A systematic review and meta-analysis of the efficacy and safety of Mavacamten therapy in international cohort of 524 patients with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is the most common heritable myocardial disorder worldwide. Current pharmacological treatment options are limited. Mavacamten, a first-in-class cardiac myosin inhibitor, targets the main underlying pathology of HCM. We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of Mavacamten in patients with HCM. PRISMA flow chart was utilized using PubMed, SCOPUS, and Cochrane databases for all up-to-date studies using pre-defined keywords. Pre-specified efficacy outcomes comprised several parameters, including an improvement in peak oxygen consumption (pVO2) and ≥ 1 NYHA class, the need for septal reduction therapy (SRT), change from baseline in Kansas City Cardiomyopathy Questionnaire (KCCQ), changes in biochemical markers and LVEF, along with peak left ventricular outflow tract gradient at rest and after Valsalva maneuver. Safety outcomes included morbidity and serious adverse events. This systematic review included five studies, four RCTs and one non-randomized control trial comprised a total of 524 (Mavacamten [273, 54.3%] vs placebo [230, 45.7%] adult (≥ 18 years) patients with a mean age of 56 years. The study. comprised patients with Caucasian and Chinese ethnicity and patients with obstructive (oHCM) and non-obstructive (nHCM) HCM. Most baseline characteristics were similar between the treatment and placebo groups. Mavacamten showed a statistically significant increase in the frequency of the primary composite endpoint (RR = 1.92, 95% CI [1.28, 2.88]), ≥ 1 NYHA class improvement (RR = 2.10, 95% CI [1.66, 2.67]), a significant decrease in LVEF, peak left ventricular outflow tract gradient at rest and after Valsalva maneuver. Mavacamten also showed a significant reduction in SRT rates (RR = 0.29, 95% CI [0.21, 0.40], p < 0.00001), KCCQ clinical summary scores (MD = 8.08, 95% CI [4.80, 11.37], P < 0.00001) troponin levels and N-terminal pro-B-type natriuretic peptide levels. However, there was no statistically significant difference between Mavacamten and placebo regarding the change from baseline peak oxygen consumption. Mavacamten use resulted in a small increase in adverse events but no statistically significant increment in serious adverse events. Our study showed that Mavacamten is a safe and effective treatment option for Caucasian and Chinese patients with HCM on the short-term. Further research is needed to explore the long-term safety and efficacy of Mavacamten with HCM. In addition, adequately powered studies including patients with nHCM is needed to ascertain befits of Mavacamten in those patients.

Clinical Effect of the Modified Morrow Septal Myectomy Procedure for Biventricular Hypertrophic Cardiomyopathy.

Background: Right ventricular involvement in hypertrophic cardiomyopathy is uncommon. This study aimed to evaluate clinical outcomes of the modified septal myectomy in patients diagnosed with biventricular hypertrophic cardiomyopathy (BHCM), a subject seldom explored in the literature. Methods: We conducted a retrospective cohort study from January 2019 to January 2023, enrolling 12 patients with BHCM. Each patient underwent a modified septal myectomy and was followed postoperatively. Clinical data and echocardiographic parameters, including the ventricular outflow tract peak pressure gradient and maximum interventricular septum thickness, were collected and analyzed. Results: The study cohort had a median age of 43.0 (interquartile range 14.5-63.0) years at surgery, with four patients (33.3%) being children. Two patients (16.7%) previously underwent percutaneous transluminal septal myocardial ablation. Surgical relief of biventricular outflow tract obstruction (BVOTO) was achieved in five patients (41.7%), aside from those managed solely for left ventricular outflow tract obstruction. In five instances, three-dimensional (3D) printing technology assisted in surgical planning. The postoperative interventricular septum thickness was significantly reduced (21.0 mm preoperative vs. 14.5 mm postoperative, p < 0.001), effectively eliminating residual ventricular outflow tract obstruction. There were no severe complications, such as septal perforation or third-degree atrioventricular block. During a mean follow up of 21.2 ± 15.3 months, no sudden deaths, residual outflow tract obstruction, permanent pacemaker implantation, recurrent systolic anterior motion, or reoperations were reported. Conclusions: Our findings affirm that the modified septal myectomy remains the gold standard treatment for BHCM, improving patient symptoms and quality of life. BVOTO relief can be safely and effectively achieved through septal myectomy via transaortic and pulmonary valve approaches in selected patients. For intricate cases, the application of 3D printing technology as a preoperative planning tool is advised to optimize surgical precision and safety.

