Severe pulmonary hypertension: data from the Swiss Registry

Background: Severe pulmonary hypertension (PH) is a rare disease with a dis mal prognosis if untreated. Progress in diagnosis and in the development of effective therapeutic options has created new interest in this pathology. There are, however, only limited data on the prevalence of severe PH unrela ted to chronic left ventricular failure or COPD, on the associated conditio ns and on the parameters with a prognostic impact. With the aid parameters with a prog of a retrospective registry we have collected data from 5 centr es in Switzerland and attempted to answer the above questions. Methods: Data on patients, with PH from 4 university facilities (Zurich, Ba sle, Geneva and Lausanne 1) and one well-defined geographical area (Ticino) were retrospectively collected and analysed up to December 1999. Clinical and haemodynamic parameters and associated diseases were noted. We were als o interested in the age distribution of the patients and the year of diagno sis of PH. Results: We found 106 patients with severe PH (43 men, 63 women, median age 43 years); 79% were in NYHA class III or IV. There was a steep rise in dia gnosis of PH after 1995. In 74% PH was either primary or associated with co llagen vascular disease or thromboembolic disease. By the end of the observ ation period 30% of the patients had died. The best distinguishing paramete rs between surviving patients and those who eventually died were the 6-minu te walking test (363 vs. 235 metres, p = 0.002), the NYHA class (II vs III/ IV,, p = 0.015), and mixed venous saturation (66.5 vs. 57.9%, p = 0.006). T herapy consisted of calcium antagonists in 18% and of (inhaled) prostanoids , chiefly iloprost, in 33 %. Seven patients underwent lung transplantation. Conclusions: We conclude that PH is diagnosed more often as diagnostic and therapeutic options improve; that primary forms, and those associated with collagen vascular disease and with chronic venous thromboembolism, make up three-quarters of the aetiologies; and that the 6-minute walking test, the functional class and mixed venous; saturation are the best prognostic param eters.