International Journal of Cardiology

International Journal of Cardiology | Vol. 8, No. 6, June 2017 | pp. 41–48

DOI: 10.46882/2017/IJC/000099

Original Research Article

Impact of Obstructive Sleep Apnea Severity on Atrial Fibrillation Recurrence After Radiofrequency Catheter Ablation

Marc-André Dubois¹, Thomas Keller², Lukas Weber²

¹Department of Cardiology, Hôpital Cardiovasculaire Louis Pradel, Lyon, France

²Division of Electrophysiology, University Hospital Zurich, Zurich, Switzerland

Abstract:
Obstructive sleep apnea (OSA) is highly prevalent in patients with atrial fibrillation (AF) and promotes continuous atrial electrical and structural remodeling. However, the direct impact of unrecognized or untreated OSA severity on long-term arrhythmia recurrence following radiofrequency catheter ablation remains incompletely quantified. This prospective study evaluated the relationship between the apnea-hypopnea index (AHI) measured via pre-procedural polysomnography and post-ablation AF recurrence. We enrolled 150 patients with symptomatic paroxysmal or persistent AF scheduled for their first catheter ablation (pulmonary vein isolation). All patients underwent overnight polysomnography prior to the procedure. OSA was defined as an AHI greater than or equal to 5 events per hour and categorized into mild (5–14.9), moderate (15–29.9), and severe (greater than or equal to 30). Recurrence was defined as any documented atrial tachyarrhythmia lasting longer than 30 seconds after a 3-month blanking period. OSA was diagnosed in 78 patients (52.0%). Over a 24-month follow-up, arrhythmia recurrence was significantly higher in patients with OSA than in those without OSA (48.7% vs. 27.8%, p = 0.01). Recurrence rates exhibited a dose-dependent relationship with OSA severity, reaching 64.0% in the severe OSA subgroup. Multivariable Cox proportional hazards regression identified severe OSA (AHI greater than or equal to 30) as a potent, independent predictor of AF recurrence (hazard ratio: 2.45, 95% CI: 1.34–4.48, p = 0.003). Sleep apnea severity is strongly and independently associated with higher rates of atrial fibrillation recurrence after catheter ablation.

Keywords: Atrial fibrillation, Catheter ablation, Obstructive sleep apnea, Apnea-hypopnea index, Recurrence, Polysomnography, Rhythm control

Received: March 11, 2012; Revised: April 25, 2012; Accepted: May 12, 2012; Published: June 19, 2017

International Journal of Cardiology | Vol. 8, No. 9, September 2017 | pp. 65–72

DOI: 10.46882/2017/IJC/000102

Original Research Article

Real-World Clinical Efficacy and Safety of Ticagrelor versus Clopidogrel in Acute Coronary Syndrome Patients Undergoing PCI

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, 2017

International Journal of Cardiology | Vol. 8, No. 7, July 2017 | pp. 49–56

DOI: 10.46882/2017/IJC/000100

Original Research Article

Prognostic Value of Right Ventricular Free-Wall Longitudinal Strain in Patients with Stable Chronic Heart Failure

Alexei Volkov¹, Elena Sokolova¹, Nikolai Petrov²

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

²Division of Cardiovascular Imaging, Research Institute of Cardiology, Tomsk, Russia

Abstract:
Right ventricular (RV) failure is a critical determinant of survival in patients with chronic heart failure (CHF). While conventional echocardiographic metrics like tricuspid annular plane systolic excursion (TAPSE) are widely used, they are limited by angle dependency and localized regional tracking. Two-dimensional speckle-tracking derived RV free-wall longitudinal strain (RV-FWS) offers a more sensitive method to quantify global RV myocardial function. This study evaluated the long-term prognostic value of baseline RV-FWS in patients with stable chronic heart failure. We prospectively followed 185 stable CHF patients with an LVEF less than 40%. Standard echocardiography and off-line speckle-tracking analyses were performed at enrollment to measure TAPSE, RV fractional area change (FAC), and RV-FWS. The primary endpoint was a composite of cardiovascular mortality or heart failure hospitalization over a 3-year follow-up period. During a median follow-up of 32 months, 54 patients (29.2%) reached the primary endpoint. Impaired RV-FWS (defined as an absolute value less than 16%) was strongly associated with a higher event rate. Kaplan-Meier analysis showed significantly reduced event-free survival in patients with impaired strain (log-rank p < 0.001). After adjusting for age, NYHA class, LVEF, and NT-proBNP levels, multivariable Cox regression confirmed that impaired RV-FWS remained an independent predictor of adverse outcomes (hazard ratio: 1.15 per 1% absolute reduction, 95% CI: 1.06–1.25, p = 0.001). Right ventricular free-wall longitudinal strain is a powerful independent predictor of long-term cardiovascular mortality and heart failure hospitalization.

