QT dispersion at rest and during adenosine stress myocardial perfusion imaging correlation with Myocardial Jeopardy...

The usefulness of QT dispersion (QTd) during adenosine myocardial perfusion imaging (MPI) to predict severity of coronary artery disease (CAD) has not been studied.

Eighty-eight patients referred for diagnostic cardiac catheterization after abnormal MPI were included. Thirty-four patients with no stenosis (Duke Score = 0) were included in Group 1, and 54 patients with significant CAD (Duke Score > or = 2) formed Group 2. Resting and stress QTd and prolongation in QTd (delta QTd) were measured and evaluated as independent predictors for severity of CAD.

Resting QTd was higher in Group 2 as compared with Group 1. During peak infusion of adenosine, QTd was significantly prolonged in Group 1 but remained unchanged, or fixed, in Group 2. In addition, in patients with significant CAD, resting QTd positively correlated with the Duke Score. On multiple regression analysis; independent predictors for significant CAD (odds ratio [OR], 95% confidence interval [CI], p-value) were resting QTd (4.9, 95% CI 1.1-21.6, < 0.05 for fourth Quartile compared with first Quartile) and delta QTd (4.0, 1.4-11.2, < 0.01 for first and second Quartiles compared with third and fourth Quartiles).

In patients with abnormal stress MPI, prolonged resting QTd, and fixation of QTd during stress are independent predictors of significant CAD. In addition, resting QTd correlate with the Duke Jeopardy Score and therefore, may have independent prognostic value.