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).

Is There a Role for Alcohol Septal Ablation in Young Patients with Medically Refractory Hypertrophic Obstructive Cardiomyopathy?

Surgical myectomy is recommended for symptomatic hypertrophic obstructive cardiomyopathy (HOCM) after optimal pharmacological therapy. Percutaneous transluminal septal myocardial ablation (PTSMA) is reserved for high-risk adults. Symptomatic patients below 25 years underwent either surgery or PTSMA after heart-team discussion and informed consent. Echocardiography assessed gradients in surgical group. PTSMA group underwent invasive transseptal hemodynamic assessment, selective coronary angiography and super-selective cannulation of septal perforators using microcatheters. Contrast echocardiography through the microcatheter identified the myocardial target for PTSMA. Hemodynamic and electrocardiographic monitoring guided alcohol injection. Both groups were continued on beta-blockers. Symptoms, echocardiographic gradients and Brain natriuretic peptide (NTproBNP) measurements were assessed on follow-up. Twelve patients aged 5-23 years (11-98 kg) formed the study group. Indications for PTSMA in 8 patients included abnormal mitral valve anatomy warranting replacement (n = 3), Jehovah's witness (n = 2), severe neurodevelopmental and growth retardation (n = 1) and refusal of surgery (n = 2). PTSMA targeted first perforator (n = 5), second perforator (n = 2) and anomalous septal artery from left main trunk (n = 1). Outflow gradient reduced from 92.5 ± 19.7 to 33.1 ± 13.5 mmHg. At a median follow-up of 38 months (range 3-120 weeks), the peak instantaneous echocardiographic gradient was 32 ± 16.5 mmHg. Gradient reduced in four surgical patients from 86.5 ± 16.3 mmHg to 42 ± 14.7 mm Hg. All patients were in NYHA class I/II on follow-up. The mean NTproBNP in PTSMA group reduced from 6084 ± 3628 pg/ml to 3081 ± 2019 pg/ml; it was 1396 and 1795 pg/ml in surgery. PTSMA may be considered in medically refractory high-risk young patients. It relieves symptoms and reduces gradient. Though surgery is preferred in young patients, PTSMA may have a role in selected patients.

Septal Myectomy and Subvalvular Repair in Hypertrophic Cardiomyopathy, a Systematic Review and Pooled Analysis.

Background: Some patients with hypertrophic obstructive cardiomyopathy (HOCM) still exhibit systolic anterior motion (SAM) and mitral regurgitation (MR) even after undergoing an isolated ventricular septectomy. Currently, there are disputes regarding whether to perform a mitral valve intervention and which type of operation is more effective. Methods: By searching PubMed, Cochrane, Embase, Web of Science, FDA.gov, and ClinicalTrials.gov, as well as other resource databases, we obtained all articles published before December 2022 on ventricular septal myectomy combined with mitral valve intervention for hypertrophic cardiomyopathy. Demographic information and outcome variable data were extracted from 10 screened studies on ventricular septal resection combined with mitral valve repair. The risk of bias was assessed using methodological index for non-randomized studies (MINORS). Student's t-test was used for comparisons of continuous variables, and the chi-square or Fisher's exact test was used for dichotomous variables. A total of 692 patients across 10 studies were analyzed. Results: There were 5 (0.7%) deaths in the perioperative period. The average cardiopulmonary bypass time was 64.7 ± 22.2 minutes, and the average follow-up time was 39.6 ± 36.3 months. Compared with baseline levels, the left ventricular outflow tract gradient (83.6 ± 32.2 mmHg vs. 11.0 ± 7.8 mmHg, p < 0.01), maximum interventricular septal thickness (22.5 ± 5.1 mm vs. 14.7 ± 5.5 mm, p < 0.01), III/IV mitral regurgitation (351/692 vs. 17/675, p < 0.01), anterior mitral leaflet (AML)-annulus ratio (0.49 ± 0.14 vs. 0.60 ± 0.12, p < 0.01), tenting area (2.72 ± 0.60 cm 2 vs. 1.95 ± 0.60 cm 2 , p < 0.01), and SAM (181/194 vs. 11/215, p < 0.01) were significantly improved. 14 (2.1%) patients were in New York Heart Association functional class III/IV, which was significantly improved compared with the preoperative state (541/692 vs. 14/682, p < 0.01). Conclusions: Ventricular septectomy combined with mitral valve repair can be a safe and effective treatment option for patients suffering from HOCM with SAM and severe MR.

