Eight-year results of Freestyle stentless bioprosthesis in the aortic position: a single-center study of 500 patients.

BACKGROUND AND AIM OF THE STUDY: Stentless bioprostheses may be the future valve of choice for aortic valve replacement (AVR). The study aim was to investigate mid-term clinical outcome after AVR with the Medtronic Freestyle valve. METHODS: Between April 1997 and November 2004, a total of 500 patients (241 females, 259 males) was implanted with a Freestyle bioprosthesis for AVR, without population selection, by a single surgical team at the authors' institutions. Mean patient age was 74.5 +/- 9.6 years (range: 26-91 years); 34 patients (7%) were aged < 60 years, 121 (24%) were aged > 80 years, and 205 (41%) were in NYHA classes III or IV. The surgical procedure used included a modified subcoronary technique in 482 cases and complete root replacement in 18, conducted with mini-extracorporeal circulation. Concomitant procedures included coronary artery bypass grafting in 123 patients (25%), mitral valve repair/replacement in five, and maze in two. Follow up was 98% complete; the mean follow up was 31.3 months (range: 4-95 months). RESULTS: The mean cardiopulmonary bypass time was 98 +/- 26 min, and total aortic cross-clamp time 77 +/- 19 min. Operative mortality was 5.2% (n = 26), and no patients aged under 60 years died. At eight years, freedom from structural valve deterioration was 100% (0% in the young population), freedom from endocarditis 97.2%, freedom from reoperation 97%, and overall survival 83%. Most of the late deaths (n = 56) were of non-cardiac origin, and occurred in older patients. After one year, the mean aortic echocardiographic gradient was 11.5 +/- 1.1 mmHg, and was improved compared to that at discharge. No significant aortic insufficiency occurred. CONCLUSION: Use of the Freestyle stentless bioprosthesis for AVR resulted in excellent short-term survival in the octogenarian population, and excellent mid-term results in the younger population. In time, experience will indicate whether the Freestyle should be considered as the bioprosthesis of choice for patients of all ages.

Echocardiographic Doppler assessment of pulmonary capillary wedge pressure in surgical patients with postoperative circulatory shock and acute lung injury.

BACKGROUND: In cardiac patients, pulmonary capillary wedge pressure (PCWP) is estimated using color M-mode Doppler study of left ventricular filling and Doppler tissue imaging. The goal of this study was to assess whether echocardiography accurately estimates PCWP in critically ill patients. METHODS: Sixty ventilated patients admitted for septic shock and acute lung injury were prospectively studied using simultaneously transesophageal echocardiography and pulmonary artery catheterization. Initial PCWP values and their changes measured invasively were compared to initial values and corresponding changes of early diastolic velocity of mitral annulus displacement measured by Doppler tissue imaging (Ea), flow propagation velocity of early diastolic mitral inflow measured by color M-mode Doppler (Vp), and their respective ratio to early mitral inflow velocity (E) measured by conventional Doppler: E/Ea and E/Vp. Relations between E/Ea, E/Vp, and PCWP were prospectively tested in 20 additional patients. RESULTS: E/Ea and E/Vp gave a rough estimate of initial PCWP values with mean biases of 0.4 +/- 2.2 and 0.1 +/- 2.9 mmHg, respectively. Receiving operating characteristic curves demonstrated that an E/Ea of 6 or greater is an accurate predictor of a PCWP of 13 mmHg or greater and that an E/Ea of 5.4 is a good predictor of a PCWP of 8 mmHg or less. Changes in PCWP were significantly correlated to changes in E/Ea (Rho = 0.84, P < 0.0001). CONCLUSIONS: In patients with postoperative circulatory shock and acute lung injury, transesophageal echocardiography estimates noninvasively PCWP. However, echocardiographic estimation of PCWP may not be accurate enough for adjusting therapy.