NEW ORLEANS — An echocardiographic substudy of the COAPT trial failed to identify any baseline echo characteristics to differentiate patients with heart failure (HF) and secondary mitral regurgitation (MR) that would or would not benefit from the MitraClip (Abbott).
Posted March 3,2019 in General Medicine.
NEW ORLEANS An echocardiographic substudy of the COAPT trial failed to identify any baseline echo characteristics to differentiate patients withheart failure(HF) and secondarymitral regurgitation(MR) that would or would not benefit from theMitraClip(Abbott).
The MitraClip provided "substantial death and heart failure hospitalization benefits in all the cohort-adjusted subgroups, regardless of the degree of left ventricular (LV) dysfunction, LV dimensions,pulmonary hypertension, severity of TR [tricuspid regurgitation], or individual mitral regurgitation parameters," Federico Asch, MD, Medstar Health Research Institute, Washington, DC, said here at theACC 2019 Scientific Session(ACC.19). "All subgroups were responders."
Speaking withtheheart.org| Medscape Cardiology, Asch said there is a possibility that the extremes in the cohort actually did behave differently.
"Someone, let's say, with an ejection fraction of 45% and someone with an EF of 22%, those patients probably did behave differently," he said. "We did not perform that analysis here. So we may have to break the population into tertiles or quartiles or find thresholds to define who can do better or not."
"But as of now, the data that we have do not support that we should be cherry-picking patients here," he said. "If patients have the criteria to get into the COAPT trial, they should have a clip."
Last year,COAPTinvestigators reported that the MitraClip reduced the primary end point of HF hospitalizations at 2 years by 47% over guideline-directed medical therapy alone (GDMT), and reduced mortality by 38%.
The results were met with wild enthusiasm but also skepticism in light of the FrenchMITRA-FRtrial, which used the same device but showed no added benefit over medical therapy for the primary composite end point of all-cause death and unplanned hospitalization at 1 year.
Despite being unable to find echocardiographic nonresponders and using a relatively similar composite end point, 45.4% of patients treated with the MitraClip and 67.4% of patients treated with GDMT alone died or had a first HF hospitalization at 2 years, Asch reported.
He noted that expert panels have disagreed on how to define secondary MR severity, resulting in conflicting European and American guidelines. Although MITRA-FR used the European guidelines, COAPT adapted the American guidelines and created a three-tier screening protocol.
At baseline, 85.7% of the 665 patients met the tier1 criteria of an effective regurgitant orifice area (EROA) of at least 0.3cm2or pulmonary vein systolic flow reversal.
Another 10.5% of patients met the tier2 criteria of an EROA of 0.2cm2to less than 0.3 cm2with one of three additional criteria: regurgitant volume (RV) of at least 45mL/beat; regurgitant fraction (RF) of at least 40%; or vena contracta (VC) width of at least 0.5cm.