Long-term follow-up of the first patients to undergo transcatheter alcohol septal ablation

Transcatheter septal ablation in hypertrophic obstructive cardiomyopathy: a technical guide and review of published results

Transcatheter alcohol septal ablation (ASA) treatment of symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM) is based on the existence and degree of intraventricular obstruction. Patients with significant gradient and symptoms who do not respond to optimal medical therapy are eligible to gradient reduction through a surgical (septal myectomy) or a transcatheter (alcohol septal ablation) septal reduction. The latter encompasses occlusion of a septal branch perfusing the hypertrophied septum, which is involved in the generation of obstruction, by injecting ethanol into the supplying septal branch(es). ASA has been established as a highly effective and safe method and has outnumbered the surgical gold standard. Although the technique is straightforward, patient selection and some technical details may influence the efficacy and safety of the procedure. The technique is based on echocardiographic contrast guidance, which allows accurate target septal branch selection and optimisation of the result. Published long-term results from high-volume centres have confirmed the effectiveness of ASA and have shown excellent survival, which is comparable to that in the general population. Choice and performance of the surgical or interventional treatment should be implemented in highly specialised centres in terms of a heart-team approach, taking notice of anatomic characteristics as well as comorbidities. Involvement of all cases in international registries may reveal the individual merits and indications for the surgical and interventional treatment in HOCM.

Alcohol septal ablation vs myectomy for symptomatic hypertrophic obstructive cardiomyopathy: Systematic review and meta-analysis

BACKGROUND

Surgical myectomy (SM) and Alcohol septal ablation (ASA) are effective therapies for patients with hypertrophic cardiomyopathy who remain symptomatic despite medical therapy. A plethora of data has recently emerged on the long-term outcomes of these procedures. We hence sought to perform an updated meta-analysis comparing both procedures.

METHODS

Studies reporting long-term (>3-years) outcomes of SM and/or ASA were included. The primary endpoint was all-cause mortality. Secondary endpoints included cardiovascular mortality, sudden cardiac death (SCD), reintervention, and complications including death, pacemaker implantation, and stroke.

RESULTS

Twenty-two ASA cohorts (n = 4213; follow-up = 6.6-years) and 23 SM cohorts (n = 4240; follow-up = 6.8-years) were included. Septal myectomy was associated with higher periprocedural mortality and stroke (2% vs 1.2%, P = 0.009 and 1.5% vs 0.8% P = 0.013, respectively), but ASA was associated with more need of pacemaker (10% vs 5%, P < 0.001). During long-term follow-up, all-cause mortality, cardiovascular mortality, and sudden cardiac death rates were 1.5%, 0.4%, and 0.3% per person-year in the ASA group and 1.1%, 0.5%, and 0.3% per person-year in the SM group (P = 0.21, P = 0.53, P = 0.43), respectively. Repeat septal reduction intervention(s) were more common after ASA (11% vs 1.5%, P < 0.001).

CONCLUSION

Compared with SM, ASA is associated with lower periprocedural mortality and stroke but higher rates of pacemaker implantations and reintervention. However, there was no difference between ASA and SM with regards to long-term all-cause mortality, cardiovascular mortality, or SCD.

Alcohol Septal Ablation for Obstructive Hypertrophic Cardiomyopathy: A Word of Endorsement

Twenty years after the introduction of alcohol septal ablation (ASA) for the treatment of obstructive hypertrophic cardiomyopathy, the arrhythmogenicity of the ablation scar appears to be overemphasized. When systematically reviewing all studies comparing ASA with myectomy with long-term follow-up, (aborted) sudden cardiac death and mortality rates were found to be similarly low. The focus should instead shift toward lowering the rate of reinterventions and pacemaker implantations following ASA because, in this area, ASA still seems inferior to myectomy. Part of the reason for this difference is that ASA is limited by the route of the septal perforators, whereas myectomy is not. Improvement may be achieved by: 1) confining ASA to hypertrophic cardiomyopathy centers of excellence with high operator volumes; 2) improving patient selection using multidisciplinary heart teams; 3) use of (3-dimensional) myocardial contrast echocardiography for selecting the correct septal (sub)branch; and 4) use of appropriate amounts of alcohol for ASA.

Obstruction after alcohol septal ablation is associated with cardiovascular mortality events

BACKGROUND

Left ventricular outflow tract obstruction (≥30 mm Hg at rest; LVOTO) is considered a possible risk of long-term outcomes in patients with hypertrophic cardiomyopathy (HCM). However, the influence of LVOTO on the occurrence of cardiovascular mortality events in patients after alcohol septal ablation (ASA) for obstructive HCM remains unresolved.

METHODS

We compared the outcomes of patients treated with ASA with residual LVOTO <30 mm Hg with those with residual LVOTO ≥30 mm Hg at the first postdischarge check-up (1-6 months after the procedure).

RESULTS

A total of 270 patients (60±12 years, median follow-up 5.1 years; 95% CI 4.5 to 5.9 years) treated with a single ASA were included; 208 (77%) and 62 (23%) patients had post-ASA LVOTO <30 and ≥30 mm Hg at the first postdischarge clinical check-up, respectively (LVOTO 13±6 vs 50±27 mm Hg; p<0.01). Freedom from cardiovascular mortality events at 1, 5 and 10 years were 99% (95% CI 96% to 100%) vs 94% (95% CI 85% to 98%), 95% (95% CI 89% to 97%) vs 80% (95% CI 66% to 89%) and 82% (95% CI 69% to 89%) vs 72% (95% CI 55% to 84%) (log-rank test, p<0.01), respectively. In multivariable analysis adjusted for age at ASA, sex, baseline LVOTO and baseline septum thickness, the independent predictors of cardiovascular mortality events were early postdischarge LVOTO ≥30 mm Hg (HR 2.95, 95% CI 1.26 to 6.91; p=0.01) and baseline septum thickness (HR 1.07, 95% CI 1.01 to 1.13; p=0.02).

