Evaluating the efficacy and safety of mavacamten in hypertrophic cardiomyopathy: A systematic review and meta-analysis focusing on qualitative assessment, biomarkers, and cardiac imaging

BACKGROUND

Hypertrophic Cardiomyopathy (HCM) is a complex cardiac condition characterized by hypercontractility of cardiac muscle leading to a dynamic obstruction of left ventricular outlet tract (LVOT). Mavacamten, a first-in-class cardiac myosin inhibitor, is increasingly being studied in randomized controlled trials. In this meta-analysis, we aimed to analyse the efficacy and safety profile of Mavacamten compared to placebo in patients of HCM.

METHOD

We carried out a comprehensive search in PubMed, Cochrane, and clinicaltrials.gov to analyze the efficacy and safety of mavacamten compared to placebo from 2010 to 2023. To calculate pooled odds ratio (OR) or risk ratio (RR) at 95% confidence interval (CI), the Mantel-Haenszel formula with random effect was used and Generic Inverse Variance method assessed pooled mean difference value at a 95% CI. RevMan was used for analysis. P<0.05 was considered significant.

RESULTS

We analyzed five phase 3 RCTs including 609 patients to compare mavacamten with a placebo. New York Heart Association (NYHA) grade improvement and KCCQ score showed the odds ratio as 4.94 and 7.93 with p<0.00001 at random effect, respectively. Cardiac imaging which included LAVI, LVOT at rest, LVOT post valsalva, LVOT post-exercise, and reduction in LVEF showed the pooled mean differences for change as -5.29, -49.72, -57.45, -36.11, and -3.00 respectively. Changes in LVEDV and LVMI were not statistically significant. The pooled mean difference for change in NT-proBNP and Cardiac troponin-I showed 0.20 and 0.57 with p<0.00001. The efficacy was evaluated in 1) A composite score, which was defined as either 1·5 mL/kg per min or greater increase in peak oxygen consumption (pVO2) and at least one NYHA class reduction, or a 3·0 mL/kg per min or greater pVO2 increase without NYHA class worsening and 2) changes in pVO2, which was not statistically significant. Similarly, any treatment-associated emergent adverse effects (TEAE), treatment-associated serious adverse effects (TSAE), and cardiac-related adverse effects were not statistically significant.

CONCLUSION

Mavacamten influences diverse facets of HCM comprehensively. Notably, our study delved into the drug's impact on the heart's structural and functional aspects, providing insights that complement prior findings. Further large-scale trials are needed to evaluate the safety profile of Mavacamten.

COVID-19 Vaccination and Cardiac Arrhythmias: A Review

PURPOSE OF REVIEW

In this review, we aim to delve into the existing literature, seeking to uncover the mechanisms, investigate the electrocardiographic changes, and examine the treatment methods of various cardiac arrhythmias that occur after administration of the COVID-19 vaccine.

RECENT FINDINGS

A global survey has exposed an incidence of arrhythmia in 18.27% of hospitalized COVID-19 patients. Furthermore, any type of COVID-19 vaccine - be it mRNA, adenovirus vector, whole inactivated, or protein subunit - appears to instigate cardiac arrhythmias. Among the cardiac adverse events reported post-COVID-19 vaccination, myocarditis emerges as the most common and is thought to be a potential cause of bradyarrhythmia. When a patient post-COVID-19 vaccination presents a suspicion of cardiac involvement, clinicians should perform a comprehensive history and physical examination, measure electrolyte levels, conduct ECG, and carry out necessary imaging studies. In our extensive literature search, we uncovered various potential mechanisms that might lead to cardiac conduction abnormalities and autonomic dysfunction in patients who have received the COVID-19 vaccine. These mechanisms encompass direct viral invasion through molecular mimicry/spike (S) protein production, an escalated inflammatory response, hypoxia, myocardial cell death, and the eventual scar/fibrosis. They correspond to a range of conditions including atrial tachyarrhythmias, bradyarrhythmia, ventricular arrhythmias, sudden cardiac death, and the frequently occurring myocarditis. For treating these COVID-19 vaccination-induced arrhythmias, we should incorporate general treatment strategies, similar to those applied to arrhythmias from other causes.

Abstract WP82: Racial Disparities Affecting Hospitalization For Acute Ischemic Stroke: A National Inpatient Sample Analysis

Introduction: Stroke affects more than 795000 individuals annually, of which 87% are ischemic. We aimed to determine the socioeconomic and racial disparities in this prevalent cerebrovascular disease.

