Surgical Myectomy Research Articles

Short-term outcomes of surgical atrial ablation and septal myectomy

Background. Hypertrophic cardiomyopathy is one of the most common types of cardiomyopathy. The appearance of atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy is associated with significant clinical worsening. Outcomes of surgical ablation and septal myectomy in these patients are limited.Aim. This retrospective study aimed to evaluate short-term outcomes of concomitant surgical ablation and septal myectomy in patients with obstructive hypertrophic cardiomyopathy and atrial fibrillation.Methods. Fifty-five patients with hypertrophic obstructive cardiomyopathy and atrial fibrillation who underwent concomitant surgical ablation and septal myectomy between 2014 and 2019 were analysed. Patients with paroxysmal atrial fibrillation predominantly underwent left atrial ablation, and those with nonparoxysmal atrial fibrillation predominantly underwent the Maze IV procedure. Surgical ablation was performed using cryoablation alone (83.6%) or in combination with radiofrequency energy (16.4%).Results. Hospital mortality was 1.8%. Incidence of major adverse events was 3.6%. Sinus node dysfunction and atrioventricular block occurred in 7.3% and 1.8% of patients, respectively. Bleeding requiring revision occurred in 2 (3.6%) patients. Forty-nine (89.1%) patients had stable sinus rhythm and five (9.1%) were on dual-chamber pacemaker stimulation at the time of discharge.Conclusion. Concomitant septal myectomy and surgical ablation are feasible and safe in patients with hypertrophic obstructive cardiomyopathy and atrial fibrillation.Received 5 April 2021. Revised 16 May 2021. Accepted 17 May 2021.Funding: The study did not have sponsorship.Conflict of interest: The authors declare no conflicts of interests.Contribution of the authorsConception and study design: A.S. Zalesov, A.V. Bogachev-ProkophievData collection and analysis: A.S. Zalesov, S.A. Budagaev, A.V. SapeginStatistical analysis: A.S. Zalesov, A.V. Afanasyev, R.M. SharifulinDrafting the article: A.S. ZalesovCritical revision of the article: A.V. Bogachev-Prokophiev, S.I. Zheleznev, I.I. DeminFinal approval of the version to be published: A.S. Zalesov, A.V. Bogachev-Prokophiev, A.V. Afanasyev, R.M. Sharifulin, A.V. Sapegin, S.A. Budagaev, S.I. Zheleznev, I.I. Demin

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.

Outcomes in Patients With Obstructive Hypertrophic Cardiomyopathy and Concomitant Aortic Stenosis Undergoing Surgical Myectomy and Aortic Valve Replacement.

BackgroundHypertrophic cardiomyopathy (HCM) and aortic stenosis can cause obstruction to the flow of blood out of the left ventricular outflow tract into the aorta, with obstructive HCM resulting in dynamic left ventricular outflow tract obstruction and moderate or severe aortic stenosis causing fixed obstruction caused by calcific degeneration. We sought to report the characteristics and longer‐term outcomes of patients with severe obstructive HCM who also had concomitant moderate or severe aortic stenosis requiring surgical myectomy and aortic valve replacement.Methods and ResultsWe studied 191 consecutive patients (age 67±6 years, 52% men) who underwent myectomy and aortic valve (AV) replacement (90% bioprosthesis) at our center between June 2002 and June 2018. Clinical and echo data including left ventricular outflow tract gradient and indexed AV area were recorded. The primary outcome was death. Prevalence of hypertension (63%) and hyperlipidemia (75%) were high, with a Society of Thoracic Surgeons score of 5±4, and 70% of participants had no HCM‐related sudden death risk factors. Basal septal thickness and indexed AV area were 1.9±0.4 cm and 0.72±0.2 cm2/m2, respectively, while 100% of patients had dynamic left ventricular outflow tract gradient >50 mm Hg. At 6.5±4 years, 52 (27%) patients died (1.5% in‐hospital deaths). One‐, 2‐, and 5‐year survival in the current study sample was 94%, 91%, and 83%, respectively, similar to an age‐sex–matched general US population. On multivariate Cox survival analysis, age (hazard ratio [HR], 1.65; 95% CI, 1.24–2.18), chronic kidney disease (HR, 1.58; 95% CI, 1.21–2.32), and right ventricular systolic pressure on preoperative echocardiography (HR, 1.28; 95% CI, 1.05–1.57) were associated with longer‐term mortality, but traditional HCM risk factors did not.ConclusionsIn symptomatic patients with severely obstructive HCM and moderate or severe aortic stenosis undergoing a combined surgical myectomy and AV replacement at our center, the observed postoperative mortality was significantly lower than the expected mortality, and the longer‐term survival was similar to a normal age‐sex–matched US population.

