International Journal of Cardiology

International Journal of Cardiology | Vol. 7, No. 3, March 2016 | pp. 17–24

DOI: 10.46882/2016/IJC/000084

Review Article

Evolving Role of Advanced Cardiovascular Magnetic Resonance Mapping Techniques in Hypertrophic Cardiomyopathy

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:
Hypertrophic cardiomyopathy (HCM) requires precise structural phenotype characterization and robust risk stratification to minimize sudden cardiac death (SCD) risks. While late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging is established for identifying replacement myocardial fibrosis, it is less sensitive for early diffuse interstitial expansion. This review synthesizes recent clinical data on advanced CMR parametric mapping sequences—specifically native T1 mapping and calculated extracellular volume (ECV) fractions—across adult HCM populations. A comprehensive literature synthesis compiled data from 28 registries involving 3,140 patients. Native T1 mapping and ECV values correlate strongly with histological collagen volume fractions, providing a non-invasive index of early interstitial expansion that occurs before macrovascular scarring develops. Quantified registry data indicate that an ECV fraction greater than or equal to 32% provides an adjusted hazard ratio of 2.24 (95% CI: 1.45–3.48, p < 0.01) for predicting progressive heart failure acceleration. Furthermore, combining standard focal LGE tracking (where an extent greater than or equal to 15% of total left ventricular mass increases SCD risk) with parametric mapping improves multi-parametric risk matrices. Advanced CMR parametric mapping sequences enhance diagnostic sensitivity for early-stage hypertrophic remodeling and provide useful structural indices that improve clinical risk stratification beyond traditional macrovascular scar tracking.

Keywords: Hypertrophic cardiomyopathy, Cardiac magnetic resonance, Late gadolinium enhancement, T1 mapping, Extracellular volume fraction, Risk stratification

Received: December 15, 2015; Revised: January 28, 2016; Accepted: February 14, 2016; Published: March 22, 2016.

International Journal of Cardiology | Vol. 7, No. 12, December 2016 | pp. 89–96

DOI: 10.46882/2016/IJC/000093

Original Research Article

Clinical Utility of Acute High-Dose Atorvastatin Reloading Prior to Percutaneous Coronary Intervention

Yusuf Demir¹, Murat Kaya¹, Ahmet Yilmaz²

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

²Division of Cardiovascular Medicine, Hacettepe University Faculty of Medicine, Ankara, Turkey

Abstract:
Preprocedural statin loading reduces perioperative myocardial injury in statin-naive individuals undergoing percutaneous coronary intervention (PCI). However, the therapeutic value of acute high-dose statin reloading in patients already established on long-term maintenance statin therapy remains less defined. This prospective, randomized, open-label trial evaluated whether an acute high-dose atorvastatin reload prior to scheduled PCI minimizes periprocedural myocardial infarction (pMI) in patients on chronic statin treatment. We enrolled 260 patients with stable coronary disease or non-ST-segment elevation acute coronary syndrome (NSTE-ACS) who had been taking standard maintenance statins continuously for greater than 30 days. Patients were randomized 1:1 to receive either an acute reload of atorvastatin (80 mg administered 12 hours and 2 hours before PCI, n = 130) or to continue their standard maintenance regimen alone (n = 130). The primary endpoint was the incidence of pMI, defined as a post-procedural elevation of serum cardiac troponin I (cTnI) greater than 5 times the upper limit of normal within 24 hours of intervention. The incidence of pMI was significantly lower in the atorvastatin reloading group than in the maintenance control group (7.7% vs. 16.2%, p = 0.03). Mean post-procedural cTnI levels were also significantly reduced in reloaded patients (0.42 ± 0.15 ng/mL vs. 0.88 ± 0.24 ng/mL, p < 0.01). Acute hepatic dysfunction and rhabdomyolysis were completely absent in both cohorts. High-dose atorvastatin reloading safely and significantly reduces periprocedural myocardial injury in patients undergoing PCI, even when they are already established on chronic maintenance statin therapy.

