A novel know-how known as intravascular lithotripsy-facilitated percutaneous balloon mitral valvuloplasty (IVL-PBMV) exhibits promise for treating sufferers with extreme calcific mitral stenosis (MS) and no different surgical or transcatheter therapy choices. However till lately, proof of its worth has been sparse, consisting primarily of remoted case stories from numerous facilities.
The interventional cardiology and structural coronary heart workforce at Henry Ford Well being, Detroit, Michigan, reported its first use of the know-how in 2019 for an 81-year-old man with calcified mitral stenosis, a imply diastolic gradient of 11 mmHg, and New York Coronary heart Affiliation practical class III coronary heart failure. Though initially deemed “inoperable,” after IVL-PBMV, the person recovered neurologically intact.
Since then, the workforce has been utilizing the know-how for comparable difficult-to-treat sufferers. They lately reported a case sequence of 24 sufferers with extreme mitral annular calcification (MAC) and extreme MS handled at Henry Ford between 2019 and 2023.
“That is a particularly difficult group of sufferers to deal with, so any development or new choice in our armamentarium is vital,” Pedro Engel-Gonzalez, MD, senior workers doctor, Interventional Cardiology and Structural Coronary heart Interventions Middle for Structural Coronary heart Illness at Henry Ford instructed theheart.org | Medscape Cardiology.
“Kissing” Balloons
Conventional percutaneous mitral balloon valvuloplasty makes use of a big noncompliant balloon. The process will not be often carried out in older sufferers with extreme MS due to the chance of inflicting extreme mitral valve (MV) regurgitation. The upshot is these sufferers had been typically left untreated, Engel-Gonzalez mentioned.
The brand new method makes use of Shockwave balloons (Intravascular Shockwave Lithotripsy System/Shockwave Medical, Santa Clara, California), that are authorized, utilizing totally different catheters, for the therapy of calcified coronary and peripheral vascular arterial illness. This off-label use of the know-how goals to handle calcification in mitral valve illness.
Tailored from urologic lithotripsy used within the therapy of kidney stones, the intravascular lithotripsy system employs the same know-how to interrupt up calcium within the cardiovascular system by inflicting acoustic disruptions within the calcium it is available in contact with when inflated, Engel-Gonzalez defined.
“We noticed through intra-op transesophageal echocardiogram that after this therapy of the calcium on the leaflets and commissures, there’s higher pliability, which very seemingly mitigates the chance of extreme mitral regurgitation once we then stretch the valve with a extra conventional noncompliant balloon.”
The balloons within the Shockwave system had been supposed for the peripheral vasculature and so are comparatively small, he famous. Due to this fact, the interventional heart specialist wants to make use of the “kissing balloon” approach — inserting two or extra balloons collectively to realize complete contact with the valve partitions.
Within the case sequence, a single IVL balloon was used for just one affected person; two balloons had been utilized in 5 sufferers and three balloons in 18.
The workforce additionally makes use of a Sentinel system (Sentinel Cerebral Safety System, Boston Scientific) to guard the mind from any calcium or particles that may get dislodged through the valvuloplasty process, probably inflicting an embolic stroke. The system is actually a basket-type filter that sits within the brachiocephalic and left carotid artery through the process.
The Sentinel system was utilized in 17 of the 24 reported instances, however as a result of one affected person in whom it was not used had a stroke attributable to calcium embolizing to the mind, “we determined from that time on to make use of it for all sufferers” present process IVL-PBMV, Engel-Gonzalez mentioned. Notably, the affected person who had the stroke was handled by interventional radiologists, who had been capable of take away components of the calcium emboli.
Within the case sequence general, IVL-PBMV gave the impression to be secure and did lead to efficient discount within the mitral valve gradients. Nonetheless, outcomes diverse. One affected person had a residual MV imply gradient > 10 mm Hg, and 7 had a imply gradient > 5 mm Hg (gentle stenosis < 5 mm Hg).
Problems additionally occurred. One affected person skilled worsening mitral regurgitation from baseline, and one had an intraprocedural main complication — a proper ventricular perforation requiring pressing extracorporeal membrane oxygenation and surgical restore.
As well as, one affected person had a late pericardial effusion requiring pericardiocentesis. Two had simultaneous alcohol septal ablation and developed full coronary heart block, which required implantation of a everlasting pacemaker. As famous earlier, one in whom a Sentinel system was not used developed a periprocedural stroke.
Earlier than IVL-PBMV can be utilized extra broadly, bigger potential research are wanted to validate the single-center, retrospective sequence, the authors mentioned.
“The subsequent step could be a mechanistic examine to attempt to quantify as a lot as doable, through pre- and post-CT and echocardiographic evaluation, how IVL therapy is modifying the MV calcium and pliability of the leaflets,” Engel-Gonzalez mentioned. “We’d additionally prefer to collaborate with different facilities which may be all in favour of performing this process to create a multicenter registry to higher characterize efficacy, sturdiness, and security.”
As well as, he added, the workforce want to collaborate with a tool firm to develop a devoted IVL balloon for valvuloplasty procedures.
“Seems Promising”
“These knowledge present a proof of idea supporting the protection and effectiveness of this progressive process as a therapy for extreme calcific MS in sufferers which have very excessive or prohibitive surgical threat,” Hani Jneid, MD, a member of the Writing Committee for the 2020 AHA/ACC Pointers for the Administration of Sufferers with Valvular Coronary heart Illness, instructed theheart.org | Medscape Cardiology.
“It is rather unlikely {that a} randomized trial will ever be carried out to prospectively study the efficacy of this system,” mentioned Jneid, who’s chief, Division of Cardiovascular Drugs and medical director, Cardiovascular Service Line on the College of Texas Medical Department in Galveston, Texas. “You will need to notice that this a small case sequence from a tertiary middle, and the outcomes must be confirmed by different facilities and operators and in a bigger variety of sufferers.”
Like Engel-Gonzalez, he famous that “sustaining a potential and detailed medical registry to look at security and effectiveness endpoints, together with long-term hemodynamic and exhausting outcomes, is critically vital to adequately study and refine this progressive approach.”
Nonetheless, “PBMV seems promising and helped obtain a median discount in transmitral valve gradient of > 5 mm Hg, which is clinically significant,” he added. Nonetheless, the long-term security outcomes, together with MR, stroke, and pericardial issues, will must be examined, as nicely.
“I doubt it’ll have as a giant a therapeutic position as transcatheter mitral valve substitute or valve-in-MAC,” Jneid famous. “I additionally see no position for this know-how in sufferers with extreme rheumatic MS, the place PBMV has established security and efficacy and has a Class I indication by ACC/AHA pointers.”
“Utilizing PBMV off-label by skilled operators in complete valve facilities and in choose sufferers is cheap,” Jneid mentioned, “so long as it’s thought of in a shared-decision making mannequin with the affected person and after deliberations concerning the dangers, advantages, and alternate options to this remedy.”
Engel-Gonzalez and Jneid had no related relationships to reveal.
Marilynn Larkin, MA, is an award-winning medical author and editor whose work has appeared in quite a few publications, together with Medscape Medical Information and its sister publication MDedge, The Lancet (the place she was a former contributing editor), Reuters Well being, and Scientific American.