Intraoperative changes and prognostic implications of pulmonary hypertension in patients with hypertrophic obstructive cardiomyopathy undergoing surgical septal myectomy

OBJECTIVES

Patients with hypertrophic cardiomyopathy often have concomitant pulmonary hypertension, which has a negative prognostic effect in patients undergoing myectomy. Our objective was to investigate the effect of myectomy on pulmonary artery pressure obtained via Swan-Ganz catheter and characterize how changes in pulmonary artery systolic pressure may indicate outcomes in these patients.

METHODS

We performed a single-center retrospective analysis of 271 patients with recordings of intraoperative pulmonary artery pressures during surgical myectomy. We analyzed primary composite outcomes as 30-day or in-hospital major cardiopulmonary adverse events.

RESULTS

There was a 5.17% adverse event rate. Patients with adverse events were older, were more likely to be female, had chronic obstructive pulmonary disease, and had longer cardiopulmonary bypass times. Some 35.7% of those with adverse events had moderate to severe pulmonary hypertension (pulmonary artery systolic pressure ≥50 mm Hg) on postbypass stress test, compared with 4.3% of those without adverse events (P < .001). Further, 21.4% of patients with adverse events had pulmonary artery systolic pressure 50 mm Hg or greater at the end of surgery, compared with 1.9% of patients without adverse events (P < .001). The pulmonary artery systolic pressure decrease after surgery in those without adverse events was on average 5 mm Hg more than in those with adverse events.

CONCLUSIONS

Postoperative pulmonary hypertension was associated with a higher rate of adverse cardiopulmonary events. This may influence the decision to use Swan-Ganz catheters in patients undergoing septal myectomy in monitoring pulmonary artery pressures to better risk stratify and manage these patients postoperatively.

Clinical results in a national referral center

OBJECTIVES

Extended septal myectomy and alcohol septal ablation are two invasive treatments for hypertrophic obstructive cardiomyopathy. We aim to compare which of these techniques achieves a higher reduction in gradients, improvement in NYHA class and reduction in medical treatment.

METHODS

This is a single-center observational and retrospective analysis. This is a single-center observational and retrospective analysis. We have used multivariable regression analyses to assess the association of ablation/myectomy with different outcomes. Odds ratio or coefficient along with the 95% confidence interval were estimated according to the group, and adjusting for the corresponding pre procedural variables and Euroscore II.

RESULTS

78 patients underwent septal myectomy and 25 patients underwent alcohol septal ablation. Basal and Valsalva gradients after myectomy were reduced in a higher degree in comparison to ablation, 21.0 mmHg (p < 0.001, 95%CI -30.7; -11.3), and 34.3 mmHg (p < 0.001, -49.1; -19.5) respectively. Those patients who received myectomy had lower probability of presenting moderate mitral regurgitation (OR = 0.18, p = 0.054). Patients after septal myectomy were more likely to be in NYHA I (80.4%); whilst patients after ablation were more likely to be NYHA III (48%). Both groups continued with betablocker therapy, but disopyramide could be discontinued after myectomy in more cases (20% - 36% vs. 59% - 1.3%; p < 0.001) and there is a tendency in the discontinuation of calcium channel blockers (48% - 16% vs. 15.4-3.8%; p = 0.054).

CONCLUSIONS

After adjustment by pre procedural gradients and Euroscore II, myectomy achieves greater reduction in left ventricular outflow tract gradients compared to septal ablation.

alcohol septal ablation for hypertrophic cardiomyopathy with outflow tract obstruction: An update and insights from the national inpatient sample from 2011 to 2019

Septal Myectomy (SM) and Alcohol Septal Ablation (ASA) improve symptoms in patients with Hypertrophic Cardiomyopathy with outflow tract obstruction (oHCM). However, outcomes data in this population is predominantly from specialized centers. The National Inpatient Database was queried from 2011 to 2019 for relevant international classification of diseases (ICD)-9 and -10 diagnostic and procedural codes. We compared baseline characteristics and in-hospital outcomes of patients with oHCM who underwent SM vs ASA. A p-value  < 0.001 was considered statistically significant. We identified 15,119 patients with oHCM who underwent septal reduction therapies, of whom 57.4% underwent SM, and 42.6% underwent ASA. Patients who underwent SM had higher all-cause mortality (OR: 1.8 (1.3-2.5)), post-procedure ischemic stroke (OR: 2.3 (1.7-3.2)), acute kidney injury (OR: 1.4 (1.2-1.7)), vascular complications (OR: 3.6 (2.3-5.3)), ventricular septal defect (OR: 4.4 (3.2-6.1)), cardiogenic shock (OR: 1.7 (1.3-2.3)), sepsis (OR: 3.2 (1.9-5.4)), and left bundle branch block (OR: 3.5 (3-4)), compared to ASA. Patients who underwent ASA had higher post-procedure complete heart block (OR: 1.3 (1.1-1.4)), right bundle branch block (OR: 6.3 (5-7.7)), ventricular tachycardia (OR: 2.2 (1.9-2.6)), supraventricular tachycardia (OR: 1.6 (1.4-2)), and more commonly required pacemaker insertion (OR: 1.4 (1.3-1.7)) (p < 0.001 for all) compared to SM. This nationwide analysis evidenced that patients undergoing SM had higher in-hospital mortality and periprocedural complications than ASA; however, those undergoing ASA had more post-procedure conduction abnormalities and pacemaker implantation. The implications of these findings warrant further investigation regarding patient selection strategies for these therapies.

Cardiopulmonary exercise test in patients with obstructive hypertrophic cardiomyopathy

OBJECTIVE

The study objective was to analyze performance on cardiopulmonary exercise testing and its prognostic value in patients with obstructive hypertrophic cardiomyopathy undergoing septal myectomy.

METHODS

We reviewed patients with obstructive hypertrophic cardiomyopathy who had cardiopulmonary exercise testing before septal myectomy from 2005 to 2016. Causes of functional impairment and their impact on survival were analyzed.

RESULTS

A total of 752 patients had cardiopulmonary exercise testing at a median of 16 days (interquartile range, 2-56) before myectomy. The median exercise time was 6.6 (5.3-8.0) minutes. Functional aerobic capacity was 64% (53%-75%) of predicted, and metabolic equivalent of task was 5.2 (4.1-6.4). The peak oxygen consumption was 18.0 (14.2-21.9) mL/kg/min, which was 60% (49%-72%) of the predicted value. The primary causes for low peak oxygen consumption were impaired cardiac output (73.7%), limited heart rate reserve (52.0%), and obesity (48.2%). Resting outflow tract gradient correlated poorly to peak oxygen consumption, but the use of beta-blockers was associated with reduced peak oxygen consumption. During a median (interquartile range) of 9.0 (6.8-11.7) years of follow-up, the estimated 5- and 10-year survivals were 97% and 91%, respectively. Greater adjusted peak oxygen consumption (hazard ratio, 0.98; P = .011) and abnormal pulse oxygen increase (hazard ratio, 0.44; P = .003) were independently associated with better long-term survival after myectomy.

