CMR feature tracking in Kawasaki Disease convalescence

Abstract

Objective: To determine whether left ventricular (LV) myocardial deformation indices can detect subclinical myocardial abnormalities in Kawasaki Disease (KD) convalescence. We hypothesized that subclinical myocardial abnormalities due to inflammation represent an early manifestation of the disease that persist in convalescence. Background: Myocardial inflammation has been described as a global finding in the acute phase of Kawasaki Disease. Despite normal LV systolic function by routine functional measurements, reduced longitudinal strain (S) and strain rate (SR) have been detected by echocardiography in the acute phase, which may potentially predict late onset heart failure. Method and results: Peak systolic LV myocardial longitudinal, radial and circumferential S and SR were examined in 29 KD convalescent patients (15 males; mean (SD) age 11 (6.6) years, range 3- 27 years; median interval from KD onset 5.8 (5.4) years) and 10 healthy volunteers (5 males; mean age 14 (3.8) years, range 6-19 years) with the use of cardiac magnetic resonance feature tracking (CMR-FT). Routine indices of LV systolic function were normal in both groups. Comparisons were made between normal controls and (i) the entire KD group, (ii) KD group subdivided by coronary artery involvement. Compared to controls, KD patients had lower longitudinal S. Average longitudinal and circumferential S at all levels was lower in KD patients compared normal controls. In subgroup analysis, both KD patients with and without any history of CAD had similar longitudinal and circumferential S at all levels and lower when compared against controls. There was a non-significant trend for lower circumferential and longitudinal values in KD patients with persisting CAD when compared against those with regressed CAD. Conclusion: In this CMR-FT study in KD convalescent patients with preserved conventional functional indices, we observed a trend for lower circumferential and longitudinal strain in KD patients compared to normal controls, irrespective of their coronary artery status.