COMPARISON OF THE NYHA CLASSIFICATION AND THE CARDIOPULMONARY EXERCISE TESTING IN PATIENTS WITH CONGESTIVE-HEART-FAILURE

In this study a correlation was sought between the NYHA class, the res ults of cardiopulmonary exercise testing (CPX) and the ejection fracti on (EF) measured by echocardiography and scintigraphy. Of 36 patients enrolled, CHF in 20 patients was due to CAD and in 16 patients due to DCM. The NYHA class was determined independently by two cardiologists who were blinded to the CPX, echocardiography or scintigraphy results. Sixteen patients were classified as class II and 20 as class III. As a control, 23 patients without cardiopulmonary disease were examined. The CPX was done according to a ramp protocol with continuous measurem ent of respiratory gases, maximal oxygen consumption (V over dot O-2-m ax) and oxygen consumption at the anaerobic threshold (V over dot O-2- AT). A correlation (p = 0.0425) between the NYHA classification and th e Weber classification for V over dot O-2-AT was found. There was no c orrelation for V over dot O-2-max. V over dot O-2-AT was significantly higher in NYHA II patients as compared to NYHA III patients. No signi ficant difference was seen in relation to the V over dot O-2-max. In c omparison to the normal group, the V over dot O-2-AT and V over dot O- 2-max were significantly lower in NYHA II and III patients. There was no significant correlation between V over dot O-2-AT and EF, V over do t O-2-max and EF, or between NYHA class and EE During a 16-month follo w-up period lethality was 8/14 patients with V over dot O-2-AT < 10 ml /kg/min. Although the NYHA classification provides a valid method for determining the prognosis of CHF patients, if feasible, the CPX examin ations should be used to provide updates of the disease progress.