CONCLUSIONS

Among patients with hypertrophic cardiomyopathy undergoing septal myectomy, functional capacity is severely impaired despite receiving optimal medical treatment. We identified risk factors of reduced long-term survival from preoperative cardiopulmonary exercise testing that may aid risk stratification in patients undergoing septal myectomy.

PlasmaBlade-assisted surgical septal myectomy: technique and our experience

Background

The pulsed-electron avalanche knife (PEAK) PlasmaBlade provides an atraumatic, scalpel-like cutting precision and electrocautery-like hemostasis. PlasmaBlade operates near body temperature, and its long, thin, and malleable tip can overcome the limitations of a surgical knife. In this study, we aimed to evaluate our clinical experience and histopathological outcomes of septal myectomy using PlasmaBlade.

Methods

Electronic medical records were reviewed for preoperative, operative, and follow-up data of the patients who underwent septal myectomy using PEAK PlasmaBlade at our institute between January 2019 and December 2022. Histopathology of the myectomy specimens was reviewed for the depth of muscle necrosis and compared with the left atrial appendage (LAA) specimen.

Results

Twenty-nine patients underwent septal myectomy using the PEAK PlasmaBlade. No mortality was reported. The mean age was 60.6 ± 12.5 years, and 58.6% of patients were male. Peak left ventricular outflow tract (LVOT) gradients were 40.5 ± 34.9 mmHg at rest and 56.5 ± 34.9 mmHg after provocation. Concomitant procedures performed were LAA ligation in 20 (69.0%), aortic valve replacement in 5 (17.2%), and coronary artery bypass grafting in 3 (10.3%) patients. Postoperative complications were complete heart block in one (3.4%) and ventricular septal defect in two (6.9%) patients. Both the ventricular septal defects were identified intraoperatively and repaired. Histopathology of myectomy specimens demonstrated cautery artifact limited to <50 µm depth compared to >1,000 µm with conventional electrocautery. At a mean follow-up of 8.4 ± 10.3 months, the mean LVOT gradient was 4.4 ± 5.8 mmHg at rest and 9.5 ± 3.3 mmHg after provocation. All patients were alive and in New York Heart Association class I/II. No patient developed complications or required reintervention or reoperation.

Conclusion

Adequate septal myectomy can be precisely and safely performed using the PEAK PlasmaBlade with minimal collateral damage.

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.

Complete Heart Block After Aortic Valve Repair and Septal Myectomy in a Patient With Rheumatic Heart Disease

Surgical myectomy with concomitant valvular repair has been demonstrated to be safe in the treatment of hypertrophic obstructive cardiomyopathy (HOCM). It is unclear which risk factors predispose patients to develop complete heart block (CHB). We present a unique case of a 66-year-old female with rheumatic heart disease and HOCM admitted for aortic valve (AV) repair and septal myectomy, complicated by a presentation of complete heart block. The histology slide showed fibrosis of the septum, suggesting atrioventricular conduction disease from rheumatic fever, which likely contributed to her presentation. This case highlights the importance of elucidating the etiology of HOCM before undergoing cardiac surgery to guide postsurgical management and improve clinical outcomes.

Gender-Based Outcome Discrepancies in Patients Who Underwent Alcohol Septal Ablation or Septal Myectomy for Hypertrophic Obstructive Cardiomyopathy: A Systematic Review and Meta-Analysis

Clinical evidence and emerging studies suggest that the clinical heterogeneity observed in hypertrophic cardiomyopathy could be because of gender-based differences. We aimed to explore the gender-related differences pertaining to the treatment outcomes after alcohol septal ablation (ASA) and septal myectomy (SM). We searched PUBMED/MEDLINE, EMBASE, and SCOPUS to identify studies that report gender-stratified comparison of outcomes. The primary outcome of interest was short-term (within 30 days) mortality. A total of 15 studies totaling 31,907 patients (47% men and 53% women) were included. Women were found to be significantly older at the time of intervention (ASA: mean difference [MD] 7.55 years; SM: MD 4.41). In the ASA and SM treatment arms, women had a significantly higher risk of short-term all-cause mortality (ASA: risk ratio 0.48, 95% confidence interval 0.32 to 0.71, p = 0.0003; SM: risk ratio 0.63, 95% confidence interval 0.44 to 0.90, p = 0.01), more frequent permanent pacemaker implantation (ASA; p = 0.002, SM: p = 0.05), and longer in-hospital stay (ASA: MD 1.00 days, SM: MD 0.69). Among those who underwent ASA, women had a significantly higher rate of atrioventricular block. In conclusion, regardless of ASA or SM, women consistently presented at an older age and exhibited a higher risk-increased mortality rate, a greater incidence of atrioventricular block, and a higher likelihood of permanent pacemaker requirement-and longer hospital stay among women than men. This strongly emphasizes the need for a gender-specific approach to optimize care and improve treatment outcomes in hypertrophic cardiomyopathy.

Surgical Outcomes of Septal Myectomy With and Without Mitral Valve Surgeries in Hypertrophic Cardiomyopathy: a National Propensity-Matched Analysis (2005 to 2020)

The management of concomitant mitral valve (MV) disease in patients with hypertrophic cardiomyopathy (HCM) remains controversial. The 2020 American Heart Association/American College of Cardiology HCM guidelines recommend that MV replacement (MVR) at the time of myectomy should not be performed for the sole purpose of relieving outflow obstruction. At the national level, limited data exist on the surgical outcomes of MV repair/replacement in patients with HCM who underwent septal myectomy (SM). Hospitalizations of patients with HCM who underwent SM between 2005 and 2020 were identified using International Classification of Diseases, Ninth and Tenth Revision codes (International Classification of Diseases, Ninth and Tenth Revision Clinical Modification/Procedure Coding System). The 3 comparison cohorts were SM alone, MV repair, and MVR with concomitant SM. After propensity matching, 2 cohorts, SM + MVR versus SM + MV repair, were studied for surgical outcomes. Demographic characteristics, baseline co-morbidities, procedural complications, inpatient mortality, length of stay, and cost of hospitalization were compared between the propensity-matched cohorts. A total of 16,797 SM procedures were identified from 2005 to 2020. Among them, 11,470 hospitalizations had SM alone (68.2%), SM + MVR was seen in 3,101 (18.4%), and SM + MV repair comprised 2,226 (13.2%). After propensity matching, the MVR and MV repair formed the matched cohorts of 1,857. There were no significant differences in the odds of cardiogenic shock (adjusted odds ratio [aOR] 0.88, 95% confidence interval [CI] 0.63 to 1.24, p = 0.49), mechanical circulatory support requirement (aOR 0.58, 95% CI 0.37 to 0.90, p = 0.015), stroke (aOR 1.27, 95% CI 0.81 to 1.99, p = 0.29), and major bleeding (aOR 0.52, 95% CI 0.34 to 0.79, p = 0.0026) between the comparison groups. MVR, compared with MV repair, was associated with a higher risk of procedural mortality (8.02% vs 3.18%, aOR 2.98, 95% CI 2.05 to 4.33, p <0.0001), complete heart block (16.36% vs 12.15%, aOR 1.76, 95% CI 1.44 to 2.12, p <0.0001), and the need for permanent pacemaker (16.39% vs 10.62%, aOR 1.83, 95% CI 1.41 to 2.38, p <0.0001). The total length of hospital stay and median hospitalization cost was higher in the MVR group. SM in HCM concomitant with MVR is associated with higher procedural mortality and in-hospital complication risk. These real-world data support the 2020 American Heart Association/American College of Cardiology guidelines that in patients who are candidates for surgical myectomy, MVR should not be performed as part of the operative strategy for relieving outflow obstruction in HCM.

