How are the predictors of sudden death modified after septal myectomy surgery?

BACKGROUND: Hypertrophic cardiomyopathy is a condition associated with an increased risk of sudden death compared to the general population. Extended septal myectomy surgery has been suggested to impact the reduction of sudden death events according to various publications. The aim of this study was to assess changes in the prevalence of sudden death predictors in a population of patients undergoing extended septal myectomy surgery. METHODS: Ninety-four consecutive patients underwent extended septal myectomy surgery due to symptomatic hypertrophic cardiomyopathy. Risk factors for sudden death, as defined by the American Heart Association and the European Society of Cardiology, were evaluated before and three months after surgery. RESULTS: The mean age of the population was 57 ± 13 years. A significant reduction was observed in the maximum septal thickness from 21.3 to 14 mm (p<0.001), along with a decrease in the anteroposterior diameter of the left atrium from 51 to 47 mm (p=0.021). Resting intraventricular gradients decreased from 49.2 to 6.4 mmHg (p<0.001), and Valsalva-induced gradients decreased from 93.9 to 8.7 mmHg (p<0.001). Non-sustained ventricular tachycardia decreased from 6% to 2% (p<0.001), and atrial fibrillation decreased from 30% to 15% (p<0.001). Ischemic behavior during exercise stress echo decreased from 6% to 0%, and the European Society of Cardiology sudden death risk score reduced from 3.32 to 1.44 (p<0.001). CONCLUSIONS: In this cohort of hypertrophic cardiomyopathy patients, extended septal myectomy surgery was associated with a reduction in the number and magnitude of sudden death predictors, potentially explaining the reduced mortality reported in the literature.

Comparison of Early and Mid-Term Outcomes After Classic and Modified Morrow Septal Myectomy in Patients with Hypertrophic Obstructive Cardiomyopathy.

INTRODUCTION: The aim of our study is to compare the early and mid-term outcomes of patients with hypertrophic obstructive cardiomyopathy who underwent classic and modified Morrow septal myectomy. METHODS: Between 2014 and 2019, 48 patients (24 males; mean age 49.27±16.41 years) who underwent septal myectomy were evaluated. The patients were divided into two groups - those who underwent classic septal myectomy (n=28) and those who underwent modified septal myectomy (n=20). RESULTS: Mitral valve intervention was higher in the classic Morrow group than in the modified Morrow group, but there was no significant difference (P=0.42). Mortality was found to be lower in the modified Morrow group than in the classic Morrow group (P=0.01). In both groups, the mean immediate postoperative gradient was significantly higher than the mean of the 3rd and 12th postoperative months. The preoperative and postoperative gradient difference of the modified Morrow group was significantly higher than of the classic Morrow group (P<0.001). CONCLUSION: Classic Morrow and modified Morrow procedures are effective methods for reducing left ventricular outflow tract obstruction. The modified Morrow procedure was found to be superior to the classic Morrow procedure in terms of reducing the incidence of mitral valve intervention with the reduction of the left ventricular outflow tract gradient.

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.

Association between postoperative nadir platelet count and postoperative cardiovascular complications following septal myectomy in patients with hypertrophic cardiomyopathy: a retrospective cohort study.

