International Journal of Cardiology

International Journal of Cardiology | Vol. 14, No. 9, September 2023 | pp. 65–72

DOI: 10.46882/2023/IJC/000173

Original Research Article

Baseline Left Atrial Reservoir Strain for Predicting Late Arrhythmia Recurrence 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, 2023; Revised: July 18, 2023; Accepted: August 11, 2023; Published: September 15, 2023

International Journal of Cardiology | Vol. 14, No. 5, May 2023 | pp. 33–40

Review Article

Diagnostic Utility of Quantitative CMR Parametric Mapping Sequences for Non-Invasive Tracking of Acute 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, 2023; Revised: March 28, 2023; Accepted: April 15, 2023; Published: May 20, 2023

International Journal of Cardiology | Vol. 14, No. 7, July 2023 | pp. 49–56

DOI: 10.46882/2023/IJC/000171

Original Research Article

Diagnostic Performance of Non-Invasive FFR-CT for Identifying Ischemia-Producing Lesions in Severely Calcified Coronary Arteries

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:
Severe coronary artery calcification introduces severe blooming artifacts during computed tomography coronary angiography (CTCA), which limits structural specificity and results in false-positive findings. Fractional flow reserve derived from standard CTCA datasets (FFR-CT) utilizes computational fluid dynamics to evaluate lesion-specific ischemia non-invasively. This multi-center prospective study evaluated the diagnostic performance of FFR-CT for identifying hemodynamically significant lesions in patients with heavy coronary calcification. We enrolled 115 symptomatic patients with an intermediate anatomical coronary stenosis (30% to 70%) and a baseline Agatston coronary artery calcium (CAC) score greater than 400 who were scheduled for invasive coronary angiography and fractional flow reserve (FFR). FFR-CT was processed off-line using specialized fluid dynamics 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%). 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 an overall 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 luminal assessment alone (0.88 vs. 0.65, p < 0.001). Fractional flow reserve computed non-invasively from CTCA datasets maintains high diagnostic precision and high negative predictive value even in severely calcified coronary arteries, reducing unnecessary diagnostic invasive procedures.

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

Received: April 02, 2023; Revised: May 15, 2023; Accepted: June 08, 2023; Published: July 24, 2023

International Journal of Cardiology | Vol. 13, No. 6, June 2022 | pp. 41–48

DOI: 10.46882/2022/IJC/000159

Review Article

Diagnostic Advancements and Risk Stratification Matrices via Multi-Parametric CMR Mapping in Non-Ischemic Cardiomyopathies

Sarah L. Jenkins¹, David M. Ross²

¹Department of Cardiovascular Imaging, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada

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

Abstract:
Non-ischemic cardiomyopathies (NICMs) exhibit diverse etiopathology, requiring advanced tissue tracking to optimize clinical management. Traditional late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging pathways reliably identify focal replacement scars but remain insensitive to early microscopic diffuse interstitial expandings. This comprehensive review synthesizes recent registry data evaluating quantitative multi-parametric CMR mapping sequences—specifically native T1 mapping, T2 mapping, and calculated extracellular volume (ECV) fractions—across major adult NICM phenotypes. A structured review compiled findings from 38 clinical databases representing 4,120 individuals. Parametric T2 mapping sequences demonstrate excellent specificity for identifying active localized inflammation in acute myocarditis, providing a pooled diagnostic accuracy of 89.5% against tissue biopsies. Concurrently, native T1 and ECV metrics quantify diffuse interstitial matrix expansion in dilated and hypertrophic configurations before macroscopic scars develop. Aggregated data indicate that an elevated baseline ECV fraction greater than or equal to 32% provides an adjusted hazard ratio of 2.12 (95% CI: 1.41–3.46, p < 0.01) for predicting progressive heart failure hospitalization. Multi-parametric quantitative CMR mapping provides non-invasive mechanical tracking that maps diffuse tissue variations, enhancing diagnostic specificity and risk stratification across non-ischemic cardiomyopathies.

Keywords: Cardiac magnetic resonance, Parametric mapping, Extracellular volume fraction, Non-ischemic cardiomyopathy, Myofibrosis, Prognosis

Received: March 11, 2022; Revised: April 25, 2022; Accepted: May 12, 2022; Published: June 19, 2022

International Journal of Cardiology | Vol. 13, No. 12, December 2022 | pp. 81–88

DOI: 10.46882/2022/IJC/000164

Original Research Article

High-Dose Atorvastatin Loading Safeguards Against Periprocedural Myocardial Infarction During Bifurcation 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 frequent complication during complex percutaneous coronary intervention (PCI). Statin reloading has shown efficacy in limiting pMI in general cohorts, but its impact during complex interventions in patients already established on maintenance statin treatment requires validation. 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 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. 17.5%, p = 0.03). Post-procedural mean cTnI values were also significantly reduced with the reload (0.44 ± 0.12 ng/mL vs. 0.92 ± 0.22 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: September 15, 2022; Revised: October 28, 2022; Accepted: November 12, 2022; Published: December 19, 2022

International Journal of Cardiology | Vol. 13, No. 7, July 2022 | pp. 49–56

DOI: 10.46882/2022/IJC/000160

Original Research Article

Diagnostic Accuracy of High-Resolution 64-Slice CTCA for Coronary Stenosis Detection in Asymptomatic Hypertensive Cohorts

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:
Hypertension drastically accelerates coronary macrovascular atherosclerosis, but identifying significant structural disease before ischemic symptom onset remains clinically challenging. Computed tomography coronary angiography (CTCA) offers a non-invasive tracking alternative, but its precise accuracy within native West African hypertensive populations requires validation against gold-standard invasive coronary angiography (ICA). This prospective study evaluated the diagnostic performance of high-resolution 64-slice CTCA for detecting hemodynamically significant coronary stenoses. We evaluated 150 asymptomatic hypertensive individuals presenting with at least one additional cardiovascular risk factor who were scheduled for elective ICA. Significant obstructive CAD was defined as a luminal diameter reduction greater than or equal to 50%. On a patient-based analysis, CTCA successfully identified obstructive disease in 86 out of 92 patients confirmed via ICA. The patient-based diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 64-slice CTCA were 93.5% (95% CI: 86.3%–97.6%), 86.2% (95% CI: 74.3%–93.2%), 91.5% (95% CI: 84.0%–96.0%), and 89.3% (95% CI: 77.4%–95.6%), respectively. Segment-based specificity remained high at 95.8%. High-resolution 64-slice computed tomography coronary angiography achieves excellent diagnostic performance and an exceptional negative predictive value for ruling out significant obstructive coronary artery disease in asymptomatic hypertensive patients, serving as a reliable non-invasive triage tool.

Keywords: Computed tomography coronary angiography, Invasive coronary angiography, Hypertension, Obstructive coronary disease, Diagnostic accuracy, Negative predictive value

Received: April 05, 2022; Revised: May 18, 2022; Accepted: June 10, 2022; Published: July 24, 2022