Septal myectomy in hypertrophic obstructive cardiomyopathy: late results with stress echocardiography

Exosome-derived circUPF2 enhances resistance to targeted therapy by redeploying ferroptosis sensitivity in hepatocellular carcinoma

BACKGROUND

Advanced hepatocellular carcinoma (HCC) can be treated with sorafenib, which is the primary choice for targeted therapy. Nevertheless, the effectiveness of sorafenib is greatly restricted due to resistance. Research has shown that exosomes and circular RNAs play a vital role in the cancer's malignant advancement. However, the significance of exosomal circular RNAs in the development of resistance to sorafenib in HCC remains uncertain.

METHODS

Ultracentrifugation was utilized to isolate exosomes (Exo-SR) from the sorafenib-resistant HCC cells' culture medium. Transcriptome sequencing and differential expression gene analysis were used to identify the targets of Exo-SR action in HCC cells. To identify the targets of Exo-SR action in HCC cells, transcriptome sequencing and analysis of differential expression genes were employed. To evaluate the impact of exosomal circUPF2 on resistance to sorafenib in HCC, experiments involving gain-of-function and loss-of-function were conducted. RNA pull-down assays and mass spectrometry analysis were performed to identify the RNA-binding proteins interacting with circUPF2. RNA immunoprecipitation (RIP), RNA pull-down, electrophoretic mobility shift assay (EMSA), immunofluorescence (IF) -fluorescence in situ hybridization (FISH), and rescue assays were used to validate the interactions among circUPF2, IGF2BP2 and SLC7A11. Finally, a tumor xenograft assay was used to examine the biological functions and underlying mechanisms of Exo-SR and circUPF2 in vivo.

RESULTS

A novel exosomal circRNA, circUPF2, was identified and revealed to be significantly enriched in Exo-SR. Exosomes with enriched circUPF2 enhanced sorafenib resistance by promoting SLC7A11 expression and suppressing ferroptosis in HCC cells. Mechanistically, circUPF2 acts as a framework to enhance the creation of the circUPF2-IGF2BP2-SLC7A11 ternary complex contributing to the stabilization of SLC7A11 mRNA. Consequently, exosomal circUPF2 promotes SLC7A11 expression and enhances the function of system Xc- in HCC cells, leading to decreased sensitivity to ferroptosis and resistance to sorafenib.

CONCLUSIONS

The resistance to sorafenib in HCC is facilitated by the exosomal circUPF2, which promotes the formation of the circUPF2-IGF2BP2-SLC7A11 ternary complex and increases the stability of SLC7A11 mRNA. Focusing on exosomal circUPF2 could potentially be an innovative approach for HCC treatment.

Alcohol septal ablation vs myectomy for symptomatic hypertrophic obstructive cardiomyopathy: Systematic review and meta-analysis

BACKGROUND

Surgical myectomy (SM) and Alcohol septal ablation (ASA) are effective therapies for patients with hypertrophic cardiomyopathy who remain symptomatic despite medical therapy. A plethora of data has recently emerged on the long-term outcomes of these procedures. We hence sought to perform an updated meta-analysis comparing both procedures.

METHODS

Studies reporting long-term (>3-years) outcomes of SM and/or ASA were included. The primary endpoint was all-cause mortality. Secondary endpoints included cardiovascular mortality, sudden cardiac death (SCD), reintervention, and complications including death, pacemaker implantation, and stroke.

RESULTS

Twenty-two ASA cohorts (n = 4213; follow-up = 6.6-years) and 23 SM cohorts (n = 4240; follow-up = 6.8-years) were included. Septal myectomy was associated with higher periprocedural mortality and stroke (2% vs 1.2%, P = 0.009 and 1.5% vs 0.8% P = 0.013, respectively), but ASA was associated with more need of pacemaker (10% vs 5%, P < 0.001). During long-term follow-up, all-cause mortality, cardiovascular mortality, and sudden cardiac death rates were 1.5%, 0.4%, and 0.3% per person-year in the ASA group and 1.1%, 0.5%, and 0.3% per person-year in the SM group (P = 0.21, P = 0.53, P = 0.43), respectively. Repeat septal reduction intervention(s) were more common after ASA (11% vs 1.5%, P < 0.001).

