Distribution of current interventional clinical trials in heart failure according to (A) primary sponsors, (B) primary end points, (C) acuity of heart failure, and (D) therapies. Percentages in panels C and D exceed 100% because of minor overlap in categories. Panel C includes 2 trials that enrolled both chronic stable and acute decompensated heart failure and excludes 11 trials that did not specify the acuity of heart failure. Panel D includes 13 trials that evaluated both medical and surgical therapies, 1 trial that examined both medical and molecular therapies, and 2 trials that considered both surgical and molecular therapies.