Long-term Doppler echocardiographic follow up in normally functioning aortic St. Jude Medical prosthesis.

Background And Aims Of The Study: Mean and peak Doppler gradients remain the most frequently used parameters for follow up of prosthetic aortic valves. Gradients that deviate from baseline recordings can lead to uncertainty among physician and patient, especially if symptoms have not completely subsided after surgery, or have recurred. This study aimed to document long-term evolution of mean and peak gradients in patients with stationary clinical symptoms and signs.

Methods: Seventy-six patients (48 men, 28 women), of mean age 56.1 +/- 14.5 years (range: 23 to 82 years) who underwent St. Jude Medical bileaflet prosthesis implantation were followed up for a mean of 3.9 years (range: 1 to 7 years), both clinically and echocardiographically. Evolution of mean and peak gradients, left ventricular function, other valvular lesions and rhythm as well as adequacy of anticoagulation were examined.

Results: Mean gradient increased from 12.3 +/- 5.5 to 14 +/- 5.7 mmHg (p = 0.002). Mean gradient increased in 47 patients, decreased in 17 and was unchanged in 12. There was no correlation between left ventricular function, appropriate anticoagulation, left ventricular hypertrophy, age or gender with change in mean or peak gradient. Change in peak gradient correlated excellently (r2 = 0.82) with that in mean gradient.

Conclusions: The range of evolution of Doppler gradients in normally functioning St. Jude Medical prostheses has been defined in this study. Slight long-term increases in mean and peak pressure gradients are normal findings and do not warrant a change in management strategy if unaccompanied by deterioration of symptoms and/or clinical signs. Although we recommend routine determination of baseline flow measurements within three months of prosthesis implantation, mean and peak gradients are adequate follow up parameters. Peak gradient correlated well with mean gradient and may be a useful adjunct for follow up in clinical practice.