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. (J Thorac Cardiovasc Surg 2010;140:1338-44)Cardiolog

Clinical and Functional Effects of Restrictive Mitral Annuloplasty at Midterm Follow-Up in Heart Failure Patients

Background. Restrictive mitral annuloplasty (RMA) is increasingly applied to treat functional mitral regurgitation in heart failure patients. Previous studies indicated beneficial clinical effects with low recurrence rates. However, the underlying pathophysiology is complex and outcome in terms of left ventricular function is not well known. We investigated chronic effects of RMA on ventricular function in relation to clinical outcome. Methods. Heart failure patients (n = 11) with severe mitral regurgitation scheduled for RMA were analyzed at baseline (presurgery) and midterm follow-up by invasive pressure-volume loops, using conductance catheters. Clinical performance was evaluated by New York Heart Association class, quality-of-life-score, and 6-minute hall-walk-test. Results. All patients were alive without recurrence of mitral regurgitation at follow-up (9.4 +/- 4.1 months). Clinical parameters improved significantly (all p < 0.05). Global cardiac function, assessed by cardiac output, stroke volume, and stroke work did not change after RMA. Reverse remodeling was demonstrated by decreased end-systolic and end-diastolic volumes (16% and 11%, both p < 0.001). Systolic function improved, evidenced by increased ejection fraction (0.32 +/- 0.05 to 0.36 +/- 0.07, p = 0.001) and leftward shift of the end-systolic pressure-volume relation (ESV100: 116 +/- 43 to 74 +/- 26 mL, p < 0.001). Diastolic function, however, demonstrated impairment by increased tau (69 +/- 13 to 80 +/- 14 ms, p < 0.001) and stiffness constant (0.022 +/- 0.022 to 0.031 +/- 0.028 mL(-1), p = 0.001). Conclusions. Restrictive mitral annuloplasty significantly improved clinical status without recurrence of mitral regurgitation at midterm follow-up in patients with heart failure. Hemodynamic analyses demonstrated significant reverse remodeling with unchanged global function and improved systolic function, but some signs of diastolic impairment. Overall, RMA appears an appropriate therapy for patients with dilated cardiomyopathy and functional mitral regurgitation. (Ann Thorac Surg 2010;90:1913-21) (C) 2010 by The Society of Thoracic SurgeonsCardiolog