Journal of Postgraduate Medicine Medknow Publications and Staff Society of Seth GS Medical College and KEM Hospital, Mumbai, India ISSN: 0022-3859 EISSN: 0972-2823 Vol. 51, Num. 2, 2005, pp. 107-107

Journal of Postgraduate Medicine, Vol. 51, No. 2, April-June, 2005, pp. 107

Expert's Comments

Importance of screening and early detection of pulmonary hypertension and current treatment options

Mohan N.

University of South Dakota School of Medicine, Sioux Falls, South Dakota

Correspondence Address: University of South Dakota School of Medicine, Sioux Falls, South Dakota, nmohan@pol.net

Code Number: jp05040

Pulmonary hypertension (PHT), usually a late-stage complication, is the most common cause of death in mixed connective tissue disease (MCTD), occurring in up to 38% of patients.[1] Since PHT does not become clinically manifest until advanced, even mild elevations in pulmonary arterial pressure reflect diffuse and extensive vascular damage. Through the mid-1980s median survival from the date of diagnosis was approximately 2.8 years. However, several novel therapeutic agents developed in recent years, have made early detection and monitoring imperative for improving long-term prognosis. ECHO with Doppler ultrasound is the commonest screening tool and should be performed to establish a baseline at initial diagnosis of MCTD.[2] Pulmonary function testing (PFT) including diffusing capacity of the lung for carbon monoxide (DLCO) is a necessary part of the evaluation of all patients, primarily to exclude or characterize the contribution of underlying airway or parenchymal lung disease. A fall in DLCO in a patient with scleroderma/MCTD and normal lung volumes is suggestive of the early development of pulmonary arterial hypertension. PFTs with DLCO should be performed periodically (every 6-12 months) to improve detection of pulmonary vascular or interstitial disease with ECHO every 1-2 years, especially if the patient has had symptoms of connective tissue disease for more than 10 years. Formal assessment of exercise testing, typically 6-min walk test helps determine disease severity, response to therapy and progression.[2]

Once the diagnosis of PHT has been established, general approaches to treatment include supplemental oxygen for hypoxemia to maintain oxygen saturations >90% at all times, continuous positive airway pressure therapy and treatment of other contributing factors such as chronic thromboembolic disease with warfarin, right ventricular failure with diuretics and digitalis etc. Patients who respond to vasodilator testing have an improved long-term survival with the use of calcium channel blockers.[3] Prostacyclin derivatives (epoprostenol (IV), treprostinil (subcutaneous), iloprost (inhaled), beraprost (oral)) are potent vasodilators with antiplatelet aggregatory effects that have been shown to primarily improve exercise tolerance and survival to a lesser extent. Endothelin antagonists (bosentan, sitaxsentan, ambrisentan) block endothelin-1, which is a potent vasoconstrictor and smooth-muscle mitogen that might contribute to the increase in vascular tone and the pulmonary vascular hypertrophy associated with PAH.[4] Other agents that are currently being evaluated include phosphodiesterase inhibitors such as dipyridamole and sildenafil, inhaled nitrous oxide and arginine supplementation.[5] Surgical techniques including lung transplant remain the mainstay of treatment for patients with PHT who are unresponsive to medical management.

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