What the EARLY TAVR Trial Data Could Mean for Already Busy Heart Teams 

Heart teams may see up to 25% more severe aortic stenosis patients

On the heels of the exciting EARLY TAVR data and egnite’s Acute Valve Syndrome in Aortic Stenosis study, both led by Dr. Philippe Genereux, we’ve been asked by several cardiovascular (CV) administrators what a potential change in the management of asymptomatic severe aortic stenosis (SAS) patients could mean for their already busy heart teams. 

Luckily, here at egnite, we have a lot of data. 34,000+ severe AS patient records’ worth of data. Combine that with 10+ years working with hospitals through our CardioCare® digital health platform, and we think we have a unique viewpoint of the market. 

Key Takeaways

In a landscape where recent trial data influences FDA approvals, updates to National Coverage Determinations (NCDs), AHA/ACC guidelines, and widespread adoption of this new evidence by the clinical community for the management of asymptomatic severe aortic stenosis (AS) patients: 

• Heart teams may experience a 19-25% increase in evaluation appointments. 

• Implanters could perform 5-17% more aortic valve replacement (AVR) procedures, with 60-80% of these cases going to transcatheter aortic valve replacement (TAVR). 

The Final Breakthrough of the Sizeable ‘Not Symptomatic Enough’ SAS Patient Cohort 

We predict that the largest influx of patients will come from the cohort currently living with Class I indicated symptomatic aortic stenosis (AS), who are often classified by their cardiologists as ‘asymptomatic’ or ‘not symptomatic enough’ to justify intervention. This determination is frequently made without the use of a stress test and despite symptoms like fatigue, dizziness, and syncope that could suggest worsening disease. 

Symptom status is commonly logged in written physician notes. This assessment creates a key barrier to hospitals performing any further outreach to the MD or patient to coordinate a specialist evaluation for the patient’s progressive and sometimes deadly severe aortic stenosis.  

In our experience, there are two main headwinds for this patient cohort: very conservative (‘Partner 1’) cardiologists and the variability in how symptoms can drive actions with the average cardiologist. On a positive note, there may be an additional tailwind for this cohort with the complimentary egnite data published at TCT outlining improved outcomes for earlier treatment with AVR which we hope can support accelerated practice change. 

Headwind #1: ‘Partner 1’ Conservative Cardiologists 

Our experience on the ground operationalizing the CardioCare platform and working with clinicians has made it clear that symptom status for AS has been a clinical grey area. Many programs we work with demonstrate a higher threshold than others in determining whether a patient is ‘symptomatic enough’ to warrant a heart team consult and even treatment. This can be especially pronounced for programs with a very conservative cardiology base, which is more common than one might think.  

We were recently in discussions with a health system that benchmarked in our bottom quartile for SAS treatment nationally, where 1 in 4 untreated SAS patients were deemed ‘asymptomatic’ by the managing physician. Our investigation revealed that most of these patients had 2 or more aortic stenosis symptoms recently logged in the electronic medical record and no stress test or thorough clinical interrogation of lifestyle adaptations. If this site practiced more like a top quartile site, 25% more patients would receive treatment in the coming year for their SAS. The program acknowledged their cardiology providers are more conservative in practice, and that some were still practicing with a ‘Partner 1 mentality’ⁱ. We can attest that many programs are faced with this therapy development challenge. 

Headwind #2: Symptoms Inspire Action Inconsistently… It Often Depends on the Symptom! 

At egnite, we can also quantify that not all severe AS symptoms inspire action in the same way, even though permanent cardiac damage is often underway and getting worseⁱⁱ. Diagnosed severe AS patients presenting with angina (5% of patients) are +29% more likely to be treated at 180 days than a patient presenting with syncope (11% of patients) even though both these symptoms are classified in the guidelines as warranting at least a heart team consult if not treatmentⁱⁱⁱ. We’ve seen countless times patients with ICD.10 codes of the ‘softer’ symptoms – syncope, fatigue, dizziness – being labeled in the notes by their managing provider as ‘asymptomatic’ without a stress test or detailed interrogation of the patient’s lifestyle adaptations.

