The influence of fractional pulse pressure on the outcome of pulmonary thromboendarterectomy

Although pulmonary thromboendarterectomy is an effective modality for the t reatment of chronic thromboembolic pulmonary hypertension (CTEPH), the mort ality in patients with severe haemodynamic disease is still high. Recently it was reported that fractional pulse pressure (pulmonary arterial pulse pr essure/mean pulmonary arterial pressure) was higher in CTEPH than in primar y pulmonary hypertension (PPH). It was hypothesized that fractional pulse p ressure might be low in CTEPH with inaccessible distal thrombi and/or secon dary pulmonary hypertensive change, resulting to the high operative mortali ty. To determine the influence of fractional pulse pressure to the outcome of s urgery, 32 patients with CTEPH who had thromboendarterectomy between 1985 a nd 1998 were studied. Pulmonary haemodynamics and fractional pulse pressure were compared between survivors (n=26) and nonsurvivors (n=6) postoperativ ely. Those parameters in PPH (n=18) and large vessel pulmonary arteritis (n =6) were also analysed. Fractional pulse pressure in CTEPH (1.23+/-0.21) was significantly higher t han in PPH (0.93+/-0.22; p=0.0017) and lower than in pulmonary arteritis (1 .69+/-0.32; p=0.03). Fractional pulse pressure in survivors (1.26+/-0.21) w as significantly higher than in nonsurvivors (1.06+/-0.16; p=0.03). Fractio nal pulse pressure is a significant predictor for mortality in patients wit h high pulmonary vascular resistance >1100 dynes.sec.cm(-5). To conclude fractional pulse pressure in addition to pulmonary vascular res istance might be useful in predicting for the outcome of surgery, especiall y in patients with severe haemodynamic impairment.