Regional Wall Motion Analysis by Dobutamine Stress Echocardiography in Heart Transplant Recipients with Normal Coronary Angiographic Findings: Comparison with Intravascular Ultrasound

Coronary angiography (ANGIO) is still the reference method for diagnosis of coronary allograft vasculopathy (CAV). To investigate, if normal ANGIO excludes CAV, 42 patients (P, 51 ± 7 yrs, 49 ± 22 months after heart transplantation) were studied prospectively by ANGIO, intravascular ultrasound (IVUS, quantitative analysis of degree and extension of intimal hyperplasia; modified Stanford grading, grades 1-6) and dobutamine stress echocardiography (DSE, 5-40 mcg/kg/min, 5 min stages). Regional wall motion abnormalities (WMA) were assessed qualitatively (2-D-echo, 16 segment model) and quantitatively (M-Mode, systolic wall thickening of septum (IVS) and LV posterior wall (LPW). P with allograft rejection (>grade 1 ISHLT) were excluded from analysis. ANGIO was completely normal in 33 P; these P were allocated according to mean IVUS grading (mean, 4.1 coronary segments per P): group1, mild-to-moderate intimal hyperplasi (mean grade <3.5), N = 20; group2, marked-to-severe intimal hyperplasi (mean IVUS grade ≥3.5), N = 13. No group1 P had WM at rest, 2/20 P developed WM during DSE (6/320 segments). In group2, WM at rest were found in 6/13P (26/208 segments). During DSE, WM increased in these 6P and newly developed in 6 P (total, WM in 12/13 group2 P in 72/208 segments during DSE). Mean systolic thickening of IVS (group2 vs. 1: rest, 23 vs. 33%, p < 0.01; max.DSE, 32 vs. 62%, p < 0.01) and LPW (rest, 38 vs. 58%, p < 0.01, max.DSE, 65 vs. 96%, p < 0.01) were signif. smaller in group2 than group1. In total, in 15/33 P with normal ANGIO, evidence of CAV was found (IVUS ≥ 3.5 and WM at DSE, N = 12; IVUS ≥ 3.5 only, N = 1; WM at DSE alone, N = 2). Conclusion: normal ANGIO does not rule out CAV. WM during DSE are associated with marked to severe intimal changes as assessed by IVUS. These changes appear to preceede ANGIO changes. Analysis of WM by DSE is feasible noninvasive method for early detection of CAV. Costly and invasive ANGIO, in particular when performed without IVUS, may be not necessary at regular annual intervals in heart transplant recipients with normal DSE findings.