Medical Device Daily
MUNICH, Germany — Highly skilled surgeons have brought hope to patients with expert repair of the degenerative condition of regurgitation of the mitral valve.
Abbott Vascular (Santa Clara, California) designed a device to mimic that technique of edge-to-edge repair called the MitraClip that has the added advantage of being placed in a minimally invasive, catheter-based procedure.
Putting this technique for repair in the hands of the fast-growing number of cardiac interventionalists brought mixed results.
More than 6,000 patients have undergone the procedure already, 4,500 in Europe.
Yet detailed data on patient selection and outcomes are available for only 1 ,905 patients enrolled in trials.
After Abbott presented two-year results from the EVEREST II trial in 2011 showing percutaneous repair with the MitraClip was less effective at reducing mitral regurgitation than surgery, the procedure, like aortic valve replacement, was relegated by the cardiology community to patients at high risk for surgery.
In other words, a procedure of last resort, short of replacing the valve with a bioprothesis.
At ESC 2012 Abbott presented what it called a real-world, multicenter study of the MitraClip system following 487 patients at one year, the largest group of patients evaluated to date.
ACCESS-EUROPE enrolled truly sick patients, a very different population than the EVEREST II trial with significant baseline co-morbidities, including coronary artery disease in 63% and moderate-to-severe renal disease in 42%.
Seventy-seven percent had functional mitral regurgitation, and the average score for surgical risk was high at logistic EuroSCORE of 23.
Procedural success was nearly complete with only two procedures encountering difficulties, and the technique once again proved safe.
Mortality at 30 days was 3.4%, which compares quite favorably with transcatheter aortic valve procedures and at one year 82% were still alive, with a clear association between survival and surgical risk scores.
As for effectiveness, co-principal investigator Wolfgang Schillinger, MD, from the Göttingen University Medical Center in Germany reported at one year 79% of patients were free from mitral regurgitation above Grade 2, where all patients were rated at Grade 3 and higher before the procedure.
In a six-minute walk, these patients improved an average of 60 meters, a small but significant victory among this elderly and ill group.
Improvements in quality of life were shown to be a median improvement of 14 points between baseline and one-year scores on the Minnesota Living with Heart Failure Questionnaire.
Schillinger concluded that given the “abundant co-morbidities,“ the MitralClip presents a viable therapy option fulfilling an unmet clinical need.
In his follow up discussion, Simon Ray, MD, from the Wythenshawe Hospital (Manchester, UK) agreed that ACCESS-EUROPE “demonstrates that in expert hands the MitralClip is feasible and safe with acceptable risk for a complex patients.“
Yet noting that one-third of patients do not realize a real-world symptomatic relief, “It may be that our appreciation of valve anatomy is not sufficiently advanced.“
Cardiologists may be overestimating in applying risk scores and assessing the patient condition.
Key to further investigations will be better quantification of valves, and thereby better patient selection to better assure that patients will benefit from the procedure, he said.