scholarly journals Plasma Proteomic Profiling in Hypertrophic Cardiomyopathy Patients Before and After Surgical Myectomy Reveals Post-Procedural Reduction in Systemic Inflammation

Author(s):  
Amy Larson ◽  
Towia A. Libermann ◽  
Heather Bowditch ◽  
Gaurav Das ◽  
Nikolaos Diakos ◽  
...  

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 the differentially expressed proteins such as interferon-, TGF-1 and TNF. Biological pathways affected by the 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.

2021 ◽  
Vol 22 (5) ◽  
pp. 2474
Author(s):  
Amy Larson ◽  
Towia A. Libermann ◽  
Heather Bowditch ◽  
Gaurav Das ◽  
Nikolaos Diakos ◽  
...  

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.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Milind Y Desai ◽  
Nicholas G Smedira ◽  
Aditya Bhonsale ◽  
Nitesh Ainani ◽  
Maran THamilarasan ◽  
...  

Background: In hypertrophic cardiomyopathy (HCM) with severe left ventricular outflow tract obstruction (LVOTO), surgical myectomy (SM) performed for relief of intractable symptoms is safe and associated with excellent long-term symptom-free survival. In such patients, we sought to determine if SM also results in improvement of long-term outcomes. Methods: We studied 1530 HCM patients with severe LVOTO (50±13 years, 63% men) that were evaluated at our center [excluding <18 years of age, LV ejection fraction (LVEF) <50%, LVOT gradient <30 mm Hg). Clinical, echocardiographic and surgical data were recorded. A composite endpoint of death and/or implantable defibrillator (ICD) discharge was recorded. Results: Hypertension, coronary artery disease (CAD), family history of HCM and syncope were present in 41%, 15%, 17% and 18%, while 73% patients were in Functional Class (FC) ≥ II. Mean LVEF, basal septal thickness, LVOT gradient (resting or provocable) and indexed left atrial dimensions were 62±5%, 2.2±1 cm, 101±39 mm Hg, 2.2±0.4 cm/m2. During 8±6 years of follow-up, 990 (65%) patients underwent SM (of which 65% were isolated SM), while 540 (35%) did not. 94 (6%) patients had alcohol septal ablation (66 in the non myectomy group), while 18% developed atrial fibrillation (AF), and 18% had ICD. There were 169 (11%) events (151 deaths), with 0% 30-day mortality in the SM group. On stepwise multivariable Cox Proportional Hazard analysis, increasing age (Hazard Ratio or HR 1.22 [1.06-1.40]), CAD (HR 1.57 [1.06-2.33]), worsening FC (HR 1.34 [1.05-1.71]) and AF (HR 1.73 [1.23-2.43]) predicted higher events, while SM as a time-dependent covariate (HR 0.58 [0.41-0.81]) was associated with improved event-free survival (all p<0.01). Kaplan-Meier curve showing impact of SM on outcomes is shown in Figure. Conclusion: In HCM patients with severe LVOTO, SM is associated with significant improvement in long-term outcomes when compared to watchful waiting.


2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Alaa Alashi ◽  
Nicholas G. Smedira ◽  
Zoran B. Popovic ◽  
Agostina Fava ◽  
Maran Thamilarasan ◽  
...  

Background We report characteristics and outcomes of elderly patients with hypertrophic cardiomyopathy (HCM) with basal septal hypertrophy and dynamic left ventricular outflow tract obstruction. Methods and Results We studied 1110 consecutive elderly patients with HCM (excluding moderate or greater aortic stenosis or subaortic membrane, age 80±5 years [range, 75–92 years], 66% women), evaluated at our center between June 2002 and December 2018. Clinical and echocardiographic data, including maximal left ventricular outflow tract gradient, were recorded. The primary outcome was death and appropriate internal defibrillator discharge. Hypertension was observed in 72%, with a Society of Thoracic Surgeons (STS) score (8.6±6); while 80% had no HCM‐related sudden cardiac death risk factors. Left ventricular mass index, basal septal thickness, and maximal left ventricular outflow tract gradient were 127±43 g/m 2 , 1.7±0.4 cm, and 49±31 mm Hg, respectively. A total of 597 (54%) had a left ventricular outflow tract gradient >30 mm Hg, of which 195 (33%) underwent septal reduction therapy (SRT; 79% myectomy and 21% alcohol ablation). At 5.1±4 years, 556 (50%) had composite events (273 [53%] in nonobstructive, 220 [55%] in obstructive without SRT, and 63 [32%] in obstructive subgroup with SRT). One‐ and 5‐year survival, respectively were 93% and 63% in nonobstructive, 90% and 63% in obstructive subgroup without SRT, and 94% and 84% in the obstructive subgroup with SRT. Following SRT, there were 5 (2.5%) in‐hospital deaths (versus an expected Society of Thoracic Surgeons mortality of 9.2%). Conclusions Elderly patients with HCM have a high prevalence of traditional cardiovascular rather than HCM risk factors. Longer‐term outcomes of the obstructive SRT subgroup were similar to a normal age‐sex matched US population.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Amy Larson ◽  
Hassan Rastegar ◽  
Gordon S Huggins ◽  
Ethan J Rowin ◽  
Martin S Maron ◽  
...  

