The association between ST-segment depressions and sudden cardiac deaths and arrests after acute coronary syndrome

AIMS OF THE STUDY: ST-segment depression in the electrocardiogram (ECG) of acute coronary syndrome (ACS) patients has been associated with higher mortality. But still, its association to sudden cardiac deaths (SCDs) or sudden cardiac arrests (SCAs) has not yet been investigated. We analyzed the association between ST-segment depression in the ECG after angiography and the long-term incidence of SCD and SCA among ACS patients. METHODS: Retrospective data of 8565 consecutive ACS patients with a median follow-up time of 7.1 years were analyzed retrospectively. Patients with (n = 1957) and without (n = 6608) ST-segment depression in ECG after angiography were compared after stratification according to the location of ST-segment depression. Incidents of SCDs and SCAs were adjudicated using various sources detailing the circumstances leading to the events. Subdistribution regression (Fine-Gray) models were used in the association analyses. RESULTS: Lateral, inferior, and inferolateral ST-segment depression were associated with the long-term risk for SCD and SCA in age- and sex-adjusted analyses (p-value <0.05). However, only lateral ST-segment depression was associated with a higher risk for SCD (HR 1.58, 95 % CI 1.13-2.20, p-value 0.007) and SCA (HR 1.48, 95 % CI 1.12-1.96, p-value 0.006) when additionally adjusted with several cardiovascular risk factors. The results remained significant in lateral and inferolateral ST-segment depression even after excluding patients with LVEF ≤35 % at baseline. CONCLUSION: Lateral, inferolateral, and inferior ST-segment depressions in ECG after angiography in ACS patients are associated with a significantly higher long-term risk for SCD and SCA.