dysfunction (ie, RV/left ventricular end-diastolic diameter ratio, > 1 in the four-chamber view; paradoxical septal systolic motion and/or pulmonary hypertension [PH], defined as a RV/atrial gradient > 30 mm Hg). http://www.buy-asthma-inhalers-online.com/
Repeat echocardiographic examination was systematically performed 24 to 36 h after thrombolytic therapy, and RV dysfunction criteria were recorded.
Patients from the registry were selected for inclusion in this study if they had massive PE and had not responded to the initial thrombolysis. Unsuccessful thrombolysis within the first 36 h was defined as both persistent clinical instability and residual echo-cardiographic RV dysfunction. Persistent clinical instability was prospectively defined as the presence of at least two of the following criteria: refractory cardiogenic shock; systemic arterial hypotension (defined as systolic BP of < 90 mm Hg or a pressure drop of > 40 mm Hg for > 15 min if not caused by new-onset arrhythmia, hypovolemia, or sepsis); severe hypoxemia (ie, room-air pulse oximetry of < 90% or Pao2 without oxygen therapy of < 55 mm Hg); or tachycardia (heart rate, > 110 beats/min). Residual echocardiographic RV dysfunction was defined as the persistence of at least two initial RV dysfunction criteria.
In addition, a lack of improvement in pulmonary vascular obstruction was documented in most patients with repeat spiral CT scan or pulmonary angiogram performed within the first 36 h. The therapeutic approach was left to the discretion of the attending physician following repeat spiral CT scan or pulmonary angiography.