Usefulness of the Cryolife O'Brien stentless suprannular aortic valve to prevent prosthesis-patient mismatch in the small aortic root

Replacement of the st jude medical regent valve in the aortic position with a continuous suture technique in the small aortic root

BACKGROUND

The aim of this study is to review the strategy of performing aortic valve replacement (AVR) by using the St. Jude Medical (SJM) Regent valve with a continuous suture technique in patients with a small aortic root.

METHODS

Forty-six patients with small aortic annulus underwent AVR by using 19 or 21 mm SJM Regent valves. There were 15 males and 31 females. The mean age of the patients was 51.8 ± 12.4 years. The aortic annular diameter was 20.2 ± 0.9 mm. AVR procedures were performed with continuous suture technique using SJM Regent valves under standard cardiopulmonary bypass. Echocardiaographic data were collected before operation, at discharge, and at a follow-up time, respectively.

RESULTS

The intraoperative course was uneventful and there was no operative mortality. The implanted SJM Regent valves consisted of 21 mm valves in 15 patients and 19 mm valves in 31 patients. Echocardiography at 5.6 ± 1.3 months after operation showed a significant increase in the mean effective orifice area index (0.97 ± 0.24 cm(2) /m(2) ), decrease in the mean and peak transvavluar pressure gradient (12.5 ± 5.9 and 22.3 ± 9.6 mmHg), and decrease in the mean left ventricular mass index (106 ± 41.3 g/m(2) ). Moderate prosthesis-patient mismatch (PPM) (effective orifice area index between 0.65 and 0.85 cm(2) /m(2) ) was present in three patients and no severe PPM (effective orifice area index <0.65 cm(2) /m(2) ) occurred at discharge and during follow-up.

CONCLUSION

Replacement of SJM Regent valve with a continuous suture technique maybe a good option to prevent PPM in the aortic position.

Obesity and the risk of late mortality after aortic valve replacement with small prosthesis

BACKGROUND

Whether obesity is related to late mortality with implantation of small aortic prosthesis remains to be clarified. This study was aimed to evaluate the effect of obesity on late survival of patients after aortic valve replacement (AVR) with implantation of small aortic prosthesis (size ≤ 21 mm).

METHODS

From January 1998 to December 2008, 307 patients in our institution who underwent primary AVR with smaller prostheses survived the 30 days after surgery. Patients were defined as normal if body mass index (BMI) was < 24 kg/m2, as overweight if BMI 24-27.9 kg/m2, and as obese if BMI ≥ 28 kg/m2. Data of New York Heart Association (NYHA) functional classification, left ventricular ejection fraction (LVEF), effective orifice area index (EOAI), and left ventricular mass index (LVMI) of the patients collected at the 3rd month (M), 6th M, 1st year (Y), 3rd Y, 5th Y, 8th Y after operation respectively.

RESULTS

By multivariable analysis, obesity was an independent factor of late mortality (hazard ratio [HR]: 1.62; P = 0.01). The obesity and overweight group had more poor survival (p < 0.001) and higher proportion of NYHA class III/IV (p < 0.01) compared with the normal group. Lower EOAI and higher LVMI were found in obesity and overweight group, but we saw no significant difference about LVEF among the three groups.

CONCLUSIONS

Obesity was associated with increased late mortality of patients after AVR with implantation of small aortic prosthesis. Being obese or and overweight may also affect the NYHA classification, even in the longer term. EOAI should be improved where possible, as it may reduce late mortality and improve quality of life in obese or overweight patients.

Limited long-term durability of the Cryolife O'Brien stentless porcine xenograft valve

BACKGROUND

Despite the fact that early and midterm hemodynamic and clinical results of the Cryolife O'Brien (CLOB) stentless valve have been reported to be favorable, the long-term durability and clinical results of this valve are largely unknown. Accordingly, we analyzed 10-year outcomes after aortic valve replacement with this valve.

METHODS AND RESULTS

From January 1994 to September 2004, 185 patients (67, 73, and 75 years, 25th, 50th, and 75th quartiles, respectively; 38% older than 75 years; 56% females) underwent aortic valve replacement with the CLOB valve. Sixty-eight percent of patients were in NYHA class 3 to 4. Standard EuroSCORE was 7.1+/-2.7. Pure aortic stenosis accounted for 42% (n=79), and pure insufficiency for 12% of cases (n=22). Concomitant surgery: 28% coronary artery bypass (n=51), 11% mitral valve replacement/annuloplasty (n=21), and 2% ascending aorta replacement (n=3). Sixty-one percent of patients received a 23-mm valve or smaller size. Follow-up was 100% completed, and cumulative follow-up was 65 months/patient. The 30-day mortality was 5.4% (none were valve related). Actuarial survival at 5 and 10 years were 68% and 40%, respectively. Actuarial freedom from structural valve deterioration was 91% at 5 years and dropped to 44% at 10 years. Actuarial freedom from reoperation was 94% at 5 years and declined to 57% at 10 years.

