Alcohol septal ablation in patients with hypertrophic obstructive cardiomyopathy: low incidence of sudden cardiac death and reduced risk profile

Percutaneous intramyocardial septal radiofrequency ablation after 5-year follow-up

OBJECTIVE

The objective is to evaluate the 5-year follow-up results of percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) for hypertrophic obstructive cardiomyopathy (HOCM), including clinical status, electrocardiographic and echocardiographic characteristics.

METHODS

27 patients (age: 44.3±15.5 years; 67% men, 33% women) with severely symptomatic HOCM who underwent PIMSRA from October 2016 to September 2017 were included. Their clinical status, resting and exercise stress echocardiography, electrocardiography and cardiac MRI (CMRI) after long-term follow-up were assessed.

RESULTS

One patient died of intracerebral haemorrhage 1 year post procedurally. The New York Heart Association class, Canadian Cardiovascular Society class and exercise-induced syncopal attacks improved significantly in 26 patients (all p<0.01). Left ventricular (LV) outflow tract gradients revealed sustained reduction (resting: from 95.0 to 9.0 mm Hg, p<0.001; post exercise: from 130.5 to 21.0 mm Hg, p<0.001). The echocardiographic evaluation revealed decreased septal thickness, LV posterior wall thickness and left atrial (LA) diameter (all p<0.001). CMRI data revealed decrease in LV mass index and LA volume index and increase in LV end-diastolic volume index and stroke volume index between baseline and long-term follow-up (all p<0.05). The global longitudinal strain of LV improved from (-11.9%±3.7%) before the procedure to (-13.1%±3.9%) at the last check (p<0.001). Malignant ventricular arrhythmia and heart failure events were not observed.

CONCLUSIONS

PIMSRA can effectively alleviate symptoms in patients with HOCM and improve their hemodynamics in the long term.

TRIAL REGISTRATION NUMBER

NCT02888132.

Looking Back at 30 Years of Alcohol Septal Ablation and Looking Forward to the Future

In the 30 years since Dr Sigwart's first pioneering procedures, alcohol septal ablation (ASA) has become the standard catheterisation procedure to reduce or eliminate obstruction in the left ventricular outflow tract. This procedure reduces the pressure gradient by 70%-80%, and only 10%-20% of patients have a residual gradient > 30 mm Hg after ASA. The mortality rate of the procedure is < 1%, and ∼ 10% of patients require permanent pacemaker implantation for higher degrees of atrioventricular block. Given the potential risks, ASA should be performed only in centres with extensive experience in the treatment of hypertrophic cardiomyopathy and with comprehensive therapeutic options, including myectomy. In the future, ASA is likely to be increasingly complemented by catheter-based mitral valve repair, which will increase its efficacy.

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.

Outcomes of Alcohol Septal Ablation in Patients With Severe Left Ventricular Outflow Tract Obstruction: A Propensity Score Matching Analysis

BACKGROUND

The current ACC/AHA guidelines on hypertrophic cardiomyopathy (HCM) caution that alcohol septal ablation (ASA) might be less effective in patients with left ventricular outflow tract obstruction (LVOTO) ≥ 100 mm Hg.

METHODS

We used a multinational registry to evaluate the outcome of ASA patients according to baseline LVOTO.

RESULTS

A total of 1346 ASA patients were enrolled and followed for 5.8 ± 4.7 years (7764 patient-years). The patients with baseline LVOTO ≥ 100 mm Hg were significantly older (61 ± 14 years vs 57 ± 13 years; P < 0.01), more often women (60% vs 45%; P < 0.01), and had a more pronounced HCM phenotype than those with baseline LVOTO < 100 mm Hg. There were no significant differences in the occurrences of 30-day major cardiovascular adverse events in the 2 groups. After propensity score matching (2 groups, 257 pairs of patients), the long-term survival was similar in both groups (P = 0.10), the relative reduction of LVOTO was higher in the group with baseline LVOTO ≥ 100 mm Hg (82 ± 21% vs 73 ± 26%; P < 0.01), but the residual resting LVOTO remained higher in this group (23 ± 29 mm Hg vs 13 ± 13 mm Hg; P < 0.01). Dyspnoea (NYHA functional class) at the most recent clinical check-up was similar in the 2 groups (1.7 ± 0.7 vs 1.7 ± 0.7; P = 0.85), and patients with baseline LVOTO ≥ 100 mm Hg underwent more reinterventions (P = 0.02).

CONCLUSIONS

After propensity matching, ASA patients with baseline LVOTO ≥ 100 mm Hg had similar survival and dyspnoea as patients with baseline LVOTO < 100 mm Hg, but their residual LVOTO and risk of repeated procedures were higher.

Percutaneous Septal Reduction Therapy in a Patient with Severely Symptomatic Hypertrophic Obstructive Cardiomyopathy: An experience from a tertiary care centre

NONE

Preoperative myocardial fibrosis is associated with worse survival after alcohol septal ablation in patients with hypertrophic obstructive cardiomyopathy: A delayed enhanced cardiac magnetic resonance study

Background

Prior studies have shown that myocardial fibrosis can be detected by late gadolinium enhancement (LGE) of cardiac magnetic resonance (CMR) and might be associated with higher mortality risk in hypertrophic cardiomyopathy (HCM). The objective of this study was to examine the prognostic utility of CMR in patients with hypertrophic obstructive cardiomyopathy (HOCM) undergoing alcohol septal ablation (ASA).