Early reverse remodeling of left heart morphology and function evaluated by cardiac magnetic resonance in hypertrophic obstructive cardiomyopathy after transapical beating-heart septal myectomy.

PURPOSE: This study aimed to evaluate the early morphology and function of the left heart in hypertrophic obstructive cardiomyopathy (HOCM) after transapical beating-heart septal myectomy (TA-BSM) using cardiovascular magnetic resonance (CMR). MATERIALS AND METHODS: Between April 2022 and January 2023, HOCM patients who underwent CMR before and 3 months after TA-BSM were prospectively and consecutively enrolled in the study. Preoperative and postoperative cardiac morphological and functional parameters, including those for the left atrium (LA) and left ventricle (LV), were compared. The left ventricular remodeling index (LVRI) was defined as the ratio between left ventricular mass (LVM) and left ventricular end-diastolic volume (LVEDV). Healthy participants with a similar age and sex distribution were enrolled for comparison. Pearson or Spearman correlation analysis was used to investigate the relationships between the parameters and LVRI. Last, univariate and multivariate linear regression identified variables associated with the LVM index (LVMI) and LVRI. RESULTS: Forty-one patients (mean age ± standard deviation, 46 ± 2 years; 27 males) and 41 healthy control participants were evaluated. Eighteen (44%) HOCM patients were classified as having a sigmoid septum, and 23 patients had a reverse septal curvature. LA volume, diameter and function were significantly improved postoperatively, but still worse than healthy controls (all p < 0.001). Compared to before the operation, left ventricular wall thickness, left ventricular ejection fraction (LVEF), LVMI, and LVRI decreased after TA-BSM (all p < 0.001). The left ventricular end-diastolic volume index (LVEDVI) and left ventricular end-diastolic diameter (LVEDD) decreased in patients with a sigmoid septum. However, LVEDVI and LVEDD increased in those with a reverse septal curvature (both p < 0.001). In addition, both preoperative and postoperative LVRI was positively correlated with LVMI (r = 0.734 and 0.853, both p < 0.001) and maximum wall thickness (r = 0.679 and 0.676, both p < 0.001), respectively. In the multivariable analysis, the weight of the resected myocardium (adjusted ß = 0.476, p = 0.005) and △mitral regurgitation degree (adjusted ß = - 0.245, p = 0.040) were associated with △LVRI. Last, the △LVOTG (adjusted ß = 0.436, p = 0.018) and baseline LVMI (adjusted ß = 0.323, p = 0.040) were independently associated with greater left ventricular mass regression after TA-BSM. CONCLUSION: CMR confirmed early reverse remodeling of left heart morphology and function in HOCM patients following TA-BSM.

Myectomy with and without Mitral Subvalvular Repair in Patients with Hypertrophic Obstructive Cardiomyopathy with Grade 3 to 4+ Mitral Regurgitation without Intrinsic Mitral Valve Disease: A Retrospective Observational Study.

