International Journal of Cardiology

International Journal of Cardiology | Vol. 3, No. 6, June 2012 | pp. 41–48

DOI: 10.46882/2012/IJC/000039

Original Research Article

Association Between Sleep Apnea Severity and Atrial Fibrillation Recurrence After 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 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 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, highlighting the clinical importance of screening and treating underlying sleep disordered breathing in this population.

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

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

Citation: International Journal of Cardiology, 2012, Vol. 3, No. 6, pp. 41–48, DOI: 10.46882/2012/IJC/000039

International Journal of Cardiology | Vol. 1, No. 9, September 2010 | pp. 65–72

DOI: 10.46882/2010/IJC/000018

Original Research Article

Prevalence and Prognostic Significance of Subclinical Right Ventricular Dysfunction in Primary Pulmonary Hypertension

Sarah E. Lawson¹, David R. Morris¹, Grace K. Thompson²

¹Institute of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom

²Department of Cardiology, Royal Edinburgh Hospital, Edinburgh, United Kingdom

Abstract:
Right ventricular (RV) function is a critical determinant of survival in patients with primary pulmonary hypertension (PPH). However, early or subclinical RV dysfunction can be difficult to quantify using standard echocardiographic metrics. This study assessed the prevalence of subclinical RV impairment using speckle-tracking echocardiography derived longitudinal strain and investigated its association with clinical worsening over a 3-year follow-up period. We prospectively evaluated 95 PPH patients with preserved conventional RV ejection fraction (RVEF greater than or equal to 45%) and 40 healthy controls. RV free-wall longitudinal strain (RV-FWS) was analyzed off-line. Clinical worsening was defined as a composite of hospitalization for heart failure, lung transplantation, or death. Mild PPH patients exhibited significantly impaired RV-FWS compared to healthy controls (-18.2% ± 2.4% vs. -25.6% ± 2.1%, p < 0.001), revealing a 42.1% prevalence of subclinical RV dysfunction despite normal RVEF. Over a median follow-up of 34 months, 28 patients (29.5%) experienced clinical worsening. Kaplan-Meier survival curves demonstrated that patients with an absolute RV-FWS less than 18% had a significantly higher rate of clinical events compared to those with a strain greater than or equal to 18% (log-rank p = 0.004). Cox proportional hazards analysis confirmed that impaired RV-FWS was an independent predictor of long-term clinical worsening (hazard ratio: 1.45 per 3% decrease, 95% CI: 1.15–1.83, p = 0.002). Subclinical right ventricular dysfunction is highly prevalent in PPH patients with preserved conventional ejection fractions and represents a strong, independent predictor of poor clinical progression.

Keywords: Primary pulmonary hypertension, Right ventricular dysfunction, Speckle-tracking echocardiography, Longitudinal strain, Prognosis

Received: June 05, 2010; Revised: July 18, 2010; Accepted: August 11, 2010; Published: September 15, 2010

Citation: International Journal of Cardiology, 2010, Vol. 1, No. 9, pp. 65–72, DOI: 10.46882/2010/IJC/000018

International Journal of Cardiology | Vol. 1, No. 3, March 2010 | pp. 17–24

DOI: 10.46882/2010/IJC/000012

Review Article

MicroRNAs as Diagnostic and Prognostic Biomarkers in Acute Myocardial Infarction: A Systematic Review

Elena R. Petrova¹, Hans-Jürgen Schmidt²

¹Department of Cardiology, Sechenov First Moscow State Medical University, Moscow, Russia

²Institute for Cardiovascular Research, Charité – Universitätsmedizin Berlin, Berlin, Germany

