Researchers at the National,
Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of
Health (NIH), have developed a novel technique that prevents the obstruction of
blood flow, a common fatal complication of transcatheter mitral valve
replacement (TMVR). The new method, called LAMPOON, may increase treatment
options for high-risk patients previously ineligible for heart valve
procedures. The findings are published in the Journal of the American College
of Cardiology online on May 20, 2019.
TMVR is used to treat mitral
valve stenosis, a narrowing of the valve that restricts blood flow into the
main pumping chamber of the heart. It also treats regurgitation, which occurs
when the valve leaks and causes blood to flow back through the valve.
Untreated, these conditions can cause pulmonary hypertension, heart
enlargement, atrial fibrillation, blood clots and heart failure.
For elderly or frail patients,
TMVR offers a less invasive alternative to open heart surgery. During TMVR,
doctors replace the mitral valve by delivering an artificial valve through a
catheter, through blood vessels and into the heart. But in more than 50% of
patients, the heart’s anatomy gets in the way. The heart leaflet is pushed back
and blocks blood flow. This is known as left ventricular outflow tract (LVOT)
obstruction, a common and the most life-threatening complication of TMVR.
To increase the availability
of TMVR for this subset of patients, Khan and colleagues at NHLBI and Emory
University developed a procedure that makes an intentional laceration of the
anterior mitral leaflet to prevent left ventricular outflow tract obstruction,
dubbed LAMPOON.
In the LAMPOON procedure, the
operator inserts two catheters through the patient’s groin, and then through
the blood vessels until it reaches the heart. The doctor then uses an
electrified wire the size of a sewing thread woven through the catheter to
split open the leaflet. At that point, the patient is ready to undergo TMVR.
Surgeons cut out the leaflets when
they replace valves. They can do it, because they have cut open the chest and
the heart and can clearly see the problem. LAMPOON is designed for patients who
need a new mitral valve, but can’t, or may not want to undergo open heart
surgery.
Between June 2017 and June
2018, the LAMPOON study enrolled 30 patients, median age 76, considered at high
risk for surgical valve replacement and at prohibitive risk of LVOT obstruction
during TMVR.
All patients survived the
procedure and 93% reached the 30-day survival mark, which compares favorably to
a 38% reported with other methods. The primary outcome of the study, which
combined a successful LAMPOON, followed by a successful TMVR without
reintervention, was achieved in 73% of the patients.
(Source: NIH)
Dr KK Aggarwal
Padma Shri
Awardee
President Elect Confederation of
Medical Associations in Asia and Oceania
(CMAAO)
Group
Editor-in-Chief IJCP Publications
President Heart
Care Foundation of India
Past National President
IMA
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