Methodology: The Nationwide Inpatient Sample was queried for 2017 to identify patients with a primary or secondary diagnosis of acute ischemic stroke. Demographics were analyzed after stratifying the population by race. Multivariate regression analysis was performed taking disposition, total hospital charges and length of stay (LOS) as outcomes of interest.

Results: A total of 519904 ischemic stroke patients were included in the study of which 66.3% were white, 16.8% black, 7.9% hispanic and 8.9% in the other race category. Blacks (50.39%) and hispanics (43.43%) were significantly younger (<65 years) compared to whites (27.74%). Blacks (54.9%) and hispanics (38.4%) were significantly present in the lowest national household income quartile compared to whites (25.2%). In adjusted analysis, blacks (aOR-1.37; p<0.001), hispanics (aOR-1.20; p<0.001) and others (aOR-1.26; p<0.001) had a higher odds of increased LOS (>7days) as compared to whites. Hispanics had 9% (p<0.001) lower odds whereas blacks had 30% higher odds (p<0.001) of being discharged to short-term hospital/skilled nursing facility (SNF) compared to their white counterparts. Blacks, hispanics and others were found to have considerably higher hospital charges compared to whites(table 2).

Conclusion: Increased LOS, greater distribution in lowest quartile of income and higher total charges for blacks and hispanics compared to whites indicates continued prevalence of racial and socioeconomic disparities.

Transcriptional and translational abundance of visfatin (NAMPT) in buffalo ovary during estrous cycle and its in vitro effect on steroidogenesis

Visfatin is a highly conserved adipokine protein having multiple biological effects, including regulation of reproduction. Evidence in recent years has shown a pivotal role of visfatin in ovarian functions. The present study was conducted to evaluate the mRNA and protein abundance of visfatin in ovarian follicles and corpora lutea (CL) during different stages of their development in the ovary of water buffalo (Bubalus bubalis) and to investigate the role of visfatin on estradiol (E₂) and progesterone (P₄) secretion. Ovarian follicles were categorized in to small (F1), medium (F2), large (F3), and preovulatory (F4) follicles, whereas the CL were categorized into early (CL1), mid (CL2), late (CL3), and regressing (CL4) CL stage. In follicles, the mRNA and protein abundance of visfatin increased with an increase in follicle size in granulosa cells (GCs) and theca interna (TI) cells. In CL, the transcript of visfatin was significantly (P < 0.05) higher in the late luteal phase (CL3) than that in other phases. The translational abundance of visfatin was significantly higher in the mid and late luteal phase. Visfatin was localized in the cytoplasm of GC and TI of ovarian follicles and small and large luteal cells of CL. GCs were cultured in vitro and treated at 0, 1, and 10 ng/mL visfatin either alone or in the presence of FSH (30 ng/mL) or IGF-I (10 ng/mL) for 48 h. The luteal cells were treated with visfatin at 0, 1, and 10 ng/mL dose for 48h. There was significant (P < 0.05) increase in estradiol (E₂) secretion from GCs at 10 ng/mL dose of visfatin and visfatin (10 ng/mL) +IGF-I (10 ng/mL). Visfatin also increased (P < 0.05) progesterone (P₄) secretion from cultured luteal cells at both 1 and 10 ng/mL dose. In GCs, visfatin in the presence of IGF-I increased the transcriptional abundance of cytochrome P45019A1 (CYP19A1), the gene for key enzyme aromatase. In luteal cells, the visfatin increased mRNA abundance of factors involved in progesterone synthesis viz. steroidogenic acute regulatory protein (StAR), cytochrome P45011A1 (CYP11A1), 3beta-hydroxysteroid dehydrogenase (HSD3B1). The present study provided evidence that visfatin is expressed in ovarian follicles and CL of buffalo ovary and visfatin has a stimulatory effect on estradiol and progesterone secretion in ovarian cells of water buffalo.

Urinary bladder pheochromocytoma, an extremely rare tumor in children: case report and review of the literature

We report a case of pheochromocytoma in the urinary bladder of a 14-year-old girl who presented with headache and palpitation after voiding. This is an extremely rare condition in pediatric age group and thus can be missed easily. This case is the seventh case reported in the reviewed literature.