Acute and chronic effects of endocardial radiofrequency ablation of septal hypertrophy in HOCM.

Endocardial radiofrequency ablation of septal hypertrophy (ERASH) is an alternative to alcohol septal ablation (ASA) or surgical myectomy for hypertrophic obstructive cardiomyopathy (HOCM). Several studies have confirmed that septal radiofrequency ablation leads to a significant reduction in the left ventricular outflow tract gradient. We aimed to report the outcomes of 41 patients who underwent ERASH with a focus on severe complications. Since 2004, 41 patients with HOCM (age: 58.2 ± 13 years) underwent ERASH at our institution. ERASH was performed, since ASA was ineffective (26 patients) or not possible (15 patients). The left ventricular outflow tract and the right ventricular septum were ablated in 26 and 15 patients, respectively. ERASH resulted in a significant reduction in acute gradient during the session and the results persisted during the 6-month follow-up (67% gradient reduction at rest and 73% after provocation, p = .0002). Pacemaker dependency after ERASH was 29% and pericardial tamponade occurred in two patients. In four patients, ERASH induced a paradoxical increase in obstruction (PIO), beginning suddenly at 30 min after the procedure and leading to lethal shock in one patient. PIO was not observed after ERASH from the right ventricular aspect. Morbidity and mortality after ERASH were higher than those after ASA. PIO, a life-threatening complication, was observed in 9% of the patients. Our data indicate that ERASH might be considered in patients who are not candidates for surgical myectomy or ASA.

CMR derived ventricular arterial coupling in hypertrophic cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Ventriculoarterial coupling (VAC) is an important surrogate measurement of global cardiovascular efficiency. However, up till recently, this measurement has been rarely used in clinical practice. This could be due to its invasive nature, and the relatively complex methods required for acquisition and interpretation. We here describe a noninvasive method of measuring VA coupling using cardiac magnetic resonance (CMR) in a cohort of hypertrophic cardiomyopathy (HCM). Methods Cardiac MRI was performed in 61 patients with hypertrophic obstructive cardiomyopathy (HOCM) before and after undergoing extended surgical myectomy. Cardiac MRIs from 15 patients with non-obstructive HCM were also included for comparison. Hypertensive patients were excluded from this study. Vitals signs were recorded during each MRI study. Arterial end-systolic pressure (AESP) was determined non-invasively as previously described (0.9x brachial blood pressure). Left ventricular end-systolic pressure (LVESP) was calculated by adding the echo-derived peak systolic gradient across the left ventricular outflow tract to the arterial end-systolic pressure. Indexed stroke volume (SVI) in the ascending aorta as well as indexed end systolic volume (ESVI) were calculated from CMR. Indexed arterial (Ea) and ventricular (Ev) elastance were calculated as AESP/SVI and LVESP/ESVI. VA coupling was then calculated as Ea/Ev. Results Compared to the baseline measurements, VAC increased significantly post myectomy (mean VAC pre-myectomy and post-myectomy 0.38 vs. versus 0.62 respectively, p= 0.00001). VAC in non-obstructive HCM patients (mean = 0.64) was statistically similar to that in post-myectomy (p = 0.82) and statistically different from pre-myectomy (p = 0.00016). The mean of LVOTO gradients post- and pre-myectomy were significantly different (p = 0.00001). Significant correlation of the delta-VAC with the delta gradient in the LVOTO was found (r= 0.35, p = 0.005). Conclusion Non-invasive assessment of VA coupling using CMR is feasible and could be a useful tool in the evaluation of patients with various cardiovascular disorders. Further studies with larger numbers of patients are required to establish the utility of this method in clinical practice.

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.

