Aortic Valve Replacement in Patients Over the Age of Sixty

Abstract

Twenty-nine consecutive patients over the age of 60 with isolated aortic valvular disease, who had undergone aortic valve replacement with the Bjork-Shiley tilting disc valve prosthesis, were subjected to a clinical, angiographic and haemodynamic follow-up study. Before surgery, this material was characterized by long histories of deterioration, pre-dominance of male patients and patients with aortic stenosis, marked cardiac enlargement and by impaired functional capacity, working capacity and pump function of the left ventricle. Congestive heart failure and pulmonary hypertension were uncommon in these elderly patients, who were incapacitated by marked obstruction and/or severe regurgi-tation.

The main effect of aortic valve replacement was a shift of the central circulation to a more normokinetic type, an increase in stroke volume and a decrease in the filling pressure of the left ventricle. In patients with aortic stenosis, the systolic pressure of the left ventricle was normalized and stroke work markedly reduced. Working capacity increased and cardiac enlargement declined, both significantly. Postoperative reductions were observed in left atrial, pulmonary artery and right heart pressures both at rest and during exercise. Clinical improvement was achieved in all surviving patients and was maintained during the entire follow-up period which averaged 28 months. Aortic valve replacement involved a hospital mortality of 3 % and a total related mortality of 7%, both of which were due to aortic arteriosclerosis. Late mortality tended to parallel the normal mortality rate. Early postoperative and late complications did not differ from those in younger adult patients undergoing aortic valve surgery.

The in vivo rheology of the Björk-Shiley prosthesis was reported as highly satisfactory even in its smaller sizes. A haemodynamic comparison with a group of younger patients demonstrated an identical unloading of the left ventricle and improvement in pump function in both age groups following aortic valve replacement with this prosthesis, which may be regarded as eliminating the volume load and the pressure load of the left ventricle.

The life expectancy in the elderly patients selected for aortic valve surgery, when assessed in relation to the natural history of aortic valvular disease, appears to be satisfactory. It was therefore concluded that surgery is justified in patients over the age of 60 who are incapacitated by aortic valvular disease.