Early outcomes of alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Advancements in the Diagnosis and Treatment of Hypertrophic Cardiomyopathy: A Comprehensive Review

Hypertrophic cardiomyopathy (HCM) is characterized by excessive growth of myocardial tissue, most commonly due to genetic mutations in sarcomere proteins. This can lead to complications such as heart failure, mitral regurgitation, syncope, arrhythmias, sudden cardiac death, and myocardial ischemia. While we have come a long way in our understanding of the pathophysiology, genetics, and epidemiology of HCM, the past 10 years have seen significant advancements in diagnosis and treatment. As the body of evidence on hypertrophic cardiomyopathy continues to grow, a comprehensive review of the current literature is an invaluable resource in organizing this knowledge. By doing so, the vast progress that has been made thus far will be widely available to all experts in the field. This review provides a comprehensive analysis of the scientific literature, exploring both well-established and cutting-edge diagnostic and therapeutic options. It also presents a unique perspective by incorporating topics such as exercise testing, genetic testing, radiofrequency ablation, risk stratification, and symptomatic management in non-obstructive HCM. Lastly, this review highlights areas where current and future research is at the forefront of innovation in hypertrophic cardiomyopathy.

Invasive therapies for symptomatic obstructive hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic condition with multiple different genetic and clinical phenotypes. As awareness for HCM increases, it is important to also be familiar with potential treatment options for the disease. Treatment of HCM can be divided into two different categories, medical and interventional. Typically for obstructive forms of the disease, in which increased septal hypertrophy, abnormally placed papillary muscles, abnormalities in mitral valve or subvalvular apparatus, lead to dynamic left ventricular outflow tract (LVOT) obstruction, treatment is targeted at decreasing obstructive gradients and therefore symptoms. Medications like beta blockers, calcium channel blockers, disopyramide can often accomplish this. However, in patients with severe obstruction or symptoms refractory to medical therapy, either surgical correction of the LVOT obstruction or percutaneous via alcohol septal ablation, are treatment options. In this review, we will focus on the invasive treatment of hypertrophic obstructive cardiomyopathy.

Does a standard myectomy exist for obstructive hypertrophic cardiomyopathy? From the Morrow variations to precision surgery

OBJECTIVES

The purpose of this work is to revisit the history of surgical treatment for obstructive hypertrophic cardiomyopathy (oHCM) over the last 60 years, in the light of advancing knowledge of the pathophysiology of obstruction.

METHODS

In this narrative review the contribution of the different surgical approaches to the field will be assessed in our personal experience in Florence.

RESULTS

Septal myectomy is the treatment of choice in patients with obstructive hypertrophic cardiomyopathy who remain symptomatic despite optimal medical treatment. Over the decades, numerous "theme variations" of the Morrow operation have been proposed, each of them targeting a specific pathophysiological determinant of left ventricular outflow tract obstruction.

CONCLUSIONS

Precision surgery in oHCM patients today depends on the ability of the surgeon to combine and master these variations, with the bird's eye view allowed by climbing on the shoulders of giants.

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

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Short- and long-term outcomes of alcohol septal ablation for hypertrophic obstructive cardiomyopathy in patients with mild left ventricular hypertrophy: a propensity score matching analysis

AIMS

Based on European guidelines, alcohol septal ablation (ASA) for hypertrophic obstructive cardiomyopathy (HOCM) is indicated only in patients with interventricular septum (IVS) thickness >16 mm. The aim of this study was to evaluate the short- and long-term outcomes in ASA patients with mild hypertrophy (IVS ≤ 16 mm).

METHODS AND RESULTS

We retrospectively evaluated 1505 consecutive ASA patients and used propensity score to match 172 pairs (344 patients) in groups IVS ≤ 16 mm or IVS > 16 mm. There was no occurrence of post-ASA ventriculoseptal defect in the whole cohort (n = 1505). Matched patients had 30-day mortality rate 0% in IVS ≤ 16 mm group and 0.6% in IVS > 16 mm group (P = 1). Patients in IVS ≤ 16 mm group had more ASA-attributable early complications (16% vs. 9%; P = 0.049), which was driven by higher need for pacemaker implantation (13% vs. 8%; P = 0.22). The mean follow-up was 5.4 ± 4.3 years and the annual all-cause mortality rate was 1.8 and 3.2 deaths per 100-patient-years in IVS ≤ 16 group and IVS > 16 group, respectively (log-rank test P = 0.04). There were no differences in symptom relief and left ventricular (LV) gradient reduction. Patients with IVS ≤ 16 mm had less repeated septal reduction procedures (log-rank test P = 0.03).

