The choice of valve protheses

Mitral Repair vs Replacement for Degenerative Mitral Regurgitation in Patients Aged ≥65 Years

BACKGROUND

The benefits of mitral valve repair vs replacement are well documented. However, survival benefits in the elderly population are more controversial. In this novel lifetime analysis, we hypothesize that survival benefits for valve repair vs replacement in the elderly are sustained throughout the patient's lifetime.

METHODS

From January 1985 through December 2005, 663 patients, aged ≥65 years with myxomatous degenerative mitral valve disease underwent primary isolated mitral valve repair (n = 434) or replacement (n = 229). Propensity score matching was used to balance variables potentially related to outcome.

RESULTS

Follow-up was complete in 99.1% of mitral repair and 99.6% of mitral replacement patients. In matched patients, perioperative mortality was 3.9% (9 of 229) for repair and 10.9% (25 of 229) for replacement (P = .004). Survival estimates (95% confidence limits) from 29-year follow-up for matched patients were 54.6% (48.0%, 61.1%) and 11.0% (6.8%, 15.2%) at 10 years and 20 years for repair patients, and 34.2% (27.7%, 40.7%) and 3.7% (1%, 6.4%) for replacement patients, respectively. Median survival (95% confidence limits) was 11.3 years (9.6, 12.2 years) for repair patients compared with 6.9 years (6.3, 8.0 years) for replacement patients (P < .001).

CONCLUSIONS

This study demonstrates that although the elderly population is prone to multiple comorbidities, survival benefits of isolated mitral valve repair vs replacement are sustained throughout the patient's lifetime.

Blood flow energy loss: a predictor for the recovery of left ventricular function after bioprosthetic aortic valve replacement

OBJECTIVES

It is difficult to estimate the improvement in left ventricular (LV) function after aortic valve replacement (AVR). The present study aimed to evaluate whether energy loss (EL) can predict the postoperative LV function after AVR.

METHODS

Nine patients who underwent AVR with a bioprosthetic valve were enrolled in the present study. Porcine prostheses were used in 5 patients and bovine pericardial prostheses were used in 4 patients. The aortic flow pattern was visualized and EL and cardiac output (CO) were measured using 4-dimensional flow magnetic resonance imaging from the LV to the descending aorta; the EL/CO ratio in the extracted area was calculated as total EL/CO ratio.

RESULTS

With a porcine valve, a severe helical flow was observed in the ascending aorta during the holosystolic phase. In contrast, with a bovine pericardial valve, straight transvalvular aortic flow was observed in the early systolic phase and 2 large vortical flows occurred on both sides of the greater and lesser curvature of the ascending aorta after the mid-systolic period. The total EL/CO ratio was strongly correlated with LV ejection fraction improvement after AVR (r = 0.74, P = 0.02).

CONCLUSIONS

The aortic flow pattern is different between the porcine valve and bovine pericardial valve. The total EL/CO ratio is a valuable tool for evaluating the postoperative LV ejection fraction improvement after AVR. Optimization of total EL/CO ratio would have potential to improve haemodynamic performances after AVR.

Experimental methods to preserve male fertility and treat male factor infertility

Infertility is a prevalent condition that has insidious impacts on the infertile individuals, their families, and society, which extend far beyond the inability to have a biological child. Lifestyle changes, fertility treatments, and assisted reproductive technology (ART) are available to help many infertile couples achieve their reproductive goals. All of these technologies require that the infertile individual is able to produce at least a small number of functional gametes (eggs or sperm). It is not possible for a person who does not produce gametes to have a biological child. This review focuses on the infertile man and describes several stem cell-based methods and gene therapy approaches that are in the research pipeline and may lead to new fertility treatment options for men with azoospermia.

Comparable long-term results for porcine and pericardial prostheses after isolated aortic valve replacement

OBJECTIVES

Outcome of aortic valve replacement may be influenced by the choice of bioprosthesis. Pericardial heart valves are described to have a favourable haemodynamic profile compared with porcine valves, although the clinical notability of this finding is still controversially debated. Herein, we compared the long-term results of two commonly implanted bioprosthesis at a single centre.

METHODS

All consecutive patients undergoing isolated aortic valve replacement with either a Carpentier-Edwards Magna pericardial prosthesis or a Medtronic Mosaic porcine prosthesis between 2002 and 2008 were analysed regarding preoperative characteristics, short- and long-term survival, valve-related complications and echocardiographic findings.