Materials and methods

We conducted a retrospective study which consisted of 183 consecutive patients with symptomatic drug-refractory HOCM who underwent CMR for assessment of myocardial fibrosis before ASA. The cardiovascular disease related survival was evaluated according to LGE-CMR status.

Results

The cohort comprised 74 (40.4%) women with a mean age of 51 ± 8 years. Preoperative myocardial fibrosis was detected in 148 (80.9%) patients. After a median of 6 years (range 2–11 years) follow-up, adverse clinical events occurred in 14 (7.7%) patients. Multivariate-adjusted Cox regression analyses revealed that age [hazard ratio (HR) 1.142 (1.059–1.230), p = 0.001] and LGE [HR 1.170 (1.074–1.275), p &lt; 0.001] were independent predictors of cardiovascular mortality during follow-up.

Conclusion

Preoperative myocardial fibrosis measured by LGE-CMR was an independent predictor of increased adverse clinical outcomes in patients with HOCM undergoing ASA and could be used for the pre-operative evaluation of risk stratification and long-term prognosis after ASA in these patients.

Hypertrophic Obstructive Cardiomyopathy: Comparison of Outcomes After Myectomy or Alcohol Ablation

Introduction and Objectives

The risk of ventricular arrhythmia and heart failure in patients with hypertrophic obstructive cardiomyopathy (HOCM) is much higher than that in the general population. More and more pieces of evidence showed that HOCM is the leading cause of sudden cardiac death in young people. We reported our experience in a study, comparing surgical myectomy, alcohol septal ablation (ASA), and medical therapy.

Methods

The original cohort included 965 consecutive patients with HOCM. The patients were divided into three groups according to treatment strategies: myectomy group (n = 502), ASA group (n = 138), and medical treatment group (n = 325). The median follow-up duration was 42.99 ± 18.32 months, and the primary endpoints were all-cause mortality and heart transplantation.

Results

Both in short- and long-term observations, surgical myectomy reduced the left ventricular outflow tract (LVOT) gradients more effectively (7 days, 16.15 ± 12.07 mmHg vs. 42.33 ± 27.76 mmHg, p < 0.05; 1 year, 14.65 ± 13.18 mmHg vs. 41.17 ± 30.76 mmHg, p < 0.05). Among the three groups, the patients in the medical treatment group were at a higher risk of mortality and cardiac transplantation (vs. the myectomy group, p < 0.001 by log-rank test; vs. the alcohol septal ablation group, p = 0.017 by log-rank test), and the myectomy group shows a lower risk of reaching the primary endpoint than the two other groups. In the multivariate Cox regression analysis, previous atrial fibrillation (AF), N terminal pro B type natriuretic peptide (NT-pro-BNP), and surgical myectomy predicted an HOCM prognosis. However, the impact of surgical myectomy on HOCM prognosis seems to be limited to the <56 years group.

Conclusions

The patients with medical treatments seemed to suffer from the highest risk of achieving an all-cause mortality and the endpoint of heart transplantation. In the long-term survival and clinical outcome, myectomy seemed better than alcohol septal ablation, especially the younger patients. Due to the less-controllable degree, periprocedural complication frequency after alcohol septal ablation was higher, compared with myectomy. Furthermore, gradients after myectomy are lower at late follow-up. To sum up, when selecting treatment strategies, the patients should be individually evaluated by a multidisciplinary team of cardiologists and surgeons.

Targeting Alcohol Septal Ablation in Patients with Obstructive Hypertrophic Cardiomyopathy Candidates for Surgical Myectomy: Added Value of Three-Dimensional Intracoronary Myocardial Contrast Echocardiography

Background: Myocardial contrast two-dimensional echocardiography (MC-2DE) is widely used to address alcohol septal ablation (ASA) in obstructive hypertrophic cardiomyopathy (HCM). Owing to its limited cut-planes, MC-2DE may inaccurately identify the contrast misplacement associated with an unsuccessful or complicated ASA outcome. Objective: The aim of this study was to assess the added value of myocardial contrast three-dimensional echocardiography (MC-3DE) compared with MC-2DE to identify the appropriate matching between the target septal zone (TSZ) and coronary artery branch for safe and long-term effective ASA in HCM patients. Methods: A consecutive series of 52 symptomatic obstructive HCM patients referred for isolated surgical myectomy (SM) was analyzed with MC-2DE and MC-3DE following injection of echocontrast into one or more septal branches. MC-2DE and MC-3DE patterns were categorized according to complete (Type 1) or incomplete (Type 2) TSZ covering, high-risk (Type 3) exceeding TSZ, or life-threatening outside TSZ distribution (Type 4). Results: MC-2DE per patient analysis showed a Type 1 pattern in 32 patients and Types 2–4 in the remaining 20 patients; subsequent MC-3DE analysis provided a re-phenotyping of MC-2DE findings in 22 of the 52 patients (42%), showing a high-risk Type 2 pattern in 17 of the 32 patients with Type 1, and a new life-threatening Type 4 in three patients with Type 2, respectively. All patients with MC-3DE Type 1 pattern underwent safe and effective ASA with a long-term uneventful follow-up, while the remaining patients underwent SM. Conclusions: Refining high risk or life-threatening contrast misplacement, MC-3DE is more accurate than conventional MC-2DE to target safe and long-term effective septal reduction with ASA in obstructive HCM patients referred for isolated SM.