CONCLUSION

Selected patients with HOCM and mild hypertrophy (IVS ≤ 16 mm) had more early post-ASA complications driven by need for pacemaker implantation, but their long-term survival is better than in patients with IVS >16 mm. While relief of symptoms and LV obstruction reduction is similar in both groups, a need for repeat septal reduction is higher in patients with IVS > 16 mm.

Ten Tips and Tricks for Performing Alcohol Septal Ablation in Patients with Hypertrophic Obstructive Cardiomyopathy

Alcohol septal ablation (ASA) is an effective interventional therapeutic strategy to reduce or eliminate left ventricular outflow tract obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM). Although ASA was introduced 25 years ago, there are still no available guidelines to follow. Therefore, most interventional cardiologists rely on their own experience, which is often limited by a relatively low number of performed procedures. This paper presents ten tips and tricks to safe and effective ASA for HOCM.

Patients with hypertrophic obstructive cardiomyopathy after alcohol septal ablation have favorable long-term outcome irrespective of their genetic background

Background

The genetic background of patients with hypertrophic cardiomyopathy (HCM) treated with alcohol septal ablation (ASA) and its relationship to the outcomes are not known. We aimed to investigate whether the outcome of genotype positive (G+) patients differs from genotype negative (G-) patients treated with ASA.

Methods

We included 129 HCM patients (mean age 54±13 years) treated with ASA in a tertiary cardiovascular center and performed next generation sequencing (NGS) based genomic testing. All patients were followed-up three months after the procedure and yearly thereafter.

Results

A total of 30 (23%) HCM patients were G+ patients. At the 3-months follow-up, both groups of patients had similar left ventricular outflow tract PG (16.9±15.7 mmHg in G+ vs. 16.3±18.8 mmHg in G-, P=0.73) and symptoms (follow-up NYHA class 1.40±0.62 vs. 1.37±0.53, P=0.99, follow-up CCS class 0.23±0.52 vs. 0.36±0.65, P=0.36). The independent predictors of all-cause mortality were baseline interventricular septum (IVS) thickness (HR 1.12, 95% CI: 1.00-1.26, P=0.049) and age at the time of ASA (HR 1.11, 95% CI: 1.06-1.17, P<0.01). The adjusted all-cause mortality rate did not differ significantly between G+ and G- patients (P=0.52). The adjusted combined mortality event rate did not differ between both groups (P=0.78).

Conclusions

Despite more severe phenotype in G+ HCM patients, ASA is an equally effective treatment for LVOTO in G+ patients as it is for treating LVOTO in G- patients. The long-term outcome after ASA is similar in G+ and G- patients.

Valsartan inhibits RhoA-ROCK2-MYL pathway in rat model of alcoholic cardiomyopathy

The present study aimed to investigate variations in the Ras homolog gene family, member A (RhoA)-Rho-associated protein kinase 2 (ROCK2)-myosin light chain (MYL) pathway in a rat model of alcoholic cardiomyopathy (ACM) and the role of angiotensin-converting enzyme inhibitor drugs. Rat models of ACM were established via alcoholic gavage + free access to alcohol. The structural and functional changes of the heart were analyzed by hematoxylin-eosin staining, Masson's trichrome staining, immunohistochemistry staining, western blotting and fluorescence quantitative polymerase chain reaction. A total of 16 weeks later, a decreased ejection fraction and left ventricular fractional shortening in the alcohol group compared with the control group were demonstrated resulting in an increased left ventricular end diastolic diameter. These adverse effects were ameliorated following treatment with valsartan. In addition, the alcohol group revealed a disorganized arrangement of myocardial filaments, which was improved upon treatment with valsartan. RhoA and ROCK2 protein expression significantly increased in myocardial cells in the alcohol compared with the control group. Following drug intervention with valsartan, expression of RhoA and ROCK2 proteins were inhibited in the alcohol group. Furthermore, significantly elevated RhoA and ROCK2 and decreased MYL protein and mRNA expression in the alcohol group was demonstrated compared with the control group. Administration of valsartan reversed the expression profile of RhoA, ROCK and MYL in ACM. Expression of RhoA and ROCK were elevated with downregulation of MYL resulting in heart failure. However, the angiotensin receptor antagonist diminished the expression of RhoA and ROCK and enhanced the expression of MYL. The results of the present study suggest a curative effect of valsartan in ACM.

