RESUMEN
Rheumatic heart disease remains a major health issue in developing countries, and is commonly complicated with pulmonary hypertension. Phosphodiesterase 5 inhibitors selectively inhibit PDE5 abundantly located in the pulmonary vasculature, leading to pulmonary vasodilatation without significant systemic effects. This study aims to investigate the effect of sildenafil, given in a single dose through the nasogastric tube after induction of anesthesia, on hemodynamic parameters in patients with severe pulmonary hypertension secondary to rheumatic mitral valve disease. Thirty adult patients, males and females, with severe pulmonary hypertension [PASP > 60 mmHg] secondary to mitral valve disease and scheduled for mitral valve surgery were randomly allocated to receive either 50 mg of sildenafil [group S] or placebo [group C] through the nasogastric tube immediately after induction of anesthesia. Mean arterial pressure [MAP], systolic [PASP] and mean [MPAP] pulmonary artery pressure values, pulmonary vascular resistance index [PVRI], systemic vascular resistance index [SVRI], and cardiac index [Cl] were assessed before sildenafil administration [Tl], 30 min after administration [T2], 30 min after weaning from cardiopulmonary bypass [T3], 1, 2, and 6 hours postoperatively [T4, T5, and T6 respectively]. Right ventricular fractional area change [RVFAC] was assessed by transesophageal echocardiography at the same timings. PASP was significantly lower in group S compared to group C at T2, T3, and 4 [p<0.05]. Similarly, MPAP was significantly lower in group S compared to group S at T2 and T3 [p<0.05]. PVRI was significantly lower in group S compared to group C at T2 and T3 [p<0.05]. RVFAC was significantly higher in group S compared to group C at T2 and T3 [p<0.05]. There was no difference between both groups in SVRI or Cl. Sildenafil has resulted in a significant reduction in systolic and mean pulmonary artery pressures, as well as PVRI. This has resulted in improvement in right ventricular systolic function without any systemic effects. It is concluded that sildenafil can be very useful in patients with severe pulmonary hypertension undergoing valve surgery