Hemolysis in patients with the cloth-covered aortic valve prosthesis. Changing severity of hemolysis and prediction of anemia

Intravascular hemolysis in the late course of aortic valve

The degree of intravascular hemolysis was evaluated in 315 patients in the late course of aortic valve replacement. Starr-Edwards aortic ball valves of series 2300 caused significantly more hemolysis than did those of series 1200, as estimated from the serum lactate dehydrogenase levels. Smaller valves of series 2300 caused a higher degree of hemolysis than did the larger ones. Aortic disc valves induced a more moderate red cell destruction than did the ball valves, the Lillehei-Kaster significantly more than the Bjørk-Shiley prostheses. Crushing of red cells is thought to be a more important cause of hemolysis than shearing forces in turbulent blood. Hemolytic anemia represented a problem only in some patients with Starr-Edwards valve type 2300, although iron substitution was necessary also in some with other prostheses, since the hemoglobin-binding capacity of haptoglobin was exceeded in several patients. Valvular or paravalvular leakage was associated with stronger hemolysis in some patients, and should be suspected whenever the rate of red cell destruction increases. Longstanding intravascular hemolysis did not seriously affect renal function.

Hemolysis in the aortic prosthetic valve

A review of the incidence and severity of hemolysis in the aortic prosthesis is presented. The noncloth-covered Starr-Edwards prosthetic series 1000, 1200, and 1260 had a 2 percent (1/54) incidence of anemia. The cloth-covered Starr-Edwards aortic prosthetic series 2300 was associated with anemia in 61 percent (28/46) of patients. The modified aortic prosthetic series 2310 and 2320 had a 34 percent (19/56) incidence. Mean lactic dehydrogenase levels for the series 1000, 1200 and 1260 were 184 units; 2300 series, 574 units; 2310 and 2320 series, 334 units; and the Bjork-Shiley aortic prosthesis, 166 units. Nine patients underwent repeat surgery because of refractory anemia in the 2300 series, and one did so in the 2310 series. Four of the patients with repeat surgery had significant cloth wearing of the valve. A transvalvular gradient in excess of 30 mm Hg was present in seven of ten anemic patients studied who had the series-2300 valve. The cloth-covered Starr-Edwards aortic prosthesis carries a significant risk of anemia. At the present time the 2310 and 2320 series cause less hemolysis and a lower incidence of anemia than the original 2300 series but in excess of the noncloth-covered Starr-Edwards prosthesis.