Pieter A. Vriesendorp

Outcome and Complications after Implantable Cardioverter Defibrillator Therapy in Hypertrophic Cardiomyopathy: Systematic Review and Meta-Analysis

Background—Previous observational studies demonstrated that patients with hypertrophic cardiomyopathy at risk for sudden cardiac death (SCD) may benefit from implantable cardioverter defibrillator (ICD) therapy. A complete overview of outcome and complications after ICD therapy is currently not available. This study pools data from published studies on outcome and complications after ICD therapy in patients with hypertrophic cardiomyopathy. Methods and Results—A PubMed database search returned 27 studies on 16 cohorts reporting outcome and complications after ICD therapy in patients with hypertrophic cardiomyopathy. In case of >1 publications on a particular cohort, the publication with the largest number of patients was included in the meta-analysis. ICD interventions, complications, and mortality rates were extracted, pooled, and analyzed. There were 2190 patients (mean age, 42 years; 38% women), most of whom (83%) received an ICD for primary prevention of SCD. Risk factors for SCD were left ventricular wall thickness ≥30 mm (20%), family history of SCD (43%), nonsustained ventricular tachycardia (46%), syncope (41%), and abnormal blood pressure response (25%). During the 3.7-year follow-up, the annualized cardiac mortality rate was 0.6%, the noncardiac mortality rate was 0.4%, and the appropriate ICD intervention rate was 3.3%. The annualized inappropriate ICD intervention rate was 4.8% and the annualized ICD-related complication rate was 3.4%. Conclusions—This meta-analysis demonstrates a low cardiac and noncardiac mortality rate after ICD therapy in patients with hypertrophic cardiomyopathy. Appropriate ICD intervention occurred at a rate of 3.3%/year, thereby, most probably, preventing SCD. Inappropriate ICD intervention and complications are not uncommon.

Long-Term Outcomes After Medical and Invasive Treatment in Patients With Hypertrophic Cardiomyopathy

OBJECTIVES The aim of this study was to determine the long-term outcomes (all-cause mortality and sudden cardiac death [SCD]) after medical therapy, alcohol septal ablation (ASA), and myectomy in patients with hypertrophic cardiomyopathy (HCM). BACKGROUND Therapy-resistant obstructive HCM can be treated both surgically and percutaneously. But there is no consensus on the long-term effects of ASA, especially on SCD. METHODS This study included 1,047 consecutive patients with HCM (mean age 52 ± 16 years, 61% men) from 3 tertiary referral centers. A total of 690 patients (66%) had left ventricular outflow tract gradients ≥ 30 mm Hg, of whom 124 (12%) were treated medically, 316 (30%) underwent ASA, and 250 (24%) underwent myectomy. Primary endpoints were all-cause mortality and SCD. Kaplan-Meier graphs and Cox regression models were used for statistical analyses. RESULTS The mean follow-up period was 7.6 ± 5.3 years. Ten-year survival was similar in medically treated patients (84%), ASA patients (82%), myectomy patients (85%), and patients with nonobstructive HCM (85%) (log-rank p = 0.50). The annual rate of SCD was low after invasive therapy: 1.0%/year in the ASA group and 0.8%/year in the myectomy group. Multivariate analysis demonstrated that the risk for SCD was lower after myectomy compared with the ASA group (hazard ratio: 2.1; 95% confidence interval: 1.0 to 4.4; p = 0.04) and the medical group (hazard ratio: 2.3; 95% confidence interval: 1.0 to 5.2; p = 0.04). CONCLUSIONS Patients with obstructive HCM who are treated at referral centers for HCM care have good survival and low SCD risk, similar to that of patients with nonobstructive HCM. The SCD risk of patients after myectomy was lower than after ASA or in the medical group.