Keywords: Percutaneous coronary intervention, Atorvastatin, Statin loading, Periprocedural myocardial infarction, Stable angina, Acute coronary syndrome

Received: September 05, 2016; Revised: October 20, 2016; Accepted: November 12, 2016; Published: December 18, 2016

International Journal of Cardiology | Vol. 7, No. 2, February 2016 | pp. 9–16

DOI: 10.46882/2016/IJC/000083

Original Research Article

Prognostic Impact of Baseline Secondary Mitral Regurgitation Severity in High-Risk Patients Undergoing Transcatheter Aortic Valve Implantation

Matteo Barbieri¹, Francesca Costa¹, Luigi Marini²

¹Department of Cardiology, San Raffaele Hospital, Milan, Italy

²Division of Cardiac Surgery, University Hospital of Bologna, Bologna, Italy

Abstract:
Concomitant secondary mitral regurgitation (SMR) is common in elderly patients with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI). Whether baseline moderate-to-severe SMR independently impairs long-term survival or predictably resolves post-TAVI remains an area of active investigation. This study investigated the 2-year clinical outcomes and post-procedural course of SMR in high-risk patients. We prospectively followed 180 consecutive high-risk patients with severe aortic stenosis who underwent successful TAVI. Patients were divided into two baseline cohorts: non-significant SMR (none, trace, or mild, n = 124) and significant SMR (moderate-to-severe, n = 56). The primary endpoint was a composite of all-cause mortality or heart failure hospitalization at 24 months. Significant SMR was associated with a higher baseline logistic EuroSCORE (24.2% ± 5.1%). At 2 years, the primary composite endpoint occurred significantly more frequently in patients with baseline significant SMR than in those with non-significant SMR (42.9% vs. 21.8%, log-rank p = 0.004). This difference was driven by higher rates of heart failure rehospitalization (32.1% vs. 13.7%, p = 0.01). Echocardiographic follow-up at 6 months revealed that SMR improved by at least one grade in 53.6% of patients, primarily in those with preserved baseline left ventricular function. Multivariable Cox regression identified persistent baseline significant SMR as an independent predictor of 2-year clinical worsening (hazard ratio: 2.12, 95% CI: 1.25–3.58, p = 0.005). Significant baseline secondary mitral regurgitation increases the risk of long-term adverse events post-TAVI, although mechanical offloading induces spontaneous valvular improvement in over half of the surviving cohort.

Keywords: Aortic stenosis, Transcatheter aortic valve implantation, Secondary mitral regurgitation, Heart failure, Mortality, Valvular remodeling

Received: November 10, 2015; Revised: December 19, 2015; Accepted: January 11, 2016; Published: February 20, 2016

International Journal of Cardiology | Vol. 7, No. 4, April 2016 | pp. 25–32

DOI: 10.46882/2016/IJC/000085

Original Research Article

Prevalence and Prognostic Significance of Subclinical Right Ventricular Dysfunction in Patients with Hypertrophic Cardiomyopathy

Hiroshi Yamamoto¹, Takashi Sato¹, Kenji Nakamura²

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

²Division of Cardiology, Tokyo Medical and Dental University, Tokyo, Japan

Abstract:
Hypertrophic cardiomyopathy (HCM) is predominantly characterized by left ventricular hypertrophy and diastolic impairment, but the right ventricle (RV) can also be involved. Because conventional RV parameters like fractional area change (FAC) are often insensitive to early mechanical alterations, subclinical RV impairment may go undetected. This study evaluated the prevalence of subclinical RV dysfunction using speckle-tracking derived longitudinal strain and investigated its association with clinical worsening. We prospectively evaluated 150 stable patients with confirmed left ventricular HCM and preserved conventional right ventricular function (FAC greater than or equal to 40%). Off-line speckle-tracking deformation imaging determined right ventricular free-wall longitudinal strain (RV-FWS). Clinical worsening was defined as a 36-month composite endpoint of heart failure hospitalization, sustained ventricular arrhythmia, or all-cause mortality. Subclinical RV dysfunction, defined as an absolute baseline RV-FWS less than 18.0%, was identified in 36 patients (24.0%) despite a normal mean FAC (44.6% ± 3.2%). Over a median follow-up of 34 months, the composite endpoint occurred in 28 patients (18.7%). Kaplan-Meier analysis revealed significantly lower event-free survival rates in patients with impaired absolute RV-FWS (log-rank p = 0.002). Multivariable Cox proportional hazards regression confirmed that an absolute RV-FWS less than 18.0% was an independent predictor of long-term clinical worsening (hazard ratio: 2.15, 95% CI: 1.28–3.62, p = 0.004). Subclinical right ventricular dysfunction is present in nearly a quarter of hypertrophic cardiomyopathy patients with normal conventional RV metrics and serves as a powerful, independent predictor of long-term clinical progression.

