Defective recovery of QT dispersion following transcatheter aortic valve implantation: frequency, predictors and prognosis

Comparison of Cardiac Repolarization After Transcatheter Aortic Valve Implantation and Surgical Aortic Valve Replacement: A Longitudinal Study

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) has been established as an alternative to surgical aortic valve replacement (SAVR) for high-risk patients. To assess the impact of TAVI on cardiac repolarization, we compared QT dispersion (QTD) and the interval from the peak to the end of the T wave (Tpeak-Tend: TpTe) between the patients who underwent TAVI and those who underwent SAVR and TpTe between the patients who underwent TAVI or SAVR.

METHODS

This retrospective study was approved by the ethics committee of Dokkyo Medical University Hospital. The study included 45 patients who underwent TAVI and 45 patients who underwent SAVR. The QT, corrected QT (QTc), QTD, QTc dispersion (QTcD), Tp-Te, Tp-Te/QT, and Tp-Te/QTc were manually measured in standard 12-lead electrocardiogram (ECG) recordings obtained before surgery, immediately after surgery, 1 month, 3 months, and 6 months after surgery and compared between the two groups.

RESULTS

No change was observed in RR, QT, QTc, Tp-Te, Tp-Te/QT, and Tp-Te/QTc in the two groups throughout the study. The QTD and QTcD significant decreased immediately after surgery in the TAVI group as compared to the SAVR group (P < 0.001). In contrast, QTD and QTcD in the SAVR group gradually, but not significantly declined 6 months after surgery.

CONCLUSIONS

QTD and QTcD immediately decreased after TAVI as compared to SAVR. Our findings indicate that TAVI more rapidly improved dispersion of spatial repolarization than SAVR.

The effect of transcatheter aortic valve implantation on Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, and Tp-e dispersion in patients with severe aortic stenosis

Background

In this study, we aimed to investigate the effect of transcatheter aortic valve implantation using two types of bioprosthetic valves on novel ventricular repolarization markers including Tp-e, Tp-e/QT and Tpe/QTc ratios, and Tp-ed.

Methods

A total of 61 patients (17 males, 44 females; mean age 78.6±6.5 years; range 55 to 89 years) who underwent transcatheter aortic valve implantation with either a Medtronic CoreValve (n=40) or an Edwards SAPIEN XT valve (n=21) were retrospectively analyzed. The electrocardiographic parameters and left ventricular mass index were calculated prior to the procedure, on postoperative Day 1, and at three months after the procedure.

Results

The Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, Tp-ed, and left ventricular mass index significantly reduced at three months of the procedure, compared to baseline values (p<0.01, for all). Similar findings were observed for QT, QTc, and QT dispersion (p<0.01, for all). These changes were independent from the types of bioprosthetic valves used. Before the procedure, the left ventricular mass index was positively correlated with the Tp-e (r=0.350, p=0.007), Tp-e/QT (r=0.314, p=0.015) and Tp-e/QTc ratios (r=0.285, p=0.029). In the multivariate analysis, Tp-e interval was found to be independently associated with the left ventricular mass index (b=0.350, p=0.007).

Conclusion

In the present study, the Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, Tp-ed, and left ventricular mass index significantly reduced at three months after transcatheter aortic valve implantation indicating reverse left ventricular remodeling. The effects of two types of bioprosthetic valves on ventricular repolarization markers and left ventricular mass index were similar.