Title: A Study to Evaluate the Short-Term Efficacy of Oral Sildenafil Therapy in Patients of Pulmonary Arterial Hypertension

Authors: Rajat Kanti Biswas, Ananya Pal, Ashoke Kumar Das

 DOI: https://dx.doi.org/10.18535/jmscr/v7i6.40

Abstract

Objective: The objective was to evaluate the short- term efficacy of oral Sildenafil in symptomatic patients of Pulmonary Arterial Hypertension (PAH), both primary and secondary.

Materials and Methods: The study involved 40 patients of PAH (n=18 for primary, n=22 for secondary PAH) of both sexes & between 12 to 75 years of age, having pulmonary arterial pressure (PAP) of more than 30 mm of Hg with NYHA class II&III symptoms. Subjects received sildenafil 50 mg 8 hourly orally, or a matching placebo for six weeks each, in a randomized, double-blind, crossover design. A run-in period of two weeks was permitted at the beginning and between two therapies.  At the end of each therapy, the patients were evaluated for the study parameters i.e. distance covered in 6-minute walk test, PAP by doppler echocardiography and quality of life (QOL) assessed by ‘Minnesota Living with Heart-failure Questionnaire’. Statistical analysis was done using paired & un-paired ‘t’ test (p<0.05).

Results: The mean distance covered in 6 minute walk test improved from 283.33 ± 56.81m to 422.17 ± 79.09m (p<0.0001) for primary and from 353.23 ± 56.61m to 406.09 ± 59.33m (p<0.0001) for secondary PAH after 6 wks treatment with sildenafil. PAP decreased from 85.94 ± 11.81 mm Hg to 38.78 ± 6.90 mm Hg (p<0.0001) for primary and from 52.14 ± 10.26 mm Hg to 41.68 ± 9.09 mm Hg for secondary PAH. Sildenafil shows very significant improvement in functional capacity by lowering the QOL score in both primary and secondary PAH (p<0.0001 and p<0.0001 respectively). No serious side effects of drug were observed in the study. 

Conclusion: Sildenafil significantly improves exercise capacity and quality of life and decreases the PAP in both primary and secondary PAH. Therefore, oral sildenafil may be recommended as first-line or adjunctive treatment in PAH, particularly primary one.

Keywords: Sildenafil, placebo, primary and secondary pulmonary arterial hypertension.

References

  1. Gaine SP, Rubin LJ. Primary pulmonary hypertension. Lancet 1998;352:719-725.
  2. Zipes DP, Libby P, Borow RO, Braunwald E, editors. Braunwald’ Heart Disease. 7th Elsevier, Saunders; 1893-1913
  3. Galie N, Seeger W, Naeije R, Simonneau G, Rubin LJ. Comparative analysis of clinical trials and evidence based treatment algorithm in pulmonary arterial hypertension J Am Coll Cardiol 2004;43:Suppl 12;81S-88S.
  4. Humbert M, Sitbon O, Simonneau G. Treatment of pulmonary arterial hypertension N Engl J Med 2004;351:1425-1436
  5. Sastry BKS, Narasimhan C, Reddy NK, Raju BS. Clinical efficacy of sildenafil in primary pulmonary hypertension. J Am Coll Cardiol. 2004; 43:1149-1153.
  6. Corbin JD, Francis SH. Cyclic GMP phosphodiesterase-5: target of sildenafil. J Biol Chem 1999;274:13729-13732.
  7. Tantini B, Manes A, Fiumana E, et al. Antiproliferative effect of sildenafil on human pulmonary artery smooth muscle cells. Basic Res Cardiol 2005;100:131-138
  8. Schermuly RT, Kreisselmeier KP, Ghofrani HA, et al. Chronic sildenafil treatment inhibits monocrotaline-induced pulmonary hypertension in rats. Am J Respir Crit Care Med 2004;169:39-45
  9. Weimann J,Ulrich R, Hromi j, et al. Sildenafil is a pulmonary vasodilator in awake lambs with acute pulmonary hypertension. 2000;92: 1702-1712.
  10. Ichinose F, Erana-Garcia J, Hromi J, et al. Nebulized sildenafil is a selective pulmonary vasodilator in lambs with acute pulmonary hypertension. Crit Care Med 2001;29:1000-1005
  11. Michelakis E, Tymchak W, Lien D, Webster L, Hashimoto K, Archer S. Oral sildenafil is an effective and specific pulmonary vasodilator in patients with pulmonary arterial hypertension: comparison with inhaled nitric oxide. Circulation 2002;105:2398-2403
  12. Bhatia S, Frantz RP, Severson CJ, Durst LA, McGoon MD. Immediate and long-term hemodynamic and clinical effects of sildenafil in patients with pulmonary arterial hypertension receiving vasodilator therapy. Mayo Clin Proc 2003;78:1207-1213
  13. Galiè N, Ghofrani HA, Torbicki A, et al., for the Sildenafil Use in Pulmonary Arterial Hypertension (SUPER) Study Group. Sildenafil citrate therapy for pulmonary arterial hypertension. N Engl J Med 2005;353:2148 –2157.
  14. Miyamoto S, Nagaya N, Satoh T, et al. Clinical correlates and prognostic significance of six- minute walk testing patients with primary pulmonary hypertension: comparison with cardiopulmonary exercise testing. Am J Respir Crit Care Med 2000;161;487-492.

Corresponding Author

Ananya Pal

Assistant Professor, Department of Pathology, NRS Medical College, Kolkata

Address: Sanjeeva Garden, Unit No. 33DL, Thakdari road, Newtown, Kolkata-700156, West Bengal, India