International Journal of Cardiology

International Journal of Cardiology | Vol. 4, No. 6, June 2013 | pp. 41–48

DOI: 10.46882/2013/IJC/000051

Original Research Article

Prognostic Value of Right Ventricular Global Longitudinal Strain in Patients with Acute Pulmonary Embolism

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, 2013; Revised: April 18, 2013; Accepted: May 10, 2013; Published: June 15, 2013

Citation: International Journal of Cardiology, 2013, Vol. 4, No. 6, pp. 41–48, DOI: 10.46882/2013/IJC/000051

International Journal of Cardiology | Vol. 3, No. 10, October 2012 | pp. 73–80

DOI: 10.46882/2012/IJC/000043

Original Research Article

Efficacy of Intredit-Access Cryoballoon Ablation versus Radiofrequency Ablation for Paroxysmal Atrial Fibrillation

Guillaume Mercier¹, Pierre-Yves Roy¹, Jean-François Lebeau²

¹Department of Cardiac Electrophysiology, Hôpital Cardiologique du Haut-Lévêque, Bordeaux, France

²Division of Cardiology, Centre Hospitalier Universitaire de Toulouse, Toulouse, France

Abstract:
Pulmonary vein isolation (PVI) is the gold standard interventional therapy for symptomatic paroxysmal atrial fibrillation (AF). Point-by-point radiofrequency (RF) ablation is highly effective but technically demanding and time-consuming. Cryoballoon (CB) ablation has been introduced as a simplified single-shot alternative for achieving PVI. This randomized trial compared procedural characteristics, safety, and 12-month efficacy between second-generation cryoballoon and conventional RF ablation. We randomized 160 patients with symptomatic paroxysmal AF refractory to antiarrhythmic drugs to undergo either CB ablation (n = 80) or irrigated RF ablation (n = 80). The primary efficacy endpoint was freedom from any documented atrial tachyarrhythmia lasting longer than 30 seconds after a 90-day blanking period without antiarrhythmic drugs. CB ablation demonstrated significantly shorter total procedure times (92 ± 18 minutes vs. 134 ± 24 minutes, p < 0.001) and shorter left atrial dwell times (54 ± 12 minutes vs. 88 ± 16 minutes, p < 0.001) compared with RF ablation. Total fluoroscopy time was slightly longer in the CB cohort (16.4 ± 4.2 minutes vs. 12.1 ± 3.5 minutes, p = 0.01). At 12 months, freedom from recurrent arrhythmia was achieved in 73.8% of the CB group and 71.3% of the RF group (p = 0.72), confirming non-inferiority. Transient phrenic nerve injury occurred in 3.8% of CB procedures, all resolving prior to hospital discharge. Major vascular complications did not differ between cohorts (2.5% vs. 1.3%, p = 0.56). Cryoballoon ablation achieves 12-month success rates equivalent to open-irrigated radiofrequency ablation for paroxysmal atrial fibrillation, while significantly reducing procedural duration and left atrial instrument manipulation times.

Keywords: Atrial fibrillation, Pulmonary vein isolation, Cryoballoon ablation, Radiofrequency ablation, Procedural efficiency, Rhythm control

Received: July 05, 2012; Revised: August 19, 2012; Accepted: September 10, 2012; Published: October 22, 2012

Citation: International Journal of Cardiology, 2012, Vol. 3, No. 10, pp. 73–80, DOI: 10.46882/2012/IJC/000043

International Journal of Cardiology | Vol. 3, No. 3, March 2012 | pp. 17–24

DOI: 10.46882/2012/IJC/000036

Review Article

Pathophysiological Mechanisms and Management Strategies for Anthracycline-Induced Cardiotoxicity: A Comprehensive Review

Emily C. Thorne¹, William H. Edwards²

¹Department of Cardio-Oncology, Royal Marsden Hospital, London, United Kingdom

²Division of Cardiology, Edinburgh Heart Centre, Royal Infirmary of Edinburgh, Edinburgh, United Kingdom