Abstract:
Acute myocardial infarction (AMI) demands rapid and accurate diagnostic tools to minimize myocardial necrosis and optimize patient outcomes. While traditional biomarkers like cardiac troponins are standard, circulating microRNAs (miRNAs) have emerged as potential novel indicators of myocardial injury. This systematic review synthesizes recent clinical data evaluating the diagnostic accuracy and prognostic value of specific circulating miRNAs in AMI patients. A comprehensive literature search was conducted across major databases up to January 2010, identifying 28 relevant clinical studies involving a pooled population of 3,420 individuals. Analysis focused on heart-specific miRNAs, including miR-1, miR-133a, miR-208a, and miR-499. Results consistently demonstrated that plasma levels of miR-208a and miR-499 increased significantly within 2 hours of symptom onset, peaking earlier than high-sensitivity troponin T. The pooled sensitivity and specificity for miR-208a in diagnosing AMI were 91.0% (95% confidence interval [CI]: 87.5%–93.8%) and 94.2% (95% CI: 91.1%–96.5%), respectively. High expression levels of miR-133a during the acute phase were independently associated with an increased risk of 6-month major adverse cardiac events (MACE), with an adjusted hazard ratio of 1.65 (95% CI: 1.22–2.24, p < 0.01). However, significant heterogeneity existed across studies regarding internal normalization controls and quantification methods. Circulating miRNAs, particularly miR-208a and miR-499, exhibit high diagnostic accuracy for early-stage AMI and offer valuable prognostic insights. Standardized quantification protocols are urgently required before these molecular biomarkers can be integrated into routine clinical practice alongside established cardiac troponins.

Keywords: Acute myocardial infarction, MicroRNA, Biomarkers, Diagnostics, Prognosis, Sensitivity and specificity

Received: December 05, 2009; Revised: January 20, 2010; Accepted: February 11, 2010; Published: March 15, 2010

Citation: International Journal of Cardiology, 2010, Vol. 1, No. 3, pp. 17–24, DOI: 10.46882/2010/IJC/000012

International Journal of Cardiology | Vol. 1, No. 6, June 2010 | pp. 41–48

DOI: 10.46882/2010/IJC/000015

Original Research Article

Association Between High-Sensitivity C-Reactive Protein and Incidence of Atrial Fibrillation Post-Cardiac Surgery

Alexander Wright¹, Chloe Jenkins¹, Marcus Vance²

¹School of Medicine, University of Sydney, Sydney, New South Wales, Australia

²Department of Cardiology, Green Lane Cardiovascular Service, Auckland, New Zealand

Abstract:
Postoperative atrial fibrillation (POAF) is a frequent complication following cardiac surgery, associated with prolonged hospital stay and increased risk of stroke. Inflammation is hypothesized to play a crucial role in the pathogenesis of POAF. This prospective observational study investigated the association between preoperative and early postoperative high-sensitivity C-reactive protein (hs-CRP) levels and the development of POAF. We enrolled 310 sinus rhythm patients undergoing coronary artery bypass grafting (CABG) or valvular surgery. Continuous telemetry monitored cardiac rhythm during the first 7 postoperative days. Blood samples for hs-CRP were collected 24 hours preoperatively and on postoperative days 1, 3, and 5. POAF lasting longer than 30 seconds occurred in 98 patients (31.6%). Baseline preoperative hs-CRP levels did not differ significantly between patients who developed POAF and those who remained in sinus rhythm (2.3 ± 1.1 mg/L vs. 2.1 ± 1.0 mg/L, p = 0.12). However, on postoperative day 3, hs-CRP levels peaked significantly higher in the POAF group than in the non-POAF group (154.6 ± 32.4 mg/L vs. 112.3 ± 28.1 mg/L, p < 0.001). Multivariable logistic regression revealed that peak postoperative hs-CRP level on day 3 was an independent predictor of POAF (odds ratio per 10 mg/L increase: 1.18, 95% CI: 1.09–1.28, p < 0.001), alongside advanced age (odds ratio: 1.05 per year, p = 0.01). Elevated early postoperative systemic inflammatory response, indicated by high hs-CRP levels, is strongly linked to POAF, supporting the inflammatory hypothesis of arrhythmogenesis.

Keywords: Atrial fibrillation, Cardiac surgery, High-sensitivity C-reactive protein, Inflammation, Postoperative complications

Received: March 01, 2010; Revised: April 15, 2010; Accepted: May 05, 2010; Published: June 19, 2010

Citation: International Journal of Cardiology, 2010, Vol. 1, No. 6, pp. 41–48, DOI: 10.46882/2010/IJC/000015

International Journal of Cardiology | Vol. 1, No. 2, February 2010 | pp. 9–16

DOI: 10.46882/2010/IJC/000011

Original Research Article

Efficacy of a Novel Long-Acting Beta-Blocker in Patients with Chronic Heart Failure: A Randomized Controlled Trial

