Furthermore, there are limited data on the use ofcarvedilol in patients with more severe heart failure, who are most likely to decompensate following abrupt withdrawal of their compensatory mechanisms. Most of the available data are based on patients with mild to moderate heart failure (NYHA classes II and III, with average EFs of greater than 20%). The only trial that included patients with more severe heart failure was the study by Krum et al , which evaluated carvedilol in patients with NYHA classes III or IV, with an average EF of less than 20%. However, this trial included only 56 patients in total, with only six patients who were in NYHA class IV upon entry into the study. In spite of this, 37% of patients experienced dyspnea or fluid retention during the open-label phase of the study. Therefore, further investigation into the use of carvedilol in patients with more severe heart failure is required before it can be recommended for use in this population. ventolin inhaler
Although no direct, randomized, controlled trials comparing carvedilol with other beta-blockers are available, a recently published analysis compared hemodynamics, left ventricular function and beta-receptor density in a small group of patients from both the MDC trial (n=40) and United States Carvedilol HeartFailure Study (n=41) .