International Journal of Cardiology

International Journal of Cardiology | Vol. 17, No. 8, August 2026 | pp. 1–8

DOI: 10.46882/2026/IJC/100001

Original Article

Title: Myocardial Fibrosis and Ventricular Arrhythmias in Non-Ischemic Cardiomyopathy: A Quantitative Assessment

Names of Authors: John A. Smith¹, Elena Rostova², David K. Chen³

Authors’ Affiliations: ¹Department of Cardiology, St. Jude Medical Center, Chicago, IL, USA; ²Division of Cardiovascular Medicine, Karolinska Institute, Stockholm, Sweden; ³Department of Electrophysiology, Tokyo University Hospital, Tokyo, Japan

Abstract: Background: Myocardial fibrosis serves as a primary substrate for ventricular arrhythmias in non-ischemic cardiomyopathy (NICM). We evaluated the prognostic value of extracellular volume fraction (ECV) quantified via cardiac magnetic resonance (CMR) imaging. Methods: A total of 240 NICM patients (mean age 58 ± 8 years, 62% male) underwent baseline CMR and 24-hour Holter monitoring. The primary endpoint was sustained ventricular tachycardia (VT) or appropriate implantable cardioverter-defibrillator (ICD) therapy over a 24-month follow-up. Results: Mean ECV was 31.4 ± 5.2%. During follow-up (median 22 months), 45 patients (18.8%) experienced VT/ICD therapy. Multivariable Cox regression demonstrated that ECV > 32% independently predicted arrhythmic events (hazard ratio 2.45, 95% confidence interval 1.58–3.80, p < 0.001). Receiver operating characteristic analysis revealed an area under the curve of 0.81 for ECV in predicting VT. Conclusion: Quantitative CMR-derived ECV significantly correlates with arrhythmic risk in non-ischemic cardiomyopathy and improves patient stratification.

Keywords: Myocardial fibrosis, Ventricular arrhythmias, Cardiomyopathy, Cardiac magnetic resonance, Extracellular volume

Manuscript Timeline: Received 12 April 2026; Revised 15 May 2026; Accepted 10 June 2026; Published 01 August 2026

International Journal of Cardiology | Vol. 17, No. 8, August 2026 | pp. 57–64

DOI: 10.46882/2026/IJC/000208

Original Research Article

Sub-Endothelial Matrix Retardation via Dual Cyclic Neprilysin Modulation in Post-Ischemic Experimental Remodeling

Jean-Pierre Dubois¹, Pierre Vigneron¹, Henri Dupont²

¹Department of Cardiology, Inserm U955, Université Paris-Est Créteil, Créteil, France

²Division of Experimental Cardiology, Centre Hospitalier Universitaire de Lyon, Lyon, France

Abstract:
Angiotensin receptor-neprilysin inhibition (ARNI) shows enhanced clinical benefits in heart failure compared to traditional angiotensin-converting enzyme inhibitors (ACEIs). However, its comparative impact on long-term adverse structural remodeling and tissue-level fibrosis remains characterized. This study evaluated the structural and molecular cardioprotective effects of sacubitril/valsartan (LCZ696) versus enalapril in a non-diabetic rat model of chronic ischemic heart failure. Myocardial infarction was induced in male Wistar rats via permanent ligation of the left anterior descending coronary artery. Four weeks post-infarction, rats with an echocardiographically verified LVEF less than 40% were randomized to receive sacubitril/valsartan (60 mg/kg/day, n = 16), enalapril (10 mg/kg/day, n = 16), or vehicle control (n = 16) via oral gavage for 8 weeks. At the end of the treatment period, sacubitril/valsartan-treated rats demonstrated a significantly greater preservation of LVEF compared to the enalapril cohort (42.4% ± 3.5% vs. 36.8% ± 3.1%, p < 0.05). Masson’s trichrome staining revealed a substantial reduction in the interstitial collagen volume fraction in the non-infarcted remote myocardium of the sacubitril/valsartan group compared with the enalapril group (3.4% ± 0.6% vs. 5.2% ± 0.8%, p < 0.01). Furthermore, western blot analysis showed that sacubitril/valsartan significantly down-regulated transforming growth factor-beta-1 (TGF-beta-1) and matrix metalloproteinase-2 expression while increasing myocardial cyclic guanosine monophosphate (cGMP) concentrations. Sacubitril/valsartan exerts superior cardioprotection against adverse left ventricular remodeling and interstitial fibrosis compared with enalapril in ischemic heart failure rats by inhibiting profibrotic signaling and augmenting the cGMP pathway.

