Photo Credit: Mohammed Haneefa Nizamudeen
With appropriate patient selection, alcohol septal ablation has demonstrated efficacy and safety in people with cardiomyopathy.
The decision to pursue alcohol septal ablation (ASA) in patients with hypertrophic cardiomyopathy (HCM) is complex and requires thorough patient selection with a collaborative team approach, according to a paper published in The American Journal of Cardiology.
Pharmacologic therapy remains the cornerstone of HCM treatment. Another approach, septal myectomy (SM), is an open surgical procedure that carries the standard risks of open cardiac surgeries, such as stroke, renal failure, and prolonged recovery and hospitalization.
A third approach, ASA, is a percutaneous, minimally invasive alternative. This procedure typically is reserved for high-risk surgical candidates because of safety concerns that were mostly theoretical, according to Atul D. Bali, MD, and coauthors.
“With the dramatic increase in data demonstrating the safety and efficacy of ASA as a staple septal reduction therapy method, the use of this method for reducing LVOT (left ventricular outflow tract) obstruction is no longer restricted to older patients with prohibitive risk for cardiac surgery. Instead, ASA is being offered to a broader cohort of appropriately selected patients,” the researchers said.
Patient Eligibility & Selection
Patient and center selection are key to success in performing ASA. To optimize safety outcomes, the authors recommended a comprehensive evaluation at a multidisciplinary center with extensive experience in all forms of HCM management, including surgical and percutaneous septal reduction therapy procedures.
Younger patients tend to have more extended septal or massive hypertrophy, for which SM may be a better option. Patients with more focal hypertrophy, especially those with myocardial wall thickness less than 2.5 cm, tend to have better ASA outcomes than older patients. Citing existing literature, Dr. Bali and coauthors noted that young men may have the best safety outcomes with ASA rather than SM.
Patients must meet multiple criteria to be considered for ASA:
- Medication-refractory symptoms (New York Heart Association class III/IV and, occasionally, II in younger patients or those with presyncope or syncope);
- LVOT obstruction with gradient at rest >30 or >50 mm Hg with provocable maneuvers;
- Basal septal thickness meeting criteria for HCM (>15 mm);
- Absence of a need for another open cardiac surgery (eg, valve replacement or coronary artery bypass graft); and
- Adequate volume, operator, and institutional experience, and adequate septal perforators, in size and location, to target the myocardium.
After an electrocardiogram, patients must undergo an invasive hemodynamic evaluation and a coronary angiogram for clinicians to make the final decision to proceed with ASA, the authors explained.
“If criteria are met after a thorough evaluation, then, per the most recent studies and current HCM guidelines, there is a class 1 recommendation for either form of septal reduction therapy, either SM or ASA, to be offered as therapy for patients with medication-refractory symptoms of obstructive HCM,” Dr. Bali and colleagues said.
ASA Benefits & Risks
The most common AE after ASA is temporary or complete atrioventricular block requiring a permanent pacemaker. Since the heart block’s presentation may be delayed up to 96 hours after the ASA, the authors recommended monitoring the patient by daily electrocardiograms, continuous telemetry, and maintained temporary transvenous pacemaker (TVP) positioning for at least three days following the procedure. Patients are at greater risk for complete heart block if they are older, female, or have pre-existing conduction abnormalities, such as first-degree atrioventricular block or left bundle branch block.
Major AEs are rare when a seasoned operator conducts the procedure in an experienced center.
“Nonetheless, immediate postprocedural monitoring is done in a cardiac critical care unit setting for 1 to 2 days to allow close surveillance of telemetry, frequent electrocardiography, and blood work every 6 hours (until peak) to track cardiac enzymes for the size of the infarct,” the authors wrote. “After the first 24 to 48 hours, the risk for the aforementioned rare, acute major AEs, such as mechanical complications or sustained ventricular arrhythmias, has passed, and patients can be transferred to a standard telemetry floor for continued monitoring without any specific ambulatory or activity restrictions, with the semipermanent TVP in place.”
ASA yields significant long-term benefits in patients with HCM, such as reductions in left atrial volume, atrial fibrillation, and secondary pulmonary hypertension. Dr. Bali and coauthors emphasized that clinicians must carefully and precisely select patients for the procedure.
“Although the two septal reduction therapies are comparable, some patients are best suited anatomically and hemodynamically for myectomy, whereas others are ideally suited for ASA,” they explained. “This makes the availability of an experienced heart team imperative to assure optimal safety and efficacy outcomes, with minimal to no procedure crossover.”
