Volume Articles

Stented Porcine and Pericardial Bioprostheses - A historical review

Andrea De Martino¹, Giosuè Falcetta¹, Aldo D. Milano², Uberto Bortolotti¹*

¹Cardiovascular Surgery Divisions, University of Pisa, Italy

²Department of Cardiac Surgery, University of Bari Aldo Moro, Bari, Italy

Stented bioprostheses have been extensively used clinically to replace diseased cardiac valves with the clear advantage over mechanical prostheses of avoiding the use of chronic anticoagulation in most cases. During the past five decades, however, based on clinical and pathological experience, tissue calcification and cusp tears were identified as the main determinants of failure of porcine and pericardial bioprostheses, respectively. Tissue treatments to mitigate dystrophic calcification together with structural modifications in valve design have produced a current generation of bioprosthetic valves which show excellent overall performance and considerably increased durability when compared with old models. Further ongoing research aims to provide even more durable bioprostheses in order to allow reduction of the age threshold for implantation also in younger subjects, helping to contrast effectively the rapidly expanding role of catheter-based interventions.

Long Term Health Outcomes Following Coronary Artery Bypass Grafting: A Different Journey for Men and Women

G.M. Lindsay*, P.R. Ponaiah, I. Nomani, S.M. Lamadah, N.A. Tayyib and A. Johargy

College of Nursing, Umm Al-Qura University, Taif Road, Makkah, Saudi Arabia

Background: The applicability of the Short Form (SF36) questionnaire to disparate populations led us to use this tool to investigate how health-related quality-of-life (HRQoL) for patients who underwent coronary artery bypass grafting (CABG) is related to gender, age and survival.

Method: SF36 data and the presence of cardiac symptoms were collected from 44 women and 166 men prior to surgery and from consenting survivors at one and eight-year follow-ups. Survival data were collected from government records for 18 years post operation. Paired t-tests, Pearson correlation coefficients, chi-squared tests and the log-rank test were used to investigate connections between HRQoL and age, presence of angina/breathlessness and survival within and across genders.

Results: HRQoL improved significantly for males and females in almost all health domains at the one year follow-up. At the eight year follow-up most female domain scores showed further improvement whereas the majority of male domain scores declined. Cardiac symptoms were present in 75.8% of women and 68.3% of men (χ2=0.7120, p=0.3988) at the one-year follow-up, and 84.2% of women and 70.2% of men at the eight-year follow-up. Male long term survival (53.6% after 18 years) depended significantly on retaining post-operative improvements in HRQoL to the medium term (p<0.002 in 4 of 8 domains). Female long term survival (40.9%) was significantly less than male survival (p=0.0108) and depended on maintaining a steady upward trend in HRQoL over the medium term. Age was not a determinant in HRQoL following CABG. Long term male and female survival was not significantly different and approached those of age and gender matched samples from the general population.

Conclusion: Strategies to improve HRQoL in women may support improved survival by reducing excess short term female mortality, but the effectiveness of the same strategy for men is less apparent.

Human Perivascular Adipose Tissue as a Regulator of the Vascular Microenvironment and Diseases of the Coronary Artery and Aorta

Caitlin Stieber, Kimberly Malka, Joshua M. Boucher, Lucy Liaw*

Center for Molecular Medicine, Maine Medical Center Research Institute, United States

Perivascular adipose tissue (PVAT) is an adipose depot that surrounds blood vessels in the human body and exerts local paracrine signaling. Under physiologically healthy conditions, PVAT has an anti-contractile effect on vessels, but in obesity this effect is lost. During metabolic disease, adiponectin secretion is dysregulated, influencing nitric oxide bioavailability and macrophage infiltration and inflammation, all of which mediate PVAT signaling. However, based on the location in the body, and the type of adipocyte present, PVAT has different relationships with risk factors for disease. Imaging studies in patients with cardiovascular disease have demonstrated important associations between PVAT structure and pathology, yet insight into molecular pathways regulating human PVAT function are still lacking. This review focuses on our current understanding of human PVAT and its secretory role in the vascular microenvironment. A current area of priority is defining molecular differences in the secretome between PVAT depots, as this could inform the treatment of diseases that occur in anatomically restricted locations. In addition, understanding progressive changes in PVAT structure and function during metabolic disease is required for effective targeted therapies.