Background: Hypertrophic obstructive cardiomyopathy (HOCM) with severe mitral regurgitation (MR) remains controversial for the choice of the concomitant mitral valve (MV) management versus septal myectomy alone. The impacts of different surgical strategies (concomitant mitral subvalvular procedures versus myectomy alone) on one-year results of surgical treatment of HOCM with grade 3 to 4+ MR without intrinsic MV disease were evaluated in this single-center, retrospective observational study. Methods: A total of 146 eligible patients were retrospectively screened into a combined group (n = 40) and an alone group (n = 106), depending on whether they underwent transaortic mitral subvalvular procedures. Perioperative outcomes were collected, and results at 1-year following surgery were compared. Results: Surgical mortality did not differ (0 for combined group vs. 0.9% for alone group, p = 0.538). Six patients (5.0% vs. 3.8%, p = 0.666) developed postoperative complete atrioventricular node block with permanent pacemaker implantation. No death or reoperation was recorded during a median follow-up of 18 months. At 1-year following surgery, (1) the provoked MR severity decreased from baseline in both groups with a significant difference between groups [1.0 (0-1.0) vs. 1.0 (1.0-1.3), p < 0.001]; (2) systolic anterior motion (SAM) was observed in 10 patients (0 vs. 10 in the alone group, p = 0.043); (3) the provoked gradient was also significantly lower than baseline value for each group, with a significant difference between the two groups (8.8 ± 4.3 mmHg vs. 12.1 ± 6.7 mmHg, p = 0.006); and (4) New York Heart Association class decreased from baseline value for each group (p < 0.001). Conclusions: In HOCM patients with grade 3 to 4+ MR without intrinsic MV disease, mitral subvalvular management during septal myectomy may be associated with a low incidence of SAM, improved MR, and a lower outflow tract gradient in comparison with septal myectomy alone.

The Risk of Ventricular Arrhythmias between Alcohol Septal Ablation and Septal Myectomy in Hypertrophic Cardiomyopathy: A Meta-Analysis on Septal Reduction Therapy.

Background: Alcohol septal ablation (ASA) has been more commonly applied in medical refractory hypertrophic obstructive cardiomyopathy (HOCM) compared with septal myectomy (SM), however its potential to create a proarrhythmic substrate is increased. Methods: A systematic search was performed in PubMed, EMBASE, Web of Science, and the Cochrane Library from inception to October 2020. Fixed or random effects models were used to estimate the risk ratios (RR) for ventricular arrhythmia events or other outcomes between the SM and ASA cohorts. Results: Twenty studies with 8025 patients were included. Pool analysis showed that the incidence of ventricular tachycardia (VT)/ventricular fibrillation (VF), which included appropriate implantable cardioverter defibrillator (ICD) intervention, was significantly higher in the ASA cohort than that in the SM cohort (ASA vs SM: 10% (345/3312) vs 5% (161/3227) (RR = 1.98, 95% CI (confidence interval), 1.65-2.37; p < 0.00001, I 2 = 0%). In both groups, more than 90% of VT/VF events occurred in the early phase (during the procedure, during hospitalization or within 30 days after the procedure) (ASA: 94.20%; SM: 94.41%). Further subgroup analysis also showed that the ASA group had a higher incidence of VT/VF in both the early phase (RR = 1.94, 95% CI, 1.61-2.33; p < 0.0001, I 2 = 0%) and the late phase (RR = 2.80, 95% CI, 1.00-7.89; p = 0.05, I 2 = 33%). Furthermore, although the risks of sudden cardiac death (SCD) were similar between the ASA and SM groups, a higher incidence of sudden cardiac arrest (SCA), which included SCD and resuscitated SCA, was observed in the ASA group (RR = 2.30, 95% CI, 1.35-3.94; p = 0.002, I 2 = 0%). Conclusions: In patients with HOCM, those who received ASA showed a higher incidence of VF/VT and SCD combined with resuscitated SCA. The majority of VT/VF occurred in the early phase.

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.

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.

Hypertrophic obstructive cardiomyopathy with a basal septal thickness of 16 mm or less: clinical characteristics and surgical results.

