Catheter-directed low-dose fibrinolysis infusion for treat acute intermediate-high risk pulmonary embolism

Type of funding sources: None.

BACKGROUND 

Intermediate-high risk  (IHR) Pulmonary Embolism (PE) are a common disease witch could have a high mortality. Anticoagulation remains the first therapeutic option, but Catheter-directed therapies are being investigated as a safe and effective treatment option.

To evaluate the safety and efficacy of Catheter-directed low-dose fibrinolysis infusion to treat IHR-PE.

Retrospective analysis of 16 patients IHR-PE treated. After performing Right catheterization (RC) and angiogram, Pigtail catheters were located for intrapulmonary infusion of Alteplase 1mg/h/catheter for 24 h (25-30mg/day). Baseline and clinical characteristics, inicial and evolutive echocardiography, also clinical evaluation and echocardiography 6 months after discharge were evaluated.  

The majority were women (11) and obese (93.8%), aged 22-74 years with cardiovascular risk factors: 5 hypertension, 3 Dyslipidemia, 2 smokers and 3 severe CKD . At admission 11 patients consulted for dyspnea and 5 for syncope; all were hemodynamic stable. 68.8% presented respiratory failure. All had bilateral PE (angiography) and elevation of Nt-proBNP and troponins. The echocardiographic at admission, and its evolution are shown in Table 1.  The invasive measurement of pulmonary hypertension (PH) reflected greater severity than the estimated by echo:  5 (31.3%) Severe PH, 5 (31.3%) Moderate PH and 2 (12.5%) mild PH.

At discharge all presented a decrease in PH and 15 (93.8%) improved RV function. 2 patients suffered bleeding complications (relation with femoral access): 1 not severe, 1 severe without mortality; none suffered intracranial hemorrhage.

In the evaluation at 6-months: 13 patients (81.3%) where on functional Class I and without PH, 3 patients (18.8%) where in Class II and with mild-PH.

In short-term follow-up, intrapulmonary low-dose fibrinolysis reduces PA pressures and improves RV function, without an increased bleeding complications, especially if femoral access is avoided. However impact on long-term remains unclear.

Table 1: Echocardiography evolution.