Short- and long-term outcome after alcohol septal ablation in obstructive hypertrophic cardiomyopathy: Experience of a reference center

INTRODUCTION

In obstructive hypertrophic cardiomyopathy (HCM), alcohol septal ablation (ASA) can lead to gradient reduction and symptom improvement. We aimed to assess the efficacy and safety of ASA in a long-term outcome study.

METHODS

We analyzed patients who underwent ASA over a seven-year period in a tertiary center. The primary echocardiographic endpoint was >50% reduction in left ventricular outflow tract (LVOT) gradient within a year of the procedure. The primary clinical endpoints were improvement in functional capacity and a combined endpoint of cardiac death and rehospitalization for cardiac cause. The follow-up period was 4.17±2.13 years.

RESULTS

A total of 80 patients, mean age 63.9±12.3 years, 30.0% male, were analyzed. Baseline LVOT gradient was 96.3±34.6 mmHg and interventricular septal thickness was 21.6±3.1 mm. Minor complications were observed in 6.3% and major complications in 2.5%, and 8.8% received a permanent pacemaker. The primary echocardiographic endpoint was achieved by 85.7%. At three-month follow-up, LVOT gradient was 25.8±26.0 mmHg in the successful procedure group, compared to 69.2±35.6 mmHg in the other patients (p=0.001). At six months, LVOT gradient was 27.1±27.4 vs. 58.2±16.6 mmHg (p=0.024). Among 74 patients in NYHA class III/IV before the procedure, 57 (77%) improved to NHYA class I/II. The combined primary clinical endpoint (cardiac death and rehospitalization for cardiac cause) was observed in 27.5% (n=22). In the unsuccessful group, the combined endpoint was observed in 54.5%, compared to only 22.7% in the successful group. Only two patients died of cardiac causes.

CONCLUSION

ASA is a safe procedure with a high success rate. Patients who achieved significant reductions in LVOT gradient suffered less cardiac death and rehospitalization for cardiac cause.

Alcohol septal ablation in patients with severe septal hypertrophy

OBJECTIVE

The current guidelines suggest alcohol septal ablation (ASA) is less effective in hypertrophic obstructive cardiomyopathy (HOCM) patients with severe left ventricular hypertrophy, despite acknowledging that systematic data are lacking. Therefore, we analysed patients in the Euro-ASA registry to test this statement.

METHODS

We compared the short-term and long-term outcomes of patients with basal interventricular septum (IVS) thickness <30 mm Hg to those with ≥30 mm Hg treated using ASA in nine European centres.

RESULTS

A total of 1519 patients (57±14 years, 49% women) with symptomatic HOCM were treated, including 67 (4.4%) patients with IVS thickness ≥30 mm. The occurrence of short-term major adverse events were similar in both groups. The mean follow-up was 5.4±4.3 years and 5.1±4.1 years, and the all-cause mortality rate was 2.57 and 2.94 deaths per 100 person-years of follow-up in the IVS <30 mm group and the IVS ≥30 mm group (p=0.047), respectively. There were no differences in dyspnoea (New York Heart Association class III/IV 12% vs 16%), residual left ventricular outflow tract gradient (16±20 vs 16±16 mm Hg) and repeated septal reduction procedures (12% vs 18%) in the IVS <30 mm group and IVS ≥30 mm group, respectively (p=NS for all).

CONCLUSIONS

The short-term results and the long-term relief of dyspnoea, residual left ventricular outflow obstruction and occurrence of repeated septal reduction procedures in patients with basal IVS ≥30 mm is similar to those with IVS <30mm. However, long-term all-cause and cardiac mortality rates are worse in the ≥30 mm group.