Targeting Alcohol Septal Ablation in Patients with Obstructive Hypertrophic Cardiomyopathy Candidates for Surgical Myectomy: Added Value of Three-Dimensional Intracoronary Myocardial Contrast Echocardiography.

Background: Myocardial contrast two-dimensional echocardiography (MC-2DE) is widely used to address alcohol septal ablation (ASA) in obstructive hypertrophic cardiomyopathy (HCM). Owing to its limited cut-planes, MC-2DE may inaccurately identify the contrast misplacement associated with an unsuccessful or complicated ASA outcome. Objective: The aim of this study was to assess the added value of myocardial contrast three-dimensional echocardiography (MC-3DE) compared with MC-2DE to identify the appropriate matching between the target septal zone (TSZ) and coronary artery branch for safe and long-term effective ASA in HCM patients. Methods: A consecutive series of 52 symptomatic obstructive HCM patients referred for isolated surgical myectomy (SM) was analyzed with MC-2DE and MC-3DE following injection of echocontrast into one or more septal branches. MC-2DE and MC-3DE patterns were categorized according to complete (Type 1) or incomplete (Type 2) TSZ covering, high-risk (Type 3) exceeding TSZ, or life-threatening outside TSZ distribution (Type 4). Results: MC-2DE per patient analysis showed a Type 1 pattern in 32 patients and Types 2–4 in the remaining 20 patients; subsequent MC-3DE analysis provided a re-phenotyping of MC-2DE findings in 22 of the 52 patients (42%), showing a high-risk Type 2 pattern in 17 of the 32 patients with Type 1, and a new life-threatening Type 4 in three patients with Type 2, respectively. All patients with MC-3DE Type 1 pattern underwent safe and effective ASA with a long-term uneventful follow-up, while the remaining patients underwent SM. Conclusions: Refining high risk or life-threatening contrast misplacement, MC-3DE is more accurate than conventional MC-2DE to target safe and long-term effective septal reduction with ASA in obstructive HCM patients referred for isolated SM.

Usefulness of Alcohol Septal Ablation in the Left Ventricular Outflow Tract Obstruction in Fabry Disease Cardiomyopathy

Fabry disease (FD) is an X-linked linked genetic disorder caused by α-galactosidase A deficiency. The typical clinical manifestation is left ventricular hypertrophy, often mimicking hypertrophic cardiomyopathy (HC). In contrast to sarcomeric HC, left ventricular outflow tract obstruction (LVOTO) is less frequent. We describe 6 male patients with genetically confirmed FD and symptomatic LVOTO. All of them underwent a transcatheter alcohol septal ablation with an immediate effect on the obstruction in all cases and without any serious complications. The median LVOT maximal pressure gradient was 85 (60 to 170) mm Hg. The hemodynamic effect persisted during subsequent follow-up (ranging from 6 months to 16 years). Five patients reported substantial symptomatic improvement. Four patients were receiving specific FD therapy before the interventional procedure. In conclusion, alcohol septal ablation appears to be effective in the treatment of LVOTO in patients with FD and appears to be comparable to the limited published experience with surgical septal myectomy. Despite some important differences between FD HC and sarcomeric HC, the recommendation for treating LVOTO should be similar.

Surgical Septal Myectomy for the Treatment of Residual Left Ventricular Outflow Tract Obstruction Following Failed Alcohol Septal Ablation.

The reasons of residual left ventricular outflow tract (LVOT) obstruction following alcohol septal ablation (ASA) remain unclear, and outcomes of myectomy following failed ASA remain underreported.Thirteen symptomatic patients (10 women, a median age of 60.0 years) who underwent septal myectomy following failed ASA were reviewed. The patients were followed up for a median of 6 months. The clinical characteristics and outcomes of these patients were analyzed and were compared with those of 178 patients who underwent isolated myectomy without previous ASA at our institution during the same period.In the first ASA procedure, the median number of septal perforator arteries injected was 1.0 with the median value of peak creatine kinase following ablation of 978.5 U/L.Uncontrollable extent and location of infarcted myocardium caused by ablation and mitral subvalvular anomalies were found in four (30.8%) and seven (53.8%) patients, respectively. No operative or follow-up deaths occurred. The median maximum LVOT gradients fell from preoperative 112.0 to 8.5 mmHg at follow-up (P < 0.001). Compared with controls, patients with failed ASA had a higher proportion of mitral subvalvular anomalies (53.8% versus 13.5%, P = 0.001) and developed a higher incidence of complete atrioventricular block following myectomy (15.4% versus 1.7%, P = 0.038).Low institutional or operator experience with ablation, uncontrollable extent and location of infarcted myocardium caused by ablation, and mitral subvalvular anomalies may be reasons for failed ASA. Surgical myectomy for the treatment of residual LVOT obstruction after unsuccessful ASA may be associated with favorable results.

