Predictors of Complete Heart Block After Alcohol Septal Ablation for Hypertrophic Cardiomyopathy and the Timing of Pacemaker Implantation

Predictors of cardiovascular implantable electronic device dependence at long-term follow-up after alcohol septal ablation in hypertrophic cardiomyopathy patients

BACKGROUND

The most common complication of alcohol septal ablation (ASA) is transient periprocedural high-grade AV block (HGAVB). To date, no long-term follow-up of cardiovascular implantable electronic device (CIED) utilization after ASA has been reported. We hypothesized that CIED dependence on long-term follow-up can be predicted by ECG or procedural characteristics.

METHODS

We analyzed all patients with HCM who underwent ASA from December 1998 to December 2019 and received their first CIED within 30 days after ASA for HGAVB. All follow-up interrogations were reviewed. CIED dependence was defined as ventricular pacing of ≥ 5%.

RESULTS

A total of 138 patients with HCM underwent ASA. Of these, 35 had a prior device and were excluded. Of the remaining 103 patients, 25 patients received a CIED for HGAVB within 30 days after ASA. Average follow-up duration was 10.1 years. On long-term follow-up, 16 patients (64%) were found to be CIED-dependent. Baseline characteristics, including pre- and post-ASA ECG, were not significantly different between dependent and non-dependent patients. The only predictor for CIED dependence was > 1 ml of alcohol injected (OR 6.0, p = 0.031).

CONCLUSIONS

CIED implantation after ASA is common. Almost two thirds of patients who received a CIED for post-procedural HGAVB were CIED-dependent on long-term follow-up. CIED dependence can be predicted by the amount of injected alcohol > 1 ml.

Predicting complete heart block after alcohol septal ablation for hypertrophic cardiomyopathy using a risk stratification model and clinical tool

BACKGROUND

Alcohol septal ablation (ASA) is a proven method of septal reduction for patients with drug refractory, symptomatic hypertrophic obstructive cardiomyopathy (HOCM). This procedure is associated with a 6.5-11% risk of complete heart block (CHB).

OBJECTIVE

The aim of this study is to determine factors that predict CHB and to develop a clinical tool for risk stratification of patients.

METHODS

Patients were enrolled into an ongoing ASA study. A total of 636 patient procedures were included, 527 of whom were used in the development of the prediction tool, and 109 of whom were used for independent validation. Multivariate analysis was performed with odds ratios used to develop the clinical prediction tool. This was then internally and externally validated.

RESULTS

Of the 527 in the prediction cohort, 46 developed CHB. The predictors of CHB were age ≥50 years, pre-ASA left bundle branch block (LBBB), transient procedural high-grade block, post-ASA PR prolongation ≥68 ms, and new bifascicular block. An 11-point clinical prediction tool was developed to classify these factors. Internal validation using a receiver operating characteristic curve revealed an area under the curve of 0.88 for the clinical prediction tool. External validation using 109 contemporary patients revealed a 98% negative predictive value, 24% positive predictive value, 75% sensitivity, and 81% specificity in high-risk patients.

CONCLUSION

Among patients undergoing ASA, the risk of CHB can be predicted with easily obtained clinical and electrocardiographic factors. This clinical prediction tool allows identification of high-risk patients who may benefit from additional monitoring and therapy.

Haemodynamic Interplay Between Concomitant Left Ventricular Outflow Tract Obstruction and Aortic Stenosis

The authors describe a patient with hypertrophic cardiomyopathy with concomitant left ventricular outflow tract obstruction and aortic stenosis. Detailed haemodynamic assessment of the serial lesions was performed. Alcohol septal ablation resulted in a significant reduction of gradients across the left ventricular outflow tract.