PURPOSES: To characterize the clinical features and surgical outcomes of symptomatic hypertrophic obstructive cardiomyopathy (HOCM) in patients with only mild septal hypertrophy. METHODS: The clinical characteristics and surgical outcomes of 53 HOCM patients with a basal septal thickness ≤ 16 mm (mild group) were compared with those of 128 HOCM patients with a basal septal thickness > 16 mm (control group). RESULTS: The mild group had a greater prevalence of mitral subvalvular anomalies than the control group (79.2% vs. 6.3%, p < 0.001). Neither iatrogenic septal perforation nor inadequate septal myectomy was observed after myectomy in the mild group. There were no deaths during a median follow-up of 10 months. Transthoracic echocardiography 6 months after myectomy revealed a significant decrease in maximum gradients in both groups, from baseline 90.5 ± 21.5 mmHg to 10.3 ± 4.4 mmHg in the mild group (p < 0.001) and from 95.0 ± 22.0 mmHg to 12.0 ± 5.9 mmHg (p < 0.001) in the control group. Neither residual obstruction nor residual mitral regurgitation was recorded in the mild group. CONCLUSIONS: Symptomatic patients with hypertrophic obstructive cardiomyopathy and mild septal hypertrophy may have a higher prevalence of mitral subvalvular abnormalities. Mitral subvalvular management during myectomy can achieve outstanding results for these patients.

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.

Midterm results of different treatment methods for myocardial bridging in patients after septal myectomy.

BACKGROUND: Myocardial bridging (MB) is commonly treated in patients with hypertrophic cardiomyopathy. However, whether and how MB should be treated in patients with hypertrophic obstructive cardiomyopathy (HOCM) who underwent septal myectomy remain unclear. METHODS: A total of 823 adults with HOCM who underwent septal myectomy at the Fuwai Hospital from 2011 to 2017 were retrospectively studied. RESULTS: Overall, 31 events occurred: 24 patients died and 7 had nonfatal myocardial infarction (MI). The 3-year cumulative event-free survival of all-cause death (97.9% vs. 100% vs. 100% vs. 98.4%, p = .89) and cardiovascular death (98.3% vs. 100% vs. 100% vs. 98.4%, p = .63) were similar among the four groups (non-MB, coronary artery bypass grafting [CABG], unroofing, untreated, respectively). However, the 3-year cumulative event-free survival of nonfatal MI (100% vs. 97.5% vs. 98.0% vs. 89.9%, p < .001) and combined endpoints (97.9% vs. 97.5% vs. 98.0% vs. 88.4%, p = .02) were significantly lowest in untreated MB (non-MB, CABG, unroofing, untreated, respectively). Cox regression analysis indicated that untreated MB was a significant independent predictor of combined endpoints (hazard ratio: 4.06, 95% confidence interval: 1.60-10.32, p < .001). Moreover, 49 patients underwent coronary artery computed tomography 1 year after surgery. The patency rate of the saphenous vein graft was significantly higher than that of the left internal mammary artery (13.3% vs. 84.2%, p < .001). No MB was detected in the unroofing group. CONCLUSIONS: Surgical MB treatment could be beneficial and performed safely during septal myectomy. Myocardial unroofing is the recommended treatment for MB, and unroofing when technically possible may be preferable for long-term 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.

Septuagenarians with hypertrophic obstructive cardiomyopathy undergoing myectomy: the experience of a single center.

PURPOSES: A previous study reported that the ventricular septum is more fragile in geriatric patients, and thus myectomy may expose geriatric patients to a higher risk of serious complications. This single-center study evaluates the impacts of the advanced age on the results following myectomy for symptomatic hypertrophic obstructive cardiomyopathy (HOCM). METHODS: All eligible patients were divided into an elderly group (septuagenarians, n = 35) and a control group (patients under 70 years, n = 197). The patients were followed up for a median of 10 months. Thereafter, the perioperative and follow-up results were compared. RESULTS: Thirteen patients (8.6% for the elderly group and 5.1% for the control group, p = 0.422) underwent immediate repeat surgery. Surgical mortality did not differ between groups (0 vs. 0.5%, p > 0.05). There was no significant difference in the incidence of complete atrioventricular block between groups (5.7 vs. 3.0%, p = 0.346). No follow-up deaths occurred in either group. The maximum gradients at the latest follow-up were significantly lower than the preoperative values in either group. Additionally, grouping (septuagenarians vs. patients under 70 years of age) was not an independent risk factor for surgical complications and results via multivariable logistic regression. CONCLUSIONS: Septuagenarians with HOCM may obtain favorable results following septal myectomy, the same as did HOCM patients under 70 years of age.

Edge-to-Edge Repair Versus Secondary Cord Cutting During Septal Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy: A Pilot Randomised Study.

