P1779 Myocardial work is a predictor of exercise tolerance in patients with dilated cardiomyopathy and left ventricular dyssynchrony

Abstract

Background the assessment of myocardial work (MW) by pressure-strain loops is a recently introduced tool for the assessment of myocardial performance. Aim of the present study is to evaluate the relationship between myocardial work and exercise tolerance in patients with dilated cardiomyopathy (DCM) Methods 51 patients with DCM (mean age 57 ± 13 years, left entricular ejection fraction : 32 ± 9%) underwent cardiopulmonary exercise test (CPET) to assess exercise performance. Trans-thoracic echocardiography (TTE) was performed CPET. The following indices of myocardial work (MW) were measured regionally and globally: constructive work (CW), wasted work (WW), and work efficiency (WE). Left ventricular (LV) dyssynchrony (DYS) was defined by the presence of septal flash or apical rocking at TTE. Results LV-DYS was observed in 16 (31%) patients and associated with lower LV ejection fraction (LVEF), GLS, global and septal WE, and higher global and septal WW (Table 1). In patients with LV-DYS, septal WE was the only predictor of exercise peak VO2max at multivariable analysis (Figure 1), whereas LVEF (β=0.47, p = 0.05) and age (β=-0.42, 47, p= 0.04) were predictors of exercise capacity in patients without LV-DYS. Conclusions In patients with DCM, LV-DYS is associated with an heterogeneous distribution of myocardial work. Septal WE is the best predictor of exercise performance in these patients. Table 1 All n = 51 No-dyssynchrony n = 35 (69%) LV-Dyssynchrony n = 16 (31%) p-value LVEF, % 32 ± 9 34 ± 10 28 ± 7 0.04 GLS, % -12 ± 3 -13 ± 3 -10 ± 3 0.001 GCW, mmHg% 1325 ± 398 1342 ± 354 1287 ± 491 0.65 GWW, mmHg% 201 ± 147 154 ± 95 304 ±191 <0.0001 GWE, % 85 ± 9 88 ± 7 78 ±10 <0.0001 CWsept, mmHg% 1172 ± 459 1274 ± 398 949 ± 516 0.017 CWlat, mmHg% 1518 471 1472 ± 386 1620 ± 622 0.30 WWsept, mmHg% 283 ± 275 174 ± 98 522 ±376 <0.0001 WWlat, mmHg% 135 ± 88 117 ± 81 176 ± 92 0.02 WEsept, % 78 ± 16 84 ± 9 62± 18* <0.0001 WElat, % 90 ± 7 91 ± 7 88 ± 7 0.16 Abstract P1779 Figure.