Age-Based Outcomes in Patients Who Underwent Septal Reduction Therapy

There are no national data on age-based outcomes of septal reduction therapy. Using the National Inpatient Sample, we included all adult patients who underwent septal myectomy (SM) or alcohol septal ablation (ASA) from 2005 to 2019. The primary objective was to evaluate the in-hospital mortality and new permanent pacemaker (PPM) placement after SM and ASA in 3 age groups. In total, 9,564 patients underwent SM and 5,084 underwent ASA. Compared with the age group 18 to 39 years, the odds of in-hospital mortality after SM were similar in age group 40 to 64 years and 4.46 times higher than in age group ≥65 years; the higher mortality in the older group was explained by higher co-morbidity burden on the risk-adjusted analysis. Furthermore, compared with age group 18 to 39 years, the odds of new PPM placement after SM were higher in the age groups 40 to 64 years and ≥65 years, despite the risk adjustment (adjusted odds ratio [AOR] 3.17, 95% confidence interval [CI] 1.33 to 7.58 and AOR 4.39, 95% CI 1.78 to 10.8, respectively). The odds of in-hospital mortality after ASA were similar in age groups 65 to 79 years and 18 to 64 years. However, the odds of in-hospital mortality were higher in the age group ≥80 years than in the age group 18 to 64 years, although this difference were not present after risk adjustment. The odds of new PPM after ASA were higher for the age groups 65 to 79 years and ≥80 years than age group 18 to 64 years, despite the risk adjustment (AOR 1.78, 95% CI 1.22 to 2.60 and AOR 3.10, 95% CI 2.09 to 6.57, respectively). Finally, we also estimated these absolute risks in different age groups. In conclusion, this national data will inform health care providers to better understand the aged-based risks of outcomes after septal reduction therapy.

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).

Percutaneous approach for reducing outflow tract obstruction in hypertrophic obstructive cardiomyopathy

Hypertrophic obstructive cardiomyopathy (HOCM) affects approximately 1 in 500 people globally. The condition results in hypertrophy of the interventricular septum and thickening of the left ventricular wall. Surgical management to resect the thickened myocardium or septal alcohol ablation are currently considered the mainstay treatment option for HOCM refractory to pharmacological therapy. In this special report we aim to highlight the current landscape of septal mass reduction in HOCM. Next, we describe the evolving discipline of minimally invasive techniques for reducing outflow tract obstruction in patients with HOCM. We further consider future options and outline a possible percutaneous approach for septal myectomy with a novel device.

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.

Hospital Procedural Volume and Clinical Outcomes Following Septal Reduction Therapy in Obstructive Hypertrophic Cardiomyopathy

Background Prior national data showed a substantial in-hospital mortality in septal myectomy (SM) with an inverse volume-outcomes relationship. This study sought to assess the contemporary outcomes of septal reduction therapy and volume-outcome relationship in obstructive hypertrophic cardiomyopathy. Methods and Results All septal reduction therapy admissions between 2010 to 2019 in the United States were analyzed using the National Readmission Databases. Hospitals were stratified into tertiles of low-, medium-, and high-volume based on annualized procedural volume of alcohol septal ablation and SM. Of 19 007 patients with obstructive hypertrophic cardiomyopathy who underwent septal reduction therapy, 12 065 (63%) had SM. Two-thirds of hospitals performed ≤5 SM or alcohol septal ablation annually. In all SM encounters, 482 patients (4.0%) died in-hospital post-SM. In-hospital mortality was <1% in 1505 (88.4%) hospitals, 1% to 10% in 30 (1.8%) hospitals, and ≥10% in 167 (9.8%) hospitals. There were 63 (3.7%) hospitals (averaging 2.2 SM cases/year) with 100% in-hospital mortality. Post-SM (in low-, medium-, and high-volume centers, respectively), in-hospital mortality (5.7% versus 3.9% versus 2.4%, P=0.003; adjusted odds ratio [aOR], 2.86 [95% CI, 1.70-4.80], P=0.001), adverse in-hospital events (21.30% versus 18.0% versus 12.6%, P=0.001; aOR, 1.88 [95% CI, 1.45-2.43], P=0.001), and 30-day readmission (17.1% versus 12.9% versus 9.7%, P=0.001; adjusted hazard ratio, 1.53 [95% CI, 1.27-1.96], P=0.001) were significantly higher in low- versus high-volume hospitals. For alcohol septal ablation, the incidence of in-hospital death and all other outcomes did not differ by hospital volume. Conclusions In-hospital SM mortality was 4% with an inverse volume-mortality relationship. Mortality post-alcohol septal ablation was similar across all volume tertiles. Morbidity associated with SM was substantial across all volume tertiles.

Aortic Valve Regurgitation following Transaortic Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy - Incidence and Impact on Late Outcomes

OBJECTIVE

In this study, we describe the incidence, sites of valve injury, and the impact of aortic valve regurgitation (AR) on outcomes of septal myectomy for obstructive hypertrophic cardiomyopathy (HCM).

METHODS

We analyzed patients who underwent transaortic septal myectomy for obstructive HCM from 2001 to 2022. The primary study endpoint was incidence of procedure-related AR, defined as the need for an unplanned aortic valve (AV) procedure or new-onset moderate AR on early postoperative echocardiography.

RESULTS

There were 2807 patients who underwent transaortic septal myectomy for HCM and had pre- and post-operative transthoracic echocardiograms. Procedure-related AR was observed in 55 (2%) patients; 27 (1%) required unplanned AV procedures at the time of myectomy, and 29 (1%) additional patients developed moderate AR postoperatively. During follow-up, 9 total patients underwent late AV reoperation; one patient who developed new moderate AR postoperatively required late AVR due to severe calcific AS; none of the patients who had unplanned AV procedures required late reoperation. The overall cumulative incidence of aortic valve reoperation at 10 and 15 years was 1% and 5%. The predicted probability of moderate or severe AR at 5 and 10 years was 1.4% and 1.8%. There was no difference in survival comparing patients with or without early postoperative mild or worse AR (p=0.69).