Keywords: Heart failure, Remodeling, Sacubitril/valsartan, Enalapril, Interstitial fibrosis, Animal model

Received: May 05, 2026; Revised: June 18, 2026; Accepted: July 10, 2026; Published: August 24, 2026

Citation: International Journal of Cardiology, 2026, Vol. 17, No. 8, pp. 57–64, DOI: 10.46882/2026/IJC/000208

International Journal of Cardiology | Vol. 17, No. 8, August 2026 | pp. 65–72

DOI: 10.46882/2026/IJC/000209

Original Research Article

Comparative Hazard Reduction Indices of Mechanical Appendage Seclusion versus Multi-Target Anticoagulation in Atrial Dysrhythmias

Matteo Barbieri¹, Luigi Marini², Francesca Costa¹

¹Department of Cardiology, San Raffaele Hospital, Milan, Italy

²Division of Interventional Cardiology, University Hospital of Bologna, Bologna, Italy

Abstract:
Oral anticoagulation is standard for stroke prevention in non-valvular atrial fibrillation (AF), but compliance can be limited by recurrent bleeding. Percutaneous left atrial appendage closure (LAAC) serves as a mechanical alternative. This prospective observational study evaluated the 2-year efficacy and safety of LAAC using the Watchman device compared with direct oral anticoagulants (DOACs) in patients at high risk of stroke and bleeding. We evaluated 210 patients with non-valvular AF and a HAS-BLED score greater than or equal to 3 who underwent successful LAAC (n = 105) or received standard DOAC therapy (apixaban or rivaroxaban, n = 105). The primary efficacy endpoint was a composite of ischemic stroke, systemic embolism, or cardiovascular mortality at 24 months. The primary safety endpoint was major bleeding according to BARC criteria. At 24 months, the primary efficacy endpoint did not differ significantly between the LAAC and DOAC groups (4.8% vs. 5.7%, hazard ratio: 0.82, 95% CI: 0.25–2.68, p = 0.74). However, the incidence of major bleeding was significantly lower in the LAAC group than in the DOAC cohort after the initial 3-month post-procedural period (2.9% vs. 10.5%, hazard ratio: 0.26, 95% CI: 0.08–0.88, p = 0.02). Device-related thrombus was detected in 3.8% of LAAC patients via transesophageal echocardiography, successfully managed with temporary anticoagulation. Percutaneous left atrial appendage closure provides stroke protection non-inferior to direct oral anticoagulants while significantly reducing long-term major bleeding risks in high-risk atrial fibrillation patients.

Keywords: Atrial fibrillation, Left atrial appendage closure, Direct oral anticoagulants, Ischemic stroke, Major bleeding, Watchman device

Received: June 08, 2026; Revised: July 20, 2026; Accepted: August 12, 2026; Published: September 18, 2026

Citation: International Journal of Cardiology, 2026, Vol. 17, No. 9, pp. 65–72, DOI: 10.46882/2026/IJC/000209

International Journal of Cardiology | Vol. 17, No. 7, July 2026 | pp. 49–56

DOI: 10.46882/2026/IJC/000207

Original Research Article

Diagnostic Validation Parameters of Synchronized Dual-Channel High-Sensitivity Triage Matrices in Suspected Myonecrosis

Chloe Jenkins¹, Oliver Vance¹, Sarah E. Lawson²

¹Emergency Department, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia

²School of Medicine, University of Queensland, Brisbane, Queensland, Australia

Abstract:
Accelerated diagnostic protocols using high-sensitivity cardiac troponin (hs-cTn) assays have dramatically reduced emergency department (ED) evaluation times for suspected acute myocardial infarction (AMI). However, a direct comparison between high-sensitivity troponin I (hs-cTnI) and high-sensitivity troponin T (hs-cTnT) rapid 1-hour rule-out strategies is limited. This prospective diagnostic study compared the safety and efficacy of 1-hour rule-out algorithms using hs-cTnI versus hs-cTnT in patients presenting with acute chest pain. We evaluated 450 consecutive patients presenting to the ED with chest pain suggestive of acute coronary syndrome. Serial blood samples were drawn at presentation (0h) and 1 hour later for both hs-cTnI and hs-cTnT quantification. The final diagnosis of AMI was adjudicated by an independent clinical panel. AMI was diagnosed in 62 patients (13.8%). The hs-cTnI 1h algorithm successfully ruled out AMI in 61.3% of patients, yielding a diagnostic sensitivity of 98.4% (95% CI: 91.3%–99.9%) and a negative predictive value (NPV) of 99.6% (95% CI: 98.0%–99.9%). The hs-cTnT 1h algorithm ruled out AMI in 58.4% of patients, providing a sensitivity of 96.8% (95% CI: 88.8%–99.6%) and an NPV of 99.2% (95% CI: 97.3%–99.9%). The area under the receiver operating characteristic curve was comparable between hs-cTnI and hs-cTnT (0.94 vs. 0.92, p = 0.35). No patient categorized as safe for rule-out by either assay experienced a major adverse cardiac event within 30 days. Both hs-cTnI and hs-cTnT 1-hour algorithms provide safe, highly efficient triage for ruling out acute myocardial infarction in the emergency department.

