LONG-TERM FOLLOW-UP AND DOBUTAMINE STRESS ECHOCARDIOGRAPHY OF 19-MM PROSTHETIC HEART-VALVES

Background: In patients with a small aortic root, the use of 19-mm val ve prostheses for valve replacement is controversial because of the sm all orifice area of these valves. Methods: To assess stress hemodynami cs in patients with 19-mm valve prostheses, to find predictors of unfa vorable hemodynamics, and to document the long-term follow-up, we exam ined 30 patients (age, 64 +/- 19 years; 27 women and 3 melt; follow-up , 38 +/- 50 months) clinically and with the use of dobutamine stress e chocardiography. A history was taken, and a physical examination was p erformed. At rest and during dobutamine stress, Doppler echocardiograp hy was performed. Results: At rest, transprosthetic gradients were mod erately elevated with mean and peak gradients of 15 +/- 7 and 32 +/- 1 4 mmHg, and effective orifice areas were small (0.91 +/- 0.31 cm(2)). Gradients rose markedly during stress (mean, 37 +/- 14 mmHg; peak, 83 +/-: 41 mmHg). Predictors of high transprosthetic gradients were large r body surface area, younger age, and valve type. Mean and peak gradie nts were Lower with St. Jude Medical Hemodynamic Plus valves than. wit h standard St. Jude Medical (P < 0.05) and other valves, and the effec tive orifice area was highest (1.07 +/- 0.29 cm(2); P < 0.05 versus st andard St. Jude Medical) in this valve model. Sixty percent of patient s developed significant dynamic subvalvular or intraventricular gradie nts (84 +/- 41 mmHg) during dobutamine stress. Conclusions: After aort ic valve replacement with 19-mm prostheses in patients with a small ao rtic root, dobutamine stress leads to high transvalvular gradients, wh ich are dependent on, valve model, age, and body surface area. In addi tion, 60% of patients develop significant dynamic outflow obstructions . These findings and the persistence of some degree of exercise-induce d symptoms in 70% of patients suggest that alternative surgical techni ques should be considered if the size of the aortic annulus demands a 19-mm valve, especially if the patient seeks physical activity, is you ng, or is of larger body size.