RESULTS

The Medtronic Mosaic was implanted in 163 patients and the Carpentier-Edwards Magna in 295 patients. The sizes of implanted valves were 22.4 ± 1.5 mm for the Mosaic and 21.8 ± 1.8 mm for the Magna (P = 0.001). The long-term survival rate was 76 and 56% after 5 and 10 years for the Medtronic Mosaic, which was comparable with the Carpentier-Edwards Magna (77 and 57%; P = 0.92). Overall long-term survival was comparable with an age- and sex-matched Austrian general population for both groups. Valve-related adverse events were similar between groups. The postoperative mean transvalvular gradient was significantly increased in the Mosaic group (24 ± 9 mmHg vs 17 ± 7 mmHg; P < 0.001).

CONCLUSIONS

Both types of aortic bioprostheses offer excellent results after isolated aortic valve replacement. Despite relevant differences in gradients, long-term survival was comparable with the expected normal survival for both bioprostheses. Patients with a porcine heart valve had a higher postoperative transvalvular gradient.

Is the degeneration of aortic valve bioprostheses similar to that of native aortic valves? Insights into valvular pathology

Aortic stenosis (AS) is the most common valvular disease requiring valve replacement with a prevalence of 2-4% in adults greater than or equal to 65 years of age. There is increasing evidence that AS is an active inflammatory process that is highly regulated, displaying multiple hallmarks of atherosclerosis. Clinically, the definite therapy of advanced AS is prosthetic valve replacement. Herein, bioprosthetic tissue valves (BPs) possess superior thromboresistant and hemodynamic properties compared with mechanical valves. However, cusp degeneration and calcification also limit their long-term outcome. The pathogenesis of BP calcification as well as that of native valves is still poorly understood. Recent studies suggest a similar valvular pathology, that underlies both types of valvular degeneration, but also an even more important role of inflammatory and repair processes in the case of BP degeneration.

Durability of pericardial versus porcine bioprosthetic heart valves

OBJECTIVES

To compare the probability, and modes, of explantation for Carpentier-Edwards pericardial versus porcine valves.

METHODS

Our porcine series began in 1974 and our pericardial series in 1991, with annual prospective follow-up. We used the Kaplan-Meier method and Cox regression for estimation and analysis of patient mortality, and the cumulative incidence function and competing risks regression for estimation and analysis of valve durability.

RESULTS

Through the end of 2010, we had implanted 506 porcine and 2449 pericardial aortic valves and 181 porcine and 163 pericardial mitral valves. The corresponding total and maximum follow-up years were 3471 and 24, 11,517 and 18, 864 and 22, and 645 and 9. The corresponding probabilities (cumulative incidence function) of any valve explant were 7%, 8%, 22%, and 8%, and of explant for structural valve deterioration were 4%, 5%, 16%, and 5% at 15 years for the first 3 series and at 8 years for the fourth (pericardial mitral valve) series. Using competing risks regression for structural valve deterioration explant, with age, gender, valve size, and concomitant coronary bypass surgery as covariates, a slight (subhazard ratio, 0.79), but nonsignificant, protective effect was found for the pericardial valve in the aortic position and a greater (subhazard ratio, 0.31) and almost significant (P = .08) protective effect of the pericardial valve in the mitral position. Leaflet tear was responsible for 61% of the structural valve deterioration explants in the porcine series and 46% in the pericardial series.

CONCLUSIONS

Using competing risks regression, the pericardial valve had a subhazard ratio for structural valve deterioration explant of less than 1 in both positions, approaching statistical significance in the mitral position. The mode of structural valve deterioration was predominantly leaflet tear for porcine valves and fibrosis/calcification for pericardial valves.

Fifteen-year results with the Hancock II valve: A multicenter experience

OBJECTIVES

The purpose of this multi-institutional study was to review the 15-year outcome of patients who received isolated aortic or mitral valve replacement with the Hancock II bioprosthesis.

METHODS

From 1983 through 2002, 1274 patients underwent 1293 isolated valve replacements, 809 aortic valve replacements and 484 mitral valve replacements, at hospitals in the Venetian area (Padova, Treviso, and Venice). Mean age was 68 +/- 8 years in patients undergoing aortic valve replacement and 66 +/- 9 years in patients undergoing mitral valve replacement; 52% of patients undergoing aortic valve replacement and 63% of patients undergoing mitral valve replacement were in New York Heart Association class III or greater. Coronary artery disease was present in 32% of patients who had undergone aortic valve replacement and 18% of patients who had undergone mitral valve replacement. Follow-up included 8520 patient-years, with a median of 12 years, and was 97% complete.