A systematic review and meta-analysis of long-term outcomes after septal reduction therapy in patients with hypertrophic cardiomyopathy

OBJECTIVES The aim of this meta-analysis was to compare long-term outcomes after myectomy and alcohol septal ablation (ASA) in patients with hypertrophic cardiomyopathy (HCM). BACKGROUND Surgical myectomy and ASA are both accepted treatment options for medical therapy-resistant obstructive HCM. Previous meta-analyses only evaluated short-term outcomes. METHODS A systematic review was conducted for eligible studies with a follow-up of at least 3 years. Primary outcomes were all-cause mortality and (aborted) sudden cardiac death (SCD). Secondary outcomes were periprocedural complications, left ventricular outflow tract gradient, and New York Heart Association functional class after ≥3 months, and reintervention. Pooled estimates were calculated using a random-effects meta-analysis. RESULTS Sixteen myectomy cohorts (n = 2,791; mean follow-up, 7.4 years) and 11 ASA cohorts (n = 2,013; mean follow-up, 6.2 years) were included. Long-term mortality was found to be similarly low after ASA (1.5% per year) compared with myectomy (1.4% per year, p = 0.78). The rate of (aborted) SCD, including appropriate implantable cardioverter defibrillator shocks, was 0.4% per year after ASA and 0.5% per year after myectomy (p = 0.47). Permanent pacemaker implantation was performed after ASA in 10% of the patients compared with 4.4% after myectomy (p < 0.001). Reintervention was performed in 7.7% of the patients who underwent ASA compared with 1.6% after myectomy (p = 0.001). CONCLUSIONS Long-term mortality and (aborted) SCD rates after ASA and myectomy are similarly low. Patients who undergo ASA have more than twice the risk of permanent pacemaker implantation and a 5 times higher risk of the need for additional septal reduction therapy compared with those who undergo myectomy.

Validation of the 2014 European Society of Cardiology Guidelines Risk Prediction Model for the Primary Prevention of Sudden Cardiac Death in Hypertrophic Cardiomyopathy

Background—The recently released 2014 European Society of Cardiology guidelines of hypertrophic cardiomyopathy (HCM) use a new clinical risk prediction model for sudden cardiac death (SCD), based on the HCM Risk-SCD study. Our study is the first external and independent validation of this new risk prediction model. Methods and Results—The study population consisted of a consecutive cohort of 706 patients with HCM without prior SCD event, from 2 tertiary referral centers. The primary end point was a composite of SCD and appropriate implantable cardioverter-defibrillator therapy, identical to the HCM Risk-SCD end point. The 5-year SCD risk was calculated using the HCM Risk-SCD formula. Receiver operating characteristic curves and C-statistics were calculated for the 2014 European Society of Cardiology guidelines, and risk stratification methods of the 2003 American College of Cardiology/European Society of Cardiology guidelines and 2011 American College of Cardiology Foundation/American Heart Association guidelines. During follow-up of 7.7±5.3 years, SCD occurred in 42 (5.9%) of 706 patients (ages 49±16 years; 34% women). The C-statistic of the new model was 0.69 (95% CI, 0.57–0.82; P=0.008), which performed significantly better than the conventional risk factor models based on the 2003 guidelines (C-statistic of 0.55: 95% CI, 0.47–0.63; P=0.3), and 2011 guidelines (C-statistic of 0.60: 95% CI, 0.50–0.70; P=0.07). Conclusions—The HCM Risk-SCD model improves the risk stratification of patients with HCM for primary prevention of SCD, and calculating an individual risk estimate contributes to the clinical decision-making process. Improved risk stratification is important for the decision making before implantable cardioverter-defibrillator implantation for the primary prevention of SCD.

Long-term benefit of myectomy and anterior mitral leaflet extension in obstructive hypertrophic cardiomyopathy