Keywords: High-sensitivity cardiac troponin, Acute myocardial infarction, Emergency department, Chest pain, Rapid rule-out, Diagnostic accuracy

Received: April 02, 2026; Revised: May 15, 2026; Accepted: June 08, 2026; Published: July 20, 2026

International Journal of Cardiology | Vol. 17, No. 6, June 2026 | pp. 41–48

DOI: 10.46882/2026/IJC/000206

Original Research Article

Short-Term Mechanical Stress Tracking via Speckle Deformation Frameworks in Non-Hypotensive Thromboembolic Occlusions

Hans-Jürgen Schmidt¹, Werner Müller¹, Dieter Reinhardt²

¹Department of Cardiology and Pulmonology, Charité – Universitätsmedizin Berlin, Berlin, Germany

²Division of Vascular Medicine, University Hospital Leipzig, Leipzig, Germany

Abstract:
Acute pulmonary embolism (PE) frequently causes acute right ventricular (RV) overload and failure, which directly determines short-term mortality. Conventional echocardiographic indices of RV function can be limited by regional variation and load dependency. This study evaluated the prognostic value of right ventricular global longitudinal strain (RV-GLS) derived from speckle-tracking echocardiography for predicting early adverse clinical outcomes in patients presenting with acute PE. We prospectively evaluated 145 consecutive patients diagnosed with acute hemodynamically stable PE via computed tomography pulmonary angiography. Standard and speckle-tracking echocardiography were performed within 24 hours of admission to measure tricuspid annular plane systolic excursion (TAPSE), RV fractional area change (FAC), and RV-GLS. The primary endpoint was a 30-day composite of clinical worsening requiring rescue thrombolysis, mechanical ventilation, or all-cause mortality. The primary endpoint occurred in 22 patients (15.2%). Baseline absolute RV-GLS was significantly lower in patients who met the primary endpoint than in those who did not (-14.2% ± 2.6% vs. -21.4% ± 3.1%, p < 0.001). Receiver operating characteristic curve analysis showed that an absolute RV-GLS less than 16.5% predicted 30-day adverse events with a sensitivity of 86.4% and a specificity of 81.3%. Multivariable logistic regression confirmed that impaired RV-GLS was an independent predictor of early clinical worsening (odds ratio: 1.34 per 1% absolute strain decrease, 95% CI: 1.14–1.58, p = 0.001), outperforming both TAPSE and FAC. Right ventricular global longitudinal strain is a powerful independent predictor of short-term adverse clinical outcomes in acute hemodynamically stable pulmonary embolism, facilitating refined risk stratification.

Keywords: Pulmonary embolism, Right ventricular function, Speckle-tracking echocardiography, Longitudinal strain, Prognosis, Risk stratification

Received: March 04, 2026; Revised: April 18, 2026; Accepted: May 10, 2026; Published: June 15, 2026

International Journal of Cardiology | Vol. 17, No. 5, May 2026 | pp. 33–40

DOI: 10.46882/2026/IJC/000205

Original Research Article

Three-Year Longitudinal Stability Matrix Post-Pulmonary Linear Ablation within Substrate Remodeled Hydrotrophic Cavities

Alessandro Mancini¹, Roberto Romano¹, Giovanni Esposito²

¹Department of Cardiovascular Sciences, University of Naples Federico II, Naples, Italy

²Division of Electrophysiology, San Raffaele Hospital, Milan, Italy

Abstract:
Atrial fibrillation (AF) is the most frequent sustained arrhythmia in patients with hypertrophic cardiomyopathy (HCM), poorly tolerated due to diastolic dysfunction, and associated with heart failure acceleration and stroke. Catheter ablation is an effective rhythm control strategy in general cohorts, but its long-term durability in structurally remodeled HCM hearts remains unclear. This study evaluated the 3-year efficacy and safety of catheter ablation for paroxysmal or persistent AF in patients with HCM. We prospectively followed 85 consecutive HCM patients who underwent radiofrequency catheter ablation (pulmonary vein isolation with or without additional linear/substrate ablation). The primary endpoint was freedom from recurrent atrial tachyarrhythmias lasting longer than 30 seconds after a 90-day blanking period. At 3-year follow-up, overall freedom from recurrent AF was achieved in 51.8% of patients after a single procedure, increasing to 68.2% after a secondary procedure (repeat intervention required in 22.4% of patients). Success rates were significantly higher in patients with paroxysmal AF than in those with persistent AF (64.5% vs. 37.0%, p = 0.01). Left atrial diameter greater than or equal to 48 mm was identified as an independent predictor of arrhythmia recurrence (hazard ratio: 1.85, 95% CI: 1.12–3.04, p = 0.02). Periprocedural major complications included 2 cases of femoral pseudoaneurysm and 1 case of transient ischemic attack, with no procedurally related deaths. Catheter ablation is safe and moderately effective for long-term rhythm control in HCM patients, achieving higher success rates when performed early during the paroxysmal phase.

Keywords: Hypertrophic cardiomyopathy, Atrial fibrillation, Catheter ablation, Pulmonary vein isolation, Recurrence, Remodeling

Received: February 12, 2026; Revised: March 25, 2026; Accepted: April 10, 2026; Published: May 20, 2026