Intraventricular conduction delays as a predictor of mortality in acute coronary syndromes.

AIMS: Initial proof suggests that a non-specific intraventricular conduction delay (NIVCD) is a risk factor for mortality. We explored the prognosis of intraventricular conduction delays (IVCD)-right bundle branch block (RBBB), left bundle branch block (LBBB), and the lesser-known NIVCD-in patients with acute coronary syndrome (ACS). METHODS AND RESULTS: This is a retrospective registry analysis of 9749 consecutive ACS patients undergoing coronary angiography and with an electrocardiographic (ECG) recording available for analysis (2007-18). The primary outcome was cardiac mortality. Mortality and cause of death data (in ICD-10 format) were received from the Finnish national register with no losses to follow-up (until 31 December 2020). The risk associated with IVCDs was analysed by calculating subdistribution hazard estimates (SDH; deaths due to other causes being considered competing events). The mean age of the population was 68.3 years [standard deviation (Sd) 11.8]. The median follow-up time was 6.1 years [interquartile range (IQR) 3.3-9.4], during which 3156 patients died. Cardiac mortality was overrepresented among IVCD patients: 76.9% for NIVCD (n = 113/147), 67.6% for LBBB (n = 96/142), 55.7% for RBBB (n = 146/262), and 50.1% for patients with no IVCD (n = 1275/2545). In an analysis adjusted for age and cardiac comorbidities, the risk of cardiac mortality was significantly higher in all IVCD groups than among patients with no IVCD: SDH 1.37 (1.15-1.64, P < 0.0001) for RBBB, SDH 1.63 (1.31-2.03 P < 0.0001) for LBBB, and SDH 2.68 (2.19-3.27) for NIVCD. After adjusting the analysis with left ventricular ejection fraction, RBBB and NIVCD remained significant risk factors for cardiac mortality. CONCLUSION: RBBB, LBBB, and NIVCD were associated with higher cardiac mortality in ACS patients.

High-risk ECG patterns in ST elevation myocardial infarction for mortality prediction.

AIM: We explored the pre-intervention (first medical contact) electrocardiographic (ECG) patterns and their relation to survival among patients with acute myocardial infarction, who presented either with ST elevation (ST elevation myocardial infarction, STEMI) or LBBB, and who underwent emergent coronary angiography in a region with a 24/7/365 STEMI network. METHODS: This is a retrospective analysis of 1363 consecutive patients hospitalized for first STEMI between the years 2014 and 2018. We assessed the prognostic significance of a variety of ECG categories, including location of ST elevation, severity of ischemia, intraventricular and atrioventricular conduction disorders, atrial fibrillation or flutter, junctional rhythms, heart rate, left ventricular hypertrophy and Q waves. The primary outcome was all-cause mortality between January 2014 and the end of 2020. RESULTS: The mean age of the patients was 67.9 (SD 12.8) years. The majority were treated by percutaneous coronary intervention (93.8%, n = 1278). Median follow-up time was 3.7 years (IQR 2.5-5.1 years) during which 22.5% (n = 307) of the patients died. According to Cox regression analysis, adjusted for pre-existing conditions and age, the ECG variables with statistically significant association with survival were elevated heart rate (>100 bpm) (HR 2.34, 95% CI 1.75-3.12), atrial fibrillation or flutter (HR 1.94, 95% CI 1.41-2.67), left bundle branch block (LBBB) (HR 2.62, 95% CI 1.49-4.63) and non-specific intraventricular conduction delay (NIVCD) (HR 1.85, 95% CI 1.22-2.89). CONCLUSION: Higher heart rate, atrial fibrillation or flutter, LBBB and NIVCD are associated with worse outcome in all-comers with STEMI. Ischemia severity was not associated with impaired prognosis.