Looking back on 15 years of ultrasound-guided alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Background: Septal reduction remains an important target of current therapeutic modalities in hypertrophic obstructive cardiomyopathy (HOCM). Surgical septal myectomy has long been considered the gold standard in pharmacotherapy-refractory severely symptomatic patients with marked left ventricular outflow tract (LVOT) obstruction. In recent years, percutaneous alcohol septal ablation (ASA) has matured into the preferred strategy for patients with favourable anatomy and no other coexisting surgically amenable disease.Methods: We discuss 26 HOCM patients with persistent dyspnoea, angina or syncope despite optimal medical treatment. Baseline septal wall thickness was 20 ± 3 mm, with peak resting/provoked LVOT gradients of 53 ± 35/112 ± 40 mmHg. Guided by echocardiography, alcohol injection could be restricted to the first septal coronary artery in 85% of patients, provoking basal septal infarction with average troponin rise of 3.0 ng/ml.Results: Eighty-six per cent of patients experienced sustained clinical improvement, associated with a reduction of septal wall thickness to 15 ± 3 mm and resting LVOT gradient to 21 ± 15 mmHg. One of the two non-responders underwent additional septal myectomy 11 years after ASA. Notable adverse events during the follow-up of 7.2 ± 4.7 years included: persistent conduction disturbances (65%) necessitating early postprocedural permanent pacemaker implantation (15%); atrial fibrillation (32%); ventricular tachycardia (4%) and aortic stenosis (14%). Six patients died, of which only 1 cardiac death.Conclusions: Our case series underscores the efficacy of ASA at relieving LVOT obstruction and improving symptoms in properly selected HOCM patients, with acceptably low procedural and long term mortality and morbidity.

Alcohol Septal Ablation versus Septal Myectomy Treatment of Obstructive Hypertrophic Cardiomyopathy: A Systematic Review and Meta-Analysis

Surgical myectomy (SM) and alcohol septal ablation (ASA) are two invasive therapies for symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM), despite medical therapy. This meta-analysis aims to compare the efficacy of the two procedures. We searched all electronic databases until February 2020 for clinical trials and cohorts comparing clinical outcomes of ASA and SM treatment of patients with HOCM. The primary endpoint was all-cause mortality, cardiovascular (CV) mortality, sudden cardiac death (SCD), re-intervention, and complications. Secondary endpoints included relief of clinical symptoms and drop of left ventricular outflow tract (LVOT) gradient. Twenty studies (4547 patients; 2 CTs and 18 cohorts) comparing ASA vs. SM with a mean follow-up of 47 ± 28.7 months were included. Long term (8.72 vs. 7.84%, p = 0.42) and short term (1.12 vs. 1.27%, p = 0.93) all-cause mortality, CV mortality (2.48 vs. 3.66%, p = 0.26), SCD (1.78 vs. 0.76%, p = 0.20) and stroke (0.36 vs. 1.01%, p = 0.64) were not different between procedures. ASA was associated with lower peri-procedural complications (5.57 vs. 10.5%, p = 0.04) but higher rate of re-interventions (10.1 vs. 0.27%; p < 0.001) and pacemaker dependency (12.4 vs. 4.31%, p = 0.0004) compared to SM. ASA resulted in less reduction in LVOT gradient (-47.8 vs. -58.4 mmHg, p = 0.01) and less improvement of clinical symptoms compared to SM (New York Heart Association (NYHA) class III/IV, 82.4 vs. 94.5%, p < 0.001, angina 53.2 vs. 84.2%, p = 0.02). Thus, ASA and SM treatment of HOCM carry a similar risk of mortality. Peri-procedural complications are less in alcohol ablation but re-intervention and pacemaker implantations are more common. These results might impact the procedure choice in individual patients, for the best clinical outcome.

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.

Hypertrophic cardiomyopathy: an updated review on diagnosis, prognosis, and treatment

Hypertrophic cardiomyopathy (HCM) represents a phenotype of left ventricular hypertrophy unexplained by abnormal loading conditions. The definition is based on clinical criteria; however, there are numerous underlying etiologic factors. The MOGE(S) classification provides a standardized approach for multimodal characterization of HCM. HCM is associated with increased morbidity and mortality, and especially the assessment of the risk of sudden cardiac death is of paramount importance. In this review, we summarize essential knowledge and recently published data on clinical presentation, diagnosis, genetic analyses, differential diagnosis, prognosis, and treatment options that are necessary for understanding and management of HCM.

Risk stratification in hypertrophic cardiomyopathy

Sudden cardiac death (SCD) is the most devastating complication of hypertrophic cardiomyopathy (HCM). The greatest challenge in the management of HCM is identifying those at increased risk, since an implantable cardioverter-defibrillator (ICD) is a potentially life-saving therapy. We sought to summarize the available data on SCD in HCM and provide a clinical perspective on the current differing and somewhat conflicting data on risk stratification, with balanced guidance regarding rational clinical decision-making. Additionally, we sought to determine the status of the current implementation of guidelines compiled by HCM experts worldwide. The HCM Risk-SCD model helps improve the risk stratification of HCM patients for primary prevention of SCD by calculating an individual risk estimate that contributes to the clinical decision-making process. Improved risk stratification is important for decision-making before ICD implantation for the primary prevention of SCD.

Temporal Occurrence of Arrhythmic Complications After Alcohol Septal Ablation

BACKGROUND

The temporal occurrence of arrhythmic complications after alcohol septal ablation (ASA) is unclear. As a result, the appropriate time to monitor patients after ASA is controversial. The purpose of this study is to determine the temporal occurrence of complete heart block (CHB) and ventricular tachyarrhythmia (VT) after ASA to better understand when patients can be safely discharged.

