A Novel Risk Stratification Score for Sudden Cardiac Death Prediction in Middle-Aged, Nonischemic Dilated Cardiomyopathy Patients: The ESTIMATED Score.

BACKGROUND

We aimed to develop a risk score (LGE Based Prediction of SCD Risk in Nonischemic Dilated Cardiomyopathy [ESTIMATED]) based on late gadolinium enhancement (LGE) cardiac magnetic resonance to predict sudden cardiac death (SCD) in patients with nonischemic dilated cardiomyopathy (NIDCM) and left ventricular ejection fraction ≤ 35%.

METHODS

We recruited 395 consecutive middle-aged patients with NIDCM and performed 3-year follow-up for SCD events. The score was developed and verified in 295 primary prevention patients, and the predictive value was confirmed by comparing the SCD events between the high-risk patients stratified by the score and 100 secondary prevention patients.

RESULTS

The ESTIMATED score (constructed by the LGE extent > 14%, syncope, atrial flutter/fibrillation, nonsustained ventricular tachycardia, advanced atrioventricular block, and age ≤ 20 or > 50 years) showed good calibrations for SCD prediction in the derivation (C-statistic: 0.80, 95% confidence interval: 0.74-0.86) and validation set (C-statistic: 0.80, 95% confidence interval: 0.71-0.87). By the score, 20.3% of primary prevention patients were categorized as high risk (≥ 3 points), 28.1% as intermediate risk (2 points), and 51.6% as low risk (0-1 points) for 3-year SCD events (45.9% vs 20.1% vs 5.1%, P < 0.0001). The 3-year SCD events were also well in agreement with the score stratification in patients without implantable cardioverter-defibrillator. High-risk primary prevention patients selected by the score in the derivation and validation sets had 3-year SCD events comparable with that in secondary prevention patients (47.6% vs 40.6% vs 38.7%, P = 0.81).

CONCLUSIONS

Our study derived and validated an LGE-based (ESTIMATED) risk score providing refined SCD prediction. The score may help to identify candidates for primary prevention implantable cardioverter-defibrillator in patients with NIDCM.