BACKGROUND: Platelet count is associated with cardiovascular risk and mortality in several cardiovascular diseases, but the association of the nadir platelet counts post-septal myectomy with the cardiovascular complication risk in hypertrophic obstructive cardiomyopathy patients remains unclear. METHODS: This retrospective cohort study reviewed all adult patients who underwent septal myectomy at a single tertiary referral center over a 5-year period. Postoperative nadir platelet count was defined as the lowest platelet count in the first 4 postoperative days or until hospital discharge. The composite outcome included cardiovascular death, myocardial infarction, heart failure, malignant arrhythmia, cardiac tamponade, and major bleeding events within 30 days postoperatively. Univariable and multivariable logistic regression and restricted cubic spline models were used to assess the association between postoperative nadir platelet count and the 30-day postoperative cardiovascular complication risk. RESULTS: Among the 113 enrolled patients, 23 (20.4%) developed cardiovascular events within 30 days postoperatively. The incidence of postoperative cardiovascular complications was significantly higher in patients with a nadir platelet count ≤ 99 × 109/L than in those with a nadir platelet count > 99 × 109/L (33.3% vs. 7.1%, crude risk ratio: 4.67, 95% confidence interval: 1.69-12.85, P < 0.001). Multivariable logistic regression revealed that postoperative nadir platelet count was negatively associated with 30-day postoperative cardiovascular complications (adjusted odds ratio: 0.97; 95% confidence interval: 0.95-0.99; P = 0.005) and the association was linear (Pnonlinearity = 0.058) after full adjustment. The association between nadir platelet count and cardiovascular complications within 30 days post-surgery was consistent in all predefined subgroups (Pinteraction > 0.05). CONCLUSION: The postoperative nadir platelet count was significantly associated with the 30-day post-myectomy risk of cardiovascular complications in hypertrophic obstructive cardiomyopathy patients. TRIAL REGISTRATION: This trial was registered at ClinicalTrials.gov (NCT04275544).

Improvement in gastrointestinal bleeding after septal myectomy for hypertrophic cardiomyopathy.

OBJECTIVE: Patients with obstructive hypertrophic cardiomyopathy may have occult gastrointestinal bleeding. In this study, we analyzed outcomes of septal myectomy in patients who had a history of gastrointestinal bleeding preoperatively to understand patient characteristics and impact of septal reduction on recurrent gastrointestinal bleeding. METHODS: We analyzed 73 adult patients who had a history of gastrointestinal bleeding before transaortic septal myectomy for obstructive hypertrophic cardiomyopathy and compared outcomes to 219 patients without gastrointestinal bleeding preoperatively. RESULTS: Patients with preoperative history of gastrointestinal bleeding were older (median (IQR) age, 65 (59-69) years, P < .001) and were more likely to have systemic hypertension (70% vs 53%, P = .020) and coronary artery disease (25% vs 13%, P = .026). Preoperatively, patients with gastrointestinal bleeding had a larger left atrial volume index (median, 53 mL/m2; interquartile range, 42-67; P = .006) and greater right ventricular systolic pressure (median, 36 mm Hg; interquartile range, 32-49; mm Hg, P = .005) but no significant difference in severity of outflow tract obstruction (P = .368). There were no perioperative deaths. The estimated 5- and 10-year survivals were 96.6% and 81.8%, respectively. At a median of 3.4 (interquartile range, 1.9-9.1) years after septal myectomy, 11 patients (15%) had recurrence of gastrointestinal bleeding, which was attributed to angiodysplasia or unknown causes in 6 patients (8%). CONCLUSIONS: Patients with a preoperative history of gastrointestinal bleeding have favorable short- and long-term outcomes after septal myectomy for obstructive hypertrophic cardiomyopathy. Remission of gastrointestinal bleeding was observed in 85% of patients postprocedure, and only 8% of the patients had recurrent gastrointestinal bleeding due to angiodysplasia or unknown causes.

Adding Surgical Edge-to-Edge Mitral Valve Repair to Myectomy in Hypertrophic Obstructive Cardiomyopathy: Long-Term Functional and Echocardiographic Outcome.

