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.

Can the long-term outcomes of percutaneous balloon mitral valvotomy and surgical commissurotomy be expected to be similar?

The ultimate role of percutaneous balloon mitral valvotomy will depend on its potential for sustained improvement. Long-term outcome data including survival, reoperation and thromboembolism are available for surgical commissurotomy. However, length of follow up for percutaneous balloon mitral valvotomy is inadequate to acquire similar end-point data. We therefore hypothesized that comparison of changes in mitral valve area following balloon or surgical commissurotomy would serve as a useful surrogate end-point by which the long-term benefit of percutaneous balloon mitral valvotomy could be determined. Mitral valve area was determined by Doppler echocardiography following percutaneous balloon mitral valvotomy (N = 230) and surgical commissurotomy (N = 241, 130 closed and 111 open mitral commissurotomy). Regression lines of mitral valve area versus interval from intervention were constructed for each of the two groups. Nine clinical and echocardiographic variables were also analyzed to determine their predictive value for low mitral valve areas. Both groups showed similar and significant negative correlations for mitral valve area versus time (r = -0.48, r = -0.6, balloon vs. surgical commissurotomy respectively, p = 0.001 for both groups). The slopes of the regression lines for both groups were also similar (y = -0.007 x +1.9, y = -0.005 x +1.8, y = -0.006 x +1.8, p = NS). There were no differences in the prevalence of mitral regurgitation. Independent predictors of mitral restenosis according to multivariate analysis were time interval from surgery (p < 0.03), composite mitral valve morphology score (p < 0.04) and subvalvular disease (p < 0.04). Thus, there is a progressive decrease in mitral valve area following percutaneous mitral balloon valvotomy that, at least for the available duration of follow up, appears to parallel changes in valve area following closed or open mitral commissurotomy. A less pliable valve and more subvalvular disease are independent predictors of smaller valve areas. These data suggest that the long term clinical outcome following percutaneous balloon mitral valvotomy may be expected to be similar to the available data for surgical commissurotomy.

Frequency of prosthetic valve-related complications with very low level warfarin anticoagulation combined with dipyridamole after valve replacement using St. Jude Medical prostheses.

The safety of a very low level of anticoagulation combined with dipyridamole in a rheumatic population (mean age 31 +/- 13 years) with the St. Jude Medical (SJM) prosthesis has not yet been tested. Furthermore, no data are available on the safety of relatively infrequent monitoring of anticoagulation levels and of the necessity for different therapeutic targets according to valve position, number of risk factors, and other baseline risk factors for thromboembolism. In this study, the performance of the SJM prosthesis was tested using a target international normalized ratio (INR) of 2.0 to 2.5 combined with dipyridamole 300 mg/day applied uniformly to all patients. Clinical, biochemical, and echocardiographic data were acquired prospectively in 200 consecutive patients at 3-month intervals. Follow-up (mean 27 +/- 13 months) was complete in 95% of patients. Thirteen patients died (2.9%/patient year). Severe left ventricular dysfunction was the cause of death in 10 of 13 patients. Probability of survival (Kaplan-Meier) was 0.92 at 36 months and of event-free survival 0.84 at 36 months. The median INR was 2.0 +/- 0.9. Valve obstruction did not occur, and there were 3 thromboembolic events (0.6%/patient year). Incidence of bleeding was 1.6%/patient year (n = 7) and was major (hemorrhagic stroke) in 1 (0.2%/patient year). Thus, the SJM prosthesis performs very well despite the use of very low level warfarin anticoagulation combined with dipyridamole. A 3-month assessment of the anticoagulation level is safe. Left ventricular dysfunction rather than valve-related complications is the leading cause of mortality in this population.

Six month pilot study of captopril for mildly symptomatic, severe isolated mitral and isolated aortic regurgitation.

Long term therapy with vasodilating drugs has been shown to reduce left ventricular size and improve performance in chronic aortic regurgitation (AR). Similar trials in mitral regurgitation (MR) have not been published, nor has the effect of medium or long term therapy with angiotensin-converting enzyme (ACE) inhibitors been examined in either of these regurgitant lesions. Such therapy, if demonstrated to be effective in reducing left ventricular end-systolic size, might be anticipated to delay the need for valve replacement in asymptomatic patients. Medium term studies of the effects of ACE inhibitors on left ventricular size in regurgitant disease would therefore be helpful in designing long term trials to assess their impact on the timing of surgery. Patients with severe isolated MR (n = 32) or isolated AR (n = 23) and mild or no symptoms received either placebo or captopril 25 mg three times daily in a randomized, double blind, six month pilot study of left ventricular size using echocardiography. Treatment was well tolerated with no reported side effects. In MR, there were no significant immediate or 6-month effects of treatment on left ventricular diameter at end-systole (mean change at six months vs. baseline = +1% vs. +3% in placebo, p = 0.58 between groups) or end-diastole (+3% vs. 0% for placebo, p = 0.33). Nor was ejection fraction computed from radionuclide angiography effected by 6-month treatment (0.00 units vs. -0.01 units change in placebo).(ABSTRACT TRUNCATED AT 250 WORDS)