[Aortic valve replacement in old age. The results and follow-up echo-Doppler study of the prostheses].

BACKGROUND

To analyze the results of aortic valve replacement in elderly patients and to evaluate the hemodynamic performance of valvular prostheses, we have retrospectively studied the patients 70 years of age or older, who consecutively underwent aortic valve replacement in our Center.

METHODS

From January 1988 to December 1992, a series of 112 patients aged 70 to 88 years (mean 74.8 +/- 3.8 years) underwent aortic valve replacement; 49.1% of patients were male; aortic valvular lesion was: stenosis in 65.2%, insufficiency in 9.8% and mixed stenosis and insufficiency in 25.0%. In 73.2% isolated valve disease was present; in 25.0% coronary artery disease was associated. Preoperatively 58.9% were in New York Heart Association class III, and 29.5% were in class IV. Concomitant extracardiac diseases were present in 73.2%. The types of valve prostheses employed were: mechanical tilting disc (28 cases), mechanical bileaflet (40 cases), bioprosthesis (44 cases). A significantly favourable relationship between body surface area and size of prostheses was evident.

RESULTS

Overall hospital mortality was 8.9% (5.4% for elective isolated aortic valve replacement) with significant difference (p = 0.006) related to criteria for surgical indication (elective 6.4%, urgent 10.0%, emergency 37.5%). Valvular lesion, age, sex, associated coronary artery bypass surgery, the values of peak and mean aortic valve gradient, the relative wall thickness and the presence of extracardiac disease have not been identified as risk factors for hospital mortality. The mean follow-up of the 102 discharged patients is 27.1 +/- 16.5 months (range 2 to 64 months). Eight late deaths (7.8%) occurred; the overall actuarial freedom from all deaths (excluding hospital mortality) was 95.6 +/- 2.2% at 1 year and 88.6 +/- 4.0% at 3 and 5 years. Five non fatal valve related complications occurred: hemorrhage in 4 cases (1.8% pt/yr) and hemolysis in 1 case (0.4% pt/yr). Ninety-seven percent of patients were found to be in NYHA functional class I or II. Comparative echocardiographic evaluation of the prostheses showed significant differences in mean gradient: regarding 21 mm size lower in bileaflet than in tilting disc and regarding 23 mm size lower in bileaflet than in tilting disc or bioprostheses.

CONCLUSIONS

Aortic valve replacement has proved to be safe and effective in the elderly population and is considered the procedure of choice for aortic valve disease. Although we consider mandatory to choose the valve substitute matching different physiopathological and psychological attitudes of individual patient, mechanical prostheses and particularly bileaflet type for size < or = 21 mm should be preferred.