METHODS

Consecutive patients treated with ASA for hypertrophic cardiomyopathy from 2003 to 2019 at a tertiary referral center were reviewed retrospectively. The incidence and timing of CHB or sustained VT within 30 days post-ASA were assessed.

RESULTS

A total of 243 patients were included in this study. Mean maximal septal thickness was 19.0±3.9 mm, and total volume of ethanol injected was 1.7±0.6 mL. CHB occurred in 59 (24.3%) patients, including transient CHB in 33 (13.6%) and permanent in 26 (10.7%). The initial episode of CHB occurred within 24 hours post-ASA in 51 (21.0%) patients, between 24 and 48 hours in 3 (1.2%), between 48 and 72 hours in 3 (1.2%), and after 72 hours in 2 (0.8%). New permanent pacemaker was placed in 46 (18.3%). Presence of baseline bundle branch block and age ≥70 were significantly associated with CHB but not CHB presenting after 24 hours. VT occurred in 3 (1.2%) patients, including 1 (0.4%) within 24 hours, 1 (0.4%) between 24 and 48 hours, and 1 (0.4%) after 72 hours. VT required cardioversion in 2 patients and new implantable cardioverter-defibrillator placement in 2.

CONCLUSIONS

The incidence of CHB or VT presenting after 72 hours post-ASA was low. These findings suggest that timely discharge of patients without evidence of early conduction disturbances after ASA can be considered as a potentially safe management strategy, especially in patients without preexisting conduction abnormalities.

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.

Guideline-Based Referral for Septal Reduction Therapy in Obstructive Hypertrophic Cardiomyopathy Is Associated With Excellent Clinical Outcomes

BACKGROUND

The outcome of medically refractory patients with obstructive hypertrophic cardiomyopathy treated according to the American College of Cardiology/American Heart Association consensus guideline recommendations is not known. The objectives of this study were to define the short- and long-term outcomes of medically refractory obstructive hypertrophic cardiomyopathy patients undergoing alcohol septal ablation (ASA) and surgical septal myectomy (SM) with patient management in accordance with these consensus guidelines, as well as to quantify procedural risk and burden of comorbid conditions at the time of treatment.

METHODS AND RESULTS

Patients with obstructive hypertrophic cardiomyopathy referred for either ASA or SM from 2004 to 2015 were followed for the primary end point of short- and long-term mortality and compared with respective age- and sex-matched US populations. Of 477 consecutive severely symptomatic patients, 99 underwent ASA and 378 SM. Compared with SM, ASA patients were older ( P<0.001), had a higher burden of comorbid conditions ( P<0.01), and significantly higher predicted surgical mortality ( P<0.005). Procedure-related mortality was 0.3% and similarly low in both groups (0% in ASA and 0.8% in SM). Over 4.0±2.9 years of follow-up, 95% of patients had substantial improvement in heart failure symptoms to New York Heart Association class I/II (96% in SM and 90% in ASA). Long-term mortality was similar between the 2 groups with no difference compared with age- and sex-matched US populations.

CONCLUSIONS

Guideline-based referral for ASA and SM leads to excellent outcomes with low procedural mortality, excellent long-term survival, and improvement in symptoms. These outcomes occur in ASA patients despite being an older cohort with significantly more comorbidities.

Long-term outcome of conservative and invasive treatment in patients with hypertrophic obstructive cardiomyopathy

Background and objective: Treatment for patients with hypertrophic obstructive cardiomyopathy (HOCM) can be either conservative or invasive (alcohol septal ablation (ASA) and myectomy). As there is no clear consensus on the long-term effects of these different strategies, the aim was to compare the long-term outcome in a large tertiary referral university hospital. Methods: We retrospectively included 106 HOCM patients. Twenty-nine (27.4%) patients were treated conservatively, 25 (23.6%) underwent ASA and 52 (49.0%) myectomy. Endpoints were all-cause mortality and sudden cardiac death (SCD)-related events (including SCD, aborted SCD and appropriate ICD shocks). Kaplan-Meier survival analysis and Cox proportional hazard regression models were used. Results: The mean follow-up period was 7.7 ± 4.9 years. Overall, there was no significant difference in survival between the three treatment strategies (p = 0.7). Annual rates of SCD-related events at 5 years and the complete follow-up period were significantly higher (p = 0.034) after conservative treatment (4.9%/year and 2.7%/year, respectively) compared to ASA (0.9%/year, 0.5%/year) and myectomy (1.0%/year, 0.6%/year). Independent predictors of SCD-related events were: conservative treatment (HR 10.66; 1.88-60.55), a known mutation (HR 9.36; 1.43-61.20), left ventricular wall thickness (LVWT) > 30 mm (HR 6.48; 1.05-39.92) and non-sustained VT (HR 16.82; 2.29-123.29). Invasive treatment resulted in a significant higher proportion of patients requiring pacing (p = 0.033). Conclusions: Long-term mortality rates for patients with HOCM are similarly low between treatment groups. However, conservative treatment was associated with SCD-related events, as were known mutations, increased LVWT and non-sustained VT. Invasive treatment was associated with a higher need for implantation of a pacemaker.