This study evaluates the early and long-term clinical and echocardiographic outcome of edge-to-edge (E2E) mitral valve repair (MVr) concomitant to septal myectomy (SM) in patients with symptomatic hypertrophic obstructive cardiomyopathy (HOCM). A retrospective single-center analysis was performed of patients who underwent isolated SM or SM with E2E MVr from 2011 to 2022. Exclusion criteria were primary mitral valve (MV) disease or concomitant valve surgery. Early and long-term safety, functional and echocardiographic outcomes were compared between groups. Between January 2011 and April 2022, 76 consecutive patients underwent SM for HOCM: 42 patients (55%) underwent SM without additional E2E MVr (Group 1) and 34 patients (45%) underwent SM with additional E2E MVr (Group 2). At latest follow-up, 87% of patients were in New York Heart Association (NYHA) class I-II with no significant differences in NYHA class between groups. Incidence of safety events was comparable between groups. Echocardiographic relief of left ventricular outflow tract (LVOT) obstruction was comparable at early follow-up (P = 0.68), with a significant but small difference in maximum LVOT pressure gradient at latest follow-up in favor of E2E MVr (P = 0.04). Furthermore, patients who underwent SM with E2E MVr showed less residual systolic anterior motion at early and latest follow-up (P = 0.020; P = 0.178). Reintervention on the MV was absent in both groups at 1 year and equally low at follow-up (P = 0.27). This study demonstrates that adding E2E MVr to septal myectomy is as safe as isolated myectomy for the treatment of HOCM. Moreover, the addition of E2E MVr is associated with similar excellent functional improvement and freedom from MV reintervention.

Transapical beating-heart septal myectomy for hypertrophic cardiomyopathy with latent obstruction.

OBJECTIVES: A novel transapical beating-heart septal myectomy (TA-BSM) procedure was performed for patients with latent obstruction through the left intercostal incision and without cardiopulmonary bypass. This study aims to demonstrate the experience of the TA-BSM procedure for patients with latent obstruction and compare outcomes to patients with resting obstruction. METHODS: We studied 120 symptomatic hypertrophic obstructive cardiomyopathy patients (33 with latent obstruction and 87 with resting obstruction) who underwent TA-BSM. Demographic profiles, echocardiogram-derived ventricular morphology and haemodynamics and clinical outcomes were analysed. RESULTS: There were no important differences in baseline clinical characteristics between patients with latent obstruction and resting obstruction, including age, symptoms, comorbidities and medical history. Patients with latent obstruction had lower basal septum thickness, higher midventricular wall thickness, smaller left atrial chamber size and more frequency of mitral subvalvular anomalies. There was no difference in early (<30 days) deaths (0/33 vs 1/87, P > 0.999) and mid-term survival between patients with latent obstruction and resting obstruction. At 6 months after surgery, 31 (93.9%) patients with latent obstruction and 80 (92.0%) with resting obstruction achieved optimal procedural success, which was defined as a maximal gradient (after provocation) <30 mmHg and mitral regurgitation ≤ grade 1+ without mortality. Maximal left ventricular outflow tract gradient, basal septum thickness, midventricular wall thickness, mitral regurgitation grade and left atrial chamber size were significantly decreased after TA-BSM. In the follow-up, the New York Heart Association class was significantly improved following surgery. CONCLUSIONS: TA-BSM preserved favourable gold-standard guideline desired outcomes through real-time echocardiographic-guided resection. Equipoise of outcomes for this procedure regardless of degree of resting left ventricular outflow tract gradients supports operative management with this approach in symptomatic patients with latent obstruction.

First-in-Human Transapical Beating-Heart Septal Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy.