BACKGROUND: To evaluate whether the Alfieri technique improves clinical and haemodynamic results and compare it with transaortic mitral valve secondary cord cutting in patients scheduled for septal myectomy for severely symptomatic hypertrophic obstructive cardiomyopathy. METHODS: Forty-eight (48) patients with moderate-to-severe systolic anterior motion (SAM)-mediated mitral regurgitation were randomly assigned to the Alfieri or Cutting groups in addition to septal myectomy. The primary endpoint was postoperative mean transmitral pressure gradient (TPG). The secondary endpoints were residual left ventricular outflow tract (LVOT) gradient after procedure, residual mitral regurgitation (MR), postoperative SAM, repeating bypass, and survival. RESULTS: There were no 30-day mortality and ventricular septal defects. The postoperative LVOT gradient was 15.4±7.6 mmHg and 11.1±4.9 mmHg (p=0.078) in the Alfieri and Cutting groups, respectively. The Alfieri technique was associated with higher peak (7.8±3.3 vs 4.7±2.8 mmHg; p=0.014) and mean (3.9±1.7 vs 2.1±1.6 mmHg; p=0.013) TPG. The Cutting group was associated with higher mild MR rate at discharge (six vs no patients; p=0.009). One (1) patient (4.2%) in the Alfieri group required pacemaker implantation owing to conduction disturbances (p=0.312). Two-year (2-year) freedom from late mortality and sudden cardiac death rates were 95.5%±4.4% and 100% for the Alfieri and Cutting groups, respectively (log rank, p=0.317). No patients had New York Heart Association functional class III or IV or moderate or severe MR. The maximum LVOT gradient was 20.4±15.2 mmHg and 16.7±10.4 mmHg, respectively (p=0.330). There were no reoperations during follow-up. CONCLUSIONS: Both techniques with septal myectomy effectively eliminated SAM-induced MR and LVOT obstructions in hypertrophic cardiomyopathy patients.

Effects of Septal Reduction Therapy on Acute Cardiovascular Events and All-Cause Mortality in Patients with Hypertrophic Cardiomyopathy.

Septal reduction therapy (SRT) -i.e. septal myectomy and alcohol septal ablation-has been performed to treat medically refractory hypertrophic cardiomyopathy (HCM) for decades. However, it is largely unknown whether SRT prevents HCM-related cardiovascular events or death. The objective was to examine the effects of SRT on acute cardiovascular events and all-cause mortality in HCM. We performed a propensity score (PS) -matched study using databases that capture all hospitalizations and outpatient visits in New York state. We identified patients with HCM who underwent SRT between 2007 and 2014 (i.e. the SRT group) and those who had never had SRT but had at least one hospitalization for HCM during the same period (i.e. the control group). We performed PS matching at a 1:1 ratio. The primary outcome was a composite of acute cardiovascular events and all-cause mortality during 0-180 days and 181-360 days. The secondary outcome was 180- and 360-day all-cause mortality. We included 846 patients with HCM (423 PS-matched pairs). Patients who underwent SRT had a lower risk of the primary outcome event (0-180 days: odds ratio [OR], 0.54; 95% confidence intervals (CI), 0.37-0.80; P = 0.002 and 181-360 days: OR, 0.33; 95% CI, 0.22-0.51; P < 0.0001). Furthermore, the risk of all-cause mortality was lower at 180 days (OR, 0.37; 95% CI, 0.22-0.63; P = 0.0003) and 360 days post-SRT (OR, 0.32; 95% CI, 0.20-0.51; P < 0.0001). In conclusion, our PS-matched study using population-based datasets demonstrated that SRT was associated with a reduced risk of a composite of acute cardiovascular events and all-cause mortality in HCM during the first post-SRT year.

[Surgical approaches to interventricular septum in hypertrophic cardiomyopathy]. / Varianty dostupa k mezhzheludochkovoi peregorodke serdtsa pri gipertroficheskoi kardiomiopatii.

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.

Impact of type 2 diabetes mellitus on mid-term mortality for hypertrophic cardiomyopathy patients who underwent septal myectomy.

