LAMPOON before TMVR improves symptoms without complications, long-term data confirm
Laceration of the anterior mitral leaflet to prevent outflow obstruction (LAMPOON) is a safe and effective long-term strategy for preventing left ventricular outflow tract (LVOT) obstruction after transcatheter mitral valve replacement (TMVR), according to new data published in JACC: Cardiovascular Interventions.[1]
LVOT obstruction remains a “major limitation of TMVR,” the authors wrote. The LAMPOON technique’s potential to limit LVOT obstruction has been a popular topic in interventional cardiology in recent years.
LAMPOON was previously linked to positive outcomes after 30 days, including a survival rate of 97% and no strokes, but the study’s authors hoped to paint a much more complete picture of the procedure’s value.
This updated analysis of the LAMPOON clinical trial included data from 30 TMVR patients treated in the United States form June 2017 to June 2018. The median patient age was 76 years old, and 73% were women. While 13% of patients were on dialysis for end-stage renal disease, another 13% presented with severe liver cirrhosis, and 20% were on home oxygen or severe pulmonary disease. All patients faced an increased risk of LVOT obstruction at the time of treatment.
All patients underwent LAMPOON prior to undergoing TMVR with an Edwards Lifesciences Sapien 3 valve. As a result of the LAMPOON technique, the patient’s anterior leaflet splays away from the LVOT following TMVR, which allows blood to flow through the open cells of the transcatheter heart valve.
Overall, survival was 65% after one year and 25% after five years. For patients treated with valve-in-ring TMVR, survival was 86% after one year and 36% after five years. For those treated with valve-in-MAC TMVR, however, survival was 44% after one year and 15% after five years.
The stroke rate was 0% after one year, 15% after two and then there were no additional strokes up to the five-year point. In addition, there were no myocardial infarctions at one year, two years or five years. Heart failure hospitalizations were seen in 20% of patients after one year and then 30% after five years.
In terms of quality of life, on the other hand, Kansas City Cardiomyopathy Questionnaire scores suggested patients experienced significant improvements in their overall symptoms. Six-minute walk distances also consistently increased.
Shifting to valve and hemodynamic data, the mean mitral valve gradient was 6.7 mmHg at 30 days and 6.2 mmHg at one year. Moderate or severe paravalvular leak was seen in 3.7% of patients after 30 days and 7.1% at one year. LVOT gradients “remained low,” with no patients presenting with an LVOT gradient of more than 30 mmHg after one year.
Mitral valve thrombosis was seen in 13% of patients after 30 days, meanwhile, and it recurred in a single patient.
“Patients at risk for LVOT obstruction because of long anterior mitral valve leaflets or small predicted neo-LVOTs in the setting of TMVR with an open-cell transcatheter heart valve are eligible for LAMPOON,” wrote first author Jaffar M. Khan, MD, PhD, a cardiologist with the National Heart, Lung and Blood Institute and St. Francis Hospital and Heart Center, and colleagues. “This study demonstrated universal success in leaflet traversal and laceration, even in the very early experience with this technique. No candidate was excluded because of excessive leaflet calcification; LAMPOON was technically successful even in patients with a confluent bar of calcium across the anterior leaflet.”
The authors also discussed the relatively low survival rates seen in their analysis.
“Two-thirds of the patients enrolled in this study had manifest end-organ failure at baseline and were expected to have poor long-term survival despite effective treatment of their mitral valve disease,” they wrote.
Khan et al. concluded by highlighting the importance of investigating dedicated devices for both LAMPOON and TMVR.
Read the team’s full analysis here.
Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.