Long-term effects of surgical ventricular restoration with additional restrictive mitral annuloplasty and/or coronary artery bypass grafting on left ventricular function: six-month follow-up by pressure-volume loops

Objectives: Previous studies demonstrated beneficial short-term effects of surgical ventricular restoration on mechanical dyssynchrony and left ventricular function and improved midterm and long-term clinical parameters. However, long-term effects on systolic and diastolic left ventricular function are still largely unknown.

Methods: We studied 9 patients with ischemic dilated cardiomyopathy who underwent surgical ventricular restoration with additional restrictive mitral annuloplasty and/or coronary artery bypass grafting. Invasive hemodynamic measurements by conductance catheter (pressure-volume loops) were obtained before and 6 months after surgery. In addition, New York Heart Association classification, quality-of-life score, and 6-minute hall-walk test were assessed.

Results: At 6 months' follow-up, all patients were alive and clinically in improved condition: New York Heart Association class from 3.3 ± 0.5 to 1.4 ± 0.7, quality-of-life score from 46 ± 22 to 15 ± 15, and 6-minute hall-walk test from 302 ± 123 to 444 ± 78 m (all P < .01). Hemodynamic data showed improved cardiac output (4.8 ± 1.4 to 5.6 ± 1.1 L/min), stroke work (6.5 ± 1.9 to 7.1 ± 1.4 mm Hg · L; P = .05), and left ventricular ejection fraction (36% ± 10% to 46% ± 10%; P < .001). Left ventricular 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 < .001). Left ventricular dyssynchrony decreased from 29% ± 6% to 26% ± 3% (P < .001) and ineffective internal flow fraction decreased from 58% ± 30% to 42% ± 18% (P < .005). Early relaxation (Tau, minimal rate of pressure change) was unchanged, but diastolic stiffness constant increased from 0.012 ± 0.003 to 0.023 ± 0.007 mL(-1) (P < .001).

Conclusions: Surgical ventricular restoration with additional restrictive mitral annuloplasty and/or coronary artery bypass grafting leads to sustained left ventricular volume reduction at 6 months' follow-up. We observed improved systolic function and unchanged early diastolic function but impaired passive diastolic properties. Clinical improvement, supported by decreased New York Heart Association class, improved quality-of-life score, and improved 6-minute hall-walk test may be related to improved systolic function, reduced mechanical dyssynchrony, and reduced wall stress.