Unveiling the Hidden Risks: Out-of-Hospital Mortality in Mitral TEER Patients Within 30 Days

Out-of-hospital mortality before 30 days was 1.2%, with roughly two-thirds of these patients dying from cardiovascular causes.

All-cause mortality after transcatheter-edge-to-edge repair for mitral regurgitation (M-TEER) is just 3.0% at 30 days, but roughly two out of every five deaths that occur within this early window happen after the patient has been discharged from the hospital, according to a new TVT Registry analysis.

Those discharged who died within 30 days were sicker than those who survived, but there were several modifiable predictors of early mortality, including not being discharged on guideline-directed medical therapy (GDMT).

Operators may perform the procedure, the patient survives with no complications, and they feel the patient is ready to go home or to rehab, but these frail patients may need closer follow-up.

If there’s a concern that patients aren’t fully optimized on GDMT, it might be better to do that in the hospital setting to prevent later rehospitalization and mortality.

Of the patients who died outside the hospital within 30 days, nearly two-thirds did so from cardiovascular causes.

This “concerning signal” suggests that some patients may be going home when they’re still at high risk for cardiovascular events.

One would hope that patients discharged alive following M-TEER would be optimized from a cardiovascular standpoint and have a minimal rate of short-term out-of-hospital cardiovascular death.

Interventional cardiologists must do a better job of optimizing cardiovascular risk prior to discharge and not discharging patients who are at significant risk of cardiovascular death.

M-TEER is typically reserved for patients at high or prohibitive risk for mitral valve surgery, with a 2001 analysis showing the median STS predicted risk of mortality at 30 days for surgical valve repair was 5.35%.

That the overall real-world mortality was only 3.0% suggests that either M-TEER truly carries lower mortality risk than mitral valve surgery and/or lower-risk patients now account for the majority of M-TEER patients.

With one-third of out-of-hospital deaths occurring from noncardiovascular causes, the study also suggests that this is a high-risk group with significant comorbidities that might not be captured by the STS risk score.

With every new procedure, the initial focus is on in-hospital mortality to ensure it is safe, and prior studies have shown that early mortality rates after M-TEER are declining over time.

One recent analysis of the Society of Thoracic Surgeons/American College of Cardiology TVT Registry showed that 30-day mortality was 3.5%, with in-hospital mortality rates dropping as well, but there has been little information about out-of-hospital mortality within 30 days.

The new paper, published in JACC: Cardiovascular Interventions, included 61,139 consecutive patients who underwent isolated M-TEER at 539 sites between 2014 and 2024.

Overall, 1,813 (3.0%) died either in or out of the hospital within 30 days, with 744 patients dying after discharge.

The rate of out-of-hospital mortality within 30 days was 1.2%, a percentage that was similar between those treated for functional and degenerative mitral regurgitation (MR).

For those who died out of hospital but within 30 days, the median time until death was 11 days.

Lower baseline hemoglobin, lower baseline Kansas City Cardiomyopathy Questionnaire (KCCQ) overall summary scores, home oxygen use, lower LVEF, presentation as NSTEMI, and lower body surface area were all independent predictors of 30-day out-of-hospital mortality.

A higher acuity presentation, in-hospital complications, and procedural factors, such as moderate or worse residual mitral MR, use of more than one device, and postprocedural gradient greater than 5 mm Hg, were also associated with a higher risk of early mortality after discharge, as was not being treated with an ACE inhibitor/ARB at discharge.

The analysis shows that patients who fail to survive to 30 days after discharge represent an elderly group with multiple comorbidities.

These data also show that prognosis after M-TEER is determined not solely by the mitral valve damage but more critically by potentially irreversible cardiac damage beyond the mitral valve itself.

With the low 30-day mortality rate, these data confirm that M-TEER is a safe procedure.

However, it’s also telling that some discharged patients “don’t make it past 30 days.”

Patients are discharged and asked to follow up with their doctor within 2 or 3 weeks, but the median time of death was less than 2 weeks, meaning half of the discharged population might not even be seen in a follow-up visit.

The study highlights the importance of appropriate patient selection for M-TEER, as patients who died out of the hospital had significantly lower baseline KCCQ scores by roughly 15 points than those who survived.

Complications, such as bleeding, can be unexpected, but GDMT and patient selection deserve more attention.

Many predictors of out-of-hospital mortality after discharge are the “usual suspects,” such as severity of illness or comorbidities, emphasizing the importance of choosing patients appropriately.

Quite a few were modifiable risk factors that can be addressed to improve outcomes, such as avoiding procedural complications, ensuring moderate residual MR isn’t left behind, and prescribing neurohormonal blockade with an ACE inhibitor/ARB for all patients.

The days of “fire and forget” after M-TEER are gone, and clinicians need to optimize GDMT to ensure the best possible outcome.

Data suggest many patients can tolerate uptitration of heart failure therapies after M-TEER, likely the result of hemodynamic stabilization.

The findings underscore the need for rigorous implementation of GDMT protocols starting on day 1 after the procedure, leveraging heart failure clinics, patient education programs, and electronic health record alerts.

Take-Home Points:

• M-TEER is a safe procedure with a 3.0% 30-day mortality rate, but 1.2% of patients die out-of-hospital within that time, often from cardiovascular causes.
• Modifiable predictors like lack of GDMT, procedural complications, and residual mitral regurgitation contribute to early mortality and can be addressed to improve outcomes.
• Patients discharged after M-TEER need closer follow-up and optimization of cardiovascular risk, as many don’t survive past 2 weeks without it.
• Appropriate patient selection is critical, as sicker patients with lower KCCQ scores and significant comorbidities are at higher risk of death.
• Interventional cardiologists must prioritize GDMT protocols and ongoing care, moving away from a “fire and forget” approach to ensure long-term success.