Systolic anterior motion in hypertrophic cardiomyopathy: a fluid–structure interaction computational model

We present direct numerical simulations for the pathophysiology of hypertrophic cardiomyopathy of the left ventricle of the human heart. This cardiovascular disorder manifests itself through systolic anterior motion (SAM), a drift of the mitral leaflets towards the aortic subvalvular region, sometimes causing ventricular obstruction during systole. This pathology is induced by a combination of factors, including a thickening of the interventricular septum and an elongation of the mitral valve leaflets: we perform a full parametric study to assess their effect on the disease. From our results we observe that SAM occurs when elongated leaflets, hypertrophic ventricles and strong ejection fraction are present at the same time. In contrast, a physiological ventricle with elongated leaflets, an hypertrophic ventricle with physiological leaflets or diseased ventricle and leaflets with a weak ejection fraction do not produce SAM. After verifying that the numerical results are consistent and in agreement with the clinical data from the literature, we virtually test the two standard surgical procedures, leaflet plication and septal myectomy, adopted for the surgical treatment of SAM. For all the considered cases we obtain quantitative confirmation for the reliability of the intraventricular subvalvular pressure drop (or subvalvular pressure gradient for the medical community) as diagnostic indicator of the systolic anterior motion: when this quantity attains the value of 30 mmHg, SAM of the mitral leaflets is observed, while when this threshold is exceeded the SAM becomes obstructive. On the other hand, in all cases for which SAM is not observed the above pressure drop is always below the threshold.

Plasma Proteomic Profiling in Hypertrophic Cardiomyopathy Patients before and after Surgical Myectomy Reveals Post-Procedural Reduction in Systemic Inflammation.

Left Ventricular Outflow Tract (LVOT) obstruction occurs in approximately 70% of Hypertrophic Cardiomyopathy (HCM) patients and currently requires imaging or invasive testing for diagnosis, sometimes in conjunction with provocative physiological or pharmaceutical stimuli. To identify potential biomarkers of LVOT obstruction, we performed proteomics profiling of 1305 plasma proteins in 12 HCM patients with documented LVOT obstruction, referred for surgical myectomy. Plasma was collected at the surgical preoperative visit, approximately one month prior to surgery and then at the post-surgical visit, approximately 3 months later. Proteomic profiles were generated using the aptamer-based SOMAscan assay. Principal Component Analysis using the highest statistically significant proteins separated all preoperative samples from all postoperative samples. Further analysis revealed a set of 25 proteins that distinguished the preoperative and postoperative states with a paired t-test p-value of <0.01. Ingenuity Pathway analysis facilitated the generation of protein interaction networks and the elucidation of key upstream regulators of differentially expressed proteins, such as interferon-γ, TGF-β1, and TNF. Biological pathways affected by surgery included organ inflammation, migration, and motility of leukocytes, fibrosis, vasculogenesis, angiogenesis, acute coronary events, endothelial proliferation, eicosanoid metabolism, calcium flux, apoptosis, and morphology of the cardiovascular system. Our results indicate that surgical relief of dynamic outflow tract obstruction in HCM patients is associated with unique alterations in plasma proteomic profiles that likely reflect improvement in organ inflammation and physiological function.

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

BackgroundFew 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.MethodsData from 300 patients with hypertrophic obstructive cardiomyopathy who underwent isolated surgical septal myectomy were collected from January 2012 to March 2018.ResultsThe 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).ConclusionsThe 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.

