International Journal of Cardiology

International Journal of Cardiology | Vol. 6, No. 9, September 2015 | pp. 65–72

DOI: 10.46882/2015/IJC/000078

Original Research Article

Association Between Left Atrial Strain and Recurrence of Atrial Fibrillation Following Cryoballoon Catheter Ablation

Sven Lindstrom¹, Ingrid Johansson¹, Anders Nielsen²

¹Department of Cardiology, Karolinska University Hospital, Stockholm, Sweden

²Department of Clinical Physiology, Aarhus University Hospital, Aarhus, Denmark

Abstract:
Cryoballoon catheter ablation is highly effective for achieving pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (AF), but anatomical left atrial (LA) diameter alone is a limited predictor of long-term rhythm stability. Left atrial reservoir strain (LA-RS) evaluated by speckle-tracking echocardiography provides a direct metric of structural tissue remodeling and wall compliance. This study investigated the independent association between baseline LA-RS and long-term arrhythmia recurrence following cryoballoon ablation. We prospectively followed 150 patients with symptomatic paroxysmal AF scheduled for cryoballoon catheter ablation. Transthoracic speckle-tracking deformation imaging quantified LA-RS prior to the intervention. The primary endpoint was any documented recurrence of atrial tachyarrhythmia lasting longer than 30 seconds after a 90-day post-ablation blanking period over a 24-month follow-up. Recurrent tachyarrhythmias occurred in 46 patients (30.7%). Baseline mean LA-RS was significantly lower in patients with recurrent events compared to those who maintained stable sinus rhythm (17.8% ± 3.1% vs. 27.8% ± 4.2%, p < 0.001). Multivariable Cox proportional hazards regression identified a depressed baseline LA-RS (absolute value less than 20%) as a powerful independent predictor of post-ablation AF recurrence (hazard ratio: 2.38, 95% CI: 1.32–4.35, p = 0.003), whereas conventional indexed left atrial volumes did not retain independent predictive significance. Left atrial reservoir strain is strongly and independently associated with atrial fibrillation recurrence following cryoballoon ablation, providing superior risk assessment compared to conventional volumetric parameters.

Keywords: Atrial fibrillation, Cryoballoon ablation, Speckle-tracking echocardiography, Left atrial strain, Recurrence, Structural remodeling

Received: June 05, 2015; Revised: July 18, 2015; Accepted: August 11, 2015; Published: September 15, 2015

International Journal of Cardiology | Vol. 6, No. 7, July 2015 | pp. 49–56

DOI: 10.46882/2015/IJC/000076

Original Research Article

Diagnostic Performance of Fractional Flow Reserve derived from Computed Tomography in Patients with Severe Coronary Calcification

Arjun Patel¹, Rohan Mehta¹, Vikram Singh²

¹Department of Cardiology, Post Graduate Institute of Medical Education and Research, Chandigarh, India

²Division of Cardiovascular Radiology, All India Institute of Medical Sciences, New Delhi, India

Abstract:
Computed tomography coronary angiography (CTCA) exhibits lower diagnostic specificity in patients with heavy coronary calcification due to blooming artifacts that falsely accentuate luminal narrowing. Fractional flow reserve derived from standard CTCA datasets (FFR-CT) applies computational fluid dynamics to evaluate lesion-specific ischemia non-invasively. This study evaluated the diagnostic performance of FFR-CT for identifying ischemia-producing lesions specifically in patients with high baseline coronary artery calcium (CAC) scores. We prospectively enrolled 115 symptomatic patients with intermediate anatomical coronary stenoses and an Agatston CAC score greater than 400 who were scheduled for diagnostic invasive angiography and fractional flow reserve (FFR). FFR-CT was processed off-line using specialized fluid software. Ischemia was defined as an invasive FFR 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%). Non-invasive FFR-CT demonstrated a diagnostic sensitivity of 86.7% (95% CI: 73.2%–94.9%), a specificity of 81.4% (95% CI: 72.3%–88.6%), and a negative predictive value (NPV) of 92.9% (95% CI: 85.3%–97.4%). The area under the receiver operating characteristic curve for FFR-CT was significantly superior to standard anatomical CTCA narrowing criteria alone (0.88 vs. 0.65, p < 0.001). Fractional flow reserve computed from CTCA datasets maintains high diagnostic accuracy and strong negative predictive value for identifying hemodynamically significant lesions even in the presence of severe calcification, optimizing triage and avoiding unnecessary invasive procedures.

