DISCUSSION
This is the first prospective evaluation of the Magna Ease bioprosthesis
for surgical AVR. These results demonstrate good safety and
effectiveness, with functional and hemodynamic outcomes that remain
consistent over the 8‑year follow‑up.
Survival
Kaplan–Meier analyses showed freedom from all‑cause and valve‑related
mortality at 8 years were 80.7% (95% CI 74.9, 86.4) and 95.8% (95%
CI 92.8, 98.8), respectively. A recent retrospective study of AVR with
the Magna Ease valve, with a median follow-up of 4.5 years, revealed
overall survival at 12 years of 54% (95% CI 47.8, 62), albeit with
limited numbers of patients. [13] Another retrospective,
single-center study of the Magna Ease valve in 1,126 consecutive
patients reported 78.2% survival probability at 9 years.[11]
Studies of the Trifecta valve (Abbott Laboratories, IL, US) have shown
comparable midterm all-cause and valve‑related mortality.[14-16] The
Freestyle valve (Medtronic, Dublin, Ireland) showed similar rates of
10-year survival to Magna Ease in a retrospective cohort analysis.[17,
18] In another multivariable retrospective analysis, the Mitroflow
valve (LivaNova, London, UK) was associated with a higher risk of
mortality compared with the Magna Ease valve at 5 years (hazard ratio
1.57 [95% CI 1.17, 2.11], p<0.01).[19]
Thromboembolic events, bleeding, and
endocarditis
Early and late complications in this study were consistent with
others.[5, 14] Freedom from endocarditis, thromboembolism, and major
bleeding at 8 years were 97.3% (95% CI 95.1, 99.5), 86.7% (95% CI
81.9, 91.5), and 85.1% (95% CI 80.0, 90.1), respectively. The reported
rate of bleeding events does not pose an unexpected or additional risk
to patients treated with the Magna Ease valve. Most of the bleeding
events had no further clinical consequences, and those observed were
typical for older patients following cardiac surgery.
Hemodynamic performance
Mean gradient remained acceptable at 8 years: 14.8±8.3 mmHg compared
with 12.2±5.0 mmHg at 1 year, and was consistent with findings of a
recent study.[11] Although one meta‑analysis concluded gradients
were lower for the Trifecta valve than the Magna and Magna Ease valves
at 6 months (mean difference 4.1 mmHg; 95% CI 3.5, 4.7;
p<0.0001),[20] a recent large comparative analysis found a
concerning decline in Trifecta hemodynamics over 5 years, with an
increased rate of explant due to structural deterioration, compared with
the original PERIMOUNT valve.[21]
The hemodynamic improvement seen in this study resulted in a sustained
improvement in NYHA functional class for nearly two-thirds of patients.
Valve durability
Freedom from SVD was 99.1% (95% CI 97.9, 100.0) at 5 years and 90.1%
(95% CI 84.7, 95.4) at 8 years. The 8-year rate is slightly lower than
the 10-year freedom from SVD rates with the Magna Ease valve reported by
Bourguignon et al. (94.2%) and Forcillo et al.(98±0.2%), or the 12-year rates from Piperata et al.(93%).[5, 13, 22] However, comparing SVD rates from different
studies is challenging because of differing SVD definitions and cohort
ages. Freedom from SVD with the Trifecta valve was reported to be 98.7%
and 93.3% at 5 and 8 years, respectively,[15] although a recent
study demonstrated increased risk of valve failure in the Trifecta valve
compared with the Magna Ease valve at 48 months.[18]
Freedom from reintervention due to SVD was 99.1% (95% CI 97.9, 100.0)
at 5 years and 93.6% (95% CI 89.3, 97.8) at 8 years. Rates reported
for the Trifecta valve were 97.3% (95% CI 94.7, 98.6) at 6
years.[14, 23] In a propensity score-matched analysis between the
Trifecta valve and the Magna Ease valve, the Trifecta valve cohort had a
significantly higher risk of repeat AVR for structural valve failure at
7 years (5.7% vs 0%, p=0.009).[16] Another propensity
score-matched analysis showed a significantly lower freedom from explant
for the Trifecta valve compared with the PERIMOUNT valve at 5 years
(95.9% vs 98.7%, p<0.001).[21]
In an effort to reduce SVD and improve durability of bioprosthetic
valves, Edwards Lifesciences has developed RESILIA tissue with advanced
anticalcification technology, but durability data beyond 5 years with
this tissue are still awaited.[24, 25]
LIMITATIONS
This study has some limitations. While it includes outcomes from 14
centers and used an independent CEC to adjudicate safety events, an echo
core lab was not used, potentially introducing variability, as
echocardiographic data were collected and evaluated by individual
centers. Secondly, this study did not include a comparator study arm to
compare these Magna Ease valve outcomes to those of other contemporary
valves.
CONCLUSION
This is the first multicenter, prospective cohort study of the Magna
Ease valve, with clinical events committee adjudication of all safety
events. The Magna Ease valve demonstrated satisfactory freedom from
mortality and valve-related complications requiring reintervention, and
sustained improvement in hemodynamics at 8 years. These data support the
continued use of this valve, adding to the growing body of evidence that
the Magna Ease valve represents a standard of performance against which
other surgical valves may be compared.[7, 11]