International Journal of Cardiology

International Journal of Cardiology | Vol. 12, No. 11, November 2021 | pp. 81–88

DOI: 10.46882/2021/IJC/000152

Original Research Article

Long-Term Impact of Subclinical Leaflet Thrombosis on Valve Hemodynamics After Transcatheter Aortic Valve Implantation

Jean-Pierre Dubois¹, Pierre Vigneron¹, Lucia Rossi²

¹Department of Interventional Cardiology, Hôpital Européen Georges-Pompidou, Paris, France

²Department of Cardiac Surgery, University of Milan, Milan, Italy

Abstract:
Subclinical leaflet thrombosis, characterized by hypo-attenuated leaflet thickening (HALT) on multi-detector computed tomography (MDCT), is frequently detected following transcatheter aortic valve implantation (TAVI). However, its long-term impact on transvalvular pressure gradients and clinical major adverse cardiac events (MACE) remains controversial. This prospective registry study evaluated the chronological progression of HALT and its association with late valve dysfunction. We evaluated 165 consecutive patients who underwent successful TAVI with newest-generation balloon-expandable or self-expanding bioprostheses. Four-dimensional MDCT scans were performed at 30 days post-procedure to identify HALT. Serial transthoracic echocardiography at discharge, 6 months, 12 months, and 36 months monitored mean transvalvular pressure gradients. HALT was identified in 24 patients (14.5%) at the 30-day screen. At 36 months, patients with early subclinical leaflet thrombosis demonstrated a significantly higher mean transvalvular gradient compared to those without HALT (16.4 ± 4.2 mmHg vs. 11.2 ± 3.1 mmHg, p < 0.01). Ischemia-driven target valve reintervention or stroke occurred in 16.7% of the HALT cohort versus 5.0% in the non-HALT group (p = 0.04). Multivariable logistic regression confirmed that early HALT was independently associated with a 3-year mean gradient rise greater than or equal to 5 mmHg (odds ratio: 3.42, 95% CI: 1.54–7.62, p = 0.003). Subclinical leaflet thrombosis identified early after TAVI is not benign, as it correlates with a significant rise in late transvalvular pressure gradients and an increased risk of mid-term thromboembolic events.

Keywords: Transcatheter aortic valve implantation, Hypo-attenuated leaflet thickening, Subclinical leaflet thrombosis, Computed tomography, Valve hemodynamics, Stroke

Received: August 01, 2021; Revised: September 15, 2021; Accepted: October 10, 2021; Published: November 20, 2021

International Journal of Cardiology | Vol. 12, No. 5, May 2021 | pp. 33–40

DOI: 10.46882/2021/IJC/000146

Original Research Article

Speckle-Tracking Echocardiography Derived Left Atrial Reservoir Strain for Predicting Arrhythmic Recurrence Post-PVI

Sven Lindstrom¹, Ingrid Johansson¹, Anders Nielsen²

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

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

Abstract:
Catheter ablation using pulmonary vein isolation is an effective rhythm control strategy for paroxysmal atrial fibrillation (AF), but anatomical left atrial (LA) diameter alone poorly predicts recurrence. Left atrial reservoir strain (LA-RS) evaluated by speckle-tracking echocardiography offers a direct indicator of structural remodeling and compliance. This study investigated the independent association between baseline LA-RS and long-term arrhythmia recurrence post-catheter ablation. We prospectively enrolled 150 patients with symptomatic paroxysmal AF scheduled for radiofrequency catheter ablation. LA-RS was analyzed off-line using apical four- and two-chamber views before the intervention. The primary endpoint was any documented recurrence of atrial tachyarrhythmia lasting longer than 30 seconds after a 90-day blanking period over a 24-month follow-up. Arrhythmia recurrence occurred in 48 patients (32.0%). Baseline mean LA-RS was significantly lower in patients with recurrent events compared to those who maintained sinus rhythm (18.4% ± 3.2% vs. 28.5% ± 4.1%, 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 AF recurrence (hazard ratio: 2.45, 95% CI: 1.34–4.48, p = 0.003), whereas conventional LA volume indexing lost statistical significance. No major procedural access complications occurred. Left atrial reservoir strain is strongly and independently associated with atrial fibrillation recurrence following catheter ablation, outperforming traditional volumetric metrics for predicting long-term rhythm stability.