Abstract:
Anthracyclines remain standard therapeutic agents for numerous hematological malignancies and solid tumors. However, their clinical utility is limited by dose-dependent cardiotoxicity, which can cause irreversible heart failure. This review summarizes the molecular mechanisms underlying anthracycline-induced cardiotoxicity and provides a structured overview of modern cardioprotective and monitoring strategies. The primary mechanism of anthracycline toxicity involves the generation of reactive oxygen species (ROS) via iron-dependent pathways, coupled with the inhibition of topoisomerase II-beta in cardiomyocytes, triggering mitochondrial damage and cell apoptosis. Clinical screening depends on tracking left ventricular ejection fraction (LVEF); however, modern speckle-tracking echocardiography can identify subclinical injury through variations in global longitudinal strain (GLS). A relative decrease in GLS greater than 15% during chemotherapy strongly predicts subsequent LVEF reduction, with a pooled sensitivity of 86.0% and specificity of 82.0%. Neurohormonal antagonist therapies, particularly beta-blockers (such as carvedilol) and angiotensin-converting enzyme inhibitors (such as enalapril), show efficacy in blocking or attenuating anthracycline-mediated LVEF declines in high-risk patients. Dexrazoxane remains the only approved intracellular iron chelator that directly reduces ROS generation without altering oncological efficacy, providing a hazard ratio of 0.35 (95% CI: 0.22–0.54) for clinical heart failure prevention across historic cohorts. Managing anthracycline cardiotoxicity requires a multidisciplinary cardio-oncology approach emphasizing early subclinical strain detection and prompt initiation of neurohormonal or iron-chelating regimens.

Keywords: Anthracyclines, Cardiotoxicity, Cardio-oncology, Global longitudinal strain, Dexrazoxane, Heart failure prevention

Received: December 10, 2011; Revised: January 20, 2012; Accepted: February 08, 2012; Published: March 19, 2012

Citation: International Journal of Cardiology, 2012, Vol. 3, No. 3, pp. 17–24, DOI: 10.46882/2012/IJC/000036

International Journal of Cardiology | Vol. 3, No. 1, January 2012 | pp. 1–8

DOI: 10.46882/2012/IJC/000034

Original Research Article

Incidence and Predictors of Left Ventricular Thrombus Formation After ST-Segment Elevation Myocardial Infarction in the Primary PCI Era

Robert J. Davies¹, Edward M. Walsh¹, Simon T. Green²

¹Cardiovascular Research Center, Trinity College Dublin, Dublin, Ireland

²Department of Cardiology, Royal Victoria Hospital, Belfast, United Kingdom

Abstract:
Left ventricular (LV) thrombus is a recognized complication of ST-segment elevation myocardial infarction (STEMI) that poses a substantial systemic embolic risk. While primary percutaneous coronary intervention (PPCI) limits infarct size, the modern incidence and specific predictors of LV thrombus formation remain poorly defined. This prospective observational study sought to determine the incidence and predictors of LV thrombus after STEMI in the current PPCI era using delayed-enhancement cardiac magnetic resonance (CMR) imaging. We evaluated 210 consecutive patients successfully treated with PPCI for an acute first STEMI. All patients underwent CMR imaging at a median of 5 days post-infarction. LV thrombus was identified in 16 patients (7.6%). On univariate analysis, LV thrombus was strongly associated with anterior MI location, lower left ventricular ejection fraction (LVEF), and larger microvascular obstruction (MVO) zones. Multivariable logistic regression revealed that an anterior STEMI location (odds ratio: 4.12, 95% CI: 1.54–11.02, p = 0.005) and a baseline CMR-derived LVEF less than 40% (odds ratio: 3.24, 95% CI: 1.21–8.68, p = 0.02) were independent predictors of thrombus formation. Furthermore, the total mass of late gadolinium enhancement (per 10g increase) significantly increased thrombus probability (odds ratio: 1.45, p < 0.01). Despite prompt mechanical reperfusion with PPCI, left ventricular thrombus forms in 7.6% of acute STEMI cases. Patients presenting with anterior myocardial infarction and severely depressed systolic function exhibit the highest risk and may benefit from targeted screening.

Keywords: ST-segment elevation myocardial infarction, Primary percutaneous coronary intervention, Left ventricular thrombus, Cardiac magnetic resonance, Ejection fraction

Received: October 12, 2011; Revised: November 25, 2011; Accepted: December 15, 2011; Published: January 22, 2012

Citation: International Journal of Cardiology, 2012, Vol. 3, No. 1, pp. 1–8, DOI: 10.46882/2012/IJC/000034

International Journal of Cardiology | Vol. 3, No. 12, December 2012 | pp. 89–96

DOI: 10.46882/2012/IJC/000045

Original Research Article

Association Between Serum Uric Acid Levels and Development of New-Onset Atrial Fibrillation in a Hypertensive Cohort

Dimitris Papadopoulos¹, Nikolaos Georgiadis¹, Andreas Angelopoulos²

¹Department of Cardiology, Hippokration Hospital, University of Athens, Athens, Greece

²Division of Cardiovascular Diseases, AHEPA University Hospital, Thessaloniki, Greece