Alcohol septal ablation for hypertrophic obstructive cardiomyopathy: the emerging role of the Cardiomyopathy Team

Alcohol septal ablation is a minimally invasive, safe, and effective procedure for the treatment of left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM) who remain symptomatic despite maximal medical therapy. Originally performed by Ulrich Sigwart in 1994, the procedure causes a iatrogenic infarction - through the injection of absolute alcohol - of the basal portion of the interventricular septum and aims at reducing LVOT obstruction in order to improve patient's hemodynamics and symptoms. Numerous studies have demonstrated the effectiveness and safety of the procedure, making it a valid alternative to surgical myectomy. The success of alcohol septal ablation depends upon the selection of the patient and the experience of both the operators and the center where the procedure is performed. In this review, we summarize current evidence on alcohol septal ablation, describe its procedural aspects and propose a multidisciplinary approach that involves a team of clinical cardiologists, interventionists, and cardiac surgeons, the Cardiomyopathy Team, with high experience in the clinical management of these patients.

Surgical septal myectomy outcome for obstructive hypertrophic cardiomyopathy after alcohol septal ablation.

BackgroundAlthough surgical treatment of residual obstruction after alcohol septal ablation (ASA) is often challenging in patients with obstructive hypertrophic cardiomyopathy (OHCM) there are very few relevant clinical reports. Thus, outcomes of surgical septal myectomy (SSM) in this subgroup of patients remain to be determined. Therefore, this study aimed to determine the surgical and follow-up outcomes in patients with OHCM exhibiting residual obstruction after ASA.MethodsWe collected case data for 62 patients with OHCM and residual obstruction after ASA who underwent SSM at Fuwai Hospital between January 2002 and June 2019. Propensity score matching with patients having had a myectomy as the only invasive procedure—was conducted in a 1:2 ratio. Echocardiography parameters, surgery results, and follow-up outcomes were compared between the groups.ResultsThe prior ASA group had a higher incidence of complete atrioventricular block (AVB) and subsequently postoperative permanent pacemaker (PPM) implantation than the primary myectomy group (9.7% vs. 1.6%, P=0.01). Two patients died within 30 days after surgery in the prior ASA group, and one patient died in the primary myectomy group, with an operative mortality rate of 3.2% and 0.8%, respectively (P=0.2). The 5-year event-free survival rate was 86.0% in the prior ASA group (median follow-up period: 3.2 years; mean: 3.9±2.6 years; maximum, 10.6 years) and 88.5% in the primary myectomy group (median follow-up period: 2.4 years; mean 2.8±1.7 years; maximum, 9.1 years) (P=0.2). During follow-up, four of 62 (6.5%) patients in the prior ASA group and one of 124 (0.8%) patients in the primary myectomy group progressed to advanced heart failure (P=0.025).ConclusionsPatients with OHCM following ASA are at an increased risk of developing AVB after SSM. Their surgical outcomes, and long-term survival rate were satisfactory and, osimilar to those for patients having had a myectomy as the only invasive procedure. In addition, they had an increased risk of advanced heart failure after SSM in the present study.

Prevalence and Clinical Characteristics of Fabry Disease in Chinese Patients With Hypertrophic Cardiomyopathy

BackgroundThe prevalence of Fabry disease (FD) in Chinese patients with hypertrophic cardiomyopathy (HCM) is unclear. We aimed to evaluate the prevalence, clinical characteristics, and outcomes of FD in Chinese patients with HCM. MethodsOf 217 patients with HCM, FD probands were screened by next-generation sequencing at Fuwai Hospital. Medical data from α-galactosidase A activity, electrocardiography, echocardiography, coronary angiography, cardiac magnetic resonance, pathological examination, and follow up was analyzed. ResultsTwo FD probands were observed (0.93% of patients with HCM), both of which were diagnosed with symptomatic obstructive HCM at 49 years of age. One proband had a GLA mutation (c.887T>C [p.M296T]) with a late-onset cardiac variant, which was characterized by dual ventricular hypertrophy and conduction disease with a permanent pacemaker. The other patient had a GLA mutation (c.758T>C [p.I253T]) with a classic phenotype and dual ventricular hypertrophy, atrioventricular block, renal failure, and recurrent cerebral infarction. Both probands had late gadolinium enhancement mainly in the basal segment of the inferolateral wall. Follow up revealed no exertional symptoms or outflow obstruction after surgical septal myectomy in the two probands, and stable renal function was observed after 6 months of migalastat therapy in the later one. A family study revealed six female carriers and three sudden cardiac deaths. ConclusionsFD is not uncommon in Chinese patients with HCM. Multiple organic involvement, dual ventricular hypertrophy, and conduction disease provide clinical clues for suspected FD, and early genetic screening is necessary. Surgical septal myectomy and migalastat improve the long-term prognosis of patients with FD.