Alcohol Septal Ablation: An Option on the Rise in Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) can cause symptoms due to the obstruction of the left ventricle outflow tract (LVOT). Although pharmacological therapy is the first step for treating this condition, many patients do not fully respond to the treatment, and an invasive approach is required to manage symptoms. Septal reduction therapies include septal myectomy (SM) and alcohol septal ablation (ASA). ASA consists of a selective infusion of high-grade alcohol into a septal branch supplying the basal interventricular septum to create an iatrogenic infarction with the aim of reducing LVOT obstruction. Currently, SM and ASA have the same level of indication; however, ASA is normally reserved for patients of advanced age, with comorbidities or when the surgical approach is not feasible. Recent data suggests that there are no differences in short- and long-term all-cause mortality, cardiovascular mortality and sudden cardiac death between ASA and SM. Despite the greater experience and refinement of the technique gained in recent years, the most common complication continues to be complete atrio-ventricular block, requiring a permanent pacemaker. Septal reduction therapies should be performed in experienced centres with comprehensive programs.

Unmet needs in the treatment of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a complex heterogeneous cardiovascular disorder characterized by hypertrophied and disorganized myocytes with varying degrees of interstitial fibrosis. The current management strategies include genetic and familial screening, symptom control and prevention of sudden cardiac death in those at high risk. Until recently, septal reduction therapy and heart transplantation were the only disease modifying treatments available to manage HCM, but emerging pharmacotherapies show promising results in controlled clinical trials. In this article, we will review the unmet needs in the treatment of HCM incorporating novel therapies.

Alcohol-induced right bundle branch block is associated with a benign outcome in HOCM after alcohol septum ablation (ASA)

INTRODUCTION

Alcohol septum ablation (ASA) is a treatment option for hypertrophic obstructive cardiomyopathy (HOCM). We examined the impact of ASA-induced bundle branch block (BBB) on clinical and hemodynamic features.

METHODS AND RESULTS

We retrospectively analysed 98 HOCM patients with regard to ASA-induced BBB. Clinical examination was performed at baseline, early after ASA and at chronic follow-up (FU). ASA reduced left ventricular outflow tract gradient (LVOTG) during chronic FU (69.2 ± 41.6 pre vs. 31.8 ± 30.3 mmHg post ASA; p < 0.05) and interventricular septal diameter (21.7 ± 3.4 pre vs. 18.7 ± 5.0 mm post ASA; p < 0.05). ASA-induced early right BBB (RBBB) until discharge was observed in 44.9% and chronic RBBB at FU in 32.7%. Left BBB (LBBB) occurred in 13.3% early after ASA and in only 4.1% at chronic FU. Chronic RBBB was associated with more pronounced exercise-induced LVOTG reduction (102.1 ± 55.2 with vs. 73.6 ± 60.0 mmHg without; p < 0.05). 6-min-walk-test (6-MWT) and NYHA class were not affected by RBBB. LBBB had no influence on LVOTG, 6-MWT and symptoms. More ethanol was injected in patients with early RBBB (1.1 ± 0.4 vs. 0.8 ± 0.3 ml without; p < 0.05), who also showed higher mean CK release (827 ± 341 vs. 583 ± 279 U/l without; p < 0.05). Pacemaker implantation during FU was necessary in 11.5% of patients with early RBBB, 3.1% with chronic RBBB, 7.7% with early LBBB and 0% with chronic LBBB (p = n.s. for BBB vs. no BBB).

CONCLUSION

ASA-induced RBBB is associated with a higher volume of infused ethanol and higher maximum CK release. RBBB does not adversely affect the clinical outcome or need for pacemaker implantation but was associated with higher exercise-induced LVOTG reduction during chronic FU.

Cardiac implantable electronic device placement following alcohol septal ablation for hypertrophic cardiomyopathy in the United States

BACKGROUND

Cardiac implantable electronic devices (CIED) are sometimes required after alcohol septal ablation (ASA) for hypertrophic cardiomyopathy (HCM). The primary objectives of this study were to characterize the incidence, timing, and predictors of CIED placement after ASA for HCM.

METHODS

Patients were identified from the 2010-2015 Nationwide Readmissions Databases. Incidence, timing and independent predictors of CIED placement, as well as 30-day readmission rates were examined.

