Randomized trial of telephone intervention in chronic heart failure (DIAL): Study design and preliminary observations

Background: In the last few years different approaches based on comprehensive patient care and close surveillance by multidisciplinary teams have shown promising results in heart failure. However, current evidence mainly derives from small and often nonrandomized studies performed at a single center, with selected populations, using dissimilar and complex strategies. We designed a large randomized study to test the hypothesis that a single program, based on a centralized telephone intervention performed by trained nurses, could reduce morbidity and mortality in chronic heart failure. Methods: The Randomized Trial of Telephone Intervention in Chronic Heart Failure (DIAL) is a randomized, controlled, open trial designed to compare frequent telephone follow-up intervention versus control. We enrolled 1518 patients with stable chronic heart failure and optimal treatment from 51 centers in Argentina. DIAL trial intervention strategy is based on frequent telephone follow-up provided by nurses trained in heart failure and performed from a single surveillance center, assuring a homogeneous and high quality intervention. The primary objective is to determine the effect of the intervention as compared with the usual follow-up on the combined endpoint of all-cause mortality or hospitalization for worsening heart failure. The objectives of the intervention are education, counseling, and monitoring to enhance self-control mechanisms, timely medical visits, diet, and drug therapy compliance. Telephone call frequency was determined according to preestablished criteria of clinical status severity assessed at each phone contact. The study ended in August 2002. Conclusion: The results of this study may provide information about mortality, hospitalizations, and quality of life contributing to set standards for management programs in the current treatment of chronic heart failure.