CONCLUSIONS

After ASA for obstructive HCM, LVOTO ≥30 mm Hg at the first postdischarge clinical check-up is associated with significantly higher occurrence of subsequent cardiovascular mortality events.

Intervention in HCM: patient selection, procedural approach and emerging techniques in alcohol septal ablation

Hypertrophic cardiomyopathy (HCM) is a highly heterogeneous disease with varied patterns of hypertrophy. Basal septal hypertrophy and systolic anterior motion (SAM) of the mitral valve (MV) are the key pathophysiological components to left ventricular outflow tract (LVOT) obstruction in HCM. LVOT is associated with higher morbidity and mortality in patients with HCM. Percutaneous septal reduction therapy with alcohol septal ablation (ASA) can lead to a significant improvement in left ventricle haemodynamics, patient symptoms and perhaps prognosis. ASA delivers pure alcohol to an area of myocardium via septal coronary arteries; this creates damage to tissue akin to a myocardial infarction. The basal septal myocardium involved in SAM-septal contact is the target for this iatrogenic infarct. Appropriate patient selection and accurate delivery of alcohol are critical to safe and effective ASA. Securing the correct diagnosis and ensuring suitable cardiac anatomy are essential before considering ASA. Pre-procedural planning and intra-procedural imaging guidance are important to delivering precise damage to the desired area. The procedure is performed worldwide and is generally safe; the need for a pacemaker is the most prominent complication. It is successful in the majority of patients but room for improvement exists. New techniques have been proposed to perform percutaneous septal reduction. We present a review of the relevant pathophysiology, current methods and a summary of available evidence for ASA. We also provide a glimpse into emerging techniques to deliver percutaneous septal reduction therapy.

Left ventricular systolic function following alcohol septal ablation for symptomatic hypertrophic cardiomyopathy

Because alcohol septal ablation (ASA) for the treatment of symptomatic hypertrophic cardiomyopathy (HC) with left ventricular (LV) outflow tract (LVOT) obstruction results in a myocardial infarct of up to 10% of ventricular mass, LV systolic function could decline over time. We evaluated LV function during longitudinal follow-up in a cohort of patients who underwent ASA. We studied 145 consecutive patients with HC that underwent 167 ASA procedures from 2002 to 2011. Echocardiographic follow-up was available in 139 patients (96%). Echocardiographic indexes included LV ejection fraction (LVEF), mitral regurgitation severity, systolic anterior motion of the anterior mitral leaflet, and resting and provoked LVOT gradients. All patients had a baseline LVEF of >55%. LVEF was preserved in 97.1% of patients over a mean follow-up time of 3.1±2.3 years (maximum 9.7). Mild LV systolic dysfunction was observed (LVEF range 44% to 54%) in only 4 patients. Mitral regurgitation severity improved in 67% (n=112 of 138 with complete data). Resting LVOT gradient declined from a mean of 75 to 19 mm Hg (p<0.001), and provoked gradient declined from a mean of 101 to 33 mm Hg (p<0.001). New York Heart Association class improved from a mean of 2.9±0.4 to 1.3±0.5 (p<0.001). In conclusion, LV systolic function is only mildly reduced in a minority of patients after ASA for symptomatic HC; other echocardiographic and functional measures were significantly improved.

Coronary-cameral fistulas in adults: Acquired types (second of two parts)

Acquired coronary artery fistulas (CCFs) are infrequently detected during conventional coronary angiography. To delineate the characteristics of congenital (first part) and acquired (second part) CCFs in adults, a PubMed search was conducted for papers dealing with congenital or acquired CCFs. None of the publications describing patients with coronary-vascular fistulas were included. Papers dealing with pediatric subjects were excluded. From the world literature, a total of 243 adult patients were selected who had congenital (n = 159/243, 65%) and acquired (n = 84/243, 35%) CCFs. Among the acquired types (n = 72, 85.7%) were traumatic (iatrogenic (n = 65/72, 90%), accidental (n = 7/72, 10%) and (n = 12, 14.3%) spontaneously developing in relation to severe coronary atherosclerosis or myocardial infarction. A high incidence of spontaneous resolution of iatrogenic CCFs resulting from endomyocardial biopsy or following post-septal myectomy was reported. Spontaneous CCFs associated with myocardial ischemia or infarction resolved completely in 8% of the subjects. Early surgical intervention was the treatment of choice in acquired traumatic accidental CCFs. The congenital types are addressed in a previous issue of this journal (first part). In this review (second of two parts, part II), we describe the acquired coronary-cameral fistulas.

A decade of percutaneous septal ablation in hypertrophic cardiomyopathy

Percutaneous septal ablation has emerged as a less invasive treatment of symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). In the past decade, the availability of this sophisticated technique has revived the interest of cardiologists in left ventricular outflow tract obstruction, which led to the recognition that most patients with HCM have the obstructive type. Follow-up studies have already shown the safety and efficacy of the procedure, which offers symptomatic relief in most patients. Long-term survival is comparable to historical reports after surgical myectomy. Complications are rare and can be further reduced with increased experience of the operators, and the theoretical concern for possible ventricular arrhythmogenicity of the myocardial scar has not been documented by the existing data. Although there are still no randomized trials, percutaneous septal ablation is undeniably a viable alternative for patients with HOCM.