Abstract 4310: Chronic Effects of Surgical Ventricular Restoration on Left Ventricular Function: 6 Months Follow-Up by Pressure-Volume Loops

Abstract

Previous studies have demonstrated beneficial acute effects of surgical ventricular restoration (SVR) on mechanical dyssynchrony and left ventricular (LV) function, and improved mid- and long-term clinical parameters. However, chronic effects on systolic and diastolic LV function are still largely unknown. We studied 9 patients with ischemic dilated cardiomyopathy who underwent SVR. In all patients, invasive hemodynamic measurements by the conductance catheter (pressure-volume loops) were obtained during catheterization before and 6 months after surgery. In addition, NYHA classification, Minnesota Quality of Life (QoL)-score and 6-minute-hall-walk-test (6min-HWT) were assessed. At 6 months follow-up, all patients were alive and clinically significantly improved: NYHA class from 3.3±0.5 to 1.4±0.7, QoL-score from 46±22 to 15±15 and 6min-HWT from 302±123 to 444±78 m (all p<0.01). Hemodynamic data at fixed paced heart rate (80 bpm), showed improved cardiac output (4.8±1.4 to 5.6±1.1 L/min) (p =0.09), stroke work (6.5±1.9 to 7.1±1.4 mmHg.L) (p =0.05) and LV ejection fraction (36±10 to 46±10%) (p <0.001). LV surgical remodeling was sustained at 6 months: end-diastolic volume decreased from 246±70 to 180±48 mL and end-systolic volume from 173±77 to 103±40 mL (both p<0.001). LV mechanical dyssynchrony decreased from 29±6 to 26 ±3% (p<0.001) and ineffective internal LV flow fraction decreased from 58±30 to 42±18% (p<0.005). Early relaxation (tau, −dP/dt MIN ) was unchanged, but diastolic stiffness constant (K ED ) increased from 0.012±0.003 to 0.023±0.007 mL −1 (p<0.001) at 6 months follow-up. SVR leads to maintained LV volume reduction at 6 months follow-up. In addition, we observed improved systolic function and unchanged early diastolic function, but impaired passive diastolic properties. Clinical improvement, supported by decreased NYHA class, improved QoL-score and improved 6-min-HWT may be related to improved systolic function and reduced mechanical dyssynchrony.