Transthoracic echo-Doppler assessment of coronary microvascular function late after Kawasaki disease.

The goal of this study was to demonstrate that Doppler transthoracic echocardiography (TTE) may represent a valuable tool for the noninvasive demonstration of coronary microvascular dysfunction in children with previous Kawasaki disease (KD) by the measurement of coronary flow reserve (CFR) during cold pressor test (CPT). Twenty-five children with previous KD (mean follow-up, 4.6 +/- 2.6 years) were included in the study-16 with no evidence of coronary artery lesions (CALs(-)) by TTE and 9 with coronary aneurysms (CALs(+)). Seventeen age-matched healthy subjects were also recruited. Diastolic peak velocity was measured by pulsed Doppler both at rest (DPV(Rest)) and during CPT (DPV(CPT)) in the anterior descending artery. CFR was calculated as DPV(CPT)/DPV(Rest). KD patients demonstrated significantly higher values of DPV(Rest) (0.21 +/- 0.05 vs 0.13 +/- 0.01 cm/sec, p < 0.0001) and DPV(CPT) (0.33 +/- 0.07 vs 0.27 +/- 0.03 cm/sec, p < 0.005). CFR was reduced in KD compared to control subjects (1.5 +/- 0.4 vs 2.1 +/- 0.2, p < 0.0001). CFR was decreased in a similar manner in both CALs(+) patients (1.4 +/- 0.4, p = 0.002 vs controls) and CALs(-) patients (1.6 +/- 0.4, p < 0.0001 vs controls). Doppler TTE at rest and during CPT may represent a valuable modality for CFR evaluation in children with a history of KD. CFR is significantly reduced in KD patients independently of the presence of CALs.