Keywords: Atrial fibrillation, Catheter ablation, Speckle-tracking echocardiography, Left atrial strain, Recurrence, Remodeling

Received: February 14, 2021; Revised: March 28, 2021; Accepted: April 15, 2021; Published: May 20, 2021

International Journal of Cardiology | Vol. 11, No. 5, May 2020 | pp. 33–40

DOI: 10.46882/2020/IJC/000134

Original Research Article

Diagnostic Utility of High-Resolution Intravascular OCT for Vulnerable Plaque Characterization in NSTE-ACS Patients

Giovanni Rossi¹, Matteo Bianchi¹, Elena Rossi²

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

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

Abstract:
Identifying vulnerable coronary atherosclerotic plaques prone to rupture is essential for optimizing acute coronary syndrome (ACS) interventions. Optical coherence tomography (OCT) offers high-resolution intravascular visualization, but its systematic diagnostic accuracy for characterizing thin-cap fibroatheromas (TCFA) requires verification against intravascular ultrasound (IVUS). This prospective clinical study evaluated the diagnostic performance of high-resolution intravascular OCT for identifying vulnerable TCFA structures in patients presenting with non-ST-segment elevation ACS (NSTE-ACS). We evaluated 120 patients with NSTE-ACS who underwent ad hoc coronary angiography accompanied by both OCT and radiofrequency IVUS imaging of the culprit vessel. TCFA was defined by OCT as a lipid-rich plaque with a fibrous cap thickness less than 65 μm. Intravascular imaging safely evaluated a total of 142 distinct plaques. OCT successfully identified 42 TCFAs, demonstrating a diagnostic sensitivity of 91.3% (95% CI: 79.2%–97.6%) and a specificity of 89.6% (95% CI: 81.7%–94.9%) using IVUS as the comparative reference. The mean fibrous cap thickness quantified by OCT was 54.2 ± 11.4 μm in the ruptured plaque cohort. Multivariable logistic regression revealed that an OCT-derived fibrous cap thickness less than 65 μm was an independent predictor of microvascular obstruction post-stenting (odds ratio: 3.24, 95% CI: 1.45–7.24, p = 0.004). Intravascular optical coherence tomography achieves excellent diagnostic accuracy for characterizing thin-cap fibroatheromas, providing high-resolution morphological tracking to optimize risk stratification in acute coronary syndrome.

Keywords: Optical coherence tomography, Intravascular ultrasound, Thin-cap fibroatheroma, Acute coronary syndrome, Vulnerable plaque, Diagnostic accuracy

Received: February 14, 2020; Revised: March 25, 2020; Accepted: April 10, 2020; Published: May 22, 2020

International Journal of Cardiology | Vol. 11, No. 4, April 2020 | pp. 25–32

DOI: 10.46882/2020/IJC/000133

Original Research Article

Cardioprotective Effects of Empagliflozin in a Rat Model of Diabetic Cardiomyopathy: Interplay with Mitochondrial Dynamin-Related Protein 1 Pathways

Kenji Tanaka¹, Satoshi Yamada¹, Takashi Sato²

¹Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan

²Division of Metabolic Diseases, Tokyo Medical and Dental University, Tokyo, Japan

Abstract:
Diabetic cardiomyopathy leads to progressive diastolic failure and myocardial structural derangement. Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce heart failure event rates, but their direct impact on cardiomyocyte mitochondrial dynamics remains characterized. This study investigated the protective effects of empagliflozin on myocardial remodeling and mitochondrial structural integrity in a rat model of type 2 diabetes. Type 2 diabetes was induced in adult male Wistar rats via a high-fat diet combined with a low-dose streptozotocin injection. Diabetic rats were randomized to receive either empagliflozin (10 mg/kg/day, n = 15) or vehicle control (n = 15) via oral gavage for 8 weeks. Cardiac function was monitored using tissue Doppler echocardiography, and structural mitochondrial alignment was assessed via transmission electron microscopy. Empagliflozin significantly improved the diastolic mitral inflow E/A ratio compared to the vehicle group (1.45 ± 0.12 vs. 1.05 ± 0.08, p < 0.01). Electron microscopy revealed that empagliflozin treatment prevented mitochondrial fragmentation, preserving mitochondrial aspect ratios (2.42 ± 0.15 vs. 1.54 ± 0.11, p < 0.01). Western blot analysis demonstrated that empagliflozin up-regulated the expression of mitofusin-2 (Mfn2) and down-regulated dynamin-related protein 1 (Drp1), suppressing pro-apoptotic pathways. Empagliflozin significantly improves diastolic performance and mitigates diabetic cardiomyopathy in rats by preserving mitochondrial fusion structural pathways and optimizing metabolic morphology.

