Increased Global Post-Systolic Contraction During 1st Interstage Predicts Medium-Term Death or Transplantation in Children With Hypoplastic Left Heart Syndrome

Background

Echocardiography parameters of right ventricular (RV) dysfunction, fractional area change (RVFAC), and global longitudinal strain during the first interstage have been shown to be associated with death or transplantation in patients with HLHS. However, both parameters lack adequate discriminatory characteristics. This study sought to examine global post-systolic contraction (PSC), a marker of myocardial inefficiency, as a predictor of death or transplantation (Tx) in patients with classic hypoplastic left heart syndrome (HLHS).

Methods

We performed a post-hoc analysis of 62 prospectively recruited patients with HLHS prior to the bidirectional cavopulmonary anastomosis (BCPA) surgery. We measured RV function parameters: RVFAC, global longitudinal strain, strain rate, mechanical dispersion index (MDI), and PSC. For each parameter, the receiver operating characteristic analysis determined the optimal cut-offs for the primary endpoint of death/Tx, followed by a Kaplan-Meier analysis. Parameters interobserver variability testing was performed.

Results

Median follow-up from pre-BCPA echocardiogram was 7.4 years. HLHS with outcome of death/Tx (n = 14) had lower RVFAC, longitudinal strain and strain rate, and increased PSC when compared with survivors. PSC of >5% performed the best, with the greatest area under the curve 0.75, sensitivity 64% and specificity 83%, hazard ratio 5.54 (95% CI 1.63–18.66), for the primary endpoint of death/Tx. PSC and strain parameters had excellent reproducibility.

Conclusion

Increased global post-systolic contraction during the first interstage is associated with an outcome of death or transplantation in the medium term follow up of patients with HLHS. PSC has a greater specificity and reproducibility than global longitudinal strain and RV FAC. Investigation into its use in clinical practice as a predictor of outcome is warranted.