Introduction: Hypertrophic cardiomyopathy (HCM) is a common inherited cardiovascular disease, often resulting in left ventricular outflow tract obstruction, relieved by surgical myectomy. Current treatments are largely palliative and do not target the root causes. Understanding the molecular drivers of the disease could lead to alternative treatment strategies through identification of novel therapeutic targets. Methods: We performed single nuclei RNA-sequencing (snRNA-seq) on thousands of nuclei from 9 patient myectomy samples and septal tissue from 4 unused donor hearts selected randomly without regard to genotype to identify the cell populations and determine the gene expression patterns in individual cells. Each sample was processed individually using Seurat v3 for quality control and normalization. Next, all 13 samples were integrated into a combined dataset for clustering and differential gene expression analysis to identify markers specific to each cluster and to assign cell identities. Results: Our results revealed several clusters of cardiomyocytes with differences in sarcomeric and metabolic gene expression. Several fibroblast populations were also observed. Numerous genes were differentially expressed between the HCM and normal samples. For example, RARRES1 expression was observed in many of the fibroblast populations in the normal samples, but was absent in the HCM samples. RARRES1 is involved in regulating fatty acid metabolism and autophagy, both of which are altered in HCM. Additionally, expression of PLA2G2A was absent in the HCM samples but was present in almost every cell type in the normal controls. PLA2G2A is involved in suppression of RTK mediated hypertrophic signaling, impacts lipid signaling, and has tumor suppressor properties. Thus, both RARRES1 and PLA2G2A may represent novel targets in HCM. Conclusions: This approach reveals novel potential therapeutic targets within common final HCM pathological pathways independent of genotype that have the potential to guide development of alternative treatment strategies. Further analysis of larger datasets using this approach will likely identify even more common pathway targets and identify additional common mechanisms in the pathogenesis of obstructive HCM.


2018 ◽  
Vol 2018 (3) ◽  
Author(s):  
Juan José Santos Mateo ◽  
Juan R Gimeno

Alcohol septal ablation (ASA) has become an alternative to surgical myectomy in obstructive hypertrophic cardiomyopathy since it was first introduced in 1994 by Sigwart. The procedure alleviates symptoms by producing a limited infarction of the upper interventricular septum, resulting in a decrease in left ventricular outflow tract (LVOT) gradient. The technique has been improved over time and the results are comparable with those of myectomy. Initial concerns about long-term outcomes have been largely resolved. In this review, we discuss indications, technical aspects, clinical results and patient selection to ASA.


2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Ryohei Suzuki ◽  
Yohei Mochizuki ◽  
Yunosuke Yuchi ◽  
Yuyo Yasumura ◽  
Takahiro Saito ◽  
...  

Abstract Background Inconsistency of treatment response in cats with obstructive hypertrophic cardiomyopathy is well recognized. We hypothesized that the difference in response to beta-blockers may be caused by myocardial functional abnormalities. This study was designed to compare myocardial function in cats with obstructive hypertrophic cardiomyopathy with and without response to beta-blockers. Twenty-one, client-owned, hypertrophic cardiomyopathy cats treated with carvedilol were analyzed. After carvedilol treatment, cats with decreased left ventricular outflow tract velocity were categorized as responders (n = 10); those exhibiting no response (no decrease in the left ventricular outflow tract velocity) were categorized as non-responders (n = 11). The cats were examined using layer-specific assessment of the myocardial function (whole, endocardial, and epicardial layers) longitudinally and circumferentially by two-dimensional speckle-tracking echocardiography, before and after carvedilol treatment. Results The non-responder cats had a significantly higher age, end-diastolic left ventricular posterior-wall thickness, peak velocity of left ventricular outflow tract, and dose of carvedilol than the responders (p = 0.04, p < 0.01, p < 0.01, and p < 0.01, respectively). The circumferential strain in the epicardial layer was lower and circumferential endocardial to epicardial strain ratio was higher in non-responders than responders (p < 0.001 and p = 0.006). According to the multivariate analysis, circumferential strain in the epicardial layer was the only independent correlate of treatment response with carvedilol. Conclusions Myocardial function, assessed by two-dimensional speckle-tracking echocardiography, differed in cats with hypertrophic cardiomyopathy with and without response to beta-blockers. The determination of layer-specific myocardial function may facilitate detailed pathophysiologic assessment and treatment response in cats with hypertrophic cardiomyopathy.


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