Which heart valve prosthesis for patients aged between 60 and 70 years?

Choice of Aortic Valve Prosthesis in a Rapidly Aging and Long-Living Society

PURPOSE

The aim of this study was to evaluate the long-term results of aortic valve replacement (AVR) with mechanical (M) and bioprosthetic (B) valves as recommended by the Japanese guidelines.

METHODS

From April 1995 to March 2014, 366 adult patients underwent AVR. Of these, 127 (35%) patients received M and 239 patients (65%) received B valves. A retrospective analysis of the entire and the selected 124 patients aged 60 to 70 years was carried out.

RESULTS

In patients aged 60 to 70 years, the 15-year survival and freedom from reoperation were 88% ± 7% and 100% for the M group and 34% ± 25% (p <0.001) and 73% ± 14% (p = 0.059) for the B group, respectively. Among propensity score matching of the subgroup, there was no significant difference in survival and freedom from reoperation. The rate of thromboembolism was higher in the M (M: 0.58% vs B: 0.35% patient per year, p <0.001) and the rate of hemorrhage was higher in the M group (M: 0.34% vs B: 0.12% patient per year, p <0.001).

CONCLUSION

The current strategy of aortic valve choice based on the Japanese guidelines has provided excellent long-term results so far.

[Operative risk of heart valve surgery after 80 years]

The continuous prolongation of life expectancy in developed nations and the progress made in the surgical treatment of valvulopathy have substantially increased the number of octogenarians undergoing heart valve surgery with extracorporeal circulation. Most of them have calcified aortic stenosis and the valve is replaced with a bioprosthesis. At these ages, mitral valve disease--usually insufficiency--is predominantly treated by repair rather than valve replacement. In both cases, the etiology is primarily degenerative. In addition, an ever-increasing percentage of these patients require replacement of deteriorated bioprostheses. These octogenarians are exposed to surgical risk estimated to be about 9-10%, i.e. 2-3 times higher than that of patients under 70 years of age, and even higher when surgery is a reintervention. Furthermore, morbidity affecting approximately an additional third of those undergoing surgery must be added to this mortality. Therefore, only half of the patients have uncomplicated surgical outcomes. Age is not the only factor enhancing the risk, which is also linked to comorbidities, preoperative functional class, stage of the evolving valvulopathy, and association of coronary artery disease. Predictive scores (Parsonnet, EuroScore) have been devised to evaluate the surgical risk to which these patients are subjected. Rigorous selection of patients with severe valvulopathy should enable potential candidates, willing to undergo an intervention, to be provided with indications for surgery sufficiently early so as to not enhance the risk by intervening too late.

[Can bioprostheses be implanted at younger ages?]

The choice between mechanical prosthesis (MP) and bioprosthesis (BP) depends on the respective advantages and disadvantages of the two types of valves. MP theoretically have an indefinite life span but carry the risk of thromboembolic events that requires anticoagulant therapy, which itself is responsible for hemorrhages. BP bear a theoretically lower thromboembolic risk but have a limited life span that requires reintervention at a subsequent date, latter when the patient is older at implantation and operated on for aortic replacement. Actually MP is preferred before 60 years and BP after 70 years. Between 60 and 70 years there is not consensus. The limit recommended is around 65 years for aortic replacement and 70 years for mitral replacement. This limit can change either for upper or lower limit depending on patient's life expectancy, technological improvements of MP as well as BP, improvements of medical follow up of anticoagulant therapy (either self testing or use of anti thrombin). In the future the age limit of implantation of BP can be lowered but MP didn't have their last word.