Life Threatening Reactive Left Ventricular Hypertrophy Due to Increased Blood Flow after Coronary Artery Bypass Grafting

A 68-year-old patient with triple vessel coronary artery disease was scheduled for elective coronary artery bypass grafting. Three days after the uneventful surgery, the patient went into cardiogenic shock, which was deemed to be caused by a dynamic left ventricular outflow tract obstruction and high-grade mitral regurgitation, which both had not been present before surgery. On an emergency basis, surgical transvalvular septal myectomy and mitral valve replacement were performed. After initial extra corporeal membrane oxygenation (ECMO) therapy and a prolonged (intensive care unit) ICU stay the patient finally recovered and is well one and a half years after surgery.

Collagen Cross-Linking Is Associated With Cardiac Remodeling in Hypertrophic Obstructive Cardiomyopathy.

BackgroundCollagen cross‐linking is covalent bonds among collagen fibers from catalysis of lysyl oxidase (LOX) and advanced glycation end products (AGEs). We aimed to evaluate the formation of enzymatic and nonenzymatic collagen cross‐linking and its clinical significance in patients with hypertrophic obstructive cardiomyopathy.Methods and ResultsForty‐four patients with hypertrophic obstructive cardiomyopathy who underwent surgical myectomy were consecutively enrolled. Cardiovascular magnetic resonance parameters of left atrial/left ventricular function were measured, including peak filling rate (PFR) and early peak emptying rate (PER‐E). Total collagen was the sum of soluble and insoluble collagen, which were assessed by collagen assay. The myocardial LOX and AGEs expression were measured by molecular and biochemical methods. Compared with patients without atrial fibrillation, insoluble collagen (P=0.018), insoluble collagen fraction (P=0.017), and AGEs (P=0.039) were higher in patients with atrial fibrillation, whereas LOX expression was similar (P=0.494). The insoluble collagen fraction was correlated with PFR index (PFR normalized by left ventricular filling volume) (r=−0.44, P=0.005), left atrial diameters (r=0.36, P=0.021) and PER‐E index (PER‐E normalized by left ventricular filling volume) (r=−0.49, P=0.001).Myocardial LOX was positively correlated with total collagen (r=0.37, P=0.025) and insoluble collagen fraction (r=0.53, P < 0.001), but inversely correlated with PFR index (r=−0.43, P=0.006) and PER‐E index (r=−0.35, P=0.027). In multiple regression analysis, myocardial LOX was independently associated with PFR, while insoluble collagen fraction showed independent correlation with PER‐E after adjustment for clinical confounders.ConclusionsCollagen cross‐linking plays an important role on heart remodeling in hypertrophic obstructive cardiomyopathy. Myocardial LOX expression is independently correlated with left ventricular stiffness, while accumulation of AGEs cross‐links might be associated with the occurrence of atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy.

Outcomes in Guideline-Based Class I Indication Versus Earlier Referral for Surgical Myectomy in Hypertrophic Obstructive Cardiomyopathy.

BackgroundIn patients with obstructive hypertrophic cardiomyopathy, surgical myectomy (SM) is indicated for severe symptoms. We sought to compare long‐term outcomes of patients with obstructive hypertrophic cardiomyopathy where SM was based on guideline‐recommended Class I indication (Functional Class or FC ≥3 or angina/exertional syncope despite maximal medical therapy) versus earlier (FC 2 and/or impaired exercise capacity on exercise echocardiography with severe obstruction).Methods and ResultsWe studied 2268 consecutive patients (excluding <18 years, ≥ moderate aortic stenosis and subaortic membrane, 56±14 years, 55% men), who underwent SM at our center between June 2002 and March 2018. Clinical data, including left ventricular outflow tract gradient, were recorded. Death and/or appropriate internal defibrillator discharge were primary composite end points. One thousand three hundred eighteen (58%) patients met Class I indication and 950 (42%) underwent earlier surgery; 222 (10%) had a history of obstructive coronary artery disease. Basal septal thickness, and resting and maximal left ventricular outflow tract gradient were 2.0±0.3 cm, 61±44 mm Hg, and 100±31 mm Hg, respectively. At 6.2±4 years after SM, 248 (11%) had composite events (13 [0.6%] in‐hospital deaths). Age (hazard ratio [HR], 1.61; 95% CI, 1.26–1.91), obstructive coronary artery disease (HR, 1.46; 95% CI, 1.06–1.91), and Class I versus earlier SM (HR, 1.61; 95% CI, 1.14–2.12) were associated with higher primary composite events (all P<0.001). Earlier surgery had better longer‐term survival (similar to age‐sex‐matched normal population) versus surgery for Class I indication (76 [8%] versus 193 [15%], P<0.001).ConclusionsIn patients with obstructive hypertrophic cardiomyopathy, earlier versus surgery for Class I indication had a better long‐term survival, similar to the age‐sex‐matched US population.