RESULTS

Overall 15-year survival was 39.7% +/- 2.4%, similar in both the aortic and mitral positions. Multivariable analysis of late survival showed the incremental risk of male sex, higher New York Heart Association class, coronary artery disease, and mitral position. Freedom from embolism was higher in the aortic position (81% +/- 2.9% in aortic vs 72% +/- 4.7% in mitral valve replacements). Freedom from endocarditis was similar in the aortic and mitral position (95% +/- 1.2% vs 94% +/- 1.7%). Freedom from reoperation (82% +/- 3.7% vs 71% +/- 5.0%) and from valve-related morbidity-mortality (52% +/- 3.6% vs 36% +/- 4.4%) was higher in patients who had undergone AVR. Actual freedom from structural valve deterioration for patients 60 years and older who had undergone aortic valve replacement was 96.5% +/- 1.3% versus 88% +/- 3.2% for patients who had undergone mitral valve replacement and 70% +/- 7.5% versus 77.5% +/- 5.3%, respectively, in younger patients. Multivariable Weibull analysis showed structural valve deterioration related to younger age and preoperative valve incompetence and inversely related to coronary artery disease.

CONCLUSION

Optimal 15-year durability can be expected in male patients 60 years and older who have undergone aortic valve replacement and in male patients 65 years and older who have undergone mitral valve replacement, extending safely the age limits for the use of this valve.

Flow-induced platelet activation in a St. Jude mechanical heart valve, a trileaflet polymeric heart valve, and a St. Jude tissue valve

Polymer heart valves have been under investigation since the 1960s, but their success has been hampered by an overall lack of durability mainly due to calcification of the leaflets and a relatively high rate of thromboembolic complications. A new polymer (Quatromer) trileaflet design was tested for its thrombogenic potential and was compared to that of existing prosthetic heart valves routinely implanted in patients: a St. Jude Medical bileaflet mechanical heart valve (MHV) and a St. Jude porcine bioprosthetic tissue valve. The valves were mounted in a left ventricular assist device and the procoagulant activity of the platelets was measured using a platelet activation state (PAS) assay. The PAS measurements indicated that the platelet activation level induced by the polymeric valve was very similar to that induced by the St. Jude Medical MHV and the St. Jude tissue valve. No significant difference was observed between the three valves, indicating that they have a comparable thrombogenic potential.

Cells of primarily extra-valvular origin in degenerative aortic valves and bioprostheses

AIMS

We assessed aortic valves from patients with non-rheumatic aortic valve stenosis (AS) and with degenerative aortic valve bioprostheses (BP) for the presence of progenitor cell and leukocyte subtype-specific markers.

METHODS AND RESULTS

Diseased valve probes from a total of 87 patients (60 AS and 27 BP) were studied. We assessed presence and localization of endothelial progenitor cells (EPCs: CD34, CD133), dendritic cells (DCs: S100), T-lymphocytes (CD3), and macrophages (CD68) by immunohistochemical and morphometric analyses. In the majority of valves, we detected cell-bound signals of CD34 (48% of AS, 74% of BP, respectively), CD133 (58%/81%), S100 (58%/93%), CD3 (62%/81%), and CD68 (78%/93%). Labelled cells were predominantly localized within the valvular fibrosa. As key results, frequency of EPCs, DCs, macrophages, and lymphocytes was found significantly higher in BP when compared with AS (CD34: 19.2+/-23.2 vs. 5.7+/-13.0%; CD133: 13.7+/-12.4 vs. 5.5+/-8.3%; S100: 15.2+/-12.2 vs. 5.7+/-8.9%; CD3: 3.3+/-2.7 vs. 1.1+/-1.4%; CD68: 35.3+/-26.6 vs. 3.4+/-4.1%; each P<or=0.001).

CONCLUSION

EPCs and DCs were detected in a large collective of degenerative aortic valves, more frequently in bioprostheses than in native cusps. Aortoluminal presence of these primarily extra-valvular cells co-localized with inflammatory cells is a novel key feature involved in aortic valve degeneration.