Description:
<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Sudden cardiac death (SCD) results from a complex interplay of abnormalities in autonomic function, myocardial substrate and vulnerability. We studied whether a combination of noninvasive risk stratification tests reflecting these key players could improve risk stratification.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Patients implanted with an ICD in whom 24‐hr holter recordings were available prior to implant were included. QRS fragmentation (fQRS) was selected as measure of myocardial substrate and a high ventricular premature beat count (VPB >10/hr) for arrhythmic vulnerability. From receiver operating characteristics analysis, detrended fluctuation analysis (DFA), turbulence slope, and deceleration capacity were selected for autonomic function. Adjusted Cox regression analysis with comparison of C‐statistics was performed to predict first appropriate shock (AS) and total mortality.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>A total of 220 patients were included in the analysis with an overall follow‐up of 4.3 ± 3.1 years. A model including VPB >10/hr, inferior fQRS, and abnormal nonedited DFA was the best for prediction of AS after 1 year of follow‐up with a trends toward improvement of the C‐statistics compared to baseline (<jats:italic>p</jats:italic> = 0.055). The risk increased significantly with every abnormal test (HR 1.793, 95%CI 1.255–2.564). A model including fQRS in any region and abnormal edited DFA was the best for prediction of mortality after 3 years of follow‐up with significant improvement of the C‐statistics (<jats:italic>p</jats:italic> = 0.023). Each abnormal test was associated with a significant increase in mortality (HR 5.069, 95%CI 1.978–12.994).</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>Combining noninvasive risk stratification tests according to their physiological background can improve the risk prediction of SCD and mortality.</jats:p></jats:sec>