Long term outcome
Median follow-up was 7.7 years (IQR 6.7-8.2 years). There was no difference in long-term all-cause mortality between groups (Table 4). Long-term MACE occurred in 92 patients (17.5%). Cardiac death was very low in both groups, and there was no significant difference in long-term MACE or in the individual end-points between groups (Table 4, Figure 2). ACS or revascularization accounted for 68/92 (74%) of MACE. Hospitalization for heart failure was rare even in the group of patients with worse GLS. We repeated the analysis with a GLS cutoff value of -17%, the cutoff value for abnormal GLS.24 There was no significant difference in long-term MACE between patients with normal vs. abnormal GLS (log-rank P =0.64).
To determine whether suboptimal 2D image quality was the cause of our findings, we repeated the same analysis in the 164 patients with optimal 2D image quality (better GLS: n= 97, worse GLS: n=67). Long-term MACE tended to be higher in the worse GLS group (HR=1.85, 95%CI 0.94-3.63,P =0.07(, but there was no statistically significant difference in MACE after adjustment for history of CAD, hypertension and ACS at presentation (HR=1.51, 95% CI 0.76-3.0, P =0.24).
Independent predictors of long-term MACE were male gender, hypertension, history of CAD and ACS at presentation (Table 5). Thus, a worse GLS did not predict long-term outcome.