Keywords: Chronic heart failure, Right ventricular function, Speckle-tracking echocardiography, Longitudinal strain, Prognosis, Cardiovascular mortality, Heart failure hospitalization

Received: April 05, 2012; Revised: May 18, 2012; Accepted: June 10, 2012; Published: July 24, 2017

International Journal of Cardiology | Vol. 8, No. 5, May 2017 | pp. 33–40

DOI: 10.46882/2017/IJC/000098

Original Research Article

Diagnostic Performance of Fractional Flow Reserve derived from Computed Tomography in Intermediate Coronary Lesions

Kenji Takahashi¹, Satoshi Yamada¹, Kazuo Sato²

¹Department of Cardiovascular Imaging, Tokyo Heart Center, Tokyo, Japan

²Division of Cardiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan

Abstract:
Computed tomography coronary angiography (CTCA) is well established for ruling out significant coronary artery disease (CAD), but it lacks the physiological capacity to assess the hemodynamic significance of anatomical stenoses. Fractional flow reserve derived from standard CTCA datasets (FFR-CT) utilizes computational fluid dynamics to non-invasively estimate blood flow. This prospective clinical study evaluated the diagnostic performance of FFR-CT in identifying ischemia-producing lesions, using invasive FFR as the gold standard reference. We evaluated 115 symptomatic patients with intermediate coronary lesions (defined as 30% to 70% lumen diameter reduction on CTCA) who were scheduled for diagnostic invasive coronary angiography and fractional flow reserve. FFR-CT was computed off-line using specialized fluid dynamics simulation software, with ischemia defined as an FFR-CT less than or equal to 0.80. On a vessel-based analysis (142 vessels total), invasive FFR confirmed lesion-specific ischemia in 45 vessels (31.7%). The non-invasive FFR-CT demonstrated a diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 88.9% (95% CI: 75.9%–96.3%), 86.6% (95% CI: 78.2%–92.7%), 75.5% (95% CI: 61.7%–86.2%), and 94.4% (95% CI: 87.5%–98.2%), respectively. The area under the receiver operating characteristic curve (AUC) for FFR-CT was significantly higher than that of anatomical CTCA stenosis assessment alone (0.91 vs. 0.74, p < 0.001). FFR-CT provides excellent diagnostic accuracy and a high negative predictive value for identifying hemodynamically significant coronary stenoses.

Keywords: Fractional flow reserve, Computed tomography coronary angiography, Computational fluid dynamics, Myocardial ischemia, Diagnostic accuracy, Intermediate lesions

Received: February 14, 2012; Revised: March 28, 2012; Accepted: April 14, 2012; Published: May 22, 2017

International Journal of Cardiology | Vol. 8, No. 12, December 2017 | pp. 89–96

DOI: 10.46882/2017/IJC/000105

Original Research Article

Independent Association Between Baseline Hyperuricemia and New-Onset Atrial Fibrillation in Hypertension

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

International Journal of Cardiology | Vol. 8, No. 2, February 2017 | pp. 9–16

DOI: 10.46882/2017/IJC/000095

Original Research Article

Cardiovascular Risk Profiles and Prevalence of Subclinical Carotid Atherosclerosis in an Asymptomatic West African Population

Chidi O. Okafor¹, Babajide A. Adebayo¹, Funmilayo K. Balogun²

¹Department of Medicine, College of Medicine, University of Lagos, Lagos, Nigeria

²Division of Cardiology, University College Hospital, Ibadan, Nigeria

Abstract:
The burden of non-communicable cardiovascular disease is rising rapidly in Sub-Saharan Africa due to rapid urbanization, dietary modification, and epidemiological shifts. However, clinical data detailing the precise prevalence of subclinical macrovascular disease in native African cohorts remain sparse. This cross-sectional study evaluated traditional cardiovascular risk profiles and estimated the prevalence of subclinical atherosclerosis using high-resolution carotid intima-media thickness (CIMT) measurements in an asymptomatic adult urban population. We evaluated 350 asymptomatic civil servants aged 30 to 70 years residing in Lagos, Nigeria. Traditional metabolic and anthro-biometric risk factors were analyzed via structured laboratory profiling. B-mode ultrasound quantified CIMT; subclinical atherosclerosis was defined as a maximum CIMT greater than or equal to 0.9 mm or the presence of a distinct carotid plaque. The prevalence of hypertension, obesity, dyslipidemia, and impaired fasting glucose was 42.3%, 28.6%, 34.1%, and 11.4%, respectively. Subclinical carotid atherosclerosis was identified in 54 participants (15.4%), with discrete macrovascular plaques found in 4.3% of the overall cohort. Multivariable logistic regression revealed that advanced age (odds ratio: 1.08 per year, p < 0.001), systolic blood pressure (odds ratio: 1.04 per mmHg, p = 0.01), and elevated serum low-density lipoprotein cholesterol (odds ratio: 1.32 per mmol/L, p = 0.03) were independently associated with subclinical macrovascular disease. Subclinical carotid atherosclerosis is highly prevalent among asymptomatic urban West African adults, driven primarily by high rates of undetected or poorly controlled traditional risk factors like hypertension.

Keywords: Cardiovascular risk factors, Subclinical atherosclerosis, Carotid intima-media thickness, Urban health, West Africa, Primary prevention

Received: November 04, 2011; Revised: December 19, 2011; Accepted: January 11, 2012; Published: February 15, 2017