As numerous patients await elective aortic valve intervention for aortic stenosis
(AS) during this unprecedented outbreak of severe acute respiratory syndrome coronavirus
2 in 2019 (COVID-19), there is serious concern for the possibility of morbidity and
mortality during prolonged wait-times. During this time period, the American College
of Surgeons and Center for Disease Control released their recommendation to reschedule
elective surgeries and to shift elective inpatient diagnostic and surgical procedures
to the outpatient setting . Accordingly, the Centers for Medicare & Medicaid Services
provided a framework to further group elective surgeries into levels of urgency .
A tiered framework ensures that we are providing surgical services and procedures
to those patients in whom the risk of delaying a procedure may lead to significant
morbidity or mortality. As cardiovascular healthcare providers caring for patients
with AS, we must now differentiate cases at a higher tier of urgency from the rest.
Current guidelines suggest treatment of severe AS when symptomatic (angina, heart
failure and/or syncope), and there is now growing data to support intervention even
before symptom onset . Though most hospitals are equipped for urgent/emergency
cases, the majority of aortic interventions are done on an elective basis, and therefore
have been postponed due to the COVID-19 outbreak. However, there is a significant
relationship between aortic valve replacement (AVR) wait-time and mortality as well
as hospital readmission [4, 5]. Delaying AVR has been associated with poor operative
outcomes and risk of mortality during the waiting period [6, 7]. Additionally, hospitalizations
during wait-time and urgent/emergency AVR have been associated with worse short- and
long-term outcomes . It is, therefore, essential that our established multi-disciplinary
heart team carefully reviews each patient individually, and determines who would likely
benefit from an ‘early elective’ strategy. Timing of intervention when balanced with
healthcare resources has not been a major focus among our academic community until
now. We are compelled to generate algorithms to help balance the risk of a procedure
during this critical time versus the risk of waiting for a therapy, both having potentially
life-altering consequences to patient and family.
Symptom severity is generally the largest driver for an earlier AVR strategy. Patients
with New York Heart Association (NYHA) IV symptoms and/or syncope clearly portend
a worse prognosis than less symptomatic patients . These patients should, therefore,
be treated in a timely manner. The presence of angina is always concerning, although
the natural history of patients with severe AS suggests that angina is not as ominous
a sign as syncope. Yet, since the prevalence of concomitant coronary artery disease
is as much as 50%, earlier strategies in patients with severe or unstable angina should
be strongly considered .
There is a paucity of literature addressing clinical risks (i.e. non-invasive data,
comorbidities and demographics) that are associated with higher clinical events during
wait-time. Factoring in the severity of AS into our equation is important, as we know
that patients who meet these criteria are at higher risk. Asymptomatic patients with
indexed aortic valve area <0.4 cm2 have a higher risk of events prior to intervention,
and a peak jet velocity >5 m/s is an independent predictor of mortality [11, 12].
Another important echocardiographic finding is impaired ejection fraction (EF). Patients
managed conservatively with an impaired EF (EF < 60%) have been independently associated
with poorer long-term outcomes, whilst an earlier AVR strategy has improved outcomes
. In these patients with less cardiac reserve, it is imperative to negate the
effects of AS before an event.
Furthermore, the decision for type of intervention may also have significant impact.
Transcatheter AVR (TAVR) indications have been expanded to include patients who are
at low risk for surgical AVR complications. Strategies involving shared-decision-making
with patients have been applied, particularly to patients <70 years old, remembering
that the average age in the low-risk trials was 73 ± 6 years old. From these trials,
TAVR did result in a shorter index hospitalization compared to surgical AVR (3 vs
7 days) . Understanding the dynamic constraints on healthcare systems, minimalist
TAVR can potentially help to further reduce post-care utilization of resources and
allow early patient recover at home . Balloon aortic valvuloplasty as a bridge
to TAVR has also shown an improved safety profile in the contemporary era of TAVR
. Its role as a bridge for patients with anatomical challenges for TAVR, whether
non-transfemoral or requiring adjunctive techniques (such as coronary protection with
snorkel stenting or leaflet laceration, etc.) may be more important now than ever.
As the treatment for aortic intervention continues to improve both from surgical techniques
to transcatheter technology, we need more focus on the timing and application of our
interventions. For now, symptoms and echocardiographic criteria can drive how we deliver
therapy (Fig. 1), but we also need to factor in other clinical information. Many questions
remain; should baseline comorbidities such as chronic lung disease, renal impairment
and Society of Thoracic Surgery PROM score push us to act more quickly, whereas other
factors (i.e. immunocompromised patients) push us to delay? Do NYHA IIIb symptoms
herald worse outcomes during waiting than NYHA IIIa? Should patients with NYHA III
symptoms receive an ‘early elective’ strategy versus a patient with NYHA II symptoms?
Do we need to factor in other non-invasive data such as degree of left ventricular
hypertrophy, and biomarkers (including elevated natriuretic peptide) which may portend
a higher rate of events during wait time?  Should discussions with the multi-disciplinary
team increase considerations for utilizing TAVR in the very low-risk AS patient and
balloon aortic valvuloplasty as a bridge to TAVR in efforts to decrease length of
stay, hospital resource utilization and patient/family exposure COVID-19? Further
investigation is clearly needed, and we must work on developing a risk stratification
system for suggested wait-times. Until then, we must balance the risk of delaying
therapy against the availability of hospital resources and potential exposure of COVID-19
on a case-by-case basis.
Algorithm for managing elective AVR over the long term in the era of COVID-19. *Aortic
valve area indexed <0.4, peak jet velocity >5 m/s. AVR: aortic valve replacement (transcatheter
or surgical); EF: ejection fraction; NYHA: New York Heart Association; SAVR: surgical
aortic valve replacement; TAVR: transcatheter aortic valve replacement.
Conflict of interest: Dr Chad A. Kliger is a consultant and receives speaking honoraria
from Edwards Lifescience and Medtronic. All other authors declare no conflict of interest.