Tailwind #1: Massive Database Provides Convincing Evidence that Earlier Treatment of SAS Improves Patient Survival by 3x 

The Acute Valve Syndrome in Aortic Stenosis study presented at TCT demonstrates that progressive valve syndrome (PVS) or acute valve syndrome (AVS) at the time of AVR were associated with increased mortality or recurrent hospitalization with heart failure 2-years after AVR, compared to patients undergoing AVR while asymptomatic.  Notably, asymptomatic SAS patients treated with AVR had a 3x increase in survival at two years vs. patients who already had symptoms before their AVR. 

The combination of the EARLY TAVR trial data and this study of over 17,000 AVR recipients makes a strong case for timely specialist evaluation and consideration of treatment for all severe AS patients, regardless of how conservative the cardiologist is, or which symptom is presenting. The authors hope dissemination of this evidence will make the following mentality clear: don’t wait for symptoms before sending SAS patients to the heart team.

Our Estimates 

Nationally, our data show that 80% of SAS patients are symptomatic, and over a 365-day period, 58% are treated^iv. This leaves 22% who are untreated with documented symptoms. Predicting heart team referral rates from conservative cardiologists resulting from new data over the near term is a difficult task. Heart programs, the AHA/ACC associations, and medical device manufacturers will have their work cut out for them to support therapy awareness efforts. If we assume that the message gets out to 50-66% of these patients and their providers that regardless of the presence of symptoms, they should be seen by a heart team, then we could expect 11-15% more heart team encounters for severe AS. Heart team treatment rates nationally vary by how progressive the heart team is; we see a range of 25%-68% nationally, translating to an additional 3-10% in AVR volume. We’d argue this segment would err more heavily toward TAVR, if we assume some of the reluctance to refer can be attributed to patient frailty and attribution of symptoms to other high-risk comorbidities. 

The Smaller Opportunity – On-Paper ‘Asymptomatic’ SAS Patients 

Our Estimates 

This is the smaller segment since a truly asymptomatic SAS patient is so uncommon. We see that 20% of current ‘treatable’^v SAS patients have 0 or 1 symptoms^vi coded in the EMR and about 47% are treated^vii, 66% with TAVR procedures^viii: this group is our proxy for on-paper ‘asymptomatic’ patients^ix. This nets us a potential group of 11% of patients in the population who may come into clinic. Of course, not every patient will choose to be evaluated if they aren’t experiencing symptoms. Given our symptomatic evaluation rate nationally is about 80%, let’s assume 50-66% of these asymptomatic patients are activated over the coming years and make their way into the heart team. This would result in a 5-7% increase in heart team consults and a 1-5% increase in treated patients, depending on the program.

What About Moderate-to-Severe Aortic Stenosis?  

Our Estimates 

The moderate-to-severe AS diagnosis, while not officially recognized in the ASE guidelines, is commonly used. Last year at TCT, Genereux et al. published that this group represents about 30% of the SAS population – said otherwise, for every 100 SAS patients out there, we have another 30 with a “Moderate-to-Severe” (M-S) echo diagnosis from the reading cardiologist. This study also highlighted that moderate-to-severe patients are referred to heart teams at half the rate of severe AS patients but just as likely to die^x. As recognition of the serious implications of aortic stenosis expands, there may be additional heart team referrals for the 80%+ of moderate-to-severe patients with symptoms^xi. This is a tailwind that we expect to apply at half the rate to severe AS patients, accruing another 2-3% in heart team evaluations and 1-2% in AVRs for patients who meet “severe” criteria upon re-echo. 

Can We Mobilize This Information into Practice in Less Than 17 Years? 

Studies show^xii it takes 17 years for new guidelines to become common clinical practice. We will be in an exciting time for the treatment of AS if the guidelines change to recommend heart team evaluation and a shared decision-making treatment discussion for all severe AS patients, regardless of symptoms. At egnite, we can currently see that many severe and moderate-to-severe AS patients are in a medical management holding pattern because they are not convincingly severe and symptomatic enough to be scheduled for a heart team evaluation. If the symptomatic requirement falls away and clinical practice adapts across America, we estimate heart team clinics will see a 19-25% increase in heart team encounters and 5-17% increase in AVRs for severe AS on an ongoing basis.