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

Received: April 02, 2015; Revised: May 15, 2015; Accepted: June 08, 2015; Published: July 24, 2015

International Journal of Cardiology | Vol. 6, No. 2, February 2015 | pp. 9–16

DOI: 10.46882/2015/IJC/000071

Original Research Article

Prognostic Value of Circulating Soluble ST2 in Patients with Chronic Heart Failure and Preserved Ejection Fraction

Stefan de Vries¹, Anika Janssen¹, Jan de Jong²

¹Department of Cardiology, Erasmus University Medical Center, Rotterdam, Netherlands

²Division of Cardiovascular Medicine, Leiden University Medical Center, Leiden, Netherlands

Abstract:
Heart failure with preserved ejection fraction (HFpEF) lacks well-validated biomarkers for long-term risk stratification compared to heart failure with reduced ejection fraction. Soluble ST2 (sST2) is an interleukin-1 receptor family member reflecting myocardial strain and fibrosis pathways. This study evaluated the long-term prognostic value of plasma sST2 levels in a prospective cohort of stable HFpEF patients. We enrolled 195 patients with documented HFpEF (LVEF greater than or equal to 50%). Plasma sST2 concentrations were measured at baseline during standard outpatient follow-up. The primary endpoint was a composite of cardiovascular mortality or heart failure hospitalization over a 24-month period. High baseline sST2 (defined as greater than 35 ng/mL) was identified in 38.5% of the study population. At 24 months, the primary composite endpoint occurred in 48 patients (24.6%). Survival analysis showed a significantly lower event-free survival rate in the high sST2 group compared to the low sST2 group (38.7% vs. 15.8%, log-rank p < 0.001). After adjusting for age, body mass index, estimated glomerular filtration rate, and N-terminal pro-B-type natriuretic peptide (NT-proBNP), multivariable Cox proportional hazards regression confirmed that elevated sST2 remained a powerful independent predictor of the composite outcome (hazard ratio: 2.12, 95% CI: 1.34–3.35, p = 0.001). Circulating soluble ST2 levels provide robust, independent prognostic data in patients with stable heart failure and preserved ejection fraction, outperforming traditional clinical metrics for predicting long-term decompensation.

Keywords: Heart failure with preserved ejection fraction, Soluble ST2, Biomarkers, Prognosis, Cardiovascular mortality, Heart failure hospitalization

Received: November 05, 2014; Revised: December 18, 2014; Accepted: January 10, 2015; Published: February 20, 2015

International Journal of Cardiology | Vol. 6, No. 11, November 2015 | pp. 81–88

DOI: 10.46882/2015/IJC/000080

Original Research Article

Efficacy of High Dose Atorvastatin Reloading Before Complex Percutaneous Coronary Intervention

Yusuf Demir¹, Murat Kaya¹, Ahmet Yilmaz²

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

²Division of Interventional Cardiology, Hacettepe University Faculty of Medicine, Ankara, Turkey

Abstract:
Periprocedural myocardial infarction (pMI) is a common complication during complex percutaneous coronary intervention (PCI). Acute statin reloading limits pMI in statin-naive patients, but its effectiveness during complex interventional procedures in patients already established on chronic maintenance statin treatment requires verification. This prospective, randomized, open-label trial evaluated whether high-dose atorvastatin reloading before complex PCI reduces pMI rates in patients on chronic statin therapy. We enrolled 240 chronic statin users undergoing complex PCI (defined as multi-vessel disease, bifurcation lesions, or chronic total occlusions). Patients were randomized 1:1 to receive either an acute reload of atorvastatin (80 mg given 12 hours and 2 hours pre-PCI, n = 120) or to continue standard maintenance dosing (n = 120). The primary endpoint was the incidence of pMI, defined as an elevation of cardiac troponin I (cTnI) greater than 5 times the upper limit of normal within 24 hours post-procedure. The incidence of pMI was significantly lower in the atorvastatin reloading group than in the control arm (8.3% vs. 16.7%, p = 0.04). Post-procedural mean cTnI values were also significantly reduced with the reload (0.42 ± 0.11 ng/mL vs. 0.88 ± 0.21 ng/mL, p < 0.01). No cases of hepatic dysfunction or rhabdomyolysis occurred. High-dose atorvastatin reloading safely and significantly reduces periprocedural myocardial injury during complex percutaneous coronary intervention in patients on chronic maintenance statin therapy.

