| ObjectivePulmonary Arterial hypertension (PAH) is defined as mean pulmonary artery pressure (mPAP) exceeds 25mmHg at rest and is commonly an accompaniment of long-standing left-sided valvular (mitral and/or aortic) diseases. The continuously elevated pulmonary arterial pressure leads to right ventricular overload, eventually results in RV dysfunction. In the perioperative period of valvular surgery, PAH can be exacerbated by CPB or lung ischemia-reperfusion injury, thus complicates perioperative management of patients and has adverse effects on prognosis. With the newly developments in cardiac surgery, the prognosis of left-sided valvular heart disease has been greatly improved. However, the elevated pulmonary artery pressure remains to be a challenge in those patients. Thereafter it is necessary to find an efficient and safe medicine to control secondary PH after valvular heart surgery.MethodsFirstly, we collected the data of the patients'undergone left-sided valvular surgery in our hospital from January, 2006 to December, 2008. The patients were allotted to 2 groups according to their pulmonary artery pressures, and then the recovery situations and prognosis were compared. Secondly, the PH patients in the first part were allotted to 2 groups according to their early prognoses, and then the hemodynamics of these patients after the surgery were compared. Thirdly, we enrolled patients with PH undergoing left-sided valvular surgery in our hospital from January to December, 2009. A controlled, randomized study was conducted and the hemodynamic changes caused by different dosages of sildenafil citrate/placebo were compared. Fourthly, patients with PH undergoing left-sided valvular surgery in our hospital from January to December, 2010 were enrolled and 0.5mg/Kg sildenafil citrate or placebo were administrated through nasogastric tubes, the hemodynamics changes in the following 4 hours were assessed. The sildenafil citrate/placebo was continued to the discharges and the early prognoses of these patients were compared.Results1. The elevated pulmonary artery pressure is not an absolute contraindication for valvular surgery. However, PAH leads to right ventricular overload, which are usually exacerbated by CPB in valvular surgery, eventually results in RV dysfunction. Therefore PAH complicates perioperative management of valvular surgical patients and has adverse effects on prognosis.2. PH doesn't decrease immediately after the valvular surgery. The elevated PVR can be continued in the early peroperative period because of pulmonary vascular lesions and have a bad influence on the patients'prognoses.3. Through a controlled, randomized study, we find a single dose of oral sildenafil produces marked pulmonary vasodilation when added to patients with PH after valvular surgery in ICU setting. 1mg/Kg sildenafil citrate can decrease PAP more efficiently than 0.5mg/Kg, however, this dosage causes the decrease of the systemic artery pressures.4. Through a controlled, prospective, randomized, double-blind study, we find a single dose of oral sildenafil produces marked pulmonary vasodilation within 0.5 hours when added to patients with PH after valvular surgery in ICU setting. This pulmonary vasodilation effect can be continued within 4 hours. The concomitant decreases in RCW, RVSW, RCWI and RVSWI in the sildenafil group indicate the reduction of burden in right ventricle, which is beneficial for the heart function after valvular surgery. Sildenafil citrate is beneficial for the recovery of the patients with PH afer the valvular surgery by shortening the time of mechanical ventilation, stay in ICU and the hospitalization.ConclusionsIncorporating all the findings, we concluded that secondary PH in the patients with left-sided valvular disease undergoing heart surgery should be interfered in to achieve good early prognoses. Sildenafil citrate is a good method for those patients and should be recommended clinically with the ideal dosage of 0.5mg/Kg.
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