Outcome of patients ≥ 60 years of age after alcohol septal ablation for hypertrophic obstructive cardiomyopathy

INTRODUCTION

The outcome of patients ≥ 60 years of age after alcohol septal ablation (ASA) for obstructive hypertrophic cardiomyopathy (HCM) remains unresolved. We sought to determine the long-term survival and the causes of death in this population.

MATERIAL AND METHODS

We enrolled 156 consecutive patients (69 ±6 years, 69% women, follow-up: 4.8 ±3.5 years) who underwent ASA at ≥ 60 years of age.

RESULTS

The 30-day mortality rate was 1.3%. At the last check-up, 81% of patients were in New York Heart Association class ≤ 2 and 76% had a left ventricular outflow tract gradient (LVOG) ≤ 30 mm Hg. A total of 39 patients died (51% of cardiovascular causes, 44% of non-cardiovascular causes, 5% of unknown causes) during the 734 patient-years. The annual sudden mortality, the sudden mortality and the all-cause mortality rates were 0.5%, 1.1%, and 4.8%, respectively. The all-cause mortality was higher compared to the age- and sex-matched general population (p = 0.002).

CONCLUSIONS

Alcohol septal ablation was safe and effective in the long-term follow-up. We observed a reduced life expectancy compared to the age- and sex-matched general population. Mortality was almost equally due to cardiovascular and non-cardiovascular causes of death.

Utility of preprocedural multidetector computed tomography in alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Preprocedural computed tomography (CT) imaging appears to provide an advantage in localization of the appropriate septal branch targeted for alcohol septal ablation (ASA). The objective of this study was to compare the clinical backgrounds, procedural characteristics, and outcomes of patients who underwent ASA with preprocedural CT assessment against those without CT assessment. Thirty consecutive patients with obstructive hypertrophic cardiomyopathy who underwent ASA were retrospectively included. Patients who underwent preprocedural CT (CT-guided ASA group, n = 11) were compared with patients who underwent ASA without CT (traditional ASA group, n = 19). The CT-guided ASA group had a significantly lower number of approached target vessels (1 [interquartile range {IQR}, 1-2] vs. 2 [IQR, 2-3], P = 0.036) and non-ablated target vessels (0 [IQR, 0-1] vs. 1 [IQR, 0-2], P = 0.031) than the traditional ASA group. There were no differences between the two groups in total fluoroscopy time, the amount of delivered radiation dose, and the volume of contrast medium used during the procedures. There were also no differences between the two groups in procedural success rate and improvement of left ventricular outflow tract gradient and New York Heart Association functional class at 1 month follow-up. CT had a significant impact on the ASA procedure diminishing the number of target vessels, and could be a reliable assessment modality to build its procedural strategy.

Borisov K, Seggewiß H. Hypertrophic Obstructive Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is caused by mutations in a number of genes. Its prevalence is 0.2% to 0.6%.

METHODS

This review is based on publications retrieved by a selective literature search and on the authors' clinical experi- ence.

RESULTS

70% of patients with HCM suffer from the obstructive type of the condition, clinically characterized by highly dynamic and variable manifestations in the form of dyspnea, angina pectoris, and stress-dependent presyncope and syn- cope. Younger patients are at particular risk of sudden cardiac death; thus, all patients need not only symptomatic treatment, but also risk assessment, which can be difficult in individual cases. Left ventricular obstruction, which usually causes symptoms, is treated medically at first, with either a beta- blocker or verapamil. If medical treatment fails, two invasive treatments are available, surgical myectomy and percu- taneous septum ablation. Both of these require a high level of expertise. If performed successfully, they lead to sustained gradient reduction and clinical improvement. Septum ablation is associated with low perioperative and peri-interventional mortality but necessitates permanent pacemaker implantation in 10-20% of patients.

CONCLUSION

In the absence of evidence from randomized comparison trials, a suitable method of reducing the gradient should be determined by an HCM team in conjunction with each individual patient. Important criteria for decision-making include the anatomical findings and any accompanying illnesses.

Effect of Institutional Experience on Outcomes of Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy

BACKGROUND

The current American College of Cardiology Foundation/American Heart Association guidelines on hypertrophic cardiomyopathy state that institutional experience is a key determinant of successful outcomes and lower complication rates of alcohol septal ablation (ASA). The aim of this study was to evaluate the safety and efficacy of ASA according to institutional experience with the procedure.

METHODS

We retrospectively evaluated 1310 patients with symptomatic obstructive hypertrophic cardiomyopathy who underwent ASA and were divided into 2 groups. The first-50 group consisted of the first consecutive 50 patients treated at each centre, and the over-50 group consisted of patients treated thereafter (patients 51 and above).

RESULTS

In the 30-day follow-up, there was a significant difference in the occurrence of major cardiovascular adverse events (21% in the first-50 group vs 12% in the over-50 group; P < 0.01), which was driven by the occurrence of cardiovascular deaths (2.1% vs 0.4%; P = 0.01) and implanted pacemakers (15% vs 9%; P < 0.01). In the long-term follow-up (5.5 ± 4.1 years), the first-50 group was associated with a significantly higher occurrence of major adverse events (P < 0.01) and higher cardiovascular mortality (P < 0.01). Also, patients in the first-50 group were more likely to self-report dyspnea of New York Heart Association class III/IV (16% vs 10%), to have a left ventricular outflow gradient > 30 mm Hg (16% vs 10%) at the last clinical check-up (P < 0.01 for both), and a probability of repeated septal reduction therapy (P = 0.03).

