Aortic Valve Replacement With Mechanical Valves vs Perimount Bioprostheses in 50- to 69-Year-Old Patients

Mechanical heart valves between myths and new evidence: a systematic review and meta-analysis

AIMS

The use of mechanical valve prostheses in cardiac surgery remains a necessary and indicated intervention in a large number of patients. However, predicted results associated with their use, on which current guideline recommendations have been developed, are based on dated studies at risk of bias (e.g. use of old generation models, very high international normalized ratio regimes).

METHODS

A comprehensive search in multiple electronic databases was conducted from January 1995 to January 2024 using predefined criteria. The primary outcomes included all-cause death, bleeding events and thromboembolic events (i.e. stroke) at follow-up.

RESULTS

Overall, 38 studies were included in the meta-analysis. Cumulative meta-analysis results for mortality, thromboembolic events and bleeding events were initially extremely variable and tended to become more consistent over time. A meta-regression for the impact of age and sex on mortality showed no difference, whereas a meta-regression for the impact of age and sex on thromboembolic events and on bleeding events showed a higher risk in the elderly and in female patients, respectively.

CONCLUSION

The lack of fundamental information on the type of anticoagulant treatment (e.g. dosage, monitoring method) in the studies published to date does not allow us to draw any definitive conclusions on the outcomes of mechanical valve prostheses. The most recent studies have provided more consistent results, which in the past were highly variable, probably due to overcoming the bias in the use of prosthetic models of different generations.

Medium-term survival of patients with mechanical and biological aortic prosthesis at the 6th decade of life

OBJECTIVE

The best aortic prosthesis type in 60-70 year old patients is not established. Our aim was to evaluate the survival in a National cohort of patients between 60-70 years old who required surgical aortic valve replacement for aortic stenosis (SAVR) with either a mechanical (MP) or bioprosthesis (BP) valve.

METHODS

This is a retrospective study using national data from the Ministry of Health. We included all patients between 60 to 70 years old who underwent SAVR for aortic stenosis in Uruguay from 2011 to 2021. The primary outcome was overall survival according to type of prosthesis used stratified by effect modifiers. The independent effects of gender and use of statins were evaluated.

RESULTS

We included 1196 patients (66±3.0 years old; 39.1% female). Mortality was higher for BP (296, 29.9%%) than MP (36, 17.1%; p<0.001). Median follow-up time was 4.5 years (Interquartile range [IQR] 3.4-6.5). The unadjusted incidence rate ratio was higher for BP (Incidence rate ratio [IRR] = 1.43;95%CI: 0.99, 2.14, p = 0.045). The effect of BP on mortality rate was greater in males (IRR = 1.82;95%CI:1.14,2.92. p interaction = 0.08) and patients who were not taking statins (IRR = 1.97;95%CI:1.14,3.41. p interaction = 0.06). The use of BP was an independent predictor of overall survival in male patients (Hazard ratio [HR] = 1.32;95%CI: 1.68, 1.04. p = 0.021) and in patients who were not taking statins (HR = 2.07;95%CI: 1.17, 3.67. p = 0.013).

CONCLUSION

The use of BP was associated with worse survival in male patients and patients not taking statins. Gender and statins use should contribute to type of prosthesis decision in the 60-69 age group.

Decision-Making Approach to the Treatment of Young and Low-Risk Patients With Aortic Stenosis

Over a decade of randomized controlled trial data demonstrate excellent outcomes with transcatheter aortic valve replacement or surgical aortic valve replacement for patients with symptomatic severe aortic stenosis regardless of surgical risk. The 2020 American College of Cardiology/American Heart Association guidelines recommend both options for low-risk AS patients aged 65 to 80 years. However, the fastest growing population of patients receiving transcatheter aortic valve replacement in the United States is <65 years old, with little data to support the practice. The American College of Cardiology's Cardiac Surgery Team Section Leadership and Interventional Cardiology Councils, a multidisciplinary collaboration of cardiologists and cardiac surgeons, sought to summarize the relevant data into a decision-making tool for heart valve teams. A literature review was completed, and guidelines, randomized controlled trials, and large observational studies were summarized into a pragmatic decision-making approach to treating young and low-risk patients with AS.

Mechanical or biological prosthesis for aortic valve replacement in patients aged 45 to 74 years

OBJECTIVE

The selection of valve prostheses for patients undergoing surgical aortic valve replacement remains controversial. In this study, we compared the long-term outcomes of patients undergoing aortic valve replacement with biological or mechanical aortic valve prostheses.

METHODS

We evaluated late results among 5762 patients aged 45 to 74 years who underwent biological or mechanical aortic valve replacement with or without concomitant coronary artery bypass from 1989 to 2019 at 4 medical centers. The Cox proportional hazards model was used to compare late survival; the age-dependent effect of prosthesis type on long-term survival was evaluated by an interaction term between age and prosthesis type. Incidences of stroke, major bleeding, and reoperation on the aortic valve after the index procedure were compared between prosthesis groups.

