Longer-term clinical outcomes
At a median follow-up of 7 months, the composite primary clinical outcome composed of all-cause mortality or heart failure rehospitalization did not differ between the two groups: a 28% rate in the CS group and 25.6% in non-CS patients. All-cause mortality occurred in 16% with CS and 9.3% without, again not a significant difference.
In a Cox regression analysis, neither surgical risk score, patient age, left ventricular geometry, nor CS was independently associated with the primary composite endpoint. Indeed, the only independent predictor of freedom from mortality or heart failure readmission at follow-up was procedural success, which is very much a function of the experience of the heart team, Dr. Estevez-Loureiro continued.
Michael A. Borger, MD, PhD, who comoderated the late-breaking clinical science session, was wowed by the IREMMI results.
“The mortality rates, I can tell you, compared to traditional surgical series of acute MR in the face of ACS [acute cardiogenic shock] are very, very respectable,” commented Dr. Borger, director of the cardiac surgery clinic at the Leipzig (Ger.) University Heart Center.
“Extremely impressive,” agreed discussant Vinayak N. Bapat, MD, a cardiothoracic surgeon and valve scientist at the Minneapolis Heart Institute Foundation. He posed a practical question: “Should we take from this presentation that patients should be stabilized with something like ECMO [extracorporeal membrane oxygenation] or Impella [left ventricular assist device], then transferred to an expert center for the procedure?”
“I think that the stabilization is essential in the patients with cardiogenic shock,” Dr. Estevez-Loureiro replied. “Unlike with surgery, it’s very difficult to establish a MitraClip procedure in a couple of hours in the middle of the night. You have to stabilize them and then treat for shock with ECMO, Impella, or both. I think they should be transferred to a center than can deliver the best treatment. In centers with less experience, patients can be put on mechanical support and transferred to an expert valve center, not only for MitraClip implantation, but for discussion of all the treatment possibilities, including surgery.”
At a press conference in which Dr. Estevez-Loureiro presented highlights of the IREMMI study, discussant Dee Dee Wang, MD, said the international coinvestigators “need to be applauded” for this study.
“Having these outcomes is incredible,” declared Dr. Wang, a structural heart disease specialist at the Henry Ford Health System, Detroit.
While this is an observational study, it’s a high-quality dataset with excellent methodology. And conducting a randomized trial in patients with such high surgical risk scores – the CS group had an average EuroSCORE II of 21 – would be extremely difficult, according to the cardiologist.
Dr. Estevez-Loureiro reported receiving research grants from Abbott and serving as a consultant to that company as well as Boston Scientific.
SOURCE: Estevez-Loureiro, R. TCT 2020, LBCS session IV.