Keywords: Percutaneous coronary intervention, Atorvastatin, Statin reloading, Periprocedural myocardial infarction, Complex coronary lesions

Received: August 04, 2015; Revised: September 15, 2015; Accepted: October 10, 2015; Published: November 18, 2015

Citation: International Journal of Cardiology, 2015, Vol. 6, No. 11, pp. 81–88, DOI: 10.46882/2015/IJC/000080

International Journal of Cardiology | Vol. 6, No. 5, May 2015 | pp. 33–40

DOI: 10.46882/2015/IJC/000074

Review Article

The Growing Role of Advanced Cardiac Magnetic Resonance Parametric Mapping in Evaluating Myocarditis

Sarah L. Jenkins¹, David M. Ross²

¹Department of Cardiovascular Sciences, British Heart Foundation Centre, King's College London, London, United Kingdom

²Division of Cardiology, Alfred Hospital, Monash University, Melbourne, Victoria, Australia

Abstract:
Acute myocarditis presents with highly variable clinical phenotypes, complicating definitive diagnostic stratification. Traditional cardiac magnetic resonance (CMR) imaging pathways relying on the Lake Louise Criteria offer reasonable diagnostic accuracy but lack sensitivity for diffuse interstitial changes or subtle inflammatory resolution tracking. This systematic review synthesizes recent clinical data regarding the utility of quantitative CMR parametric T1 and T2 mapping methods for diagnosing and monitoring suspected acute myocarditis. A comprehensive database search identified 34 clinical trials involving a combined sample of 2,840 individuals. Quantitative T2 mapping holds exceptional accuracy for detecting localized myocardial edema, showing a pooled sensitivity of 88.0% (95% CI: 83.2%–91.8%) and a specificity of 91.2% (95% CI: 86.5%–94.7%) against endomyocardial biopsy findings. Native T1 mapping and calculated extracellular volume (ECV) fractions successfully quantify diffuse interstitial fibrosis and remodeling that occur secondary to continuous cellular inflammation. Elevated native T1 values provide an adjusted hazard ratio of 2.15 (95% CI: 1.42–3.26, p < 0.01) for predicting 6-month major adverse cardiovascular events (MACE). Quantitative T1 and T2 mapping techniques markedly enhance the diagnostic specificity of CMR for acute myocarditis, offering non-invasive markers to track active inflammatory expansion and refine clinical risk prediction.

Keywords: Myocarditis, Cardiac magnetic resonance, T1 mapping, T2 mapping, Extracellular volume fraction, Myocardial edema, Inflammation

Received: February 14, 2015; Revised: March 28, 2015; Accepted: April 15, 2015; Published: May 20, 2015

International Journal of Cardiology | Vol. 6, No. 6, June 2015 | pp. 41–48

DOI: 10.46882/2015/IJC/000075

Original Research Article

Association Between High-Sensitivity Cardiac Troponin T Release and Incident Atrial Fibrillation Post-Cardiac Surgery

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:
Postoperative atrial fibrillation (POAF) complicates up to 30% of cardiac surgical interventions, increasing the risks of stroke and long-term healthcare expenditure. Subtle periprocedural myocardial injury may serve as an arrhythmogenic substrate, but its correlation with POAF development requires clarification. This prospective observational study evaluated the association between early postoperative high-sensitivity cardiac troponin T (hs-cTnT) elevations and the subsequent development of new-onset POAF. We enrolled 210 consecutive patients in baseline sinus rhythm who underwent elective coronary artery bypass grafting (CABG) or valvular replacement surgery. Serial plasma hs-cTnT levels were collected preoperatively and at 6, 12, and 24 hours postoperatively. Continuous cardiac telemetry monitored heart rhythms throughout the index hospitalization. POAF lasting longer than 30 seconds occurred in 64 patients (30.5%). Preoperative baseline hs-cTnT levels did not differ between cohorts. However, at 12 hours post-surgery, hs-cTnT levels peaked significantly higher in the POAF group than in the non-POAF group (425.4 ± 84.6 ng/L vs. 284.2 ± 62.1 ng/L, p < 0.001). Multivariable logistic regression revealed that a 12-hour postoperative hs-cTnT elevation above 350 ng/L was an independent predictor of POAF development (odds ratio: 2.34, 95% CI: 1.41–3.88, p = 0.002), alongside advanced age (odds ratio: 1.06 per year, p = 0.01). Elevated early postoperative hs-cTnT concentrations are strongly and independently linked to POAF development, indicating that subclinical periprocedural myocardial injury represents a primary contributor to postoperative atrial arrhythmogenesis.

Keywords: Atrial fibrillation, Cardiac surgery, High-sensitivity cardiac troponin T, Myocardial injury, Postoperative complications, Arrhythmogenesis

Received: March 12, 2015; Revised: April 25, 2015; Accepted: May 10, 2015; Published: June 19, 2015