BACKGROUND: To simplify surgical septal reduction therapy for hypertrophic obstructive cardiomyopathy (HOCM), we developed a novel transapical beating-heart septal myectomy (TA-BSM) procedure. OBJECTIVES: In this study, we sought to evaluate the clinical utility of TA-BSM in a first-in-human trial. METHODS: Patients with HOCM were enrolled if they presented with drug-refractory disabling symptoms. TA-BSM was performed via minithoracotomy with the use of our beating-heart myectomy device under echocardiographic guidance, without the use of cardiopulmonary bypass. Repeated resections were performed to tailor the extent of the septal myectomy for sufficient abolishment of left ventricular outflow tract (LVOT) obstruction and mitral regurgitation (MR). The primary outcome measure was procedural success, defined by resting/provoked LVOT gradient <30/50 mm Hg and residual MR grade ≤1+ (of 4+) at 3-month follow-up. RESULTS: A total of 47 patients aged 12 to 77 years were enrolled. Of the 46 patients who were followed for 3 months, 42 achieved procedural success. The maximal LVOT gradient decreased from 86 mm Hg (IQR: 67-114 mm Hg) at baseline to 19 mm Hg (IQR: 14-28 mm Hg) at 3 months. MR grade was ≤1+ in 3 patients at baseline and in 45 patients at 3 months. One patient died on postoperative day 10 owing to device-unrelated reasons. Other major adverse events included 1 delayed ventricular septal perforation and 1 intraoperative left ventricular apical tear. CONCLUSIONS: TA-BSM is a safe and efficient minimally invasive procedure for septal reduction of heterogeneous HOCM. Compared with conventional septal myectomy, TA-BSM provides real-time evaluation to guide resection while reducing surgical trauma. (Transapical Beating-Heart Septal Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy; NCT05332691).

Residual or recurrent obstruction after septal myectomy in young children and infants with hypertrophic cardiomyopathy: cohort study.

BACKGROUND: The outcomes after septal myectomy in young children and infants with hypertrophic obstructive cardiomyopathy (HOCM) are not clear. The study sought to report the outcomes after septal myectomy in young children and infants and identify the mechanisms of residual or recurrent obstruction after surgery. METHODS: The authors performed an observational cohort study of children and infants under the age of 14 who underwent septal myectomy for HCOM from January 2013 to December 2020. Mean follow-up among 94.3% ( n =50) of hospital survivors was 42.09±24.38 months. RESULTS: In total, 56 children and infants [mean (SD) age, 5.38 (3.78) years; 29 (58.1%) were male] underwent septal myectomy for HOCM. Cumulative survival was 100, 96.6, 93.0, and 81.4% at 1, 3, 5, and 7 years, respectively, among hospital survivors. The incidence of residual and recurrent obstruction was 14.3% (8/56) and 13.0% (6/46), respectively. The mechanisms of residual obstruction were identified as subaortic obstruction caused by inadequacy of previous septal excision in two patients, midventricular obstruction caused by inadequacy of septal excision in five patients, and untreated abnormal papillary muscles in one patient. Recurrent obstruction was caused by isolated midventricular obstruction ( n =4) and newly emerged systolic anterior motion (SAM)-related subaortic obstruction combining abnormal mitral valve apparatus ( n =2). Residual or recurrent obstruction was associated with age less than 2 years at surgery (OR=6.157, 95% CI: 1.487-25.487, P =0.012) and biventricular outflow obstruction (OR=6.139, 95% CI: 1.292-29.172, P =0.022). Recurrent obstruction was associated with age less than 2 years at surgery (OR=6.976, 95% CI: 1.233-39.466, P =0.028). CONCLUSIONS: Septal myectomy is still effective and safe in young children and infants. The rate of residual or recurrent obstruction with diverse causes is relatively high, which is more likely to occur in children aged less than 2 years at surgery and those with biventricular obstruction.

Septal Myectomy Outcomes in Children and Adolescents With Obstructive Hypertrophic Cardiomyopathy.