Troponin Assay in the Real World: Is it Always a Diagnosis of Acute Myocardial Infarction?

Aidan (Jia Sheng) Yu¹*, James Nguyen¹, Anthony Brown²

¹Royal Brisbane and Women’s Hospital Butterfield Street and Bowen Bridge Road, Herston, Queensland, 4029, Australia

²Gold Coast University Hospital, 1 Hospital Blvd, Southport QLD 4215

Background: The soon to be implemented state-wide introduction of high-sensitivity troponin assays will allow the use of a lower threshold in identifying patients with acute myocardial infarction (AMI). Whether this assay will be too sensitive and therefore produce increased false positive results is still unclear. We aim to investigate whether a significantly elevated cardiac troponin using the current troponin assay (cTnI) will result in a clinical diagnosis of AMI.

Methods: A retrospective study was performed at a Queensland Hospital with all cTnI ordered across a single month reviewed. Patients who were diagnosed with Non ST-Elevation Myocardial Infarction or ST-Elevation Myocardial Infarction were labelled as having an AMI.

Results: In total, 944 investigations were ordered for 628 patients. Using the hospital laboratory cutoff of >0.040 μg/L(>99th percentile) for significance, a positive result was obtained in 105 patients (16.7%) and a negative result in 523 patients (83.3%). The positive troponin results were attributed to AMI (20%), congestive heart failure (20%), sepsis (19%), tachyarrhythmias (16.2%), renal failure (8.6%), airway disease (8.6%), pulmonary embolism (3.8%) and others - pericarditis, post angioplasty etc (3.8%). cTnI was found to be highly sensitive (100%, 95%CI 84-100%) and specific (86%, 95%CI 83-89%) for AMI. However, only 21 (3.3%) of 628 patients investigated received a diagnosis of AMI. The positive predictive value was poor (20%, 95% CI 13-29%), with the negative predictive value absolute (100%, 95% CI 99-100%).

Conclusion: Current troponin assays were found to be highly sensitive and specific in diagnosing AMI. However, its poor positive predictive value may be contributed by inappropriate requests.

Long Non-Coding RNAs: Crucial Players of Cardiomyocyte Apoptosis

Xiatian Chen^1,2, Ziqian Liu^1,2, Zhe Li^1,2, Jinning Gao^1,2, Zhongjie Yu^1,2, Peifeng Li¹*, Lynn Htet Htet Aung¹*

¹Center for Molecular Genetics, Institute for Translational Medicine, Qingdao University, Qingdao, 266000, Shandong, China

²School of Basic Medicine, Qingdao University, Qingdao, 266000, Shandong, China

Long non-coding RNAs (lncRNAs) have gained more attention in recent years as a potential new regulator of nearly all biological regulation. LncRNAs are over 200 nucleotides in length, and it can interact with other non-coding RNAs or specific proteins to influence the gene expression. Cardiomyocyte apoptosis is associated with cardiovascular diseases. Accumulating studies have uncovered novel lncRNAs-mediated regulation of cardiovascular diseases; however, the knowledge of the mechanisms by how to act is still limited. This review highlights the role of lncRNAs involved in cardiomyocyte apoptosis with a focus on the regulatory axis. These examples may provide helpful insights on how lncRNAs interfere with cardiomyocyte apoptosis.

Pleuropericardial Cyst: A Review of the Literature

Christina Koumantzia, Nikolaos Saridakis, Andreas Eleftheriou*

Department of Neurology, and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden

Background: Pleuropericardial cysts (PPCs), account for 5 - 10% of all mediastinal tumours, are rare lesions occurring in approximately 1 in 100000 persons and are usually congenital and rarely acquired. They are detected post-mortem or incidentally on routine chest X-ray (CXR) and in most cases multi detector Computer Tomography is used to confirm the diagnosis. As benign course and clinical latency are characteristic features of such cysts and the occurrence of complications is rare, the majority of them can be left untreated.

Methods: The aim of the study is to review the literature regarding PPCs and create a table which summarises all the published cases in order to draw a conclusion about the epidemiology, as well as the diagnostic and therapeutic approach to PPCs exclusively. We reviewed retrospectively the clinical manifestation, diagnostic and therapeutic approach in 101 cases of PPCs since the 19^th century.