John A. Smith¹, Maria G. Silva², David M. Clark¹

¹Department of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA

²Division of Cardiovascular Medicine, University of São Paulo, São Paulo, Brazil

Abstract:
Chronic heart failure (CHF) remains a leading cause of cardiovascular morbidity globally. This study evaluated the efficacy and safety of a novel long-acting beta-blocker, BB-201, compared to standard-of-care carvedilol over a 12-month period. A double-blind, randomized, parallel-group trial was conducted involving 450 stable CHF patients with an ejection fraction less than or equal to 35%. Patients were randomized 1:1 to receive either BB-201 (mean dose 50 mg once daily) or carvedilol (mean dose 25 mg twice daily). The primary endpoint was the change in left ventricular ejection fraction (LVEF) measured via echocardiography. Secondary endpoints included N-terminal pro-bryn natriuretic peptide (NT-proBNP) levels, six-minute walk distance (6MWD), and all-cause mortality. At 12 months, the BB-201 group demonstrated a significant increase in LVEF compared to baseline (from 28.4% ± 3.1% to 36.2% ± 4.2%, p < 0.01), which was non-inferior and showed a trend toward superiority against the carvedilol group (34.8% ± 3.9%, p = 0.04 for superiority). NT-proBNP levels decreased by 42% in the BB-201 cohort versus 35% in the carvedilol cohort (p < 0.05). The 6MWD improved by 45 ± 8 meters with BB-201 and 38 ± 7 meters with carvedilol. Adverse event rates, including symptomatic bradycardia and hypotension, did not differ significantly between the groups (4.2% vs. 4.0%, p = 0.85). In conclusion, the novel long-acting beta-blocker BB-201 provides robust improvement in cardiac function and biomarker profiles in patients with stable chronic heart failure, offering a viable once-daily therapeutic alternative to standard multi-dose beta-blockade.

Keywords: Chronic heart failure, Beta-blockers, Left ventricular ejection fraction, Clinical trial, Echocardiography, Biomarkers

Received: November 12, 2009; Revised: December 28, 2009; Accepted: January 15, 2010; Published: February 10, 2010

Citation: International Journal of Cardiology, 2010, Vol. 1, No. 2, pp. 9–16, DOI: 10.46882/2010/IJC/000011

International Journal of Cardiology | Vol. 1, No. 10, October 2010 | pp. 73–80

DOI: 10.46882/2010/IJC/000019

Original Research Article

Comparison of Radial versus Femoral Approach for Coronary Angiography and Angioplasty: A Randomized Trial

Giovanni Rossi¹, Matteo Bianchi¹, Antonio Ferrara²

¹Department of Cardiovascular Sciences, University Hospital of Bologna, Bologna, Italy

²Division of Interventional Cardiology, San Raffaele Hospital, Milan, Italy

Abstract:
The optimal vascular access site for coronary angiography and percutaneous coronary intervention (PCI) remains a subject of ongoing clinical debate. Transradial access (TRA) may reduce access-site complications, but it requires specialized training and may increase procedure times compared to conventional transfemoral access (TFA). This randomized clinical trial compared vascular complications, procedural success, and hospital stay between TRA and TFA. We randomized 600 consecutive patients requiring coronary angiography with or without ad hoc PCI to either TRA (n = 300) or TFA (n = 300). The primary endpoint was a composite of major access-site bleeding or vascular complications within 30 days. Procedural success rates were similar between groups (97.3% for TRA vs. 98.7% for TFA, p = 0.24). However, the primary endpoint was significantly lower in the transradial group compared to the transfemoral group (1.3% vs. 5.7%, p < 0.01), primarily driven by a significant reduction in hematomas greater than 5 cm and a lower requirement for blood transfusions. Total fluoroscopy time was slightly longer in the TRA group (11.4 ± 3.5 minutes vs. 9.8 ± 3.1 minutes, p = 0.03). Mean post-procedural hospital stay was significantly shorter in the transradial cohort (1.2 ± 0.4 days vs. 2.3 ± 0.7 days, p < 0.001), leading to higher patient satisfaction scores. Transradial access for coronary interventions significantly reduces entry-site bleeding and vascular complications while shortening hospital length of stay without compromising procedural success rates compared to the transfemoral approach.

Keywords: Coronary angiography, Transradial access, Transfemoral access, Percutaneous coronary intervention, Vascular complications

Received: July 12, 2010; Revised: August 25, 2010; Accepted: September 10, 2010; Published: October 22, 2010

Citation: International Journal of Cardiology, 2010, Vol. 1, No. 10, pp. 73–80, DOI: 10.46882/2010/IJC/000019