Dual-source cardiac CT accurately measured opening angles of normally functioning mechanical aortic valves, showing excellent agreement with manufacturers' values for seven valve types (ICC 0.977).
Observational (n=140)
Single-blind
No
Does dual-source computed tomography accurately measure opening and closing angles of mechanical aortic valves compared to manufacturers' values?
Dual-source cardiac CT provides accurate in vivo measurements of opening and closing angles for most mechanical aortic valves, which can help identify valve dysfunction.
Effect estimate: ICC 0.977 (95% CI 0.962-0.987)
OBJECTIVE: The aims of this study were to compare opening and closing angles of normally functioning mechanical aortic valves measured on dual-source computed tomography (CT) with the manufacturers' values and to compare CT-measured opening angles according to valve function. MATERIALS AND METHODS: A total of 140 patients with 10 different types of mechanical aortic valves, who underwent dual-source cardiac CT, were included. Opening and closing angles were measured on CT images. Agreement between angles in normally functioning valves and the manufacturer values was assessed using the interclass coefficient and the Bland-Altman method. CT-measured opening angles were compared between normal functioning valves and suspected dysfunctioning valves. RESULTS: The CT-measured opening angles of normally functioning valves and manufacturers' values showed excellent agreement for seven valve types (intraclass coefficient ICC, 0.977; 95% confidence interval CI, 0.962-0.987). The mean differences in opening angles between the CT measurements and the manufacturers' values were 1.2° in seven types of valves, 11.0° in On-X valves, and 15.5° in ATS valves. The manufacturers' closing angles and those measured by CT showed excellent agreement for all valve types (ICC, 0.953; 95% CI, 0.920-0.972). Among valves with suspected dysfunction, those with limitation of motion (LOM) and an increased pressure gradient (PG) had smaller opening angles than those with LOM only (p < 0.05). CONCLUSION: Dual-source cardiac CT accurately measures opening and closing angles in most types of mechanical aortic valves, compared with the manufacturers' values. Opening angles on CT differ according to the type of valve dysfunction and a decreased opening angle may suggest an elevated PG.
Suh et al. (2015) conducted an observational in Mechanical aortic valve replacement (n=140). Dual-source computed tomography (CT) vs. Manufacturers' values was evaluated on Agreement of opening angles between CT measurements and manufacturers' values (seven valve types) (ICC 0.977, 95% CI 0.962-0.987). Dual-source cardiac CT accurately measured opening angles of normally functioning mechanical aortic valves, showing excellent agreement with manufacturers' values for seven valve types (ICC 0.977).