Severely symptomatic patients with obstructive hypertrophic cardiomyopathy (HC) may benefit from surgical myectomy. In patients with enlarged mitral leaflets and mitral regurgitation, myectomy can be combined with anterior mitral leaflet extension (AMLE) to stiffen the midsegment of the leaflet. The aim of this study was to evaluate the long-term results of myectomy combined with AMLE in patients with obstructive HC. This prospective, observational, single-center cohort study included 98 patients (49 ± 14 years, 37% female) who underwent myectomy combined with AMLE from 1991 to 2012. End points included all-cause mortality and change in clinical and echocardiographic characteristics. Mortality was compared with age- and gender-matched patients with nonobstructive HC and subjects from the general population. Long-term follow-up was 8.3 ± 6.1 years. There was no operative mortality, and New York Heart Association class was reduced from 2.8 ± 0.5 to 1.3 ± 0.5 (p <0.001), left ventricular outflow tract gradient from 93 ± 25 to 9 ± 8 mm Hg (p <0.001), mitral valve regurgitation from grade 2.0 ± 0.9 to 0.5 ± 0.8 (p <0.001), and systolic anterior motion of the mitral valve from grade 2.4 ± 0.9 to 0.1 ± 0.3 (p <0.001). The 1-, 5-, 10-, and 15-year cumulative survival rates were 98%, 92%, 86%, and 83%, respectively, and did not differ from the general population (99%, 97%, 92%, and 85%, respectively, p = 0.3) or patients with nonobstructive HC (98%, 97%, 88%, and 83%, respectively, p = 0.8). In conclusion, in selected patients with obstructive HC, myectomy combined with AMLE is a low-risk surgical procedure. It results in long-term symptom relief and survival similar to the general population.

Long-Term Outcome of Alcohol Septal Ablation for Obstructive Hypertrophic Cardiomyopathy in the Young and the Elderly

OBJECTIVES The aim of this study was to compare outcomes of alcohol septal ablation (ASA) in young and elderly patients with obstructive hypertrophic cardiomyopathy (HCM). BACKGROUND The American College of Cardiology Foundation/American Heart Association guidelines reserve ASA for elderly patients and patients with serious comorbidities. Information on long-term age-specific outcomes after ASA is scarce. METHODS This cohort study included 217 HCM patients (age 54 ± 12 years) who underwent ASA because of symptomatic left ventricular outflow tract obstruction. Patients were divided into young (age ≤55 years) and elderly (age >55 years) groups and matched by age in a 1:1 fashion to nonobstructive HCM patients. RESULTS Atrioventricular block following ASA was more common in elderly patients (43% vs. 21%; p = 0.001), resulting in pacemaker implantation in 13% and 5%, respectively (p = 0.06). Residual left ventricular outflow tract gradient, post-procedural New York Heart Association functional class, and necessity for additional septal reduction therapy was comparable between age groups. During a follow-up of 7.6 ± 4.6 years, 54 patients died. The 5- and 10-year survival following ASA was 95% and 90% in patients age ≤55 years and 93% and 82% in patients age >55 years, which was comparable to their control groups. The annual adverse arrhythmic event rate following ASA was 0.7%/year in young patients and 1.4%/year in elderly patients, which was comparable to their control groups. CONCLUSIONS ASA is similarly effective for reduction of symptoms in young and elderly patients; however, younger patients have a lower risk of procedure-related atrioventricular conduction disturbances. The long-term mortality rate and risk of adverse arrhythmic events following ASA are low, both in young and elderly patients, and are comparable to age-matched nonobstructive HCM patients.

Impact of Adverse Left Ventricular Remodeling on Sudden Cardiac Death in Patients With Hypertrophic Cardiomyopathy

Adverse left ventricular (LV) remodeling predicts heart failure symptoms and overt LV dysfunction in patients with hypertrophic cardiomyopathy (HCM), but its influence on the occurrence of sudden cardiac death (SCD) is unknown. The aim of this study was to investigate the effect of adverse LV remodeling on SCD risk in patients with HCM.

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.

Effect of alcohol dosage on long-term outcomes after alcohol septal ablation in patients with hypertrophic cardiomyopathy

The aim of this study is to assess the long‐term effects of alcohol dosage in alcohol septal ablation (ASA) on mortality and adverse arrhythmic events (AAE).

Microsphere embolisation as an alternative for alcohol in percutaneous transluminal septal myocardial ablation.

BackgroundPercutaneous transluminal septal myocardial ablation using microsphere embolisation is a new interventional technique to treat patients with hypertrophic obstructive cardiomyopathy.Methods and resultsIn two patients, considered at high risk for myectomy, targeted septal perforators were occluded with microsphere embolisation instead of alcohol ablation to reduce left ventricular outflow gradient. In both cases the left ventricular outflow tract gradient was immediately reduced. No adverse events occurred.ConclusionThis is the first clinical experience with Embozene® Microspheres in the Netherlands as an alternative for alcohol septal ablation. In both cases it resulted in immediate improvement in the haemodynamics, without any adverse events.