The investigational FORMA system seems safe and may be effective in patients with NYHA Class III/IV heart failure and severe tricuspid valve regurgitation, based on 13 first-in-human cases.
A Canadian surgical team employed the FORMA system (Edwards Lifesciences) as compassionate use therapy for a set of patients with inoperable tricuspid regurgitation. The device was successfully deployed in 12 of the 13 patients, according to data presented at the Transcatheter Cardiovascular Therapeutics annual meeting. There were no deaths or major clinical complications in any of the patients.
A report on seven of these patients was simultaneously published in the Journal of the American College of Cardiology. All of the patients had severe tricuspid regurgitation and heart failure; before surgery, six had a New York Heart Association (NYHA) Functional Classification of III/IV. By 30 days after the procedure, all had improved to NYHA II, wrote Dr. Francisco Campelo-Parada of the Quebec Heart and Lung Institute, the paper’s primary author. Peripheral edema declined and all patients experienced functional improvement, as well.
According to Edwards Lifesciences, the FORMA device uses a foam-filled polymer balloon spacer to reduce tricuspid regurgitation by occupying the regurgitant orifice area and providing a surface for the coaptation of the valve’s native leaflets. Implantation is performed via the left axillary vein.
Patients in the series were a mean of 76 years old. All had severe tricuspid regurgitation. The mean maximal vena contracta was 15.5 mm.
Six had coronary artery disease and five had previously undergone open heart surgery. Additionally, two had previously undergone mitral valve surgery and two had undergone aortic valve surgery. Pulmonary hypertension was present in five. Five patients also had persistent atrial fibrillation. Six had renal insufficiency, with one patient on dialysis. The baseline furosemide dose was 80 mg/day.
All procedures were performed under general sedation and fluoroscopic guidance, with postprocedural positioning checked by cardiac-CT and/or a chest x-ray. The mean postop stay was 4 days.
Tricuspid regurgitation was reduced by at least 1 degree in all patients during the operation; four patients had an immediate 2-degree reduction, reclassifying their regurgitation as mild. Two experienced new-onset atrial fibrillation, and one had several episodes of nonsustained ventricular tachycardia that was managed with beta-blockers.
At the first clinical follow-up 30 days after surgery, all but one patient had an improvement to Class II NYHA status.
Two patients were able to reduce their diuretic dosage; there were no other medication changes. Peripheral edema declined in the entire cohort. Tricuspid regurgitation was graded as moderate in all patients.
There were also associated improvements in quality of life, based on scores on the Kansas City Cardiomyopathy Questionnaire, which increased from 59 before surgery to 86 after surgery. Exercise capacity as measured by the 6-Minute Walk Test improved from 297 meters to 326 meters.
The authors suggested that the 15-mm spacer used in the FORMA device was not well-matched with the mean 15.5-mm vena contracta size in the cohort. Better outcomes might be possible if a larger spacer were available.
“Despite good device positioning, complete coaptation was not achieved, resulting in significant residual degree of postprocedural tricuspid regurgitation,” they said. “Also, the very advanced stage of the disease in most patients may have played a role in the mild reduction at 30 days.”
Despite the rather mild, 1-degree improvement, patients did make considerable improvements in heart failure and functional status. Therefore, the team recommended further study for FORMA, with an eye toward optimizing patient selection.
“Specific criteria for quantifying right ventricular dysfunction and pulmonary hypertension, along with novel quantitative echocardiographic imaging criteria may be required,” they said. “It is conceivable that larger than the currently available spacer sizes may be required to improve echocardiographic results in patients with large noncoaptation defects and vena contracta.”
Dr. Campelo-Parada had no financial disclosures with regard to the device.