RESULTS

Overall, 61% (n = 3508) of patients received a bioprosthesis. The 30-day mortality rate was 1.7% (n = 58) in the bioprosthesis group and 1.5% (n = 34) in the mechanical group (P = .75). During a mean follow-up of 9.0 years, the adjusted risk of mortality was higher in the bioprosthesis group (hazard ratio, 1.30, P < .001). The long-term survival benefit associated with mechanical prosthesis persisted until 70 years of age. Bioprosthesis (vs mechanical prosthesis) was associated with a similar risk of stroke (P = .20), lower risk of major bleeding (P < .001), and higher risk of reoperation (P < .001).

CONCLUSIONS

Compared with bioprostheses, mechanical aortic valves are associated with a lower adjusted risk of long-term mortality in patients aged 70 years or less. Patients aged less than 70 years undergoing surgical aortic valve replacement should be informed of the potential survival benefit of mechanical valve substitutes.

Commentary: The Never-Ending Debate on the Type of Aortic Prosthesis in Patients Aged 50-70, as TAVR Peaks in Popularity: Which Prosthesis Should Be Used for Aortic Valve Replacement?

See Article page 242.

Aortic Valve Repair Results in Better 1-Year Survival Than Replacement: Results From German Aortic Valve Registry

BACKGROUND

Aortic valve (AV) repair is an evolving surgical strategy in the treatment of nonelderly adults with aortic regurgitation. We aimed to determine the 1-year outcome after AV repair vs surgical AV replacement (sAVR) using real-world data from the German Aortic Valve Registry.

METHODS

A total of 8076 aortic regurgitation patients (mean age, 59.1 ± 15.0 years; 76% men; mean The Society of Thoracic Surgeons score, 1.3 ± 1.1), who underwent AV surgical procedures between 2011 and 2015, were identified from German Aortic Valve Registry. The AV was repaired in 2327 patients (29%), and the remaining 5749 patients (71%) underwent sAVR. A weighted propensity score model, including the variables of age, sex, and The Society of Thoracic Surgeons score, was used to correct for baseline differences between AV repair and sAVR cohorts. The primary end point was 1-year survival after AV repair vs sAVR. Secondary end points were freedom from cardiac events and AV reinterventions.

RESULTS

Survival at 1 year was 97.7% (95% CI, 97.0%-98.5%) in the AV repair cohort vs 96.4% (95% CI, 95.9%-96.9%) in the propensity score-weighted sAVR cohort (log-rank P < .001). Cox regression revealed a significant advantage of AV repair vs sAVR (hazard ratio, 0.68; 95% CI, 0.51-0.90; P < .0001) on 1-year survival, which was independent of age. Cardiac event-free survival at 1 year was 85.7% (95% CI, 483.8%-87.7%) in the AV repair group vs 81.7% (95% CI, 80.7%-82.9%) in the sAVR group (log-rank P < .001). AV reintervention was required in 38 AV repair patients (1.6%) compared with 1.6% in the sAVR cohort (P = .59).

CONCLUSIONS

AV repair surgery, whenever intraoperatively feasible, is associated with a significantly better 1-year survival and 1-year cardiac event-free survival compared with sAVR.

Early and mid-term outcomes after aortic valve replacement using a novel tissue bioprosthesis: a systematic review

OBJECTIVES

While current data show a clear trend towards the use of bioprosthetic valves during aortic valve replacement (AVR), durability of bioprosthetic valves remains the most important concern. We conducted a 1st systematic review of all available evidence that analysed early and mid-term outcomes after AVR using the Inspiris RESILIA™ bioprosthesis.

METHODS

A systematic literature search was performed to identify all relevant studies evaluating early and mid-term outcomes after AVR using the Inspiris RESILIA bioprosthesis and including at least 20 patients with no restriction on the publication date. Subgroup meta-analysis was performed to compare Inspiris RESILIA and PERIMOUNT Magna Ease bioprosthesis and to pool the early postoperative mortality and stroke rates.

RESULTS

A total of 416 studies were identified, of which 15 studies met the eligibility criteria. The studies included a total of 3202 patients with an average follow-up of up to 5.3 years. The average age of patients across the studies was 52.2-75.1 years. Isolated AVR was performed in 39.0-86.4% of patients. In-hospital or 30-day postoperative mortality was 0-2.8%. At the mid-term follow-up, freedom from all-cause mortality was up to 85.4%. Among studies with mid-term follow-up, trace/mild paravalvular leak was detected in 0-3.0%, while major paravalvular leak was found only in up to 2.0% of patients. No statistically significant differences in terms of mortality (P = 0.98, odds ratio 1.02, 95% confidence interval 0.36-2.83) and stroke (P = 0.98, odds ratio 1.01, 95% confidence interval 0.38-2.73) between the Inspiris RESILIA bioprosthesis and PERIMOUNT Magna Ease bioprosthesis were observed in the subgroup meta-analysis.

CONCLUSIONS

Mid-term data on the safety and haemodynamic performance of the novel aortic bioprosthesis are encouraging. Further comparative studies with other bioprostheses and longer follow-up are still required to endorse durability and safety of the novel bioprosthesis.