BACKGROUND: Little data exist regarding characteristics and outcomes of pediatric patients undergoing septal myectomy. We evaluated this in a large referral population. METHODS: Septal myectomy was performed in 199 consecutive patients aged ≤18 years with obstructive hypertrophic cardiomyopathy from January 1, 1976, to June 30, 2021. RESULTS: Median age was 13 years (interquartile range [IQR], 8-15 years). Left ventricular myectomy approaches included transaortic (163 of 198 [82%]), transapical (16 of 198 [8%]), and combined (19 of 198 [10%]). Right ventricular interventions included myectomy (13 of 199 [7%]) and patch reconstruction of the outflow tract (15 of 199 [8%]). Maximum left ventricular outflow tract gradients decreased after myectomy (prebypass: 50 mm Hg [IQR, 31-73 mm Hg] vs postbypass: 4 mm Hg [IQR, 0-9 mm Hg], P < .001), and this was sustained long-term (5 mm Hg [IQR, 5-10 mm Hg] at 10 years). Iatrogenic aortic and mitral valve injuries occurred in 13 of 199 (7%) and 1 of 199 (1%), respectively; however, all were successfully repaired. Operative mortality was 2 of 199 (1%). The cumulative incidence of redo myectomy was low, at 5.8% at 5 and 8.3% at 10 years. Redo myectomy patients had higher maximum left ventricular outflow tract gradients on echocardiography at predischarge and 1 year and were younger at the index operation (8 years [IQR, 2.5-10 years] vs 13 years [IQR, 9-16 years], P < .001). Overall survival at 10 years was 90%, relative to 47% in a previously reported pediatric nonoperative cohort. CONCLUSIONS: Pediatric septal myectomy provides safe, effective, and durable relief of ventricular outflow tract obstruction. Iatrogenic valve injury remains a low but nonnegligible risk. Recurrent obstruction requiring redo myectomy is infrequent and can be identified early. Long-term survival in this pediatric septal myectomy cohort appears to fare better than pediatric hypertrophic cardiomyopathy cohorts managed nonoperatively.

Alcohol septal ablation versus surgical septal myectomy of obstructive hypertrophic cardiomyopathy: systematic review and meta-analysis.

OBJECTIVES: To elucidate the optimal septal reduction therapy for obstructive hypertrophic cardiomyopathy, we conducted a meta-analysis comparing alcohol septal ablation (ASA) and septal myectomy. METHODS: MEDLINE, EMBASE and Cochrane CENTRAL were searched to identify studies investigating the outcomes of ASA and septal myectomy in patients with obstructive hypertrophic cardiomyopathy in January 2023. The primary outcome of interest was all-cause mortality in studies with ≥1 year of follow-up. The secondary outcomes of interest comprised left ventricular outflow tract (LVOT) pressure gradient reduction and reoperations of LVOT. A subgroup analysis of all-cause mortality including studies with follow-up ≥5 years was performed. RESULTS: 27 observational studies were included (15 968 patients). Analysis demonstrated similar all-cause mortality [hazard ratio (HR) (95% confidence interval) (CI) 1.24 (0.88-1.76); P = 0.21; I2 = 56%]. In contrast, ASA was associated with less reduction of LVOT pressure gradient and a reoperation rate [weighted mean difference (95% CI) 11.04 mmHg (5.60-16.48); P < 0.01; I2 = 64%, HR (95% CI) 9.14 (6.55-12.75); P < 0.001; I2 = 0%, respectively]. The subgroup analysis with follow-up ≥5 years revealed higher long-term mortality with ASA [HR (95% CI) 1.50 (1.04-2.15); P = 0.03; I2 = 52%]. CONCLUSIONS: Although both septal reduction therapies were associated with similar all-cause mortality, ASA was associated with a higher rate of reoperation and less reduction of LVOT pressure gradient. Furthermore, all-cause mortality with follow-up ≥5 years showed favourable outcomes with septal myectomy, although the result is only hypothesis-generating given a subgroup analysis.

[Surgery for obstructive hypertrophic cardiomyopathy: challenge and future].

After more than 60 years of development, with the deepening of the pathophysiological understanding of obstructive hypertrophic cardiomyopathy, the extent and resection thickness of myectomy have increased significantly. Myectomy combined with the correction of anomalies of the mitral valve apparatus has become the standard treatment of obstructive hypertrophic cardiomyopathy. Only a few centers worldwide can routinely perform it due to the difficulty. Because of the advances of new drugs and interventional therapy, the development of surgical treatment faces many challenges. At the same time, generations of cardiovascular surgeons are constantly trying to promote septal myectomy, including developing devices and the surgical field, as well as improving surgical planning by advanced technology. At present, the superior long-term efficacy of septal myectomy has been confirmed. It is necessary to work together to promote the treatment of hypertrophic obstructive cardiomyopathy, so as to guard people's health.

