Incidence and predictors of sudden cardiac death during long-term follow-up in patients with dilated cardiomyopathy on optimal medical therapy.
BACKGROUND
In spite of a total mortality reduction in recent years, sudden cardiac death (SD) remains a major problem in patients with idiopathic dilated cardiomyopathy (IDC) and its occurrence is often unpredictable. Furthermore, the risk of SD may change during follow-up because of the natural history of the disease and the effects of therapeutic interventions. In our study, we evaluated the modifications of the risk of SD during follow-up in a cohort of patients with IDC and analyzed the variables predicting SD not only at enrolment but also at the last examination during optimal medical treatment.


METHODS
Since 1978, 343 consecutive patients with IDC were enrolled in the Heart Muscle Disease Registry of Trieste (Italy) and submitted to complete invasive and non-invasive study. Patients were re-evaluated usually at intervals of 12 months.


RESULTS
After a mean of 68+/-45 months, 125 events (death, heart transplantation or aborted SD) had occurred. The cumulative risk after 5 years was 30%, while after 10 years it almost doubled (54%). During the first 3 months after enrolment, the incidence of SD was high (3%). A plateau, lasting about 3.5 years, followed. A slow but progressive rise in the risk of mortality then occurred (6% at 5 years, 18% at 10 years). No variables evaluated at enrolment were associated with SD at multivariate analysis. On the other hand, the end-diastolic left ventricular diameter (> or = 38 mm/m2) and ejection fraction (< or = 0.30) were predictive of SD if evaluated within 1 year before the event. Beta-blocker treatment was associated with a non-significant reduction of risk.


CONCLUSIONS
In patients with IDC the incidence of SD progressively increased during long-term follow-up, especially in those with persistent severe left ventricular dilation and dysfunction who were not on beta-blocker treatment. Serial clinical evaluation may help to select patients at higher risk for SD.
Zecchin
M
M
Department of Cardiology, Maggiore Hospital, University of Trieste, Italy. zecchin@adriacom.it
Lenarda
A D
AD
Bonin
M
M
Mazzone
C
C
Zanchi
C
C
Di Chiara
C
C
Davanzo
M
M
Scherl
G
G
Sabbadini
G
G
Sinagra
G
G
D000328:Adult; D017677:Age Distribution; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy*; D002423:Cause of Death; D015331:Cohort Studies; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011336:Probability; D011446:Prospective Studies; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D013997:Time Factors