RESULTS

There were 1296 patients (national estimate = 2864) with HCM who underwent ASA. CIED were implanted in 322 (25% overall; 14% permanent pacemaker, 11% implantable cardioverter defibrillator) during the index hospitalization. Of these, 21%, 23%, 21%, and 18% occurred on postprocedure day 0, 1, 2, and 3, respectively. Only 17 (1.3%) patients underwent CIED implantation between discharge and 30-day follow up. Independent predictors of index hospitalization CIED implantation included older age, diabetes, heart failure, nonelective index hospital admission and hospitalization at a privately owned hospital. Nonelective 30-day readmission rates among those who did and did not undergo CIED placement during their index hospitalization, were 6.8% and 7.9%, respectively (p = .53); median time to readmission was also similar between groups.

CONCLUSIONS

One in four HCM patients undergoing ASA underwent CIED implantation during their index hospitalization; nearly 2/3rd during the first 48 h postprocedure. Private hospital ownership independently predicted CIED placement. More data are needed to better understand the unexpectedly high rates of CIED placement, earlier than anticipated timing of implantation and differential rates by hospital ownership.

Retrospective Analysis of Risk Factors for Related Complications of Chemical Ablation on Hypertrophic Obstructive Cardiomyopathy

Background

The analysis of risk factors for predicting related complications has not been reported to date.

Objective

This study aims to investigate the risk factors of related complications of percutaneous transluminal septal myocardial ablation (PTSMA) for hypertrophic obstructive cardiomyopathy (HOCM) retrospectively.

Method

Clinical data, and one-year follow-up results of patients with HOCM, who underwent PTSMA between January 2000 and July 2013 in the Department of Cardiology, Liaoning Province People’s Hospital, Liaoning Province, China, were retrospectively analyzed to determine risk factors for operative complications with multiple logistic regression analysis. All p values are two-sided, with values of p < 0.05 being considered statistically significant.

Results

Among 319 patients with HOCM, PTSMA was performed in 224 patients (120 males and 104 females, mean age was 48.20 ± 14.34 years old). The incidence of PTSMA procedure-related complications was 36.23% (66/224), which included three cardiac deaths, two cardiac shocks, one ST-segment elevated myocardial infarction, two ventricular fibrillations, 20 third-degree atrioventricular (AV) blocks (four patients were implanted with a permanent pacemaker (PPM)), 32 complete right bundle branch blocks, two complete left bundle branch blocks, and four puncture-related complications. After multivariate logistic regression analysis, it was found that age, gender, coronary artery diseases, diabetes, heart rate, cardiac function on admission, the number of septal ablations, and the volume of alcohol were not independent risk factors correlated to the whole complications, except for hypertension (OR: 4.856; 95% CI: 1.732-13.609). Early experience appears to be associated with the occurrence of complications.

Conclusion

Hypertension was an independent risk factor for PTSMA procedure-related complications. It might be much safer and more efficient if PTSMA procedures are restricted to experienced centers, according to the analysis results for the learning curve.

Effect of impaired cardiac conduction after alcohol septal ablation on clinical outcomes: insights from the Euro-ASA registry

Aims

We analysed the impact of bundle branch block (BBB) and pacemaker (PM) implantation on symptoms and survival after alcohol septal ablation (ASA) in patients with hypertrophic cardiomyopathy (HCM).

Methods and results

Among 1416 HCM patients from the Euro-ASA registry, 58 (4%) patients had a PM and 64 (5%) patients had an implantable cardioverter-defibrillator (ICD) before ASA. At latest follow-up (5.0 ± 4.0 years) after ASA, 118 (8%) patients had an ICD and 229 (16%) patients had a PM. In patients without an implantable device prior to ASA 13% had a PM and 5% had an ICD implanted following ASA. New onset BBB was present in 44% (right BBB in 31%) of patients without previous BBB. At latest follow-up, we found no associations between BBB and New York Heart Association (NYHA) Class 3–4 [odds ratio (OR) 0.98, 95% confidence interval (CI) 0.63–1.51; P = 0.91] or Canadian Cardiovascular Society (CCS) Class 3–4 (OR 1.5, CI 0.32–6.7; P = 0.62), respectively, and no associations between PM and NYHA Class 3–4 (OR 1.2, CI 0.70–2.0; P = 0.52) or CCS 3–4 (OR 1.3, CI 0.24–6.6; P = 0.79), respectively. The survival after ASA was not reduced in patients with BBB [hazard ratio (HR) 0.73, CI 0.53–1.01; P = 0.06] or PM (HR 0.78, CI 0.52–1.17; P = 0.24).

