Long-term prognostic impact of therapeutic strategies in patients with idiopathic dilated cardiomyopathy: changing mortality over the last 30 years

Abstract

Aims: ACE-inhibitors, β-blockers, implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy (CRT) improved prognosis of heart failure. We sought to analyse the long-term prognostic impact of evidence-based integrated therapeutic strategies in patients with idiopathic dilated cardiomyopathy (IDCM).

Methods and results: From 1978 to 2007, 853 IDCM patients (45 ± 15 years, 72% males) were enrolled and classified as follows: Group 1, 110 patients (12.8%) enrolled during 1978-1987; Group 2, 376 patients (44.1%) enrolled during 1988-1997; Group 3, 367 patients (43.1%) enrolled during 1998-2007. ACE-inhibitors/angiotensin receptor blockers were administered in 34%, 93%, and 93% (P <0.001), and β-blockers in 11%, 82%, and 86% (P <0.001) in Groups 1, 2, and 3, respectively; ICDs were implanted in 2%, 14%, and 13% (P = 0.005); mean time to device implantation was lower in Group 3. At 8 years, heart transplant (HTx)-free survival rates were 55%, 71%, and 87% in Groups 1, 2, and 3, respectively (P <0.001). Similar progressive improvement was found for pump-failure death (DHF)/HTx, while survival free from sudden death (SD) was significantly improved only in Group 3. Multivariable models considering competing risk indicated early diagnosis (i.e. a baseline less advanced disease stage) and tailored medical therapy (HR 0.44, CI 95% 0.19-0.98) as independent protectors against DHF/HTx. Concerning SD, lower left ventricular ejection fraction emerged as a predictor, while ICD was the only therapy with a protective role (HR 0.08, CI 95% 0.01-0.61). Treatment with digitalis emerged as a predictor of both DHF/HTx and SD.

Conclusions: An effective management and evidence-based integrated therapeutic approach progressively and significantly improved the long-term prognosis of IDCM during the last three decades.

Keywords: Dilated cardiomyopathy; Follow-up study; Heart failure; Prognosis; Sudden death.