CONCLUSIONS

An institutional experience of > 50 ASA procedures was associated with a lower occurrence of ASA complications, better cardiovascular survival, better hemodynamic and clinical effect, and less need for repeated septal reduction therapy.

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.

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.

Clinical presentations of hypertrophic cardiomyopathy and implications for therapy

[first paragraph of article]Hypertrophic cardiomyopathy (HCM) is diagnosed in the presence of left ventricular hypertrophy of ≥15 mm in adult index cases, or ≥13 mm in relatives of known affected patients, that is not solely explained by abnormal loading conditions. In children, the left ventricle (LV) wall thickness should be more than two standard deviations above the predicted population mean. The typical anatomo-pathological findings include myocyte hypertrophy, disarray, interstitial fibrosis and small-vessel disease. Although all the myocytes are supposed to be affected, pathological alterations are not uniformly distributed throughout the myocardium. Asymmetrical hypertrophy of the interventricular septum is the most commonly observed phenotype, but any pattern of hypertrophy is consistent with the diagnosis.

Contemporary Septal Reduction Therapy in Drug-Refractory Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a complex and relatively common genetic cardiac disease that has been the subject of intense investigation for over 50 years. Most patients with HCM are asymptomatic, but some develop symptoms, often many years after the appearance of electrocardiographic or echocardiographic evidence of left ventricular hypertrophy. Symptoms due to the left ventricular outflow tract obstruction frequently worsen over time, requiring septal reduction therapy (SRT) despite optimal medical therapy. Percutaneous transluminal septal myocardial ablation (PTSMA) and surgical myectomy are collectively known as SRT. In this review, we will focus on the emerging concept and practical implication of SRT and the available evidence on either PTSMA or surgical myectomy in the literature.

[Syncope in hypertrophic (obstructive) cardiomyopathy]

Hypertrophic cardiomyopathy is the most common genetic cardiac disease. The most important pathophysiological finding is dynamic (outflow tract) obstruction of the left ventricle in about 70% of affected patients. Especially in younger patients, an increased risk of sudden cardiac death has been observed. Syncope and presyncope-in addition to extremely variable cardiac symptoms (dyspnea and angina)-are common. The etiology of syncope is complex. The most important aspect for diagnosis is a detailed history regarding the accompanying circumstances of the syncope. In principle, an attempt must be made to distinguish between rhythmogenic and hemodynamic causes. Diagnostic work-up should be performed under the criteria of a possible prognostic-with implantation of an implantable cardioverter-defibrillator (ICD) in patients at increased risk of sudden cardiac death-and symptomatic therapy. Depending on the underlying morphology and the experience of the surgeon, percutaneous septal ablation and operative myectomy are complementary options for symptomatic treatment if medical therapy with beta-blockers and/or verapamil is inadequate.

Hypertrophic Cardiomyopathy-Past, Present and Future

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy with a prevalence of 1 in 500 in the general population. Since the first pathological case series at post mortem in 1957, we have come a long way in its understanding, diagnosis and management. Here, we will describe the history of our understanding of HCM including the initial disease findings, diagnostic methods and treatment options. We will review the current guidelines for the diagnosis and management of HCM, current gaps in the evidence base and discuss the new and promising developments in this field.

Influence of Septal Thickness on the Clinical Outcome After Alcohol Septal Alation in Hypertrophic Cardiomyopathy

BACKGROUND

We assessed the influence of interventricular septal thickness (IVSd) on the clinical outcome and survival after alcohol septal ablation (ASA) in patient with hypertrophic cardiomyopathy.

METHODS AND RESULTS

We analyzed 531 patients with hypertrophic cardiomyopathy (age: 56±14 years, men 55%) treated with ASA. Survival status was obtained 7.9±4.0 years after ASA. Baseline IVSd was inversely associated with survival (hazard ratio [HR] for 1 mm increment, 1.13; confidence interval, 1.05-1.21; P<0.001) after adjustment for age, sex, body mass index, and ASA-performing center. Compared with patients with baseline IVSd <20 mm, patients with baseline IVSd ≥25 mm had reduced survival (HR, 5.0; CI, 2.1-12), whereas patients with baseline IVSd 20 to 24 mm had similar survival (HR, 1.4; CI, 0.7-2.8). Baseline IVSd was not correlated with New York Heart Association class, Canadian Cardiology Society class, or syncope. Clinical outcome was assessed 0.6±0.6 years after ASA. IVSd was not related to left ventricular outflow tract gradient reduction at rest (P=0.883) or during Valsalva maneuver (P=0.885). The proportion of patients in New York Heart Association class 3 to 4 was reduced from 86% to 10%; in Canadian Cardiology Society class 3 to 4 from 26% to 2%; and with syncope from 25% to 2%. There were no correlations between baseline IVSd and New York Heart Association class (P=0.067), Canadian Cardiology Society class (P=0.106), or syncope (P=0.426) after ASA.

CONCLUSIONS

ASA had equal effects on left ventricular outflow tract gradients and symptoms throughout the spectrum of septal hypertrophy. Severe septal hypertrophy before ASA remained a marker of reduced survival after ASA with a 5-fold increased risk of all-cause mortality in patients with baseline IVSd >25 mm compared with patients with baseline IVSd <20 mm.