CONCLUSION

Compared with SM, ASA is associated with lower periprocedural mortality and stroke but higher rates of pacemaker implantations and reintervention. However, there was no difference between ASA and SM with regards to long-term all-cause mortality, cardiovascular mortality, or SCD.

Follow-up of alcohol septal ablation for symptomatic hypertrophic obstructive cardiomyopathy the Baylor and Medical University of South Carolina experience 1996 to 2007

OBJECTIVES

This study sought to determine the long-term outcome of alcohol septal ablation (ASA).

BACKGROUND

There are inadequate data on the long-term outcome of ASA for symptomatic hypertrophic obstructive cardiomyopathy (HOCM).

METHODS

Six hundred and twenty-nine patients were enrolled consecutively (1996 to 2007) and 98.4% (n = 619) underwent ASA with 92% follow-up in 2007. Evaluation included deaths, procedural complications, pacemaker requirement, repeat ASA, and myectomy/valve surgery. Follow-up parameters included angina (Canadian Cardiovascular Society score), dyspnea (New York Heart Association functional class), exercise time, and echocardiographic indices (septal thickness, ejection fraction, resting and provoked gradients).

RESULTS

Ethanol (2.6 +/- 1.0 ml) was injected into 1.3 +/- 0.5 septal arteries, inducing a septal infarct. Complications included death 1% (n = 6), permanent pacemaker requirement 8.2% (n = 52), coronary dissection 1.3% (n = 8), and worsening mitral regurgitation 0.3% (n = 2). The mean follow-up was 4.6 +/- 2.5 years (range: 3 months to 10.2 years). During follow-up, New York Heart Association functional class decreased from 2.8 +/- 0.6 to 1.2 +/- 0.5 (p < 0.001); Canadian Cardiovascular Society angina score decreased from 2.1 +/- 0.9 to 1.0 +/- 0 (p < 0.001); and exercise time increased from 4.8 +/- 3.3 to 8.2 +/- 1.0 (p < 0.001) min. The resting and provoked left ventricular outflow tract gradients decreased progressively (p < 0.001) and remained low during follow-up. The septal thickness decreased from 2.1 +/- 0.5 cm to 1.0 +/- 0.1 cm (p < 0.001) and the ejection fraction decreased from 68 +/- 9% to 62 +/- 3% (p < 0.001). The survival estimates at 1, 5, and 8 years were 97%, 92%, and 89%, respectively.

CONCLUSIONS

The initial benefits of ASA were maintained during follow-up.

Effects of surgical septal myectomy on left ventricular wall thickness and diastolic filling

This study was conducted to examine the late effects of surgical myectomy on left ventricular (LV) structure and diastolic function in patients with obstructive hypertrophic cardiomyopathy. Patients with hypertrophic cardiomyopathy who had complete echocardiographic studies before and > or =6 months after myectomy were included in this retrospective analysis of cavity dimension, septal and LV posterior wall thicknesses, and Doppler flow variables. Compared with preoperative measurement, mean septal thickness (23.6 vs 19.5 mm, p <0.001) and LV posterior wall thickness (14.2 vs 12.4 mm, p <0.001) were smaller after myectomy. Likewise, mitral inflow Doppler velocity curves indicated improvement in LV filling, with decreased mitral E velocity (0.95 to 0.87 m/s, p = 0.008). In conclusion, the long-term benefits of this operation may be mediated in part by favorable LV remodeling and changes in LV diastolic filling.

A prospective follow-up of alcohol septal ablation for symptomatic hypertrophic obstructive cardiomyopathy--the Baylor experience (1996-2002)

BACKGROUND

There is a paucity of data on the long-term outcome of alcohol septal ablation (ASA) for symptomatic hypertrophic obstructive cardiomyopathy (HOCM).