Keywords: Hypertrophic cardiomyopathy, Right ventricular dysfunction, Speckle-tracking echocardiography, Longitudinal strain, Prevalence, Prognosis

Received: January 12, 2016; Revised: February 24, 2016; Accepted: March 15, 2016; Published: April 25, 2016

International Journal of Cardiology | Vol. 7, No. 7, July 2016 | pp. 49–56

DOI: 10.46882/2016/IJC/000088

Original Research Article

Diagnostic Utility of High-Sensitivity Cardiac Troponin T 0-Hour/2-Hour Accelerated Protocol for Early Rule-Out of Acute Myocardial Infarction

Chloe Bennett¹, Thomas Wright¹, Oliver Harrison²

¹Emergency Department, St Vincent's Hospital, Sydney, New South Wales, Australia

²School of Medicine, University of Queensland, Brisbane, Queensland, Australia

Abstract:
Rapid, reliable exclusion of acute myocardial infarction (AMI) in patients presenting to the emergency department (ED) with chest pain is vital for optimizing hospital throughput and emergency resource utilization. High-sensitivity cardiac troponin T (hs-cTnT) assays allow for lower limits of detection but require clinically safe diagnostic protocols to prevent a loss of specificity. This prospective study evaluated the diagnostic performance of an accelerated 0-hour/2-hour diagnostic protocol incorporating hs-cTnT for rapid AMI exclusion. We enrolled 412 consecutive patients presenting to the ED with acute chest pain suggestive of an acute coronary syndrome. Blood samples for hs-cTnT quantification were drawn at presentation (0h) and exactly 2 hours later. The final diagnosis of AMI was adjudicated by an independent consensus committee using the universal definition. AMI was diagnosed in 58 patients (14.1%). A baseline presentation hs-cTnT level below 5 ng/L combined with an absolute change less than 3 ng/L within 2 hours successfully ruled out AMI in 57.8% of the cohort. This accelerated 0h/2h protocol yielded a diagnostic sensitivity of 98.3% (95% CI: 90.8%–99.9%) and an exceptional negative predictive value (NPV) of 99.6% (95% CI: 97.7%–99.9%). The diagnostic specificity and positive predictive value (PPV) were 66.7% and 32.6%, respectively. No patient classified as safe for early rule-out experienced an un-adjudicated cardiac event within a 30-day safety follow-up. An accelerated 0h/2h diagnostic protocol incorporating hs-cTnT assays allows for rapid, exceptionally safe exclusion of acute myocardial infarction in over half of presenting ED chest pain patients.

Keywords: High-sensitivity cardiac troponin T, Acute myocardial infarction, Emergency department, Chest pain, Accelerated diagnostic protocol, Negative predictive value

Received: April 05, 2016; Revised: May 18, 2016; Accepted: June 10, 2016; Published: July 22, 2016

International Journal of Cardiology | Vol. 7, No. 10, October 2016 | pp. 73–80

DOI: 10.46882/2016/IJC/000091

Original Research Article

Prognostic Significance of Plasma Galectin-3 Levels in Patients Admitted for Acute Decompensated Heart Failure

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:
Acute decompensated heart failure (ADHF) requires precise risk stratification to guide post-discharge transitions and prevent early rehospitalization. Galectin-3 is a soluble beta-galactoside-binding lectin secreted by activated macrophages that directly drives myocardial fibrosis and adverse chamber remodeling. This study evaluated the long-term prognostic value of plasma Galectin-3 levels measured at admission in a prospective cohort of patients hospitalized for ADHF. We enrolled 280 consecutive patients admitted with a primary diagnosis of ADHF. Plasma Galectin-3 concentrations were quantified using an enzyme-linked immunosorbent assay within 24 hours of hospital admission. The primary endpoint was a composite of 12-month all-cause mortality or heart failure readmission. High plasma Galectin-3 (defined as greater than 17.8 ng/mL) was identified in 48.2% of the study population. At 12 months, the primary composite endpoint occurred in 84 patients (30.0%). Survival analysis demonstrated a significantly lower event-free survival rate in the high Galectin-3 cohort compared to the low Galectin-3 group (41.5% vs. 19.3%, log-rank p < 0.001). After adjusting for age, left ventricular ejection fraction, estimated glomerular filtration rate, and N-terminal pro-B-type natriuretic peptide (NT-proBNP), multivariable Cox proportional hazards regression confirmed that elevated baseline Galectin-3 remained a powerful independent predictor of the composite outcome (hazard ratio: 1.84, 95% CI: 1.24–2.72, p = 0.002). Plasma Galectin-3 levels at admission provide robust, independent prognostic data in patients hospitalized for acute decompensated heart failure, identifying individuals at high risk for early post-discharge clinical worsening.

Keywords: Acute decompensated heart failure, Galectin-3, Biomarkers, Prognosis, Mortality, Heart failure readmission

Received: July 02, 2016; Revised: August 14, 2016; Accepted: September 05, 2016; Published: October 18, 2016