Mitral valve repair in patients on chronic hemodialysis

Mitral valve repair in uremic congestive cardiomyopathy

BACKGROUND

There is limited reported experience on mitral valve repair in patients with chronic renal failure. This study was designed to evaluate the outcomes of mitral valve repair in patients suffering from congestive heart failure as a result of uremic cardiomyopathy and severe mitral regurgitation requiring chronic hemodialysis.

METHODS

From 1995 to 2002, 5 women, ages 41 to 64 years (53 +/- 8 years), with uremic congestive cardiomyopathy and end-stage renal disease on chronic hemodialysis who underwent mitral valve repair for severe mitral regurgitation were identified retrospectively and followed for clinical and echocardiographic outcomes. The preoperative New York Heart Association functional class was 3.8 +/- 0.45.

RESULTS

All patients had good results immediately after surgical mitral valve repair with no more than mild mitral regurgitation. During the follow-up at an average of 22.4 +/- 14.9 months (range, 3 to 41 months) postoperatively, all patients returned to New York Heart Association functional class I. Neither mitral calcification nor increasing peak transmitral gradient (or decreasing mitral valve orifice area) was notable by two-dimensional echocardiography. No reoperation was required.

CONCLUSIONS

Although accelerated calcification of the repaired mitral valve and high incidence of failure of the reconstruction had been reported in patients with end-stage renal disease, based on our experience we advocate mitral valve repair when this can be safely performed, especially in patients with uremic congestive cardiomyopathy, in view of the added advantage of retaining the native valve in such patients.

Valvular and perivalvular abnormalities in end-stage renal disease

Valvular and perivalvular involvement in end-stage renal disease (ESRD) is most commonly manifested as mitral annular calcification and aortic valve calcification. Both mitral and aortic valve calcification (MAC) occur more frequently and at younger age in those with ESRD than in those with normal renal function. Aortic valve calcification progresses to aortic stenosis more commonly and at a more accelerated rate than in the general population. Altered calcium and phosphate metabolism are thought to predispose to these valvular and perivalvular abnormalities. No treatment is necessary for MAC unless severe mitral regurgitation or stenosis occur (both are rare). Mitral valve repair or replacement and aortic valve replacement are indicated for severe symptomatic valve stenosis or regurgitation, albeit at a higher risk than in those with normal renal function. Infective endocarditis may complicate MAC or aortic stenosis in patients with ESRD and is associated with a high mortality rate in such patients.

Results of valve replacement with mechanical and biological prostheses in chronic renal dialysis patients

BACKGROUND

Whether biological or mechanical valves should be used in patients on chronic dialysis therapy remains to be clearly defined.

METHODS

A retrospective review was performed on 19 consecutive patients from our institution with end-stage renal disease on chronic peritoneal or hemodialysis undergoing aortic (n = 12), mitral (n = 5), or aortic-mitral (n = 2) valve replacement.

RESULTS

The 9 biological and 10 mechanical valve patients had similar ages (56.5 versus 56.6 years) and cardiovascular risk factors. The overall estimated Kaplan-Meier survival was 60% +/- 12% at 12 months and 42% +/- 14% at 60 months. Mechanical valve patients had a significantly higher rate of postoperative cerebrovascular accidents or bleeding complications (10/10 versus 0/9; chi 2 = 17.0; p < 0.001). No subsequent reoperations were required for biological valve failure at a mean follow-up of 32 +/- 53 months.

CONCLUSIONS

These results demonstrate that in patients with end-stage renal disease, use of mechanical valves is associated with significant risk of complications, whereas biological valve failure from prosthetic dysfunction is unusual. Overall survival is poor in both groups of patients. Therefore, preference should be given to biological valve instead of mechanical valve prostheses in patients on chronic renal dialysis.