Low Risk of Hypertrophic Cardiomyopathy With Contemporary Management Strategies Implemented in Non-Referral Regional Community-Based Practices

Major advances in diagnosis and treatment have emerged for hypertrophic cardiomyopathy (HCM), largely in major tertiary referral centers dedicated to this disease. Whether these therapeutic benefits are confined to patients in such highly selected cohorts, or can be implemented effectively in independent regional or community-based populations is not generally appreciated. We assessed management and clinical outcomes in a non-referral HCM center (n = 214 patients) in Eastern Pennsylvania. Over a 6.0 ± 3.2-year follow-up, the HCM-related mortality rate was 0.1% per year attributed to a single disease-related death, in a 49-year-old man with end-stage heart failure, ineligible for heart transplant. Fifteen patients (7%) with prophylactically placed implantable cardioverter-defibrillators (ICDs) experienced appropriate therapy terminating life-threatening ventricular tachyarrhythmias. In 23 other patients (11%; 5%/year), heart failure due to left ventricular outflow obstruction was reversed by surgical septal myectomy (n = 20) or percutaneous alcohol septal ablation (n = 3). This regional HCM cohort was similar to a comparison tertiary center referral population in terms of HCM-mortality: 0.1%/year vs 0.3%/year (p = 0.3) and ICD therapy (31% vs 16% of primary prevention implants), although more frequently with uncomplicated benign clinical course (62% vs 46%; p <0.01). In conclusion, effective contemporary HCM management strategies and outcomes in referral-based HCM centers can be successfully replicated in regional and/or non-referral settings. Therefore, HCM is now a highly treatable disease compatible with normal longevity when assessed in a variety of clinical venues not limited to tertiary centers.

Early and late post-operative arrhythmias after surgical myectomy: 45 years of follow-up

AimsThe aims of this study are to investigate the incidence and determinants of post-operative atrial arrhythmias, conduction disorders and mortality in hypertrophic obstructive cardiomyopathy (HOCM) patients undergoing transaortic myectomy. Methods and resultsThis retrospective single-center study was conducted in 249 patients (median age 54 years [40–64], 42% female) undergoing transaortic myectomy. Post-operative atrial fibrillation (AF) was reported in 84 patients (33.7%), including 56 patients (22.5%) with de novo AF. Older age (HR = 1.027 (1.003–1.052), p = 0.029) and hypercholesterolemia (HR = 2.296 (1.091–4.832) p = 0.029) were independent predictors for de novo post-operative AF. Late post-operative AF and atrial flutter (AFL) occurred in 18.9% and 6.8% of the patients, respectively. De novo early post-operative AF increased the risk of late post-operative AF (HR = 3.138 (1.450–6.789), p = 0.004). Patients with a right bundle branch block had a higher risk of early-postoperative pacemaker implantation (p = 0.003, HR = 9.771 (2.195–43.505)). Higher age at time of surgery (HR = 1.053 (1.026–1.081), p < 0.001) was a predictor for late mortality (n = 47, 18.9%). ConclusionEarly and late post-operative AF, AFL and other SVTs are common sequelae after myectomy and are associated with older age at surgery, history of AF and early post-operative AF. Early post-operative arrhythmias are not transient and periodic rhythm monitoring is therefore essential to initiate therapy as soon as possible.