A New Bicaval Valve Implant Could Improve Outcomes in Some Heart Transplant Patients

By Lorraine L. Janeczko

November 15, 2021

NEW YORK (Reuters Health) - A new implanted bicaval valve (BCV) could improve tricuspid regurgitation in some heart-transplant patients with severe symptomatic tricuspid regurgitation, according to a new case report.

Tricuspid regurgitation is the most common valve disease after orthotopic heart transplantation, occurring in up to 84% of patients, and it may increase in incidence and severity over time.

"Our case demonstrates that BCV implantation in (heart transplantation) patients with severe symptomatic tricuspid regurgitation is feasible," the authors write in Circulation: Heart Failure.

Dr. Sumeet S. Mitter, a heart-transplant specialist at Mount Sinai Hospital in New York City who was not involved in the study, called the findings "intriguing."

"Given the right anatomy, this novel application of the Tricvalve bicaval valve system may be an opportunity to lessen the diuretic burden of heart-transplant patients afflicted with severe tricuspid regurgitation, reducing hepatic and renal venous congestion, leg swelling, abdominal bloating and trouble breathing with exertion, and potentially leading to fewer hospitalizations," Dr. Mitter told Reuters Health by email.

In the first bicaval-valve implant in a heart-transplant patient to treat severe symptomatic tricuspid regurgitation, Dr. Rafael Romaguera of the University of Barcelona, Spain, and colleagues treated a 67-year-old man who underwent heart transplantation with biatrial anastomosis technique in 1999 due to ischemic heart disease.

In 2003, the patient developed grade-1 allograft vasculopathy with preserved biventricular ejection. He was treated with tacrolimus and later with sirolimus combined with high-intensity statins to prevent disease progression. In 2017, he underwent axillobifemoral bypass surgery, and at that time, his tricuspid regurgitation was mild and his right ventricular function was normal.

In 2018, after a surveillance coronary angiogram and endomyocardial biopsy, new-onset severe tricuspid regurgitation was seen on transthoracic echocardiography. The patient was treated with diuretics, hydralazine, digoxin, and nitrates but developed severe New York Heart Association class-III dyspnea and signs of right heart failure.

Transthoracic echocardiography performed in 2020 showed persistent severe tricuspid regurgitation and new-onset right ventricular dysfunction. While a new endomyocardial biopsy showed no signs of rejection, a coronary angiogram revealed grade-2 progressive allograft vasculopathy with untreatable distal coronary lesions in left anterior descending and right coronary arteries.

Most devices available to treat the tricuspid regurgitation were inappropriate for this case for reasons including a large coaptation defect; risk of embolization, significant leak and cardiac rupture. Due to the high surgical risk, the heart team chose percutaneous treatment.

A bicaval valve (Tricvalve; Products&Features) was implanted using a venous transfemoral approach guided by transesophageal echocardiography. Immediate hemodynamic results included a 32 mm Hg atrial V wave and an abolished V wave in the patient's inferior and superior cava veins (14 mm Hg). His femoral vein was closed with Proglides (Abbott Vascular).

After four days, the patient was discharged on oral anticoagulant treatment. On four-dimensional volume-rendered computed tomography, a normal leaflet motion was visible with no contrast leakage to the cava veins. At six months, the man's functional status improved to New York Heart Association II functional class, the diuretic treatment was tapered, and heart failure did not recur.

On new transthoracic echocardiography, similar right ventricular dysfunction and absence of systolic reverse flow to cava veins were seen.

"In contrast to the well-established technique of transcatheter aortic valve replacement, percutaneous treatment of tricuspid regurgitation is fraught with several issues such as anatomic variability or challenging imaging," the authors write. "Compared with orthotopic valves, (bicaval valve) implantation is not technically demanding and may carry lower risk of cardiac injury. However, (bicaval valve) does not modify tricuspid regurgitation or RV function. By contrast, (bicaval valve) works by avoiding reverse systolic flow into superior and inferior cava veins, which decreases stress on liver and end organs and reduces signs and symptoms of right heart failure."

The authors recommend further related research to investigate the safety and potential long-term effects of this treatment on the right atrium and right ventricle.

"For this to become a mainstream viable solution," Dr. Mitter cautioned, "more examples of such implants would need to be performed showing that it is easily replicable and can be performed without many side effects or safety issues, including thrombus formation or even infections in this immunosuppressed population."

The authors reported no conflicts of interest. The study was not funded.

SOURCE: https://bit.ly/3ql7O3i Circulation: Heart Failure, online October 18, 2021.