Intermediate-term outcomes after aortic valve replacement with a novel RESILIATM tissue bioprosthesis

Background

The durability of bioprosthetic heart valves is limited by structural valve deterioration (SVD) due to long-term calcification. A novel bioprosthetic tissue (RESILIA^TM) has been developed which, in preclinical studies, has shown reduced calcification. The purpose of this study was to evaluate the intermediate-term clinical outcomes and hemodynamic performance of this tissue.

Methods

A prospective, single-arm, observational trial was conducted in patients who required surgical aortic valve replacement (AVR). Between July 2011 and February 2013, 133 patients were implanted at two sites in Poland. Hemodynamic performance and clinical outcomes were assessed annually through 4 years of follow-up. All safety events were adjudicated by an independent Clinical Events Committee, and echocardiographic data were evaluated by a core laboratory.

Results

Patients were 65.3±13.5 years old and 26% were ≤60 years old. The average follow-up was 3.8±1.1 (median: 4.1; IQR, 4.0-4.3) years. Early (≤30 day) and late (>30 day) all-cause mortality rates were 2.3% (n=3) and 3.2% late patient-years (n=16), respectively. There were no cases of early or late SVD. There was one early case of major paravalvular leak (0.8%), and no late cases. At 4 years, the mean gradient was 14.5±7.4 mmHg and the effective orifice area was 1.6±0.4 cm², both markedly improved from baseline. At 4 years, the New York Heart Association functional class had improved from baseline in 54.5% of patients.

Conclusions

The aortic bioprosthesis with novel RESILIA^TM tissue demonstrated excellent hemodynamic performance and safety outcomes over 4 years. Longer follow-up will be important to confirm the durability of this bioprosthesis.

Bioprosthetic Heart Valves: Upgrading a 50-Year Old Technology

Prosthetic heart valves have been commonly used to address the increasing prevalence of valvular heart disease. The ideal prosthetic heart valve substitute should closely mimic the characteristics of a normal native heart valve. Despite the development of various interventions, an exemplary valve replacement does not exist. This review provides an overview of the novel engineering valve designs and explores emergent immunologic insights into age-dependent structural valve degeneration (SVD).

Aortic root enlargement to mitigate patient-prosthesis mismatch: do early adverse events justify reluctance?†

OBJECTIVES:

Concomitant aortic root enlargement (ARE) at the time of surgical aortic valve replacement can be performed to avoid patient-prosthesis mismatch, an important predictor of adverse long-term outcome.

METHODS:

We performed a single-centre, retrospective analysis of 4120 patients receiving isolated aortic valve replacement, of whom 171 (4%) had concomitant ARE between January 2005 and December 2015. The analysis of postoperative outcome and early mortality was performed. Owing to inequality of the groups, patients were matched 1:1.

RESULTS:

The mean age of all 4120 patients was 68.8 ± 10.5 years, and comorbidities were equally balanced after matching. The mean aortic cross-clamp time, cardiopulmonary bypass time and total operative time were prolonged by 19, 20 and 27 min in the ARE group, respectively. Early mortality was not statistically significantly different with 1.4% in the surgical aortic valve replacement and 1.8% in the ARE group. Postoperative complications were <5% in all matched 338 patients: bleeding (3% vs 3%), pericardial effusion (3.0% vs 4.2%), sternal instability (1.8% vs 0%) and sternal wound infection (3.0% vs 1.2%). A significant higher number of patients had respiratory failure after ARE (unmatched: 17.1% vs 9.9%, P < 0.001; matched: 18.3% vs 9.5%, P = 0.028). Factors independently associated with overall mortality were age [hazard ratio (HR) 1.71], chronic obstructive pulmonary disease (HR 1.47), diabetes (HR 1.82), atrial fibrillation (HR 2.14) and postoperative respiratory failure (HR 2.84).

CONCLUSIONS:

ARE can be performed safely in experienced centres with no significant increase in the risk of early postoperative surgical complications and early mortality. However, the surgeon and the intensive care unit team should be aware of an increased risk for postoperative respiratory failure in ARE patients.

Aggressive tissue aortic valve replacement in younger patients and the risk of re-replacement: Implications from microsimulation analysis

OBJECTIVE

Advances in transcatheter aortic valve replacement have led to the consideration of tissue aortic valve replacement in younger patients. Part of this enthusiasm is the presumption that younger patients would have more flexibility in future treatment options, such as a primary surgical aortic valve replacement followed later by transcatheter aortic valve replacement(s) (valve-in-valve), vice versa, or other permutations. We created a microsimulation model using published longevity of tissue valves to predict the outcomes of patients after primary tissue surgical aortic valve replacement.

METHODS

The model calculated survival by incorporating annual mortality (Social Security Administration) and mortality from re-replacements (Society of Thoracic Surgeons) in patients with surgical aortic valve replacement. Freedom from reoperation for structural valve degeneration incorporated best published data to determine the annual risk of re-replacement for structural valve degeneration based on implant duration and stratified by patient age. A constant rate of re-replacement for nonstructural valve degeneration indications was also incorporated. Each simulation was performed for 50,000 individuals. Kaplan-Meier curves were generated to represent survival. All simulations were run within the MATLAB environment (The MathWorks, Inc, Natick, Mass).

RESULTS

Earlier decades of life at primary surgical aortic valve replacement were associated with higher incidences of re-replacements and especially multiple re-replacements. For those patients receiving a primary tissue surgical aortic valve replacement at age 50 years, 57.2% will require a second valve, 18.0% will require a third valve, and 1.6% will require a fourth valve with average operative mortalities of 2.9%, 4.8%, and 7.3%, respectively. A 50-year-old patient at primary surgical aortic valve replacement has a 13.1% chance of re-replacement before turning 60 years of age.

CONCLUSIONS

Microsimulation incorporates changing hazards to estimate the risk of aortic valve re-replacement in patients undergoing tissue surgical aortic valve replacement and may be a starting point for patient education and health care economic planning.

Surgery for Young Adults With Aortic Valve Disease not Amenable to Repair

Aortic valve replacement is the gold standard for the management of patients with severe aortic stenosis or mixed pathology that is not amenable to repair according to currently available guidelines. Such a simplified approach may be suitable for many patients, but it is far from ideal for young adults considering emerging evidence demonstrating that conventional valve replacement in this cohort of patients is associated with inferior long-term survival when compared to the general population. Moreover; the utilisation of mechanical and bioprosthetic valves can significantly impact on quality and is linked to increased rates of morbidities. Other available options such as stentless valve, homografts, valve reconstruction and Ross operation can be an appealing alternative to conventional valve replacement. Young patients should be fully informed about all the options available - shared decision making is now part of modern informed consent. This can be achieved when referring physicians have a better understanding of the short and long term outcomes associated with every intervention, in terms of survival and quality of life. This review presents up to date evidence for available surgical options for young adults with aortic stenosis and mixed disease not amenable to repair.