Serial multidetector computed tomography assessment of left ventricular reverse remodeling, mass, and regional wall stress after restrictive mitral annuloplasty in dilated cardiomyopathy.

OBJECTIVE: To evaluate serial data on left ventricular and myocardial reverse remodeling after restrictive mitral annuloplasty.

METHODS: Thirteen patients (age, 64 ± 6 years) with functional mitral regurgitation associated with dilated cardiomyopathy (ejection fraction, ≤ 35%) were examined before (baseline), soon (1.7 ± 1.5 months), and more than 1 year (16 ± 8 months) after restrictive mitral annuloplasty using multidetector computed tomography. The left ventricular end-diastolic and end-systolic volume indexes, left ventricular ejection fraction, left ventricular mass index, and end-systolic wall stress were estimated.

RESULTS: In the period soon after restrictive mitral annuloplasty, significant reverse left ventricular remodeling was present, with decreases in the left ventricular end-diastolic volume index (149 ± 42 to 119 ± 41 mL/m(2), P = .04) and left ventricular end-systolic volume index (114 ± 44 to 78 ± 43 mL/m(2), P = .02), and an increase in left ventricular ejection fraction (25% ± 10% to 37% ± 14%, P = .01). Additional changes in these parameters were seen in the later period (103 ± 29 mL/m(2), 61 ± 23 mL/m(2), and 42% ± 9%, respectively; all P < .05 vs baseline). In the early postrestrictive mitral annuloplasty period, the left ventricular mass index did not change significantly (104 ± 22 to 104 ± 18 g/m(2), P = NS), but significant regression occurred in the later period (90 ± 17 g/m(2), P < .05 vs baseline). The end-systolic wall stress was significantly decreased in the early period (P < .05) and was sustained in the late period. Furthermore, the increase in left ventricular ejection fraction in the late period correlated significantly with the magnitude of the end-systolic wall stress reduction (r = -0.67, P = .01).

CONCLUSIONS: Our findings indicate that ventricular reverse remodeling occurs soon after restrictive mitral annuloplasty. In contrast, myocardial reverse remodeling (ie, regression of myocardial hypertrophy) occurs over time between the early and late postoperative periods. Our data also suggest that the late improvement in left ventricular systolic performance might be attributable to a decrease in the left ventricular afterload.