CONCLUSIONS

Procedure-related AR was observed in 2% of patients undergoing transaortic septal myectomy, and unplanned AV procedures were necessary for half of these patients. Intraoperative identification and valve repair mitigate the impact of cusp injury on late reintervention and survival.

Survival After Septal Reduction in Patients >65 Years Old With Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

Obstructive hypertrophic cardiomyopathy (oHCM) is increasingly being diagnosed in elderly patients.

OBJECTIVES

The authors sought to study long-term outcomes of septal reduction therapies (SRT) in Medicare patients with oHCM, and hospital volume-outcome relation.

METHODS

Medicare beneficiaries aged >65 years who underwent SRT, septal myectomy (SM) or alcohol septal ablation (ASA), from 2013 through 2019 were identified. Primary outcome was all-cause mortality, and secondary outcomes included heart failure (HF) readmission and need for redo SRT in follow-up. Overlap propensity score weighting was used to adjust for differences between both groups. Relation between hospital SRT volume and short-term and long-term mortality was studied.

RESULTS

The study included 5,679 oHCM patients (SM = 3,680 and ASA = 1,999, mean age 72.9 vs 74.8 years, women 67.2% vs 71.1%; P < 0.01). SM patients had fewer comorbidities, but after adjustment, both groups were well balanced. At 4 years (IQR: 2-6 years), although there was no difference in long-term mortality between SM and ASA (HR: 0.87; 95% CI: 0.74-1.03; P = 0.1), on landmark analysis, SM was associated with lower mortality after 2 years of follow-up (HR: 0.72; 95% CI: 0.60-0.87; P < 0.001) and had lower need for redo SRT. Both reduced HF readmissions in follow-up vs 1 year pre-SRT. Higher-volume centers had better outcomes vs lower-volume centers, but 70% of SRT were performed in low-volume centers.

CONCLUSIONS

SRT reduced HF readmission in Medicare patients with oHCM. SM is associated with lower redo and better long-term survival compared with ASA. Despite better outcomes in high-volume centers, 70% of SRT are performed in low-volume U.S. centers.

Midterm results of latent outflow tract obstruction in hypertrophic cardiomyopathy after septal myectomy: A propensity score-matched study

BACKGROUND AND AIM OF THE STUDY

The midterm clinical outcomes of patients with latent left ventricular outflow tract (LVOT) obstruction who undergo septal myectomy are unclear. Therefore, this study aimed to evaluate the clinical outcomes of patients with latent LVOT obstruction who underwent septal myectomy.

METHODS

We studied 34 patients with hypertrophic cardiomyopathy (HCM) and latent LVOT obstruction who underwent septal myectomy in 2011-2019 at Anzhen Hospital. After 2:1 propensity score matching, the study cohort included 34 patients with latent LVOT obstruction and 68 patients with resting LVOT obstruction.

RESULTS

Compared to patients with resting LVOT obstruction, patients with latent LVOT obstruction had a thinner interventricular septal thickness (18.2 ± 3.2 mm vs. 20.4 ± 5.6 mm; p = .01), while the proportion of moderate or severe mitral regurgitation was significantly higher (26.5% vs. 5.9%; p = .003). Moreover, the proportion of mitral valve procedures (26.5% vs. 5.9%; p = .004) was significantly higher in patients with latent LVOT obstruction. However, there was no intergroup difference in cardiovascular death (5.9% vs. 1.5%, p = .26). Furthermore, the 5-year survival rates after sudden cardiac death (100.0% vs. 91.7%; p = .26) and cardiovascular death (95.5% vs. 89.0%; p = .32) were similar between HCM patients with latent versus resting LVOT obstruction.

CONCLUSIONS

Midterm clinical outcomes were similar and excellent in a matched cohort of HCM patients with latent versus resting LVOT obstruction after septal myectomy.

Costs and Healthcare Resource Utilization for Obstructive Hypertrophic Cardiomyopathy With Septal Reduction Therapy

BACKGROUND

Patients with obstructive hypertrophic cardiomyopathy (oHCM) and severe refractory symptoms may require invasive septal reduction therapies (SRTs), either surgical septal myectomy (SM) or transcatheter alcohol septal ablation (ASA). The main objective of this study was to quantify all-cause and oHCM-related healthcare resource utilization (HCRU) and costs for patients receiving SM or ASA.

METHODS

This retrospective study utilized medical and pharmacy claims submitted during 2012-2020. HCRU and costs for 119 adults with oHCM who had at least 1 SM (n = 95) or ASA (n = 24) were compared for baseline and follow-up periods.

RESULTS

The mean inpatient hospitalization stay was longer for SM (8.3 days) than ASA (6.0 days). Postprocedure HCM-related medication usage was greater following SM (98%) than ASA (88%). The mean number of HCM-related outpatient visits increased from pre- to post procedure (12.2 vs 15.9 in the SM group; 7.2 vs 9.5 in the ASA group), with most patients having at least 1 cardiology visit post procedure (86% of the SM group; 83% of the ASA group). Total mean HCM-related costs (reported in United States currency) increased with both procedures ($27,045 vs $119,772 in the SM group; $11,278 vs $54,351 in the ASA group), driven by increased inpatient hospitalization ($10,325 vs $112,923 in the SM group; $5509 vs $47,450 in the ASA group) and surgical costs ($6665 vs $92,031 in the SM group; $52 vs $44,815 in the ASA group).

CONCLUSIONS

Our results indicate increasing costs for patients undergoing SRT, driven by inpatient hospitalizations and surgical costs. Commercially insured and Medicare Advantage patients with oHCM experience high healthcare costs and economic burden attributable to SRT.

Posterior Wall Thickness Associates With Survival Following Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

The left ventricular (LV) posterior wall thickness (PWT) is a predictor of sudden cardiac death in pediatric patients with hypertrophic cardiomyopathy (HCM), but the prognostic importance of PWT in adults has not been examined.

OBJECTIVES

The goal of this study was to evaluate the association of LV PWT with late survival in adult patients undergoing septal myectomy for obstructive HCM.

METHODS

This single-center study reviewed 2,418 patients who underwent transaortic septal myectomy for obstructive HCM.

RESULTS

The median preoperative PWT was 13 (IQR: 11-15) mm. Patients with PWT >13 mm tended to have systemic hypertension (55.4% vs 49.1%; P = 0.002) and a larger body mass index (median: 30.8 [IQR: 27.1-35.1] kg/m² vs 29.6 [IQR: 26.1-33.9] kg/m²; P < 0.001). Preoperatively, PWT >13 mm was associated with increased septal thickness (median: 21 [IQR: 18-24] mm vs 19 [IQR: 17-22] mm; P < 0.001), greater maximum instantaneous left ventricular outflow tract (LVOT) gradient at rest (median: 67 [IQR: 36-96] mm Hg vs 47 [IQR: 19-79] mm Hg), and increased likelihood of moderate or greater mitral valve regurgitation (54.3% vs 47.3%; P = 0.001). However, PWT was not related to the severity of limitations measured by New York Heart Association functional class (P = 0.674). After adjusting for baseline covariates, greater PWT was an independent risk factor for late mortality after septal myectomy (P = 0.003).

