Late haemodynamic performance and survival after aortic valve replacement with the Mosaic bioprosthesis

Prosthesis-Patient Mismatch after Aortic Valve Replacement with the Mosaic Ultra Bioprosthesis

BACKGROUND

 Several studies have reported high rates of prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR) with the Mosaic prosthesis. This work assesses the incidence of PPM after AVR with a modified version of the Mosaic prosthesis, the Mosaic Ultra.

METHODS

 We performed a retrospective analysis of the data of 532 patients who underwent AVR with implantation of the Mosaic Ultra prosthesis in the period 2007-2016 in our institution. Patients were classified according to their indexed effective orifice area (EOAi) to severe (EOAi < 0.65 cm2/m2), moderate (EOAi 0.65-0.85 cm2/m2), and absent/mild PPM (EOAi > 0.85 cm2/m2). In-hospital postoperative outcomes and the impact of PPM on mean transvalvular pressure gradient after stratification by prosthesis size were assessed.

RESULTS

 Overall, 3 (0.6%) patients had severe, 92 (17.3%) moderate, and 437 (82.1%) absent/mild PPM. There was a significant difference in PPM proportions (moderate/severe vs absent/mild PPM) across different prosthesis sizes overall (p < 0.0001), observing gradually increasing rates of PPM with decreasing prosthesis sizes. Patients with moderate/severe PPM had higher mean transvalvular pressure gradients (19 [13-25] vs 13 [10-17] mm Hg, p < 0.0001) than patients with absent/mild PPM. There was a significant difference in mean transvalvular pressure gradient between the different aortic valve prosthesis sizes overall (p < 0.0001), observing gradually increasing gradients with decreasing prosthesis sizes.

CONCLUSION

 Patients undergoing AVR with the smaller sized (19, 21, and 23 mm) Mosaic Ultra aortic valve prostheses exhibit a higher risk for moderate/severe PPM and higher mean aortic transvalvular pressure gradients than patients receiving the larger sized (25, 27, and 29 mm) prostheses.

Bioprosthetic aortic valve replacement in elderly patients: Meta-analysis and microsimulation

OBJECTIVE

To support decision-making in aortic valve replacement (AVR) in elderly patients, we provide a comprehensive overview of outcome after AVR with bioprostheses.

METHODS

A systematic review was conducted of studies reporting clinical outcome after AVR with bioprostheses in elderly patients (mean age ≥70 years; minimum age ≥65 years) published between January 1, 2000, to September 1, 2016. Reported event rates and time-to-event data were pooled and entered into a microsimulation model to calculate life expectancy and lifetime event risks.

RESULTS

Forty-two studies reporting on 34 patient cohorts were included, encompassing a total of 12,842 patients with 55,437 patient-years of follow-up (pooled mean follow-up 5.0 ± 3.3 years). Pooled mean age was 76.5 ± 5.5 years. Pooled early mortality risk was 5.42% (95% confidence interval [CI], 4.49-6.55), thromboembolism rate was 1.83%/year (95% CI, 1.28-3.61), and bleeding rate was 0.75%/year (95% CI, 0.50-1.11). Structural valve deterioration (SVD) was based on pooled time to SVD data (Gompertz; shape: 0.124, rate: 0.003). For a 75-year-old patient, this translated to an estimated life expectancy of 9.8 years (general population: 10.2 years) and lifetime risks of bleeding of 7%, thromboembolism of 17%, and reintervention of 9%.

CONCLUSIONS

The low risks of SVD and reintervention support the use of bioprostheses in elderly patients in need of AVR. The estimated life expectancy after AVR was comparable with the general population. The results of this study inform patients and clinicians about the expected outcomes after bioprosthetic AVR and thereby support treatment decision-making. Furthermore, our results can be used as a benchmark for long-term outcomes after transcatheter aortic valve implantation in patients who were eligible for surgery and other (future) alternative treatments (eg, tissue-engineered heart valves).

Complementary Role of the Computed Biomodelling through Finite Element Analysis and Computed Tomography for Diagnosis of Transcatheter Heart Valve Thrombosis

Introduction

The TAVR procedure is associated with a substantial risk of thrombosis. Current guidelines recommend catheter-based aortic valve implantation for prohibitive-high-risk patients with severe aortic valve stenosis but acknowledge that the aetiology and mechanism of thrombosis are unclear.

Methods

From 2015 to 2018, 607 patients with severe aortic valve stenosis underwent either self-expandable or balloon-expandable catheter-based aortic valve implantation at our institute. A complementary study was designed to support computed tomography as a predictor of complications using an advanced biomodelling process through finite element analysis (FEA). The primary evaluation of study was the thrombosis of the valve at 12 months.

Results

At 12 months, 546 patients had normal valvular function. 61 patients had THVT while 6 showed thrombosis and dislodgement with deterioration to NYHA Class IV requiring rehospitalization. The FEA biomodelling revealed a strong link between solid uncrushed calcifications, delayed dislodgement of TAVR and late thrombosis. We observed an interesting phenomenon of fibrosis/calcification originating at the level of the misplaced valve, which was the primary cause of coronary obstruction.

Conclusion

The use of cardiac CT and predictive biomodelling should be integrated into routine practice for the selection of TAVR candidates and as a predictor of negative outcomes given the lack of accurate investigations available. This would assist in effective decision-making and diagnosis especially in a high-risk cohort of patients.

Prognosis after surgical replacement with a bioprosthetic aortic valve in patients with severe symptomatic aortic stenosis: systematic review of observational studies

OBJECTIVE

 To determine the frequency of survival, stroke, atrial fibrillation, structural valve deterioration, and length of hospital stay after surgical replacement of an aortic valve (SAVR) with a bioprosthetic valve in patients with severe symptomatic aortic stenosis.

DESIGN

 Systematic review and meta-analysis of observational studies.

DATA SOURCES

 Medline, Embase, PubMed (non-Medline records only), Cochrane Database of Systematic Reviews, and Cochrane CENTRAL from 2002 to June 2016.

STUDY SELECTION

 Eligible observational studies followed patients after SAVR with a bioprosthetic valve for at least two years.

METHODS

 Reviewers, independently and in duplicate, evaluated study eligibility, extracted data, and assessed risk of bias for patient important outcomes. We used the GRADE system to quantify absolute effects and quality of evidence. Published survival curves provided data for survival and freedom from structural valve deterioration, and random effect models provided the framework for estimates of pooled incidence rates of stroke, atrial fibrillation, and length of hospital stay.

RESULTS

 In patients undergoing SAVR with a bioprosthetic valve, median survival was 16 years in those aged 65 or less, 12 years in those aged 65 to 75, seven years in those aged 75 to 85, and six years in those aged more than 85. The incidence rate of stroke was 0.25 per 100 patient years (95% confidence interval 0.06 to 0.54) and atrial fibrillation 2.90 per 100 patient years (1.78 to 4.79). Post-SAVR, freedom from structural valve deterioration was 94.0% at 10 years, 81.7% at 15 years, and 52% at 20 years, and mean length of hospital stay was 12 days (95% confidence interval 9 to 15).

CONCLUSION

 Patients with severe symptomatic aortic stenosis undergoing SAVR with a bioprosthetic valve can expect only slightly lower survival than those without aortic stenosis, and a low incidence of stroke and, up to 10 years, of structural valve deterioration. The rate of deterioration increases rapidly after 10 years, and particularly after 15 years.