BACKGROUND: Type 2 diabetes mellitus is common in cardiovascular disease. It is associated with adverse clinical outcomes for patients who had undergone coronary artery bypass and valve operations. The aim of this study was to evaluate the impact of type 2 diabetes mellitus on the midterm outcomes of patients with hypertrophic cardiomyopathy who underwent septal myectomy. METHODS: We retrospectively analyzed the data of 67 hypertrophic cardiomyopathy patients with type 2 diabetes mellitus who underwent septal myectomy from two medical centers in China from 2011 to 2018. A propensity score-matched cohort of 134 patients without type 2 diabetes mellitus was also analyzed. RESULTS: During a median follow-up of 28.0 (interquartile range: 13.0-3.0) months, 9 patients died. The cause of death of all of these patients was cardiovascular, particularly sudden cardiac death in 3 patients. Patients with type 2 diabetes mellitus had a higher rate of sudden cardiac death (4.5% vs. 0.0%, p = 0.04). The Kaplan-Meier survival analysis revealed that the rates of predicted 3-year survival free from cardiovascular death (98.1% vs. 95.1%, p = 0.14) were similar between the two groups. However, the rates of predicted 3-year survival free from sudden cardiac death (100% vs. 96.7%, p = 0.01) were significantly higher in hypertrophic cardiomyopathy patients without type 2 diabetes mellitus than in those with type 2 diabetes mellitus. Furthermore, after adjustment for age and sex, only N-terminal pro-brain natriuretic peptide (hazards ratio: 1.002, 95% confidence interval: 1.000-1.005, p = 0.02) and glomerular filtration rate ≤ 80 ml/min (hazards ratio: 3.23, 95% confidence interval: 1.34-7.24, p = 0.047) were independent risk factors for hypertrophic cardiomyopathy patients with type 2 diabetes mellitus. CONCLUSIONS: Hypertrophic cardiomyopathy patients with and without type 2 diabetes mellitus have similar 3-year cardiovascular mortality after septal myectomy. However, type 2 diabetes mellitus is associated with higher sudden cardiac death rate in these patients. In addition, N-terminal pro-brain natriuretic peptide and glomerular filtration rate ≤ 80 ml/min were independent risk factors among hypertrophic cardiomyopathy patients with type 2 diabetes mellitus.

Impact of Septal Myectomy Volume on Mitral-Valve Replacement Rate in Hypertrophic Cardiomyopathy Patients.

OBJECTIVE: Mitral regurgitation (MR) induced by systolic anterior motion in patients with hypertrophic cardiomyopathy (HCM) can frequently be abolished with a proficient septal myectomy (SM) without the need for mitral-valve replacement (MVR). ACC guidelines stress the importance of volume in improving outcomes after SM, but there is a lack of data measuring the impact of volume on the need for MVR during SM. This study was designed to assess the impact of institutional volume on MVR rates using national outcomes data. METHODS: The Nationwide Inpatient Sample was queried from 1998 to 2011 and a total of 6,207 patients had a diagnosis of HCM and a procedure code for SM. Outcomes were compared between patients who underwent SM (group I) and SM and MVR (group II). Furthermore, patients were stratified into 3 groups based on the number of SMs at the performing institution: low experience (1-24 cumulative SMs), medium experience (25-49 SMs), and high experience (>50 SMs). These patients underwent multivariable analysis to determine the impact of institutional volume on MVR rate. RESULTS: The total MVR rate was 26%. Perioperative outcomes were worse, i.e., there were higher rates of mortality, kidney injury, and urinary complications, in group II than in group I. Only 37.6% of patients were operated on at institutions meeting the guideline criteria of >50 cumulative SMs. When compared to patients in the high-experience group, patients in the low- (OR 2.7, 95% CI 2.3-3.2, p < 0.05) and medium-experience (OR 3.0, 95% CI 2.5-3.6, p < 0.05) groups were more likely to undergo MVR. CONCLUSION: Compared to reports from SM reference centers, national data suggest that MVR rates are quite high at SM. Patients undergoing SM at centers that do not meet the guideline standard have >2.5× the odds of undergoing MVR compared to those operated on at guideline-endorsed centers.