Hypertrophic Obstructive Cardiomyopathy: Surgical Myectomy and Septal Ablation

Hypertrophic cardiomyopathy is a genetic disorder characterized by marked hypertrophy of the myocardium. It is frequently accompanied by dynamic left ventricular outflow tract obstruction and symptoms of dyspnea, angina, and syncope. The initial therapy for symptomatic patients with obstruction is medical therapy with β-blockers and calcium antagonists. However, there remain a subset of patients who have continued severe symptoms, which are unresponsive to medical therapy. These patients can be treated with septal reduction therapy, either surgical septal myectomy or alcohol septal ablation. When performed by experienced operators working in high-volume centers, septal myectomy is highly effective with a >90% relief of obstruction and improvement in symptoms. The perioperative mortality rate for isolated septal myectomy in most centers is <1%. Alcohol septal ablation is a less invasive treatment. In many patients, the hemodynamic and clinical results are comparable to that of septal myectomy. However, the results of alcohol septal ablation are dependent on the septal perforator artery supplying the area of the contact between the hypertrophied septum and the anterior leaflet of the mitral valve. There are some patients, particularly younger patients with severe hypertrophy, who do not uniformly experience complete relief of obstruction and symptoms. Both techniques of septal reduction therapy are highly operator dependent. The final decision as to which approach should be selected in any given patient is dependent up patient preference and the availability and experience of the operator and institution at which the patient is being treated.

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

The management of drug-refractory symptoms of obstructive hypertrophic cardiomyopathy has long been debated and is primarily centered on the choice between surgical myectomy and alcohol septal ablation. Decision making in these patients requires consideration of procedural risk, expertise and efficacy, and the long-term impact on patients' survival. Although there have been numerous reports on these procedures that may help guide decision making, these data continue to be self-reported and voluntary. Greater insight into the real-world experience for these therapies and how they should be applied in practice would be gained from mandatory reporting, akin to other multidisciplinary, transcatheter-based therapies.

Procedural complication and long term outcomes after alcohol septal ablation in patients with obstructive hypertrophic cardiomyopathy: data from China

Data on procedural complications and long term survival after alcohol septal ablation (ASA) in Chinese patients with obstructive hypertrophic cardiomyopathy (HOCM) are lacking. We aimed to investigate long-term survival of HOCM patients after ASA and compared to the non-obstructive hypertrophic cardiomyopathy(NOHCM). A total of 233 patients with HOCM and a peak pressure gradient of ≥50 mm Hg at rest or with provocation were consecutively enrolled from Fuwai Hospital in China between 2000 and 2012. Another 297 patients without left ventricular outflow tract obstruction were regarded as control group. Periprocedural mortality of ASA were low (0.89%). Periprocedural lethal ventricular arrhythmia occurred in 9 patients (4.0%). Alcohol volume (RR 1.44, 95% CI: 1.03–2.03, P = 0.034) and age ≤40 years old (RR 4.63, 95% CI: 1.07–20.0, P = 0.040) were independent predictors for periprocedural lethal ventricular arrhythmia. The 10- year overall survival was 94.6% in the ASA group, similar with 92.9% in the NOHCM group (P = 0.930). In conclusion, periprocedural mortality and complications were rare in ASA. Long term survival after ASA were satisfactory and comparable to NOHCM. Patients under 40 years old should be more cautious undergoing ASA, for these patients were more likely to endure lethal ventricular arrhythmia during periprocedural period of ASA.

Outcome of Alcohol Septal Ablation in Mildly Symptomatic Patients With Hypertrophic Obstructive Cardiomyopathy: A Long-Term Follow-Up Study Based on the Euro-Alcohol Septal Ablation Registry

Background

The long‐term efficacy and safety of alcohol septal ablation (ASA) in patients with highly symptomatic hypertrophic obstructive cardiomyopathy has been demonstrated. The aim of this study was to evaluate the long‐term outcomes of mildly symptomatic patients with hypertrophic obstructive cardiomyopathy treated with ASA.

Methods and Results

We retrospectively evaluated consecutive patients enrolled in the Euro‐ASA registry (1427 patients) and identified 161 patients (53±13 years; 27% women) who were mildly symptomatic (New York Heart Association [NYHA] class II) pre‐ASA. The median (interquartile range) follow‐up was 4.8 (1.7–8.5) years. The clinical outcome was assessed and compared with the age‐ and sex‐matched general population. The 30‐day mortality after ASA was 0.6% and the annual all‐cause mortality rate was 1.7%, which was similar to the age‐ and sex‐matched general population (P=0.62). A total of 141 (88%) patients had resting left ventricular outflow tract gradient at the last clinical checkup ≤30 mm Hg. Obstruction was reduced from 63±32 to 15±19 mm Hg (P<0.01), and the mean NYHA class decreased from 2.0±0 to 1.3±0.1 (P<0.01); 69%, 29%, and 2% of patients were in NYHA class I, II, and III at the last clinical checkup, respectively.

Conclusions

Mildly symptomatic hypertrophic obstructive cardiomyopathy patients treated with ASA had sustained symptomatic and hemodynamic relief with a low risk of developing severe heart failure. Their survival is comparable to the general population.

Hypertrophic obstructive cardiomyopathy

Hypertrophic obstructive cardiomyopathy is an inherited myocardial disease defined by cardiac hypertrophy (wall thickness ≥15 mm) that is not explained by abnormal loading conditions, and left ventricular obstruction greater than or equal to 30 mm Hg. Typical symptoms include dyspnoea, chest pain, palpitations, and syncope. The diagnosis is usually suspected on clinical examination and confirmed by imaging. Some patients are at increased risk of sudden cardiac death, heart failure, and atrial fibrillation. Patients with an increased risk of sudden cardiac death undergo cardioverter-defibrillator implantation; in patients with severe symptoms related to ventricular obstruction, septal reduction therapy (myectomy or alcohol septal ablation) is recommended. Life-long anticoagulation is indicated after the first episode of atrial fibrillation.

