International Journal of Cardiology

International Journal of Cardiology | Vol. 4, No. 9, September 2013 | pp. 65–72

DOI: 10.46882/2013/IJC/000054

Original Research Article

Efficacy and Safety of Left Atrial Appendage Closure versus Direct Oral Anticoagulants in Patients with Non-Valvular Atrial Fibrillation

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, 2013; Revised: July 20, 2013; Accepted: August 12, 2013; Published: September 18, 2013

Citation: International Journal of Cardiology, 2013, Vol. 4, No. 9, pp. 65–72, DOI: 10.46882/2013/IJC/000054

International Journal of Cardiology | Vol. 4, No. 10, October 2013 | pp. 73–80

DOI: 10.46882/2013/

International Journal of Cardiology | Vol. 4, No. 12, December 2013 | pp. 89–96

DOI: 10.46882/2013/IJC/000057

Original Research Article

Prevalence and Prognostic Significance of Subclinical Epicardial Adipose Tissue Accumulation in Stable Coronary Artery Disease

Yusuf Demir¹, Murat Kaya¹, Ahmet Yilmaz²

¹Department of Cardiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey

²Division of Cardiovascular Radiology, Hacettepe University Faculty of Medicine, Ankara, Turkey

Abstract:
Epicardial adipose tissue (EAT) is a metabolically active visceral fat depot surrounding the myocardium that secretes various pro-inflammatory adipokines. While excessive EAT is associated with general metabolic syndromes, its independent prognostic impact on ischemic event recurrence in patients with established coronary artery disease (CAD) remains quantified. This prospective study evaluated the prevalence of increased EAT volume measured via multidetector computed tomography (MDCT) and determined its correlation with long-term cardiovascular events. We enrolled 240 patients with angiographically documented stable CAD who underwent chest MDCT scans. EAT volume was quantified off-line using volumetric tracking software. Hyper-EAT was defined as an EAT volume greater than 125 cm³. Patients were followed over a 3-year period for major adverse cardiac events (MACE), which included cardiac death, non-fatal myocardial infarction, or unstable angina requiring hospitalization. An elevated EAT volume was identified in 92 patients (38.3%). During follow-up, MACE occurred in 38 patients (15.8%). The incidence of MACE was significantly higher in the high-EAT cohort compared to the normal-EAT group (26.1% vs. 9.5%, p = 0.001). Multivariable Cox proportional hazards analysis confirmed that an increased EAT volume was an independent predictor of recurrent MACE (hazard ratio: 2.15, 95% CI: 1.28–3.62, p = 0.003) after adjusting for age, body mass index, lipid profiles, and the baseline coronary artery calcium score. Subclinical accumulation of epicardial adipose tissue is prevalent in patients with stable coronary artery disease and serves as a powerful, independent predictor of long-term ischemic events, reflecting the clinical importance of local visceral adiposity in atheroprogression.

Keywords: Epicardial adipose tissue, Coronary artery disease, Visceral fat, Computed tomography, Inflammation, Prognosis

Received: September 15, 2013; Revised: October 28, 2013; Accepted: November 15, 2013; Published: December 19, 2013

Citation: International Journal of Cardiology, 2013, Vol. 4, No. 12, pp. 89–96, DOI: 10.46882/2013/IJC/000057

International Journal of Cardiology | Vol. 4, No. 7, July 2013 | pp. 49–56

DOI: 10.46882/2013/IJC/000052

Original Research Article

Diagnostic Utility of High-Sensitivity Cardiac Troponin I vs T Rapid Rule-Out Protocols in Patients with Acute Chest Pain

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, 2013; Revised: May 15, 2013; Accepted: June 08, 2013; Published: July 20, 2013

Citation: International Journal of Cardiology, 2013, Vol. 4, No. 7, pp. 49–56, DOI: 10.46882/2013/IJC/000052

International Journal of Cardiology | Vol. 4, No. 1, January 2013 | pp. 1–8

DOI: 10.46882/2013/IJC/000046

Original Research Article

Cardioprotective Effects of Empagliflozin in a Rat Model of Ischemic Heart Failure: Modulation of Myocardial Energetics

Heinrich Scholz¹, Klaus Richter¹, Manfred Ziegler²

¹Department of Cardiovascular Pharmacology, University Heart Center Freiburg, Freiburg, Germany

²Division of Experimental Cardiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany

Abstract:
Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce heart failure hospitalizations in clinical trials, but their exact cardiac mechanism of action remains poorly defined since SGLT2 is not directly expressed in the myocardium. This study investigated the direct cardioprotective effects of empagliflozin on myocardial function and tissue energetics in a non-diabetic rat model of chronic ischemic heart failure. Heart failure was induced in adult male Wistar rats via permanent ligation of the left anterior descending coronary artery. Two weeks post-ligation, surviving rats were randomized to receive either empagliflozin (20 mg/kg/day, n = 15) or vehicle control (n = 15) via oral gavage for 6 weeks. Cardiac function was tracked using high-resolution echocardiography, and myocardial high-energy phosphate metabolites were quantified post-sacrifice using nuclear magnetic resonance spectroscopy. Treatment with empagliflozin significantly attenuated left ventricular dilation and preserved LVEF compared with the vehicle control group (38.6% ± 3.4% vs. 31.2% ± 2.9%, p < 0.01). Mechanistically, empagliflozin-treated rats demonstrated a significant increase in the myocardial phosphocreatine-to-adenosine triphosphate (PCr/ATP) ratio (1.85 ± 0.14 vs. 1.42 ± 0.11, p < 0.01), indicating enhanced mitochondrial energetic efficiency. Myocardial glucose utilization was reduced, while beta-hydroxybutyrate oxidation was up-regulated, confirming a shift toward ketone body utilization. Empagliflozin significantly preserves left ventricular systolic function and attenuates adverse remodeling in non-diabetic ischemic heart failure rats by optimizing myocardial fuel selection and enhancing high-energy phosphate availability.

Keywords: Heart failure, SGLT2 inhibitors, Empagliflozin, Myocardial energetics, Remodeling, Animal model

Received: October 05, 2012; Revised: November 18, 2012; Accepted: December 08, 2012; Published: January 15, 2013

Citation: International Journal of Cardiology, 2013, Vol. 4, No. 1, pp. 1–8, DOI: 10.46882/2013/IJC/000046

International Journal of Cardiology | Vol. 4, No. 5, May 2013 | pp. 33–40

DOI: 10.46882/2013/IJC/000050

Original Research Article

Long-Term Efficacy and Safety of Catheter Ablation for Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy

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 before severe left atrial dilation occurs.

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

Received: February 12, 2013; Revised: March 25, 2013; Accepted: April 10, 2013; Published: May 20, 2013

Citation: International Journal of Cardiology, 2013, Vol. 4, No. 5, pp. 33–40, DOI: 10.46882/2013/IJC/000050

International Journal of Cardiology | Vol. 4, No. 11, November 2013 | pp. 81–88

DOI: 10.46882/2013/IJC/000056

Original Research Article

Prognostic Significance of Myocardial Viability assessed by Cardiac Magnetic Resonance in Patients with Ischemic Cardiomyopathy

Vasily Smirnov¹, Elena Kuzmina², Dmitry Ivanov¹

¹Department of Cardiology, Almazov National Medical Research Centre, St. Petersburg, Russia

²Division of Cardiovascular Imaging, Pavlov First Saint Petersburg State Medical University, St. Petersburg, Russia

Abstract:
In patients with ischemic cardiomyopathy and severely reduced left ventricular function, selecting candidates for surgical revascularization depends on verifying viable myocardium. Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) allows for precise quantification of transmural scar extent. This prospective study evaluated the long-term prognostic value of CMR-derived myocardial viability parameters in predicting functional recovery and survival after coronary artery bypass grafting (CABG). We followed 165 patients with chronic coronary artery disease and a baseline LVEF less than or equal to 35% who underwent viability evaluation via LGE-CMR prior to planned CABG. Myocardial segments were classified as viable if the transmural extent of scar tissue was less than or equal to 50%. A significant amount of viable myocardium was defined as greater than or equal to 4 viable segments within a 17-segment model. Patients were tracked over a median of 4.5 years for a composite primary endpoint of cardiac death or heart failure hospitalization. A significant viable myocardium profile was identified in 98 patients (59.4%). At 6 months post-CABG, 78.5% of the viable cohort demonstrated an absolute increase in LVEF greater than or equal to 5%, compared with only 12.0% of the non-viable cohort (p < 0.001). Over the full follow-up period, patients with viable myocardium experienced significantly better event-free survival than non-viable individuals (log-rank p = 0.002). Multivariable Cox regression confirmed that the absolute number of viable segments was an independent predictor of long-term survival (hazard ratio: 0.78 per segment, 95% CI: 0.66–0.92, p = 0.004). Quantitative scar characterization via late gadolinium enhancement CMR effectively predicts functional recovery and long-term event-free survival in patients with ischemic cardiomyopathy undergoing surgical revascularization.

Keywords: Ischemic cardiomyopathy, Myocardial viability, Cardiac magnetic resonance, Late gadolinium enhancement, Coronary artery bypass grafting, Prognosis

Received: August 10, 2013; Revised: September 22, 2013; Accepted: October 14, 2013; Published: November 20, 2013

Citation: International Journal of Cardiology, 2013, Vol. 4, No. 11, pp. 81–88, DOI: 10.46882/2013/IJC/000056