MitraClip Appears Safe, Effective for Patients with Noncentral Regurgitatior

In patients with noncentral degenerative mitral regurgitation (MR) at high surgical risk, percutaneous treatment with a clip device is safe and results in acute and midterm outcomes similar to those for central MR, according to a study published online September 4, 2013, ahead of print in the Journal of the American College of Cardiology. The findings challenge the concept that treatment of noncentral MR carries greater risk.

Olaf Franzen, MD, of Rigshospitalet Copenhagen (Copenhagen, Denmark), and colleagues looked at 173 consecutive patients treated with MitraClip (Abbott Vascular; Santa Clara, CA) at 3 high-volume European centers between August 2009 and November 2012. They conducted a retrospective analysis of the 79 patients with degenerative MR, comparing those with central regurgitation (62%) to those with noncentral regurgitation.

Few Differences Seen

There were no differences in procedural success (about 96%; P = 0.866), procedural time (P = 0.505), or number of implanted clips (P = 0.278) between central and noncentral MR patients. Postprocedural complications were rare and similar between the groups, with no cases of prolonged clip entanglement or embolization, or septal complications.

Transthoracic echocardiography showed a reduction in MR severity in all patients at discharge, with most having grade 2 or less. There was no difference in the extent of reduction of MR between central and noncentral groups. The reduction in MR severity was sustained in both groups at 6 months, with nonsignificant differences in the proportion of patients with central vs. noncentral disease having MR severity greater than 2 (4.8% vs. 8.3%; P = 0.679). At 1 month, both groups achieved similar improvements in mean transmitral gradient and New York Heart Association functional class (both P < 0.001), the latter persisting at 6 months.

At a follow-up of 15.2±11 months there were no differences between evaluable central and noncentral patients with regard to mortality, hospital readmission due to heart failure, or partial clip detachment (table 1).

Table 1. Outcomes

“Our results show that MitraClip can be safely implanted in a noncentral position of the [mitral valve,] with a procedural success rate similar to central positioning,” the study authors write.

Defining Eligible Patients

In an accompanying editorial, Jason H. Rogers, MD, and Reginald I. Low, MD, both of UC Davis Medical Center (Sacramento, CA), note that while MitraClip therapy has been limited to patients with predominantly central MR in the randomized EVEREST trial and in the REALISM continued access registry, “it is well known that treatment in Europe and in the US Compassionate Use Pathway has included patients with noncentral MR.” MitraClip received CE mark approval in March 2008 but remains investigational in the United States.

They say the patient series importantly highlights the need for certain technical considerations for the treatment of noncentral MR. Moreover, although reports of successful surgical edge-to-edge repair in these patients have been published, no such reports exist for MitraClip, they add.

Finally, the findings regarding prevalence and patient characteristics in this population “are very important for defining the patient groups eligible for treatment, and also highlight that of high-risk patients, a significant number have degenerative and noncentral MR, and should be considered candidates for this therapy,” Drs. Rogers and Low conclude.

Sources:

1. Estévez-Loureiro R, Franzen O, Winter R, et al. Echocardiographic and clinical outcomes of central versus non-central percutaneous edge-to-edge repair of degenerative mitral regurgitation. J Am Coll Cardiol. 2013;Epub ahead of print.

2. Rogers JH, Low RI. Non-central mitral regurgitation: A new niche for the MitraClip [editorial]. J Am Coll Cardiol. 2013;Epub ahead of print.

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• Postmarketing Registry Data Show MitraClip Safe, Effective for MR
• Close FDA Panel Vote Favors MitraClip for MR Patients with No Other Options
• EVEREST II Registry Looks at MitraClip in High-Risk Patients