Twenty Years of Alcohol Septal Ablation in Hypertrophic Obstructive Cardiomyopathy

Hypertrophic obstructive cardiomyopathy is the most common genetic cardiac disease and is generally characterised by asymmetric septal hypertrophy and intraventricular obstruction. Patients with severe obstruction and significant symptoms that persist despite optimal medical treatment are candidates for an invasive septal reduction therapy. Twenty years after its introduction, percutaneous transluminal alcohol septal ablation has been increasingly preferred for septal reduction in patients with drug refractory hypertrophic obstructive cardiomyopathy. Myocardial contrast echocardiography and injection of reduced alcohol volumes have increased safety, while efficacy is comparable to the surgical alternative, septal myectomy, which has for decades been regarded as the 'gold standard' treatment. Data on medium- and long-term survival show improved prognosis with survival being similar to the general population. Current guidelines have supported its use by experienced operators in centres specialised in the treatment of patients with hypertrophic obstructive cardiomyopathy.

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.

Ablation or surgery for medically refractory HCM. Updating an imperfect dataset

Retrospective comparison of alcohol septal ablation with surgical myectomy suggests that although there is a greater reduction in LVOT gradient with surgical myectomy, symptom relief and survival are similar between the two treatment strategies. In patients who don't have an anatomic indication for surgical myectomy, alcohol septal ablation appears to be a safe and effective alternative. Patients with medication-refractory HOCM require a multi-disciplinary assessment, which is best performed at specialized treatment centers, to assess which therapy is best suited to treat them.

Low occurrence of ventricular arrhythmias after alcohol septal ablation in high-risk patients with hypertrophic obstructive cardiomyopathy

INTRODUCTION

Percutaneous alcohol septal ablation (PTSMA) is an established treatment for symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). However, there is concern of a higher risk for ventricular tachyarrhythmias and sudden death due to the myocardial scar created after PTSMA. We investigated the possibility of increased ventricular arrhythmias and risk of sudden death after PTSMA in a subgroup of patients with an already implanted ICD.

METHODS AND RESULTS

Between 2009 and 2012, 239 PTSMAs were performed in 212 patients with HOCM. In 32 of those an ICD had already been implanted before PTSMA for primary (31 patients) or secondary (1 patient) prevention of sudden death. The maximum left ventricular outflow tract gradient (LVOTG) was reduced from 114 ± 39 mmHg before PTSMA to 23 ± 19 mmHg (P < 0.0001). Among clinical risk factors for sudden death, nonsustained ventricular tachycardia (VT), syncope and family history for sudden death were most common. After a median follow-up of 5.3 (IQR 4.3-5.7) years after PTSMA only one patient had ICD shocks (annual ICD discharge 0.6 %). In another 3 patients, with already documented nonsustained VTs as risk factor before ICD implantation, VT episodes that activated antitachycardic pacing were recorded. The annual appropriate ICD intervention including all events was 2.5 % and involved only patients with a very high estimated 5-year sudden death risk before PTSMA (>14.3 %).

CONCLUSIONS

In a selected high-risk patient cohort with HOCM ominous arrhythmic events seem to be rare and predominantly occur in patients with a very high estimated risk of sudden death before PTSMA.

Relationship of basal-septal fibrosis with LV outflow tract obstruction in hypertrophic cardiomyopathy: insights from cardiac magnetic resonance analysis

Myocardial fibrosis is frequently observed and may be associated with the prognosis in patients with hypertrophic cardiomyopathy (HCM); however, the clinical pathophysiological features, particularly in terms of fibrosis, of hypertrophic obstructive cardiomyopathy (HOCM) remain unclear. This study aimed to determine a role of local fibrosis in HOCM using cardiac magnetic resonance (CMR). 108 consecutive HCM patients underwent CMR. HOCM was defined as a left ventricular outflow tract (LVOT) pressure gradient ≥30 mmHg at rest. Myocardial mass and fibrosis mass by late gadolinium-enhancement CMR (LGE-CMR) were calculated and the distribution/pattern was analyzed using the AHA 17-segment model. LV ejection fraction (LVEF) was significantly higher in patients with HOCM (n = 19) than in those with nonobstructive HCM (n = 89) (P < 0.05). Both total myocardial and fibrosis masses in LV were similar in the two groups (P = 0.385 and P = 0.859, respectively). However, fibrosis in the basal septum was significantly less frequent in the HOCM group than in the nonobstructive HCM group (P < 0.01). The LVOT pressure gradient was significantly higher in the basal-septal non-fibrosis group than in the fibrosis group (23.6 ± 37.3 vs. 4.8 ± 11.4 mmHg, P < 0.01). Multivariate analysis revealed that basal-septal fibrosis was an independent negative predictor of LVOT obstruction in addition to the local wall thickness and LVEF as positive predictors in HCM patients. In conclusion, a significant association was observed between LVOT obstruction and basal septal fibrosis by LGE-CMR in HCM patients. In addition to negative impact of basal-septal fibrosis, basal-septal hypertrophy and preserved global LV contractility may be associated with the pathophysiological features of LVOT obstruction.