Septal reduction therapy using nonalcohol agent in hypertrophic obstructive cardiomyopathy: Single center experience

AIMS

Percutaneous septal reduction therapy by either alcohol or nonalcohol agents is an alternative approach to surgery in drug-refractory symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). Nonalcohol agents have some advantages and disadvantages over alcohol during the procedure. Nowadays, a novel non-alcohol agent, named as Ethylene-vinyl alcohol (EVOH) copolymer (Onyx^® and Squid^® ), is used during septal ablation. Thus, in this study, we aimed to evaluate both acute and long-term efficacy and safety profile of EVOH during septal ablation in HOCM.

METHODS AND RESULTS

A total of 25 patients (52% female; mean age: 55.8 ± 17.1 years) with symptomatic HOCM were enrolled in the study. All subjects underwent clinical and laboratory assessment before and after the procedure. Peak left ventricular outflow tract (LVOT) gradient was significantly reduced just after the procedure (68 vs. 20 mmHg; P < 0.001). Peak serum creatine kinase-myocardial band and troponin I levels were 112 (35-282) ng/ml and 11 (4-93) ng/ml. EVOH embolization to diagonal artery was observed in 1 patient (4%) and the complete atrioventricular block was noted in 2 (8%) patients. During the 12-month follow-up, there was no mortality. There was a significant improvement in New York Heart Association functional class of the subjects P < 0.001). Both interventricular septum thickness and LVOT gradient showed a significant reduction during follow-up (P < 0.05). However, there was no reduction in the LVOT gradient of 3 patients (12%).

CONCLUSIONS

In conclusion, our small-sized preliminary study results showed that septal reduction therapy using EVOH is an effective alternative option in reducing symptoms and LVOT gradient in HOCM.

Hypertrophic obstructive cardiomyopathy: review of surgical treatment

Hypertrophic cardiomyopathy ranks among the most common congenital cardiac diseases, affecting up to 1 in 200 of the general population. When it causes left ventricular outflow tract obstruction, treatment is guided to reduce symptoms and the risk of sudden cardiac death. Pharmacologic therapy is the first-line treatment, but when it fails, surgical myectomy or percutaneous ablation of the hypertrophic myocardium are the standard therapies to eliminate subaortic obstruction. Both surgical myectomy and percutaneous ablation are proven safe and effective treatments; however, myectomy is the gold standard with a significantly lower complication rate and more complete and lasting reduction of left ventricular outflow tract obstruction.

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.

Obstructive Form of Hypertrophic Cardiomyopathy-Left Ventricular Outflow Tract Gradient: Novel Methods of Provocation, Monitoring of Biomarkers, and Recent Advances in the Treatment

Dynamic (latent or/and labile) obstruction of left ventricular outflow (LVOT) was recognized from the earliest clinical descriptions of hypertrophic cardiomyopathy (HCM) and has proved to be a complex phenomenon, as well as arguably the most audible (“visible”) pathophysiological hallmark of this heterogeneous disease. The aim of the current review is focused on two novel issues in a subgroup of obstructive HCM. Firstly, the important methodological problem in HCM is the examination of a subgroup of patients with nonobstructive hypertrophy in resting conditions and hard, but possible provoking obstruction. Recently, investigators have proposed physiological stress test (with double combined stimuli) to disclose such type of patients. The upright exercise is described in the ESC guideline on hypertrophic cardiomyopathy from 2014 and may appear as a candidate for gold standard provocation test. The second novel area of interest is associated with elevated level of signaling biomarkers: hypercoagulation, hemolysis, acquired von Willebrand 2A disease, and enhanced oxidative stress. The accelerated and turbulent flow within narrow LVOT may be responsible for these biochemical disturbances. The most recent advances in the treatment of obstructive HCM are related to nonpharmacological methods of LVOT gradient reduction. This report extensively discusses novel methods.

