Corrected QT Interval in Severe Aortic Stenosis: Clinical and Hemodynamic Correlates and Prognostic Impact.

BACKGROUND

The role of the electrocardiogram for risk stratification in patients with severe aortic stenosis is not established. We assessed the hemodynamic correlates and the prognostic value of the corrected QT interval (QTc) in patients with severe aortic stenosis undergoing aortic valve replacement.

METHODS

The QT interval was measured in a 12-lead electrocardiogram in 485 patients (age 74 ± 10 years, 57% male) with severe aortic stenosis (indexed aortic valve area 0.41 ± 0.13 cm/m, left ventricular ejection fraction 58 ± 12%) the day prior to cardiac catheterization. Prolonged QTc was defined as QTc >450 ms in men and QTc >470 ms in women. The outcome parameter was all-cause mortality.

RESULTS

Patients with prolonged QTc (n = 100; 77 men, 23 women) had similar indexed aortic valve area but larger left ventricular and left atrial size, lower left ventricular ejection fraction, more severe mitral regurgitation, lower cardiac index, and higher mean pulmonary artery pressure, mean pulmonary artery wedge pressure, and pulmonary vascular resistance, as compared with patients with normal QTc (n = 385). After a median follow-up of 3.7 years (interquartile range, 2.6-5.2) after surgical (n = 349) or transcatheter (n = 136) aortic valve replacement, patients with prolonged QTc had higher mortality than those with normal QTc (hazard ratio 2.81 [95% confidence interval, 1.51-5.20]; P < .001). Prolonged QTc was an independent predictor of death along with more severe mitral regurgitation and higher pulmonary vascular resistance.

CONCLUSIONS

In patients with severe aortic stenosis, prolonged QTc is a marker of an advanced disease stage associated with an adverse hemodynamic profile and increased long-term mortality after aortic valve replacement.