CONCLUSIONS

PWT is a newly identified predictor of reduced long-term survival after septal myectomy that is independent of septal thickness and severity of LVOT gradient. Future studies are warranted to investigate the mechanisms underlying the association and the potential usefulness of PWT in patient management.

Impact of secondary mitral valve chordal cutting on valve geometry in obstructive hypertrophic cardiomyopathy with marked septal hypertrophy

AIMS

In patients with obstructive hypertrophic cardiomyopathy (HCM) and mild septal thickness undergoing myectomy, resecting fibrotic anterior mitral leaflet (AML) secondary chordae moves the mitral valve (MV) away from the outflow tract and ejection flow, reducing the need for a deep septal excision. Aim of the present study was to assess whether chordal resection has similarly favourable effects in patients with important hypertrophy, who represent the majority of patients with obstructive HCM.

METHODS AND RESULTS

The MV position in the ventricular cavity, assessed from echocardiography as AML-annulus ratio, was compared before and after chordal resection in 150 consecutive HCM patients with important (≥20 mm) and 62 with mild (≤19 mm) septal thickness undergoing myectomy. Preoperatively, MV position was displaced towards the septum to a similar extent in both groups. Postoperatively, AML-annulus ratio increased of an equal degree in both groups, from 0.43 ± 0.05 to 0.55 ± 0.06 (P < 0.001) a 28% increase, and from 0.43 ± 0.06 to 0.55 ± 0.06 (P < 0.001) a 26% increase, respectively, indicating a similar MV shift away from the outflow tract. When AML-annulus ratio was compared in the study cohort and 124 normal subjects, MV position was within normal range in <4% of patients preoperatively and normalized in >50% postoperatively.

CONCLUSIONS

In obstructive HCM, displacement of the MV apparatus into the outflow tract interferes with the ejection flow. Resection of fibrotic secondary chordae moves the MV apparatus away from the outflow tract and enlarges the outflow area independently of septal thickness, facilitating septal myectomy by reducing the need for a deep muscular excision.

Review of Contemporary Invasive Treatment Approaches and Critical Appraisal of Guidelines on Hypertrophic Obstructive Cardiomyopathy: State-of-the-Art Review

BACKGROUND

Hypertrophic obstructive cardiomyopathy (HOCM) is a heterogeneous disease with different clinical presentations, albeit producing similar dismal long-term outcomes if left untreated. Several approaches are available for the treatment of HOCM; e.g., alcohol septal ablation (ASA) and surgical myectomy (SM). The objectives of the current review were to (1) discuss the place of the standard invasive treatment modalities (ASA and SM) for HOCM; (2) summarize and compare novel techniques for the management of HOCM; (3) analyze current guidelines addressing HOCM management; and (4) offer suggestions for the treatment of complex HOCM presentations.

METHODS

We searched the literature and attempted to gather the most relevant and impactful available evidence on ASA, SM, and other invasive means of treatment of HOCM. The literature search yielded thousands of results, and 103 significant publications were ultimately included.

RESULTS

We critically analyzed available guidelines and provided context in the setting of patient selection for standard and novel treatment modalities. This review offers the most comprehensive analysis to-date of available invasive treatments for HOCM. These include the standard treatments, SM and ASA, as well as novel treatments such as dual-chamber pacing and radiofrequency catheter ablation. We also account for complex pathoanatomic presentations and current guidelines to offer suggestions for tailored care of patients with HOCM. Finally, we consider promising future therapies for HOCM.

CONCLUSIONS

HOCM is a heterogeneous disease associated with poor outcomes if left untreated. Several strategies for treatment of HOCM are available but patient selection for the procedure is crucial.

Survival Following Alcohol Septal Ablation or Septal Myectomy for Patients With Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

There is little information regarding long-term mortality comparing the 2 most common procedures for septal reduction for obstructive hypertrophic cardiomyopathy (HCM), alcohol septal ablation (ASA), and septal myectomy.

OBJECTIVES

This study sought to compare the long-term mortality of patients with obstructive HCM following septal myectomy or ASA.

METHODS

We evaluated outcomes of 3,859 patients who underwent ASA or septal myectomy in 3 specialized HCM centers. All-cause mortality was the primary endpoint of the study.

RESULTS

In the study cohort, 585 (15.2%) patients underwent ASA, and 3,274 (84.8%) underwent septal myectomy. Patients undergoing ASA were significantly older (median age: 63.0 years [IQR: 52.7-72.8 years] vs 53.7 years [IQR: 44.9-62.8 years]; P < 0.001) and had smaller septal thickness (19.0 mm [IQR: 17.0-22.0 mm] vs 20.0 mm [IQR: 17.0-23.0 mm]; P = 0.007). Patients undergoing ASA also had more comorbidities, including renal failure, diabetes, hypertension, and coronary artery disease. There were 4 (0.7%) early deaths in the ASA group and 9 (0.3%) in the myectomy group. Over a median follow-up of 6.4 years (IQR: 3.6-10.2 years), the 10-year all-cause mortality rate was 26.1% in the ASA group and 8.2% in the myectomy group. After adjustment for age, sex, and comorbidities, the mortality remained greater in patients having septal reduction by ASA (HR: 1.68; 95% CI: 1.29-2.19; P < 0.001).

CONCLUSIONS

In patients with obstructive hypertrophic cardiomyopathy, ASA is associated with increased long-term all-cause mortality compared with septal myectomy. This impact on survival is independent of other known factors but may be influenced by unmeasured confounding patient characteristics.

Minimally invasive right infra-axillary thoracotomy for transaortic septal myectomy

Extended left ventricular septal myectomy remains the gold standard for the treatment of hypertrophic obstructive cardiomyopathy (HOCM) with refractory symptoms. On the basis of traditional modified transaortic Morrow myectomy, we innovatively performed a minimally invasive, video-assisted single-port thoracotomy through the right infra-axillary region. Our procedure can provide good visualization of the left ventricular outflow tract and hypertrophic ventricular septum for accurate resection. It also ensures optimal exposure of the mitral valve in the presence of complex mitral subvalvular structures.

