1048 myocardial work and outcome in patients paradoxical with low flow, low gradient aortic stenosis

Abstract Aim The aim of this study was to investigate the potential impact of non-invasive derived myocardial work (MW) indexes on outcome of patients with severe paradoxical low flow, low gradient (PLFLG AS) undergoing transcatheter aortic valve implantation (TAVI). Methods Complete demographic, clinical characteristics, laboratory analyses and echocardiographic parameters were collected. Severe PLFLG AS was defined as indexed aortic valve area (iAVA) ≤0.6 cm2/m2, mean transaortic gradient < 40 mmHg and stroke volume index <36 ml/m2 and preserved LVEF >50%. MW was obtained from the non-invasive strain-pressure loop obtained pressure by combining GLS and the left ventricular systolic pressure, which was derived by adding the mean aortic valve gradient to systolic brachial pressure. Constructive MW (CMW), MW index (MWI), MW efficiency (MWE), and wasted MW (WMW) were measured. The normal values ​​considered for the MW parameters were: MWI ≥ 1300 mmHg%; CMW ≥ 1500 mmHg%; WMW < 240 mmHg%; MWE ≥ 90%. Odds ratio, sensitivity and specificity were used to quantify the ability of MW parameters (abnormal vs normal values) in predicting the primary outcome defined as all-causes mortality. Results study population included 30 patients with severe PLFLG AS undergoing TAVI. The most frequent comorbidities were hypertension (93%; n=28), dyslipidaemia (66%; n=20), diabetes (23%; n=7). Atrial fibrillation/flutter and chronic kidney disease were identified in 12 (40%) and 18 (60%) patients, respectively. Concomitant coronary artery disease and history of stroke were reported in 23% (n=7) and 10% (n=3), respectively. Society of Thoracic Surgeons score in overall population was mean 11,34±4,34. During median of 209 days (IQR: 104–213 days) all-causes mortality occurred in 13 patients (43%) (just 1 for non-cardiac death). Abnormal values of MWI, CMW and MWE identified significant statistical correlation with primary outcome [(odds ratio for primary outcome: 7.5 (95% confidence interval: 1.4 to 39.8); 7.5 (1.4 to 39.5) and 5.2 (1.1 to 25.3) respectively, Table 1)]. The MWI, CMW and MWE have the same sensitivity (62%) but higher specificity (82% for MWI and CMW, 88% for WMW and 76% for MWE). Conclusion In a population of patients with PLFLG-AS characterized by normal ejection fraction the abnormal MW parameters seem to be significantly associated with all-causes mortality during mid-term follow up and might provide additional information on outcome of this peculiar subgroup of patients with AS. Table 1