Regional Disparities in the Use of Septal Reduction Therapy and Associated Outcomes in the United States (from a Real-World Database).

The regional differences in the use of septal reduction therapies and the associated outcomes in patients with Hypertrophic obstructive cardiomyopathy (HOCM) are unknown. The primary objective of our study was to evaluate the regional disparities in the use of septal reduction therapies, including septal myectomy and alcohol septal ablation, in patients with HOCM. The secondary objective was to analyze the regional differences in the outcomes in these patients. Patients with HOCM had 87% higher risk-adjusted odds of getting septal myectomy (adjusted odds ratio 1.87, p = 0.03) and 37% lower risk-adjusted odds of getting alcohol septal ablation (adjusted odds ratio 0.63, p = 0.03) in the Midwest than in the Northeast. The in-hospital mortality rate was higher for patients who underwent septal myectomy in the South versus the Northeast on the unadjusted analysis. These differences persisted despite the adjustment for demographic and clinical characteristics. Additional adjustment for hospital volume partially explained these disparities, but the adjustment for both hospital volume and hospital teaching status completely explained these disparities. The risk-adjusted in-hospital mortality in patients who underwent alcohol septal ablation was similar in the South versus other regions. In conclusion, regional disparities may exist in the use of septal myectomy and alcohol septal ablation, and patients with HOCM should be referred to high-volume teaching hospitals for septal myectomy for better outcomes, which may also eliminate the extra burden of hospital mortality in the South.

Conduction Disturbances and Arrhythmia Risk After Septal Reduction Therapy with Alternative Agents: A Pilot Study with EVOH-DMSO and Systematic Review.

OBJECTIVE: Surgical septal myectomy and alcohol septal ablation are recommended treatment modalities for alleviating Left ventricular outflow tract (LVOT) gradient in obstructive HCM. Alcohol septal ablation offers advantages over surgery in many ways. However, it is associated with some life-threatening complications. For this purpose, our center used alternative agents for septal artery embolization. This study compared and evaluated conduction system defects and arrhythmia risk after EVOH-DMSO septal ablation with other alternative agents and alcohol septal ablation. METHODS: Twenty-five patients who received septal reduction therapy with EVOH-DMSO were analyzed retrospectively, and all non-alcoholic agent's septal ablation studies were systematically reviewed and compared. RESULTS: Twenty-five patients (52% female; mean age: 55.8 ± 17.1) with symptomatic obstructive HCM were enrolled. The Peak LVOT gradient was significantly reduced after the procedure (68 vs. 20 mmHg; P <0.001). During the 12-month follow-up, no mortality occurred. The complete atrioventricular block was noted in 2 (8%) patients. The incidence of right bundle branch block (RBBB) increased after the procedure (pre-procedural 2 patients (8%), post-procedural 9 patients (36%) P = 0.002). On ECG and Holter monitorization, no sustained ventricular tachyarrhythmia occurred during follow-up, and no change was found in the frequency of atrial fibrillation. We systematically compared EVOH-DMSO to other non-alcohol agents, and we found that EVOH-DMSO can cause conduction system problems more commonly than other non-alcohol agents. CONCLUSION: EVOH-DMSO could cause conduction system problems more common than other non-alcohol agents but less than alcohol septal ablation.

Alcohol septal ablation in hypertrophic cardiomyopathy: For which patients?

Percutaneous and surgical therapies for septal reduction for hypertrophic cardiomyopathy have been going head-to-head for the past 20 years with similar outcomes and mortality rates, although contemporary myectomy seems to materialize its superiority. However, on closer analysis, the external validity of studies advocating myectomy does not translate to all centres. The aim of this review was to examine the most recent data on septal reduction therapy and to attempt to phenotype the appropriate patient for each of the two treatments. The key to similar low mortality rates between ventricular septal myectomy and alcohol septal ablation appears to be proper patient selection performed in high volume clinical environments. Furthermore, we analyse the role of mavacampten (the recently approved cardiac myosin inhibitor) in replacing or complementing the two septal reduction therapies.

