In patients with severe mitral regurgitation (MR) and cardiogenic shock, successful transcatheter edge-to-edge repair (TEER) is associated with a substantial reduction in all-cause mortality and lower morbidity at 1 year, analysis of data suggests. from the register.
Data from this analysis also confirm that “successful MR reduction can be achieved with TEER in most patients with cardiogenic shock,” reported Mohamad A. Alkhouli, MD, interventional cardiologist and professor of medicine at Mayo Clinic, Rochester, Minn.
In those with device success, achieved in 85.6% of patients, all-cause mortality was approximately 21% lower (34.6% vs. 55.5%; P < .001) per year than in those who were not successfully repaired, according to Dr. Alkhouli, who presented the findings at the Transcatheter Cardiovascular Therapeutics annual meeting in Boston. This translated to a reduction in the hazard ratio for death of almost 50% (HR, 0.52; 95% confidence interval, 0.43-0.63).
A similar relative benefit was found for the composite endpoint of mortality and heart failure admissions at 1 year. Whether unadjusted (HR, 0.54; 95% CI, 0.45 to 0.66) or adjusted (HR, 0.51; 95% CI, 0.42 to 0.62), reductions in risk with successful MR reduction, defined as an improvement of ≥1 grade and a final MR rating of ≤2+, indicated that major adverse outcomes are approximately halved.
STS/ACC TCT record data consulted
Retrieved from the American College of Cardiology/Society of Thoracic Surgeons Transcatheter Valve Therapy Registry, 3797 patients with cardiogenic shock underwent MR repair between November 2013 and December 2021. Outcomes at 1 year were evaluable in 2773 of these. patients. For inclusion, all had to meet at least one of the definitions of cardiogenic shock, such as use of inotropes or mechanical circulatory support.
At the start of the study, 94.5% had an MR severity of at least 3+ and most of them had 4+. Thirty days after treatment, 88.8% had an MR severity of 2+ or less, the majority of whom had a severity of 1+.
These data address an important question that had not been well studied before, according to Dr. Alcohol. In patients with MR, cardiogenic shock is associated with a high risk of death, but there has been little evidence that valve repair does not exacerbate, much less modify, this risk.
These data support the value of the procedure, which was performed in almost all patients with the MitraClipä (Abbott), the only device available during most of the period in which the registry was consulted. However, Dr. Alkhouli cautioned that her data is best viewed as “hypothesis generating.”
“We need a randomized trial,” he told the meeting, sponsored by the Cardiovascular Research Foundation. He noted that this is a complex population for which multiple variables can skew results when the data is analyzed retrospectively. Not least, the MR patients with cardiogenic shock in the database considered for TEER might have been relatively healthy and not representative of an unselected population with MR and cardiogenic shock.
The question might be better answered by the multicenter Canadian CAPITAL MINOS trial, which has just started. Described in an article in the american heart journal, has a planned enrollment of about 150 MR patients with cardiogenic shock randomized to TEER or medical therapy. Results are expected in about 1 year, according to Dr. Alcohol.
But regarding the current analysis, Dr. Alkhouli noted that sensitivity analyzes performed within his data across risk factors, such as degenerative versus nondegenerative MI, low left ventricular ejection fraction (LVEF) (<30% ) versus discharge, and presence or absence of an acute coronary syndrome (ACS), consistently supported a benefit of the intervention.
Additionally, cardiogenic shock did not appear to be a factor in device failure, according to Dr. Alkhouli, addressing a possible criticism that cardiogenic shock was an underlying reason for device failure.
>90% in NYHA class III or IV heart failure
In this study, the mean age was 73 years. More than 90% were in class III or IV heart failure in the 2 weeks prior to TEER. More than half had established coronary artery disease. Other concomitant cardiovascular morbidities, such as atrial fibrillation or flutter (65%), prior myocardial infarction (39%), and prior stroke or transient ischemic attack (>10%), were well represented.
When those who were successful with the device were compared with those who failed, the risk profile was comparable. The STS (Society of Thoracic Surgeons) predicted mortality for mitral valve repair between these two groups was 14.8% vs. 15% (P = 0.97), respectively.
However, those with device failure had a lower baseline left ventricular ejection fraction (40.7% vs. 42.9%; P = 0.009) and a higher prevalence of moderate-severe or severe MI (96.1% vs. 84.9%; P <0.001).
Growing experience with TEER means that benefit has now been demonstrated in several complicated MR groups, such as those with severe ventricular dysfunction, renal failure, and obstructive pulmonary disease. This was a rationale for looking at impaction or repairing MR in patients with cardiogenic shock.
It’s a pressing question, according to Dr. Alcohol. He cited studies suggesting that up to 20% of patients hospitalized for cardiogenic shock have at least one moderate to severe MI. In contrast, cardiogenic shock is not an uncommon finding in patients with MR.
while Dr Alkhouli acknowledged that the many variables that influence outcome in patients with MR and cardiogenic shock will make a randomized trial “challenging”. Many experts echoed this concern and even expressed some skepticism about the potential for an unbiased trial.
Data confirms that MR repair is safe during shock
“These data show that MR repair is safe in patients with cardiogenic shock,” said Anita W. Asgar, MD, interventional cardiologist associated with the Montreal Heart Institute, Canada. She noted that there was a 5- to 6-day delay among patients with cardiogenic shock before undergoing MR repair in this analysis, which could reflect a removal of those at very high risk. Similarly, she suggested that many interventionists are likely to consider multiple variables before proceeding.
As a result, MR repair may not be randomized in a cardiogenic shock population, as this decision is not usually made outside the context of multiple variables.
“I’m not sure a clinical trial is ethical,” she said. She would expect that doctors enrolling patients would only do so selectively.
Alexandra J. Lansky, MD, Director, Yale Heart and Vascular Research Program, Yale University, New Haven, Connecticut, also emphasized the difficulty of controlling for variables, such as the duration of cardiogenic shock, that influence decision making. .
However, he called the data “very important” in that they at least provide some objective data for deciding whether to intervene in a group of “challenging” patients that are encountered quite frequently in clinical practice.
dr Alkhouli reports financial relationships with Abbott Vascular, Boston Scientific, Johnson & Johnson, and Phillips. dr Asgar reports financial relationships with Abbott Vascular, Edwards Lifesciences, WL Gore & Associates, and Medtronic. dr Lasky does not disclose potential conflicts of interest.