Perspectives of drug therapy in heart failure.

Despite an increasingly wide range of therapeutic options in heart failure management, fatality rates and morbidity remain high and new and better drugs are still needed. Assessing drug efficacy, and comparing two drugs, is difficult. Studies with mortality as an endpoint need to be large and long-term, and studies using exercise tolerance as an endpoint have inherent problems of design and execution. Although haemodynamic measurements are useful in assessing acute drug effects they are not helpful in the chronic state and a 'surrogate' endpoint for assessing heart failure is needed. Measurements of calf blood flow at rest and after exercise provide results that correlate with the patient's clinical state and response to therapy. Measurements of calf blood flow and treadmill exercise time were found to be useful in comparing the effects of ibopamine with captopril in patients with chronic heart failure.