CONCLUSIONS

In a population with a high prevalence of elderly females with small aortic root, the CLOB valve demonstrated satisfactory clinical results till 8-years. Afterward, a significant increase in hazard for structural valve deterioration and reoperation occurred in late follow-up.

A randomized comparison of the Cryolife O'Brien and Toronto stentless replacement aortic valves

OBJECTIVE

A composite stentless valve might be less obstructive than a preparation incorporating the porcine right coronary muscle bar. The aim of this study was to compare early hemodynamic function in a prospective series of 78 patients randomized to receive either a Toronto or Cryolife O'Brien stentless valve.

METHODS

Echocardiography was performed early after surgery, between 3 and 6 months, and at 1 year after surgery.

RESULTS

The groups were matched demographically. The Cryolife O'Brien valve was significantly less obstructive in terms of effective orifice area (1.81 vs 1.30 cm2; P < .0001), mean pressure difference (7.1 vs 11.7 mm Hg; P < .0001), and peak velocity (1.7 vs 2.2 m/s) assessed at 1 year (P = .001). Bypass time was 91 (SD 22) minutes for the Cryolife O'Brien compared with 125 (SD 22) minutes (P < .0001) for the Toronto. There was a higher incidence of paraprosthetic regurgitation in the Cryolife O'Brien valve (16.7% vs 3.2%). Mortality and clinical events were similar.

CONCLUSION

The composite valve was less obstructive than the porcine valve, suggesting that stentless valves cannot be considered as a homogeneous class.

Stentless valves for aortic valve replacement: where do we stand?

PURPOSE OF REVIEW

Following more than a decade's experience with stentless valves and the development of better profiled stented valves, the article discusses the advantages of stentless valves regarding hemodynamic performance, left ventricular mass regression, durability and survival.

RECENT FINDINGS

Recent studies show that stentless valves remain hemodynamically superior compared with modern porcine stented valves. This superiority is, however, rarely reported in comparison with modern pericardial stented valves. In general, patient-prosthesis mismatch is less frequent in stentless vs. stented valves. Recent randomized trials comparing stentless valves and modern stented valves show equivalent left ventricular mass regression at 1 year. At 10 years, stentless valve durability is excellent and comparable with that of stented valves. Recent comparative studies do not confirm the previously reported midterm survival advantages of stentless valves.

SUMMARY

Improvement of stented valves has significantly reduced the hemodynamic differences between them and their stentless counterpart. Patients with small aortic annulus, however, should benefit from a stentless valve due to the better expected gradients and lower risk of patient-prosthesis mismatch. Midterm results suggest equivalent durability and survival for both prosthesis types but additional and longer-term trials are necessary to confirm these results.

Clinical and hemodynamic implications of supra-annular implant of biological aortic valves

The use of stented bioprostheses in elderly patients with degenerative aortic stenosis, despite being desirable, raises concerns about the harmful effects of residual obstruction to left ventricular outflow. To overcome this limitation new stented and stentless bioprostheses have been designed for supra-annular implant. However, the actual hemodynamic advantage of supra-annular implant over the intra-annular one remains incompletely understood. This review focuses on the geometry of biological valve prostheses designed for supra-annular implant and its implications for the echocardiographic assessment of valve hemodynamics. Available data about the hemodynamic performance of these valves implanted in the supra-annular position in comparison with the usual intra-annular implant are also reviewed. Other issues related to biological heart valve performance, such as biomaterials, tissue mechanics, durability, and clinical outcome are not addressed in this review.

Impact of Prosthesis-Patient Mismatch on Cardiac Events and Midterm Mortality After Aortic Valve Replacement in Patients With Pure Aortic Stenosis

Background— Prosthesis-patient mismatch (PPM) occurs when the effective orifice area (EOA) of the prosthesis being implanted is too small in relation to body size, thus causing abnormally high transvalvular pressure gradients. The objective of this study was to examine the midterm impact of PPM on overall mortality and cardiac events after aortic valve replacement in patients with pure aortic stenosis.

Methods and Results— The indexed EOA (EOAi) was estimated for each type and size of prosthesis being implanted in 315 consecutive patients with pure aortic stenosis. PPM was defined as an EOAi ≤0.80 cm 2 /m 2 and was correlated with overall mortality and cardiac events. PPM was present in 47% of patients. The 5-year overall survival and cardiac event-free survival were 82±3% and 75±4%, respectively, in patients with PPM compared with 93±3% and 87±4% in patients with no PPM ( P ≤0.01). In multivariate analysis, PPM was associated with a 4.2-fold (95% CI, 1.6 to 11.3) increase in the risk of overall mortality and 3.2-fold (95% CI, 1.5 to 6.8) increase in the risk of cardiac events. The other independent risk factors were history of heart failure, NHYA class III-IV, severe left ventricular hypertrophy, and absence of normal sinus rhythm before operation.

Conclusions— PPM is an independent predictor of cardiac events and midterm mortality in patients with pure aortic stenosis undergoing aortic valve replacement. As opposed to other risk factors, PPM may be avoided or its severity may be reduced with the use of a preventive strategy at the time of operation.