Improvement of prognosis in idiopathic dilated cardiomyopathy: role of early diagnosis and optimized medical treatment. Study Group on Heart Muscle Diseases

BACKGROUND: The aim of this study was to assess the extent to which a more widespread use of new effective treatments for heart failure associated with earlier detection of the disease may have contributed to enhancing the prognosis of idiopathic dilated cardiomyopathy (IDC) patients over the past 20 years. METHODS: Heart transplant-free survival curves were analyzed in 343 IDC patients, prospectively enrolled from January 1, 1978 to June 30, 1997 in the Heart Muscle Disease Registry of the Cardiology Department in Trieste (94 enrolled between 1978 and 1987, Group 1; 249 between 1988 and 1997, Group 2). At enrollment, 91 patients had no heart failure symptoms (NoHF), whereas the remaining 252 showed HF of recent (HF < or = 6 months, n = 132) or non-recent (HF > 6 months, n = 120) onset. RESULTS: In comparison to Group 1, Group 2 was treated more frequently with ACE-inhibitors and beta-blockers (p < 0.0001) and showed a better long-term survival (p = 0.0034), resulting from a reduction of death for refractory HF or need for heart transplant (p = 0.011). Conversely, the risk of sudden death did not significantly differ between the two groups. NoHF, HF > 6 months and HF < or = 6 months groups were similarly treated with ACE-inhibitors and beta-blockers. Long-term survival was better in patients without HF than in those with overt HF (p = 0.0015). As compared to Group HF > 6 months, Group HF < or = 6 months had a poorer one-year prognosis (p = 0.045), related to the presence of a subgroup of patients with refractory HF and need for heart transplant, but showed a better survival rate over the following years (p = 0.015). Over the two subsequent decades of enrollment, a significant improvement in patient survival was observed within Groups NoHF (p = 0.03) and HF > 6 months (p = 0.01), but not in Group HF < or = 6 months. CONCLUSIONS: Over the past 20 years, the increasing use of ACE-inhibitors and beta-blockers in IDC was associated with a significant improvement in long-term survival, resulting from a reduction in mortality for refractory heart failure or need for heart transplant. In addition, early diagnosis may have contributed significantly to enhancing the prognosis of IDC, since the benefits of medical therapy were lower in patients identified and treated in advanced stages of the disease. Moreover, early diagnosis was shown to be useful in recognizing patients with recent onset of heart failure who are not responders to aggressive medical treatments and urgently need heart transplant.