[Late complications of valve replacement: the benefits of non-invasive assessment]

Non-invasive techniques were assessed for their capabilities of detecting prosthetic valve malfunctions in 70 consecutive patients with angiographically-documented or surgically-proven prosthetic valve dysfunction. Their 74 dysfunctioning valves were studied using phonocardiography, M-mode and two-dimensional echocardiography and Doppler methods, including pulsed and continuous wave (CW) Doppler echocardiography and two-dimensional Doppler color flow mapping (2DD). These results were compared among the examinations, and also compared between 43 patients with 44 dysfunctioning mechanical valves and 27 patients with 30 dysfunctioning bioprosthetic valves. Symptoms related to valve malfunction were recognized in all patients with prosthetic valve endocarditis and in all patients but one with stenotic condition. In patients with valvular regurgitation, however, symptoms were observed in only six of the 21 patients with mechanical prostheses and in 12 of the 25 patients with bioprosthetic valves (p less than 0.01). Among 43 patients with 44 mechanical valve dysfunctions, the sensitivities of phonocardiography, M-mode and two-dimensional echocardiography and Doppler techniques were 85, 65 and 86 percent, respectively, in 20 patients with stenosis; 100, 57 and 80 percent in seven patients with transvalvular regurgitation; and 100, 50 and 100 percent in 14 patients with paravalvular regurgitation. Similarly, among 27 patients with bioprosthetic valve dysfunctions, the sensitivities of phonocardiography, M-mode and two-dimensional echocardiography and Doppler methods were 67, 100 and 100 percent, respectively, in three patients with stenotic condition; 85, 65 and 100 percent in 20 patients with transvalvular regurgitation; and 60, 40 and 100 percent in five patients with paravalvular regurgitation. Furthermore, 26 of the 27 patients with malfunctioning mechanical valves and 20 of the 24 patients with malfunctioning bioprostheses had abnormal findings using more than two techniques. In addition, each patient had at least one abnormal finding. In conclusion, malfunctioning mechanical or bioprosthetic prostheses could be detected using non-invasive techniques. The combined use of phonocardiography, M-mode and two-dimensional echocardiography and Doppler techniques is most helpful in detecting malfunctioning prostheses.