Intracoronary electrocardiogram during alcohol septal ablation for hypertrophic obstructive cardiomyopathy predicts myocardial injury size

Alcohol septal ablation (ASA) has been used widely to treat patients with hypertrophic obstructive cardiomyopathy (HOCM). During the routine ASA procedure, it is difficult to detect the septal injury in real-time. The aim of the present study is to assess myocardial injury during ASA by recording intracoronary electrocardiogram (IC-ECG). From 2012 to 2015, 31 HOCM patients were treated with ASA, and IC-ECG was recorded in 21 patients successfully before and after ethanol injection. The elevation of ST-segment on IC-ECG after ethanol injection was expressed as its ratio to the level before injection or the absolute increasing value. Blood samples were collected before and after ASA for measuring changes in cardiac biomarkers. The ratio value of ST-segment elevation was positively correlated with both the amount of ethanol injected (r = 0.645, P = 0.001) and the myocardial injury size (creatine kinase-MB area under the curve (AUC) of CK-MB) (r = 0.466, P = 0.017). The absolute increment of ST-segment was also positively associated with both the amount of ethanol (r = 0.665, P = 0.001) and AUC of CK-MB (0.685, P = 0.001). However, there was no statistical correlation between the reduction of left ventricular outflow tract gradient and ST-segment elevation. Additionally no severe ASA procedure-related complications were observed in our patients. In conclusion, myocardial injury induced by ethanol injection can be assessed immediately by ST-segment elevation on IC-ECG. This study is the first to show that IC-ECG is a useful method for predicting myocardial injury during ASA in real-time.

How to Treat Obstructions in Patients with Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is characterized by the presence of increased thickness of the left ventricular wall that is not solely explained by abnormal loading conditions. Two-thirds of the patients with HCM have an obstruction in the left ventricle after provocation or even while at rest. This obstruction is associated with more symptoms and a worse prognosis. The two main therapeutic approaches for treating a left ventricular obstruction are alcohol septal ablation and surgical myectomy. Both these techniques are discussed in this article. Currently, the final decision concerning the optimal invasive therapy for patients with obstructive HCM must be individualized to each patient depending on his/her wishes and expectations, way of life, age, heart morphology, and hemodynamics, as well as the experience of the treating center.

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

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

Current status and future perspectives on alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiac disease. Patients may present with a wide variety of symptoms, ranging from relatively asymptomatic to heart failure, recurrent syncope, angina, or sudden death. Once diagnosed, a thorough clinical, anatomic and physiologic assessment should be undertaken. Treatment options include both pharmacologic and invasive therapies, with a goal to reduce symptoms and possibly extend longevity. Traditionally, the "gold standard" for treating severe obstructive HCM has been ventricular septal myotomy-myomectomy. Since its introduction in 1994, alcohol septal ablation (ASA) has emerged as an acceptable alternative in patients who meet strict anatomic criteria, and has been supported in recent guidelines. We review the indications, technique, competency requirements, alternatives, outcomes, complications, and future directions of ASA.

Survival of patients ≤ 50 years of age after alcohol septal ablation for hypertrophic obstructive cardiomyopathy

BACKGROUND

The long-term efficacy and safety of alcohol septal ablation (ASA) has recently been demonstrated. However, there is still debate about the outcome of younger patients who should be treated using myectomy, according to American College of Cardiology Foundation/American Heart Association guidelines. The aim of this study was to evaluate the long-term outcome of patients ≤ 50 years of age after ASA for hypertrophic obstructive cardiomyopathy (HOCM).

METHODS

We retrospectively evaluated consecutive, highly symptomatic patients aged ≤ 50 years with HOCM who underwent ASA.

RESULTS

Institutional databases of 3 cardiovascular centres identified 290 patients with HOCM who underwent ASA; 75 (26%) of them were aged ≤ 50 years at the time of their first ASA. Median duration of follow-up was 5.1 years (range, 0.1-15.4 years). Four patients (5%) died during the study period (438 patient-years; the annual mortality rate was 0.91%; 95% confidence interval [CI], 0.25-2.34%; the annual mortality rate combined with the first appropriate implantable cardioverter-defibrillator discharge was 1.43%; 95% CI, 0.52-3.10%). Survival free of all-cause mortality at 1, 5, and 10 years was 97% (95% CI, 89-99%), 94% (95% CI, 84-98%), and 94% (95% CI, 84-98%), respectively.

CONCLUSIONS

Results of this first study focused on HOCM patients aged ≤ 50 years who underwent ASA suggest a low risk of all-cause death or appropriate implantable cardioverter-defibrillator discharge in the long-term follow-up.