Impact of Body Mass Index on Postoperative Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy Undergoing Septal Myectomy

Background Obesity is an established cardiovascular risk factor in patients with hypertrophic cardiomyopathy. Postoperative atrial fibrillation (POAF) is one of the most common complications after surgery in patients with obstructive hypertrophic cardiomyopathy (OHCM). We aimed to determine the impact of body mass index (BMI) on the occurrence of POAF in patients with OHCM who underwent septal myectomy. Methods and Results In all, 712 OHCM patients without previous atrial fibrillation who underwent septal myectomy were identified. Patients were stratified into 3 groups based on BMI. Of these, 224 (31.5%) had normal weight (BMI<24 kg/m²), 339 (47.6%) were overweight (BMI, 24 to <28 kg/m²), and 149 (20.9%) were obese (BMI≥28 kg/m²). Overweight and obese patients had increased levels of left atrial diameter (P<0.001) and left ventricular end-diastolic diameter (P<0.001), compared with patients with normal weight. Among 184 patients (25.8%) developing POAF, 32 cases (14.3%) occurred in the normal weight group, 100 cases (29.5%) occurred in the overweight group, and 52 cases (34.9%) occurred in the obese group (P<0.001). Logistic regression analysis indicated that overweight (odds ratio [OR]: 2.161, 95% CI, 1.333-3.503; P=0.002) or obesity (OR, 2.803; 95% CI, 1.589-4.944; P<0.001), age (OR, 1.037; 95% CI, 1.018-1.057; P<0.001), and left atrial diameter (OR, 1.060; 95% CI, 1.027-1.095; P<0.001) were independently associated with the occurrence of POAF in patients with OHCM. Conclusions Overweight and obesity are strong predictors of POAF in patients with OHCM. Strategies aimed at lowering BMI may be a potential way to prevent POAF.

Image-Based Computational Hemodynamics Analysis of Systolic Obstruction in Hypertrophic Cardiomyopathy

Hypertrophic Cardiomyopathy (HCM) is a pathological condition characterized by an abnormal thickening of the myocardium. When affecting the medio-basal portion of the septum, it is named Hypertrophic Obstructive Cardiomyopathy (HOCM) because it induces a flow obstruction in the left ventricular outflow tract. In any type of HCM, the myocardial function can become compromised, possibly resulting in cardiac death. In this study, we investigated with computational analysis the hemodynamics of patients with different types of HCM. The aim was quantifying the effects of this pathology on the intraventricular blood flow and pressure gradients, and providing information potentially useful to guide the indication and the modality of the surgical treatment (septal myectomy). We employed an image-based computational approach, integrating fluid dynamics simulations with geometric and functional data, reconstructed from standard cardiac cine-MRI acquisitions. We showed that with our approach we can better understand the patho-physiological behavior of intraventricular blood flow dynamics due to the abnormal morphological and functional aspect of the left ventricle. The main results of our investigation are: (a) a detailed patient-specific analysis of the blood velocity, pressure and stress distribution associated to HCM; (b) a computation-based classification of patients affected by HCM that can complement the current clinical guidelines for the diagnosis and treatment of HOCM.

Differences in Short-Term Outcomes and Hospital-Based Resource Utilization Between Septal Reduction Strategies for Hypertrophic Obstructive Cardiomyopathy

BACKGROUND

Given clinical equipoise in a subset of obstructive hypertrophic cardiomyopathy (OHCM) patients who are candidates for both alcohol septal ablation (ASA) or septal myectomy (SM), other considerations such as cost, readmissions, and hospital length of stay (LOS) may be important to optimize healthcare resource utilization and inform shared decision making.

METHODS

In this retrospective observational analysis of the United States Nationwide Readmissions Database years 2012-2014, we identified adults who underwent isolated septal reduction (SR) for OHCM. We studied the differences in short-term outcomes (inpatient mortality and 90-day readmission rate) and in-hospital resource utilization (LOS and costs) between the SR strategies.

RESULTS

Of the 2250 patients in this study, ASA was performed in 1113 (49.5%) and SM in 1137 (50.5%). Inpatient mortality occurred in 21 patients (0.9%), with similar rates between strategies (10 SM patients [0.9%] vs 11 ASA patients [1.0%]; P=.30). Of the 2229 patients who survived to discharge, 298 (13.4%) were readmitted 386 times within 90 days with a similar readmission rate between SM (14.9%) and ASA (11.8%; P=.16). During the index admission, average LOS and cost were significantly lower for ASA (3.9 days, United States [US] $20,322) compared with SM (7.6 days, US $39,470; P<.001). Average LOS and cost during 90-day readmissions were similar between ASA and SM. Combining index admissions and readmissions, patients undergoing ASA had significantly lower LOS and hospitalization costs.

CONCLUSIONS

In this non-randomized observational study of OHCM patients undergoing isolated septal reduction, ASA was associated with similar short-term outcomes, including mortality, but substantially lower hospitalization costs and LOS compared with SM.

[Surgical approaches to interventricular septum in hypertrophic cardiomyopathy]

Hypertrophic cardiomyopathy (HCM) is a hereditary myocardial disease characterized by ventricular wall and interventricular septum thickening not associated with heart valve disease or any other external cause. Considering different localization of left ventricular obstruction, surgeons should be aware of various surgical approaches to various segments of interventricular septum. A personalized approach to each patient is essential to achieve favorable postoperative effect with minimal incidence of complications. This review is devoted to various surgical approaches to interventricular septum for different phenotypic variants of HCM.

The first 200 septal myectomies: Ensuring gold standard outcomes

OBJECTIVES

Septal myectomy remains the gold standard treatment for symptomatic left ventricular outflow tract obstruction refractory to medical treatment. It is recommended that this operation be performed in dedicated hypertrophic obstructive cardiomyopathy centres by experienced surgeons. The septal myectomy option remains unavailable to many patients based solely on geography, including those who would clearly benefit more substantially from surgery than other therapeutic options. Here, we share our experience in starting new hypertrophic cardiomyopathy programmes.

METHODS

We retrospectively reviewed initial septal myectomy experiences at two hypertrophic cardiomyopathy programmes starting in 2014.

RESULTS

Two-hundred septal myectomies were performed. Mean age was 58.8 years and 51% were females. Advanced heart failure symptoms were present in 95.5% of patients and 23.5% had experienced syncope. Mean maximal intraventricular gradient was 89 mmHg and 48.5% underwent concomitant procedures at the time of septal myectomy. There was no perioperative (in-hospital or 30 days) mortality. Ninety-two per cent had provoked left ventricular gradients of ≤ 15 mmHg and 97% had none/mild mitral regurgitation at post-operative assessment. In our contemporary cohort, there were 2 (1%) intraoperative ventricular septal defects and 5% required a permanent pacemaker.

CONCLUSIONS

Our early septal myectomy experience targeted a complex population, frequently in need of concomitant procedures. Abolition of left ventricular obstruction and resolution of systolic anterior motion mediated mitral regurgitation can be expected. The safety and efficacy of septal myectomy carried at hypertrophic cardiomyopathy centres by properly trained surgeons achieved the desired outcomes established by recent hypertrophic cardiomyopathy guidelines.

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.

Surgery for Hypertrophic Obstructive Cardiomyopathy: Comprehensive LVOT Management beyond Septal Myectomy

Hypertrophic cardiomyopathy (HCM) is a complex, underestimated, multifaceted disease frequently associated with left ventricular outflow tract (LVOT) obstruction. It is clearly demonstrated that this is due not only to septal hypertrophy but also to systolic anterior motion (SAM) of mitral valve leaflets secondary to mitral valve/subvalvular apparatus abnormalities. Surgical treatment involves performing an extended septal myectomy, eventually followed by ancillary procedures to those structures responsible for maintaining LVOT obstruction, if necessary. In this review, we describe the spectrum of possible surgical techniques beyond septal myectomy and their pathophysiologic rationale.