Results: Our statistical analysis led to the following results: mean age of initial detection: 48.7 ± 17.2 years, female:male ratio: about 3:2, presence of symptomatology: 37/101 cases, most common location: right cardiophrenic angle (RCPA), most common method of initial detection: CXR in 49/101 cases, mean maximal diameter: 8,3 ± 3 cm.

Conclusion: The management of a pleuropericardial cyst should be based on an algorithm in which the cyst's size, shape and compressibility along with clinical presentation and patient's fitness and preferences are be taken into consideration. When interventional is required, surgical resection by means of traditional open surgery or minimally invasive methods are considered to be the gold standard and along with percutaneous aspiration are the methods that have mostly been used.

Healthcare Resource Utilization among Non-Valvular Atrial Fibrillation Patients Who Switched from Warfarin to a Novel Oral Anti-Coagulant

Jessica Franchino-Elder¹, Adrienne Gilligan², Xue Song²*, Briain O Hartaigh¹, Caroline Henriques², Amy Sainski-Nguyen², Cheng Wang¹

¹Boehringer-Ingelheim Pharmaceuticals, Inc., Ridgefield, CT, USA

²IBM Watson Health, Cambridge, MA, USA

Among patients with non-valvular atrial fibrillation (NVAF), switching from warfarin to novel oral anticoagulants (NOACs) is common, yet clarifying the differences in the effect of NOACs on all-cause healthcare resource utilization (HCRU) are unknown. Adult NVAF patients who switched from warfarin to dabigatran, apixaban, or rivaroxaban were identified in MarketScan databases between 10/2010-12/2015. Patients had 12 months pre-period (index date was 1st NOAC claim) and were followed up to 12 months until medication discontinuation, end of enrollment, inpatient death, or 12/2016. Overall, 8,679 and 5,761 dabigatran switchers were matched (1:1) to rivaroxaban and apixaban switchers (mean age 73-74 years). Compared with rivaroxaban switchers, a lower proportion of dabigatran switchers had an inpatient (IP) visit (20.0% vs. 21.6%, p=0.008). Dabigatran switchers had lower per-patient-per-month (PPPM) total outpatient (3.87 vs. 4.06, p=0.002), emergency department (ED; 0.48 vs. 0.52, p=0.026), outpatient office (1.17 vs. 1.22, p<0.001), and other outpatient (2.71 vs. 2.83, p=0.043) visits compared with rivaroxaban switchers. A similar proportion of dabigatran and apixaban switchers had an IP visit (20.7% vs. 21.2%); compared with apixaban switchers, dabigatran switchers had significantly more PPPM IP visits (0.23 vs. 0.21, p=0.031) but significantly lower ED visits (0.47 vs. 0.52, p=0.016). Post-discharge 30-day readmission rates were comparable among warfarin-to-NOAC switching groups. Time to readmission was longer for dabigatran versus rivaroxaban switchers (8.2 vs. 7.8 days, p<0.001), but comparable with apixaban patients (8.1 vs. 8.4 days). Switching to dabigatran after warfarin discontinuation may lower HCRU among NVAF patients compared with switching to rivaroxaban or apixaban.

Changes in Cardiac Isomyosin Composition in an Iron Loading Anemia Rat Model

Wei Ting Cheng, Na Yoon Kim, Prashant Bhattarai, Murui Han, Archita Venugopal Menon, Jonghan Kim, Ban An Khaw*

Department of Pharmaceutical Sciences, School of Pharmacy, Bouve College of Health Sciences, Northeastern University, Boston, MA. USA

A rat model of iron loading anemia resulting in hypertrophic cardiomyopathy was used to assess the composition of cardiac isomyosin by ELISAs and immunohistochemistry relative to the chronological age of these animals and their normal controls. Cardiac myosin extracts of homozygous Belgrade (b/b) rats that develop hypertrophic cardiomyopathy were compared to those from the heterozygous (b/+) control rats at 4.5 and 11.5 weeks of age. Confirmation of the ELISA data in the increase in β-isomyosin in 11.5 weeks old b/b rat hearts were obtained by immunohistochemical staining relative to 4.5 weeks old b/b hearts and control 4.5 and 11.5 weeks old b/+ hearts. Quantitation and immunohistochemical demonstration of an increase in the β-isomyosin isoform can be confirmed in hypertrophic cardiomyopathy in iron loading anemia model.