Conclusions

Development of BBB or need for a PM after ASA in patients with obstructive HCM was not associated with inferior symptomatic outcome or reduced survival, thus concerns for the negative impact of impaired cardiac conduction on the clinical outcome after ASA were not confirmed.

Value of electro-vectorcardiogram in hypertrophic cardiomyopathy

The electrocardiogram is an important tool for the initial diagnostic suspicion of hypertrophic cardiomyopathy in any of its forms, both in symptomatic and in asymptomatic patients because it is altered in more than 90 percent of the cases. Electrocardiographic anomalies are more common in patients carriers of manifest hypertrophic cardiomyopathy and the electrocardiogram alterations are earlier and more sensitive than the increase in left ventricular wall thickness detected by the echocardiogram. Nevertheless, despite being the leading cause of sudden death among young competitive athletes there is no consensus over the need to include the method in the pre-participation screening. In apical hypertrophic cardiomyopathy the electrocardiographic hallmarks are the giant negative T waves in anterior precordial leads. In the vectorcardiogram, the QRS loop is located predominantly in the left anterior quadrant and T loop in the opposite right posterior quadrant, which justifies the deeply negative T waves recorded. The method allows estimating the left ventricular mass because it relates to the maximal spatial vector voltage of the left ventricle in the QRS loop. The recording on electrocardiogram or Holter monitoring of nonsustained monomorphic ventricular tachycardia in patients with syncope, recurrent syncope in young patient, hypotension induced by strain, bradyarrhythmia, or concealed conduction are markers of poor prognosis. The presence of rare sustained ventricular tachycardia is observed in mid-septal obstructive HCM with apical aneurysm. The presence of complete right bundle branch block pattern is frequent after the percutaneous treatment and complete left bundle branch block is the rule after myectomy.

Alcohol septal ablation for hypertrophic obstructive cardiomyopathy - 8 years follow up

Background

Alcohol septal ablation is emerging as an alternative to surgical myectomy in the management of symptomatic cases of Hypertrophic obstructive cardiomyopathy (HOCM). This involves injection of absolute alcohol into 1st septal perforator thereby producing myocardial necrosis with resultant septal remodelling within 3–6 months. This results in reduction of septal thickness and LV outflow gradients with improvement in symptoms.

Methods

Fifty three patients had undergone alcohol septal ablation, there were 2 early and 2 late deaths and 4 patients lost to follow up. Forty-five (85%) of them were followed up to a mean period of 96 ± 9.2 months. Clinical, ECG, and Echocardiographic parameters were evaluated during follow up.

Results

Only 4 out of 51 patients remained in NYHA class III or IV at the end of 6 months. Significant reduction of LV outflow gradients (79 ± 35 to 34 ± 23 mmHg) and septal thickness (23 ± 4.7 mm to 19 ± 3 mm) were observed during 6 months follow up. Beyond 6 months there was no further decrease in either septal thickness or LVOT gradients noted. Ten percent of patients needed pacemaker implantation. There was 92% survival at the end of 8 years.

Conclusion

Alcohol septal ablation is a safe and effective nonsurgical procedure for the treatment of HOCM. By minimizing the amount of alcohol to ≤2 ml, one can reduce complications and mortality. The long-term survival is gratifying.

Septal perforator anatomy and variability of perfusion bed by myocardial contrast echocardiography: a study of hypertrophic cardiomyopathy patients undergoing alcohol septal ablation

OBJECTIVE

To characterize the perfusion bed of the first septal perforator by myocardial contrast echocardiography (MCE) in patients with hypertrophic cardiomyopathy undergoing alcohol septal ablation (ASA).

BACKGROUND

MCE is used to define the septal perforator anatomy prior to ASA. Occasionally, ASA cannot be performed due to unfavorable septal anatomy or perfusion outside the interventricular septum. Despite the standard use of MCE for septal mapping, there are no reports describing the territory of septal perforator perfusion.