Preintervention imaging and intraoperative management care of the hypertrophic obstructive cardiomyopathy patient

With an estimated overall mortality of less than 1 percent per year, hypertrophic cardiomyopathy, is the most common genetic cardiomyopathy. Intraoperative transesophageal echocardiography is the standard of care for assessing patients with hypertrophic obstructive cardiomyopathy undergoing surgical septal myectomy, allowing surgical planning, intraoperative hemodynamic monitoring, and postprocedural assessment of the repair, including detection of immediate complications. At various phases during surgical septal myectomy, the changing hemodynamic conditions may lead to worsening or improvement in left ventricle outflow tract obstruction by change in preload or afterload, systolic anterior motion of the mitral valve, or sympathetic stimulation. These characteristics represent unique challenges in the management of these patients, requiring a comprehensive understanding of the management of all the conditions required to decrease the left ventricle outflow tract gradient avoiding obstruction, which include the maintenance of sinus rhythm, adequate rate avoiding tachycardia and bradycardia, and avoidance of systemic hypotension preserving preload and afterload, with adequate vasoactive agents. The aim of this review is to summarize the perioperative assessment and management of patients undergoing hypertrophic obstructive myopathy surgery.

Living with hypertrophic cardiomyopathy: a patient's perspective

Hypertrophic cardiomyopathy (HCM) is a complex disease characterized by thickening of the cardiac muscle. Common symptoms include chest pain, shortness of breath, palpitations, fatigue and syncope (fainting), which are often confused for other conditions. Clinical treatment focuses on the relief of symptoms with medical therapies, which provide adequate to more variable symptomatic relief. Patients may experience more severe complications that require surgical intervention, such as implantable cardioverter-defibrillator therapy or septal myectomy. Despite the potential impact on quality of life, the humanistic burden of HCM is not well established. Here, we present four patient testimonials that highlight challenges faced by patients and clinicians in diagnosing HCM and managing symptoms. These testimonials provide valuable information on the spectrum and expression of HCM across generations. Such testimonials can better inform disease diagnosis and monitoring, maximizing quality of life and improving disease outcome.

Impact of obstructive sleep apnea on new-set atrial fibrillation after septal myectomy in patients with hypertrophic obstructive cardiomyopathy

Background

Obstructive sleep apnea (OSA) is associated with a higher prevalence of postoperative atrial fibrillation in patients who underwent cardiac surgery. However, whether OSA is a risk factor for postoperative atrial fibrillation after septal myectomy remains unclear. We hypothesized that OSA was associated with postoperative atrial fibrillation after septal myectomy.

Methods

A total of 99 patients with hypertrophic obstructive cardiomyopathy who underwent septal myectomy were included in our manuscript. Polysomnography was performed in all patients, and the heart rhythm was continuously monitored during the perioperative period.

Results

In the present study, 25 (25.3%) patients developed postoperative atrial fibrillation after septal myectomy. The prevalence of postoperative atrial fibrillation was significantly higher in patients with OSA and increased with the worsening severity of OSA. Notably, the apnea-hypoxia index was significantly higher in patients with postoperative atrial fibrillation among the different OSA groups. In receiver operating characteristic analysis, the area under the curve for the apnea-hypopnea index was 0.785 (95% CI: 0.684–0.887, P<0.001); an apnea-hypopnea index of 10.4 was the optimal cutoff point to predict postoperative atrial fibrillation. In the multivariable analysis, apnea-hypopnea index ≥10.4 (odds ratio: 6.29, 95% CI: 2.18–18.14, P=0.001), moderate-to-severe OSA (odds ratio: 4.88, 95% CI: 1.42–16.86, P=0.01), and left atrium diameter (odds ratio: 1.12, 95% CI: 1.03–1.22, P=0.01) were independent risk factors associated with postoperative atrial fibrillation after adjusting for relevant variables. However, the association between the diagnosis of OSA and postoperative atrial fibrillation was no longer statistically significant.

Conclusions

The severity of OSA reflected by the apnea-hypopnea index in patients with obstructive hypertrophic cardiomyopathy who underwent surgery is an independent risk factor for postoperative atrial fibrillation, which is associated with adverse clinical outcomes.

Enlargement of left ventricular outflow tract using an autologous pericardial patch for anterior mitral valve leaflet and septal myectomy through trans-mitral approach for the treatment of hypertrophic obstructive cardiomyopathy

OBJECTIVE

Modified Morrow procedure is the gold standard of surgical intervention for hypertrophic obstructive cardiomyopathy (HOCM). However, there are certain cases without complete relief of obstruction through trans-aortic approach, we, therefore, described an unusual technique. We aimed to retrospectively analyze this series of patients to reveal its safety and efficiency.

METHODS

We retrospectively analyzed a total of 247 consecutive HOCM patients in our center from January 2016 to December 2019. Sixteen of them who underwent enlargement of left ventricular outflow tract (LVOT) using an autologous pericardial patch for anterior mitral valve leaflet and septal myectomy through trans-mitral approach were recruited in this study. Baseline characteristics, perioperative data, and the outcomes were studied.

RESULTS

Of the 16 patients, there was no operative mortality. No permanent pacemaker implantation and ventricular septal defects formation were observed. The peak pressure gradient of LVOT decreased from 97.56 ± 23.81 mmHg to 7.56 ± 2.13 mmHg (p < .01) after operation and 10.19 ± 2.93 mmHg (p < .01) 3 months later. The average septal thickness decreased from 18.38 ± 3.56 mm to 10.00 ± 2.74 mm (p < .01). During a mean follow-up of 34.25 ± 12.85 months (range, 15-57), no patient required cardiac reoperation. At the last follow up, the mean peak pressure gradient of LVOT was 10.12 ± 2.03 mmHg and no patient had more than moderate mitral regurgitation.

CONCLUSION

Enlargement of LVOT using an autologous pericardial patch for anterior mitral valve leaflet and septal myectomy through trans-mitral approach is feasible and reliable for the treatment of certain types of HOCM cases.