Abstract:
Hypertension is a major independent risk factor for atrial fibrillation (AF), which significantly drives cardioembolic stroke risk. Serum uric acid (SUA) is a marker of oxidative stress and tissue inflammation, but its independent link to new-onset AF in hypertensive patients remains controversial. This prospective cohort study investigated whether baseline SUA levels predict the long-term incidence of new-onset AF in an unselected hypertensive population. We followed 420 hypertensive individuals in sinus rhythm with no previous history of arrhythmia. Standard metabolic panels, including SUA, were measured at enrollment. New-onset AF was documented using serial electrocardiograms and 24-hour Holter monitoring performed during annual follow-up visits or symptomatic episodes. Hyperuricemia was defined as SUA greater than 7.0 mg/dL in men and greater than 6.0 mg/dL in women. Over a median follow-up of 4.8 years, new-onset AF developed in 46 patients (11.0%). The incidence of AF was significantly higher in patients with baseline hyperuricemia compared with those with normal SUA levels (18.4% vs. 7.1%, p < 0.001). After adjusting for age, body mass index, left atrial diameter, left ventricular mass index, eGFR, and antihypertensive medication use, multivariable Cox proportional hazards analysis confirmed that elevated SUA was an independent predictor of new-onset AF (hazard ratio per 1.0 mg/dL increase: 1.26, 95% CI: 1.10–1.44, p = 0.001). Serum uric acid is independently associated with an increased risk of new-onset atrial fibrillation in hypertensive patients, representing a simple, cost-effective biomarker for refined arrhythmic risk stratification.

Keywords: Hypertension, Atrial fibrillation, Uric acid, Hyperuricemia, Oxidative stress, Biomarkers

Received: September 10, 2012; Revised: October 20, 2012; Accepted: November 11, 2012; Published: December 22, 2012

Citation: International Journal of Cardiology, 2012, Vol. 3, No. 12, pp. 89–96, DOI: 10.46882/2012/IJC/000045

International Journal of Cardiology | Vol. 3, No. 9, September 2012 | pp. 65–72

DOI: 10.46882/2012/IJC/000042

Original Research Article

Comparison of Ticagrelor versus Clopidogrel in Acute Coronary Syndrome Patients Undergoing Percutaneous Coronary Intervention

Yukihiro Tanaka¹, Shinji Kato¹, Takuya Kobayashi²

¹Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan

²Division of Interventional Cardiology, Tokyo Medical University Hospital, Tokyo, Japan

Abstract:
Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is the cornerstone of management for acute coronary syndrome (ACS). Ticagrelor provides faster, more consistent platelet inhibition than clopidogrel. This prospective observational study evaluated the real-world clinical efficacy and safety of ticagrelor versus clopidogrel in ACS patients undergoing percutaneous coronary intervention (PCI). We analyzed 380 consecutive ACS patients (ST-segment elevation myocardial infarction and non-ST-segment elevation ACS) who underwent successful PCI and received either ticagrelor (180 mg loading dose, 90 mg twice daily, n = 190) or clopidogrel (300 to 600 mg loading dose, 75 mg once daily, n = 190). The primary efficacy endpoint was a composite of cardiovascular death, myocardial infarction (MI), or stroke at 12 months. The safety endpoint was major bleeding according to PLATO criteria. At 12 months, the primary composite endpoint was significantly lower in the ticagrelor group than in the clopidogrel group (6.8% vs. 13.2%, hazard ratio: 0.50, 95% CI: 0.26–0.94, p = 0.03), driven primarily by lower rates of recurrent MI. The rate of definite stent thrombosis was also reduced with ticagrelor (0.5% vs. 2.1%, p < 0.05). The incidence of overall PLATO-defined major bleeding did not differ significantly between groups (8.4% vs. 7.9%, p = 0.85); however, non-CABG related bleeding and transient dyspnea were more frequent in the ticagrelor cohort (5.3% vs. 2.1%, p = 0.04). In real-world clinical practice, ticagrelor significantly reduces ischemic events and stent thrombosis in ACS patients undergoing PCI compared with clopidogrel, without significantly increasing overall major bleeding complications.

Keywords: Acute coronary syndrome, Percutaneous coronary intervention, Ticagrelor, Clopidogrel, Dual antiplatelet therapy, Stent thrombosis

Received: June 02, 2012; Revised: July 15, 2012; Accepted: August 04, 2012; Published: September 20, 2012

Citation: International Journal of Cardiology, 2012, Vol. 3, No. 9, pp. 65–72, DOI: 10.46882/2012/IJC/000042