Predicting cardiovascular events in out-of-hospital patients presenting with atypical chest pain and complete left bundle branch block: role of CTA and echocardiographic Global Longitudinal Strain

Background  Out-of-hospital patients presenting with atypical chest pain and complete left bundle branch block (LBBB) have to be stratified for the presence of coronary artery disease and the risk of developing heart failure (HF). We investigated the prognostic role of coronary CT-angiography (CTA) and echocardiographic global longitudinal strain (GLS) in those patients in a mid-term follow-up.

Methods  Out-of-hospital patients with LBBB underwent echocardiography and a 64-slice CT angiography were evaluated retrospectively. Development of HF or a cardiovascular death were the events scheduled.

Results  Seventy-eight patients (32 female; mean age: 66.0 ± 10.4 years were enrolled. During a follow-up of 33 months (IQR: 17-77), one patient (1.5%) experienced a cardiovascular death, 14 patients (17.9%) required urgent outpatient visits due to acute decompensated HF (12 hospitalizations). Echocardiography showed a slightly reduced left ventricular ejection fraction (LVEF) (50.0% ± 9.8%) and GLS within the normal range (-16.2% ± 4.1%). CTA analysis showed coronary stenosis > 50% in 28 patients (35.9%). A high Agatston score (> 100) was observed in 29.5%. Notably, 25 patients (32.1%) were diagnosed with left main coronary artery disease and 15 patients (16.7%) underwent revascularization during the follow up. Significant associations were observed between events and LVEF (P = 0.001), diastolic dysfunction grade ≥ 2 (P = 0.02), GLS (P < 0.001), multiple coronary stenosis (P = 0.04) and Agatston score (P = 0.05). Multivariate analysis confirmed the relationships with LVEF (R² = 0.89, P < 0.001), diastolic dysfunction (R² = 3.30, P = 0.04), GLS (R² = 1.43, P < 0.001), and Agatston score (R² = 1.01, P = 0.05).

Conclusions  In patients with complete LBBB, CTA and GLS identified those at a high risk of development HF.