Preoperative left ventricular systolic dysfunction correlates with the adverse postoperative consequences of annular-papillary disconnection in the course of mitral valve replacement for stenosis.

BACKGROUND AND AIMS OF THE STUDY: Preservation of chordae tendineae helps maintain ventricular performance in patients having surgery for mitral regurgitation. The importance of chordal integrity in patients with rheumatic mitral stenosis is unknown. The purpose of this study was to determine the influence of chordal preservation on left ventricular function following relief of rheumatic mitral stenosis. METHODS: A total of 142 patients with mitral stenosis had balloon valvulotomy (group 1, n = 63), surgical commissurotomy (group 2, n = 33) or mitral valve replacement (group 3, n = 46). Chordae were resected in all group 3 patients. Left ventricular dimension in end-diastole (LVEDD), end-systole (LVESD) and fractional shortening (FS) were measured at baseline and at a mean interval of 11 +/- months post intervention. RESULTS: At one year, FS increased in groups 1 and 2, but decreased in group 3 (+11.5%, +9%, -6.1%, p < 0.005 for group 3 versus groups 1 and 2). a borderline significant increase LVEDD was seen in group 1 compared with groups 2 and 3 (11%, 5%, 4% respectively, p = 0.05). Differences in FS at follow up were due mainly to diametrically opposite changes in LVESD in the subgroup of patients with baseline left ventricular dysfunction (-1.9%, 0%, +9.8%, p < 0.005 for group 3 versus groups 1 and 2). CONCLUSIONS: Deterioration of left ventricular function only in patients having mitral valve replacement indicates chordal resection as a putative mechanism. The result of this study suggest that chordal preservation is particularly important in patients with mitral stenosis who have depressed preoperative left ventricular systolic function.

Long-term follow-up of St. Jude Medical prosthesis in a young rheumatic population using low-level warfarin anticoagulation: an analysis of the temporal distribution of causes of death.

This study assesses the long-term (mean 52+/-24 months) performance of the St. Jude Medical (SJM) valve in 200 young (mean age 31+/-13 years) rheumatic patients on low-level warfarin anticoagulation combined with dipyridamole. Follow-up was 95% complete and comprised 867 patient-years. There were 33 deaths (3.8%/patient-year). Death was valve related in 12 cases and due to left ventricular dysfunction in 10. Death due to left ventricular dysfunction occurred earlier after surgery than death due to other causes (10+/-7 vs 29+/-18 months, p <0.005); these patients had larger preoperative left ventricular dimensions than the rest of the group (end-systolic diameter 51+/-13 vs 37+/-16 mm, end-diastolic diameter 66+/-13 vs 50+/-19 mm, p = 0.006). Actuarial probability of survival was 81% at 86 months and probability of event-free survival was 71%. The median international normalized ratio was 1.88+/-0.54. Thromboembolism (13 events) occurred at a linearized rate of 1.5%/patient-year. There were 11 major bleeding episodes (1.3%/patient-year), 4 cases of prosthetic valve endocarditis (0.8%/patient-year), and 12 paraprosthetic leaks (1.4%/patient-year). No valve obstructions or reoperations occurred. Thus, the SJM valve performs well on low-level anticoagulation combined with dipyridamole. Left ventricular dysfunction was a common cause of death in the early postoperative period.

Long-term changes in left ventricular performance following mitral valve replacement for pure rheumatic mitral regurgitation.

Our data indicate that MVR, with or without chordal preservation, for pure severe MR in symptomatic younger rheumatic patients with a good preoperative ejection fraction results in normalization of LV size and performance by 1 year. Normalization of LV performance was only achieved at 1 year after surgery, and it is therefore essential to extend the assessment of LV function to at least 1 year postoperatively.