METHODS

Forty-seven consecutive patients underwent ASA between 1/1/2004 and 12/30/2012. Blinded individuals retrospectively evaluated patients for septal perforator anatomic findings. Patients were divided into 2 groups based on presence or absence of extra-septal perfusion (ESP) as visualized by apical views after intracoronary contrast injection. The groups' procedural outcomes were compared, including infarct size, new conduction abnormalities, and major adverse events.

RESULTS

Over 25% demonstrated ESP, of which 83% predominantly involved the right ventricular (RV) moderator band. The first septal perforator (FSP) was statistically larger in ostial diameter (1.69 mm vs. 1.23 mm, P = 0.04) and numerically more likely dominant in patients with ESP (63.6% vs. 47.2%, P = 0.22). In those with ESP, the odds ratio comparing FSP diameter of 2.0 mm to the mean was 1.96 (95% CI: 1.01-3.80).

CONCLUSIONS

Downstream capillary perfusion may be discordant from epicardial territory and this study emphasizes the importance of MCE prior to ASA. Over 25% of our patients demonstrated ESP, most commonly involving the RV moderator band. The size of the FSP was the strongest predictor of ESP.

Alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Since its original description in 1994, alcohol septal ablation (ASA) has emerged as a minimally invasive modality for treatment of hypertrophic obstructive cardiomyopathy compared to surgical myomectomy. This catheter-based intervention relies on the injection of absolute alcohol into the septal perforator to induce a controlled infarction of the hypertrophied septum and consequently abolish the dynamic outflow obstruction. This gradient reduction has been correlated with a significant clinical improvement in the patient’s symptomatology and with left ventricular remodeling. The procedure has been refined throughout the years, especially with the introduction of myocardial contrast echocardiography for localization of the area at risk of infarction and the reduction in the amount of alcohol used. Major complications of ASA are uncommon in large referral centers but conduction system disturbances has been the most commonly reported complications of ASA with 10% of patients necessitating permanent pacemaker implantation for complete heart block. ASA has not been compared to the gold standard surgical myomectomy in a randomized prospective study. We review the clinical aspects of this procedure and provide some historical background.

Long-term outcome of percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy: a Scandinavian multicenter study

BACKGROUND

Single-center reports on percutaneous transluminal septal myocardial ablation (PTSMA) in patients with hypertrophic obstructive cardiomyopathy have shown considerable differences in outcome.

METHODS AND RESULTS

We report the long-term outcome of 313 PTSMA procedures performed in 279 patients with hypertrophic obstructive cardiomyopathy aged 59±14 years from 1999 to 2010 in 4 Scandinavian centers. Sixty-nine percent of patients had ≥1 comorbidity at baseline. The median (interquartile range) of left ventricular outflow tract gradient at rest was reduced from 58 mm Hg (34 to 89 mm Hg) at baseline to 12 mm Hg (8 to 24 mm Hg) at 1-year (P<0.001) and during Valsalva maneuver from 93 mm Hg (70 to 140 mm Hg) to 21 mm Hg (11 to 42 mm Hg) (P<0.001). The proportion of patients with syncope was reduced from 18% to 2% (P<0.001), and the proportion in New York Heart Association class III/IV was reduced from 94% to 21% (P<0.001). All treatment effects remained stable during the follow-up. New York Heart Association class III/IV at the most recent follow-up (2.9±2.6 years) was associated with diabetes mellitus (P=0.03), chronic obstructive pulmonary disease (P=0.02), and valve disease unrelated to hypertrophic cardiomyopathy (P<0.01). In-hospital mortality was 0.3%. The 1-, 5- and 10-year survival rates were 97%, 87%, and 67%, respectively (P=0.06 versus an age- and sex-matched background population) in all patients and 99%, 94%, and 88%, respectively (P=0.12) in patients aged <60 years (48±9 years, n=141). Age (hazard ratio, 1.07; 95% CI, 1.03 to 1.1) was the only predictor of survival.

CONCLUSIONS

In this multicenter study, the in-hospital mortality after PTSMA was low despite considerable comorbidities. The hemodynamic and symptomatic effects were sustained long term. The long-term symptomatic outcome was associated with baseline comorbidities. The 10-year survival rate was comparable to that in an age- and sex-matched background population, and age was the only predictor of survival.