Keywords: Diabetic cardiomyopathy, Empagliflozin, SGLT2 inhibitors, Mitochondrial dynamics, Mitofusin-2, Diastolic function

Received: January 08, 2020; Revised: February 22, 2020; Accepted: March 12, 2020; Published: April 18, 2020

International Journal of Cardiology | Vol. 11, No. 1, January 2020 | pp. 1–8

DOI: 10.46882/2020/IJC/000130

Original Research Article

High-Dose Atorvastatin Reloading Safeguards Against Periprocedural Myocardial Infarction During 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) frequently complicates complex percutaneous coronary intervention (PCI), worsening long-term outcomes. Acute statin loading reduces myonecrosis in statin-naive patients, but its cardioprotective efficacy during complex interventions in patients already receiving long-term maintenance statins requires validation. This prospective, randomized, open-label clinical trial investigated whether high-dose atorvastatin reloading before complex PCI reduces pMI in patients on chronic statin therapy. We enrolled 240 chronic statin users scheduled for complex PCI (defined as multi-vessel intervention, bifurcation lesions, or chronic total occlusions). Patients were randomized 1:1 to receive an acute reload of atorvastatin (80 mg administered 12 hours and 2 hours pre-PCI, n = 120) or to continue standard maintenance dosing alone (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 maintenance control group (8.3% vs. 17.5%, p = 0.03). Post-procedural mean cTnI values were also significantly lower in the reloaded cohort (0.44 ± 0.12 ng/mL vs. 0.92 ± 0.22 ng/mL, p < 0.01). No cases of acute hepatic impairment or rhabdomyolysis were reported. High-dose atorvastatin reloading safely and significantly protects against periprocedural myocardial injury during complex percutaneous coronary intervention in patients established on chronic maintenance statin therapy.

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

Received: October 12, 2019; Revised: November 24, 2019; Accepted: December 15, 2019; Published: January 18, 2020

International Journal of Cardiology | Vol. 11, No. 11, November 2020 | pp. 81–88

DOI: 10.46882/2020/IJC/000140

Original Research Article

Diagnostic Utility of Computational Fluid Dynamics Derived FFR-CT for Ischemia Detection in Single Intermediate Coronary Lesions

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) provides high structural accuracy for ruling out coronary artery disease (CAD) but lacks functional capacity to determine if intermediate anatomical stenoses induce myocardial ischemia. Fractional flow reserve computed non-invasively from CTCA datasets (FFR-CT) applies computational fluid dynamics to fill this gap. This prospective study evaluated the diagnostic accuracy of FFR-CT for identifying lesion-specific ischemia, using invasive FFR as the gold standard. We enrolled 110 symptomatic patients with a single intermediate coronary stenosis (30% to 70% lumen reduction on CTCA) who were scheduled for invasive coronary angiography and FFR testing. FFR-CT was processed off-line using specialized fluid software, with ischemia defined as an FFR-CT less than or equal to 0.80. On a vessel-based analysis (134 vessels total), invasive FFR confirmed ischemia in 42 vessels (31.3%). Non-invasive FFR-CT demonstrated a diagnostic sensitivity of 88.1% (95% CI: 74.4%–96.0%), a specificity of 85.9% (95% CI: 77.0%–92.3%), a positive predictive value of 74.0%, and an exceptional negative predictive value of 93.9% (95% CI: 86.3%–97.9%). The area under the receiver operating characteristic curve for FFR-CT was significantly superior to standard anatomical CTCA narrowing criteria alone (0.90 vs. 0.72, p < 0.001). Fractional flow reserve derived from computed tomography coronary angiography achieves excellent diagnostic accuracy and a high negative predictive value for identifying ischemia-producing intermediate lesions, presenting a reliable tool to minimize unnecessary diagnostic invasive examinations.

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

Received: August 04, 2020; Revised: September 15, 2020; Accepted: October 10, 2020; Published: November 18, 2020