Preoperative left ventricular longitudinal strain predicts outcome of septal myectomy for obstructive hypertrophic cardiomyopathy.

OBJECTIVE: The objective of this study was to determine the characteristics of longitudinal strain and its effect on outcomes in patients with obstructive hypertrophic cardiomyopathy (HCM) who underwent septal myectomy. METHODS: We reviewed patients with obstructive HCM who underwent septal myectomy at our clinic from 2007 to 2016. Data of those who had strain echocardiography within 6 months before isolated myectomy were analyzed. RESULTS: The median age of the 857 patients studied was 55 (interquartile range [IQR], 44-63) years, and 451 (52.6%) were male. Left ventricular ejection fraction was 71% (IQR, 67%-74%), and the resting peak outflow tract gradient was 58 (IQR, 27-85) mm Hg. The median global longitudinal strain (GLS) was -14.6% (IQR, -12.0% to -17.3%). Regional longitudinal strain was nonuniform as reflected by more normal values in apical segments and more abnormal in basal segments. Moreover, GLS correlated poorly with ejection fraction and outflow tract gradient. In 64 patients who had postoperative strain echocardiography, GLS was comparable before and after septal myectomy, but regional strain was more uniform after myectomy. Over a follow-up of 8.3 (IQR, 6.5-10.3) years, when patients were equally stratified according to GLS (cutoff, -14.64%), the group with worse GLS had significantly poorer survival compared with the better GLS group (P = .002). Left ventricular ejection fraction had no association with survival. CONCLUSIONS: Left ventricular longitudinal strain is nonuniform and might be significantly reduced in patients with obstructive HCM. Septal myectomy does not impair GLS but is associated with more uniform regional strains. Most importantly, reduced GLS preoperatively is strongly and independently associated with increased all-cause mortality after septal myectomy for obstructive HCM.

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.

Impact of Hospital Volume on Outcomes of Septal Myectomy for Hypertrophic Cardiomyopathy.

BACKGROUND: Left ventricular outflow tract obstruction is common among symptomatic patients with hypertrophic cardiomyopathy, yet septal reduction by surgical myectomy (septal myectomy [SM]) is performed infrequently in many centers. This study examined the possible relationship between institutional case volume and early outcomes of SM. METHODS: The Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried for patients with hypertrophic cardiomyopathy who underwent SM from January 2012 to December 2019. The study defined center case volume categories as <1, 1 to 4.99, 5 to 9.99, and ≥10 cases performed on average per year. RESULTS: The study population included 5935 patients at 481 centers with 933 surgeons. The range of average center volume was <1 to 138 cases per year. Overall early mortality was 2.6%, ventricular septal defect (VSD) occurred in 1.9%, and complete heart block occurred in 9.0%. Concomitant mitral valve (MV) repair was performed in 28.7%, and MV replacement was performed in 17.1%. In multivariable analysis, the lowest annual case volume (average <1 case/y) was consistently associated with greater early mortality (odds ratio [OR], 5.4; CI, 3.0-9.9; P < .001), greater risk of VSD (OR, 9.3; CI ,4.2-20.4; P < .001), increased incidence of complete heart block (OR, 2.0; CI, 1.5-2.7; P < .001), and a higher likelihood of MV replacement (OR, 9.4; CI, 7.5-11.8; P < .001). CONCLUSIONS: Volume of SM cases varies widely among institutions reporting to the Society of Thoracic Surgeons Adult Cardiac Surgery Database. There appears to be an important association between surgical experience, as reflected by institutional case volume, and early outcomes, including mortality, as well as the occurrence of VSD, heart block, and MV replacement.