Prognostic utility of early systolic lengthening by speckle tracking in patients undergoing coronary artery bypass graft

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Independent Research Fund Denmark Background Early systolic lengthening (ESL), a paradoxical stretch of myocardial fibers, has been linked to myocardial viability and contractile dysfunction. We assessed the long-term prognostic potential of ESL in coronary artery bypass graft (CABG) patients. Methods We retrospectively included patients (n = 709; mean age 68 years; 85% men) who underwent speckle tracking echocardiography (median 15 days) prior to CABG. Endpoints were cardiovascular death (CVD) and all-cause mortality. We assessed amplitude of ESL (%), defined as peak positive strain, and duration of ESL (ms), determined as time from Q-wave on the ECG to peak positive strain. We applied Cox proportional hazards models adjusted for the clinical risk tool, EuroSCORE II. Results During median follow-up of 3.8 years [IQR 2.7 to 4.9 years], 45 (6%) experienced CVD and 80 (11%) died. In survival analyses adjusted for EuroSCORE II, amplitude of ESL was associated with CVD (HR 1.37 [95%CI 1.13 to 1.66], P = 0.001) and all-cause mortality (HR 1.31 [95%CI 1.13 to 1.54], P = 0.001). Similar findings applied to duration of ESL and CVD (HR 1.17 [95%CI 1.08 to 1.26], P < 0.001) and all-cause mortality (HR 1.14 [95%CI 1.07 to 1.21], P < 0.001). The prognostic value of ESL amplitude was modified by sex (P interaction < 0.05), such that it was greater in women for both endpoints (Figure 1A-B). When adding ESL duration to EuroSCORE II, the net reclassification index improved significantly for both CVD and all-cause mortality. Conclusions Assessment of ESL provides independent and incremental prognostic information in addition to the EuroSCORE II for CVD and all-cause mortality in CABG patients. The prognostic value was greater in women. Abstract Figure. Prognostic value of ESL amplitude by sex