HYPOTHESIS

The study was undertaken to evaluate the longer-term outcome of ASA therapy for symptomatic HOCM.

METHODS

In all, 137 patients were enrolled consecutively (1996-1999) and 130 (95%) (74 men, 56 women, aged 51 +/- 17 years) underwent ASA and had serial prospective follow-up for up to 5 years (mean follow-up 3.6 +/- 1.4 years). Evaluation included angina (Canadian Cardiovascular Society [CCS] score), dyspnea (New York Heart Association [NYHA] class), duration of exercise on treadmill, and echocardiographic indices.

RESULTS

Ethanol (3.5 +/- 1.5 cc), injected into 1.5 +/- 0.6 arteries, induced a mean peak plasma creatine kinase (CK) of 1676 +/- 944 units. Complications of procedures included death 1.5% (2/130), heart block requiring permanent pacemaker 13% (17/130), and coronary dissection 4.4% (6/130). Baseline versus last follow-up visit: NYHA class decreased from 3.0 +/- 0.4 to 1.2 +/- 0.6 (p < 0.01); CCS angina score from 2.0 +/- 0.8 to 0.08 +/- 0.4 (p < 0.01); and duration of exercise increased from 322 +/- 207 to 443 +/- 200 s (p < 0.01). Resting left ventricular outflow tract gradient at baseline versus last follow-up visit showed a decrease from 74 +/- 30 to 4 +/- 13 (p < 0.01), and the dobutamine-provoked gradient of 88 +/- 29 decreased to 21 +/- 21 (p < 0.01) mmHg. All-cause mortality over the duration of follow-up was 7.7% (10) giving an annual rate of 2.1%, and cardiac mortality was 2.3% (3) reflecting an annual rate of 0.6%.

CONCLUSIONS

Alcohol septal ablation decreased symptoms and improved exercise performance, indicating that it is an effective procedure for symptomatic HOCM.

Left ventricular systolic dysfunction during exercise and dobutamine stress in patients with hypertrophic cardiomyopathy

OBJECTIVES

We sought to characterize stress-induced left ventricular systolic dysfunction in patients with hypertrophic cardiomyopathy (HCM).

BACKGROUND

Myocardial ischemia and diastolic dysfunction occur in patients with HCM. We hypothesized that, in the setting of transient myocardial ischemia, left ventricular systolic dysfunction occurs during exercise and dobutamine stress.

METHODS

We studied 39 patients with HCM but without obstructive symptoms at rest or coronary artery disease. A continuous ventricular function monitor equipped with cadmium telluride detectors (VEST) was used to evaluate left ventricular function during supine bicycle ergometer exercise. Dobutamine stress echocardiography (DSE) was also performed. The left ventricular ejection fraction (LVEF) and regional wall motion were determined from echocardiographic images.

RESULTS

Changes in the LVEF correlated between exercise and dobutamine stress (r = 0.643, p < 0.0001). The LVEF decreased more than 5% at peak exercise in 17 of patients (group II), while the other patients had normal responses (group I). New regional wall motion abnormalities during dobutamine infusion were detected in 18 of 110 (16.4%) segments in group I and 42 of 85 (49.4%) segments in group II. Decreased or unchanged regional wall motion occurred more frequently in hypertrophied segments than in nonhypertrophied segments (p < 0.0001). There were significant inverse correlations between the LVEF responses during both stresses and the number of abnormal segments noted during dobutamine stress in all patients (VEST: p < 0.005; DSE: p < 0.0005). Signs of left ventricular obstruction were observed in 11 of 39 patients during DSE. However, there was no significant correlation between the LVEF response and the dobutamine-induced left ventricular pressure gradient.

CONCLUSIONS

Exercise-induced systolic dysfunction occurred in 50% of patients with HCM. In these patients, regional wall motion abnormalities were present in hypertrophied segments.