Outcomes of Septal Myectomy beyond 65 Years, with and without Concomitant Procedures

Introduction and objectives: Septal myectomy remains the first septal reduction therapy for hypertrophic obstructive cardiomyopathy in young patients and those requiring concomitant procedures. Its role in advanced ages is questioned due to perceived increased risk. We assess the outcomes of surgical relief of obstruction in patients beyond 65 years old. Methods: A single-center retrospective review of patients ≥ 65 years old undergoing septal myectomy through median sternotomy between April 2015 and February 2020. Results: We identified 52 patients. Mean age was 71.8 ± 4.9 years; 36 (69.2%) were females. All were symptomatic. Mean highest LVOT gradient was 90 ± 39 mmHg. All patients had systolic anterior motion (SAM) of the mitral valve and 36 (69.2%) ≥ moderate mitral regurgitation. Additional LVOT interventions beyond myectomy were performed in 34 (65.4%). At least one other cardiac concomitant procedure was performed 44 (84.6%). No perioperative mortality in elective surgery occurred. One patient (1.9%) developed atrio-ventricular block. Postoperative mean gradient was 4.3 ± 1.9 mmHg, with 46 (88.4%) achieving complete resolution of obstruction. Mitral regurgitation was reduced to grade ≤ I in 46 (88.5%). Mean follow-up time was 2.3 ± 1.2 years and 82% of patients were in NYHA I. Survival at 2 years was 98%. Conclusion: Septal myectomy in the elderly is a safe and effective operation despite the need for concomitant procedures. LVOT interventions beyond septal myectomy to relieve obstruction are common in this advanced cohort of hypertrophic cardiomyopathy patients. This operation carried at experienced centers seems an unmatched therapeutic option.

Triglyceride-Glucose Index Independently Predicts New-Onset Atrial Fibrillation After Septal Myectomy for Hypertrophic Obstructive Cardiomyopathy Beyond the Traditional Risk Factors

The triglyceride-glucose index is a valuable marker of insulin resistance. However, the predictive value of this index for postoperative atrial fibrillation in patients undergoing septal myectomy remains unclear. A total of 409 patients with hypertrophic obstructive cardiomyopathy who underwent septal myectomy were recruited in this study. The triglyceride-glucose index was calculated for all patients preoperatively. All patients underwent clinical data collection, blood sampling, and standard echocardiographic examinations during hospitalization. The prevalence of postoperative atrial fibrillation was approximately 15% in the present study. Multivariate logistic regression revealed that age (odds ratio [OR]: 1.053, 95% CI: 1.016-1.090, P = 0.004), hypertension (OR: 2.399, 95% CI: 1.228-4.686, P = 0.010), left atrial diameter (OR: 1.101, 95% CI: 1.050-1.155, P < 0.001), and triglyceride-glucose index (OR: 4.218, 95% CI: 2.381-7.473, P < 0.001) were independent risk factors for postoperative atrial fibrillation in patients undergoing septal myectomy. In receiver operating characteristic curve analysis, the triglyceride-glucose index could provide a moderate predictive value for postoperative atrial fibrillation after septal myectomy 0.723 (95% CI: 0.650-0.796, P < 0.001). Moreover, adding the triglyceride-glucose index to conventional risk factor model could numerically but not significantly increase our ability to predict postoperative atrial fibrillation (area under the receiver: 0.742 (0.671-0.814) vs. 0.793 (0.726-0.860), p = 0.065) after septal myectomy. In our retrospective cohort study, the triglyceride-glucose index was identified as an independent predictor of postoperative atrial fibrillation in patients undergoing septal myectomy.

"Do alternative approaches work in surgical septal myectomy?"

Trans-aortic septal myectomy is the gold standard for septal reduction therapy. This technique has low peri-procedural mortality and excellent long-term survival. Moreover, it relieves the heart failure symptoms and improves the quality of life. Secondary chordal cutting along with septal myectomy has shown to improve the outcome but can potentially cause deterioration of left ventricular function. In patients with relatively thin inter-ventricular septum, abnormalities of mitral valve apparatus may be the main reason for systolic anterior motion and left ventricular outflow tract obstruction. These patients may require additional procedures on the mitral valve to shift the coaptation plane away from outflow tract. Mitral valve replacement should be performed only in patients with intrinsic mitral valve abnormalities that are not suitable for repair and its routine use along with limited septal myectomy should be discouraged. Minimal access surgery although attractive in concept requires more robust data before universal application.

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

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

The preoperative glomerular filtration rate predicts new-onset postoperative atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy who undergo isolated septal myectomy

Background

Few studies have focused on new-onset postoperative atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy who have undergone septal myectomy. Therefore, we investigated the incidence and prognosis effects of postoperative atrial fibrillation following septal myectomy in patients with hypertensive obstructive cardiomyopathy. Additionally, we investigated the relationship of estimated glomerular filtration rate and postoperative atrial fibrillation.

Methods

Data from 300 patients with hypertrophic obstructive cardiomyopathy who underwent isolated surgical septal myectomy were collected from January 2012 to March 2018.

Results

The overall incidence of postoperative atrial fibrillation during hospitalization was 22.67% (68 of 300 patients). Patients with postoperative atrial fibrillation were older (P<0.001), had lower preoperative estimated glomerular filtration rate (P<0.001), and a larger preoperative left atrial diameter (P=0.038) compared to patients without. The preoperative estimated glomerular filtration rate predicted postoperative atrial fibrillation with sensitivity and specificity of 0.824 and 0.578 (P<0.001), respectively. Multivariate regression analyses showed that age [odds ratio (OR) =1.090, 95% confidence interval (CI): 1.034-1.110], an New York Heart Association functional class ≥ III (OR =2.985, 95% CI: 1.349-6.604), hypertension (OR =2.212, 95% CI: 1.062-4.608), a history of syncope (OR =3.890, 95% CI: 1.741-8.692), and the preoperative estimated glomerular filtration rate (OR =0.981, 95% CI: 0.965-0.996) were independent risk factors associated in the development of postoperative atrial fibrillation. Survival analysis showed that the incidence of long-term cardiovascular events was higher in the patients with postoperative atrial fibrillation than that in the patients without the condition (P<0.001).

Conclusions

The preoperative estimated glomerular filtration rate was a moderate predictor of postoperative atrial fibrillation after septal myectomy. Postoperative atrial fibrillation affected the early recovery and the long-term prognoses of patients with hypertrophic obstructive cardiomyopathy who underwent septal myectomy.

Septal myectomy in the era of genetic testing

BACKGROUND

Hypertrophic obstructive cardiomyopathy (HOCM) is one of the most common genetic cardiac diseases and encompasses an array of clinical presentations. Little is known about the impact of genetic background on outcomes after septal myectomy (SM). The aim of this study was to evaluate the effect of specific genetic mutations on midterm outcomes in adults undergoing SM for HOCM.

METHODS

From 2003 to 2020, a total of 59 patients (male = 66%, mean age = 52 ± 13) underwent SM after a preoperative genetic test. Patients were divided into two groups according to their test result (positive or negative). Preoperative echocardiograms were examined to identify phenotypical characteristics of each mutation.

RESULTS

A total of thirty-one patients (53%) had a positive genetic test. MYBPC3 was the most common mutation (15/31 patients). Four different phenotypes were identified on preoperative echocardiograms. Overall, Type 1 phenotype was the most common (37% of the cohort). Type 3 was found exclusively in patients with a positive genetic test. Following SM, none of the patients required a redo myectomy or septal ablation. At 10 years, the survival was 97 ± 3% and 100% in patients with a positive and negative genetic test (p = .33), respectively.

CONCLUSION

Although our results suggest that the multiple gene mutations present with different characteristics and phenotypes, midterm results of SM appear to be good regardless of genetic mutation presence.