The pig as an optimal animal model for cardiovascular research

Cardiovascular disease is a worldwide health problem and a leading cause of morbidity and mortality. Preclinical cardiovascular research using animals is needed to explore potential targets and therapeutic options. Compared with rodents, pigs have many advantages, with their anatomy, physiology, metabolism and immune system being more similar to humans. Here we present an overview of the available pig models for cardiovascular diseases, discuss their advantages over other models and propose the concept of standardized models to improve translation to the clinical setting and control research costs.

Ten-Year Mortality in Patients With ST-Elevation Myocardial Infarction

Knowledge of the long-term prognosis (>10 years) and mortality predictors of ST-elevation myocardial infarction (STEMI) patients who have undergone primary percutaneous coronary intervention (p-PCI) is scarce. Therefore, this study evaluated the long-term prognosis and determined the predictors of long-term outcomes for STEMI patients after p-PCI. Between January, 2006 and December, 2010, we collected data and analyzed 459 consecutive patients with acute STEMI who underwent p-PCI and were discharged from the hospital (mean age, 66.8 years; male, 75.2%; peak creatine phosphokinase level, 2,292.5 IU/L). The primary endpoint was 10-year all-cause mortality. The cumulative 10-year incidence of all-cause death was 23.8%. The Cox multivariate regression analysis identified age ≥ 65 years (adjusted hazard ratio [aHR], p <0.001), body mass index (aHR, 0.93, p = 0.033), presence of atrial fibrillation (aHR, 1.69, p = 0.038), mineralocorticoid receptor antagonist use (aHR, 1.95, p = 0.008), ejection fraction <40% (aHR, 2.14, p = 0.005), and albumin <3.5 g/dL (aHR, 2.01, p = 0.005) as independent predictors of all-cause mortality. In conclusion, a post-discharge 10-year survival rate of 76.2% was identified for STEMI patients who underwent p-PCI.

Arrhythmia in Acute Myocardial Infarction: A Six-Month Retrospective Analysis From the National Institute of Cardiovascular Diseases

Introduction Acute myocardial infarction (AMI) is a devastating medical emergency that requires immediate pharmacological and radiological intervention. With the advent of techniques such as percutaneous coronary intervention (PCI), pacemakers, and percussion pacing, survival rates have improved significantly. However, there are certain factors and complications associated with AMI that still lead to a high mortality rate, such as old age, advanced heart disease, diabetes mellitus (DM), and arrhythmias. Factors such as the type of arrhythmia, the heart rate, and the level at which dissociation occurs between atrial and ventricular rhythm all influence mortality and morbidity rates. Outcomes are further influenced by the sex of the patient, the type of AMI [ST-elevation myocardial infarction (STEMI) or non-ST-elevation myocardial infarction (NSTEMI)], history of smoking, arrival times at the hospital, presence of hyperglycemia, previous history of cardiac surgery, and the need for a temporary pacemaker or a permanent pacemaker. As with most scientific studies, local data from Pakistan is hard to find on this topic as well. With this study, we hope to contribute valuable information and updates to the study of a developing problem from the developing world. Objective We aimed to analyze the frequency and outcomes of different types of arrhythmia in AMI. Methods This study involved a retrospective observational cohort. It was conducted at the National Institute of Cardiovascular Diseases (NICVD), Karachi from January 2019 to July 2019 (six months). All data were retrieved from the online database at the NICVD. Written consent was obtained from all patients. Patient confidentiality was ensured at all times. Results A total of 500 patients were included in the study. The mean age of our cohort was 56.17 ±14.01 years. NSTEMI was more prevalent than STEMI. Sinus arrhythmia (SA) was the most frequently recorded arrhythmia and had the best survival rates. Atrioventricular (AV) nodal blocks and ventricular tachycardia (VT) had the worst outcomes. The overall mortality rate was 11.4%, and the mean in-hospital length of stay was 2.07 ±1.54 days. Smoking increased mortality in all cases. Conclusions AMI is complicated by several types of arrhythmia. SA is the most common arrhythmia in AMI. Mortality in AMI is largely due to AV nodal blocks and VT. Smoking increases mortality in all cases.

Revisiting myocardial necrosis biomarkers: assessment of the effect of conditioning therapies on infarct size by kinetic modelling

Infarct size is a major predictor of subsequent cardiovascular events following ST-segment elevation myocardial infarction (STEMI) and is frequently used in clinical trials focused on cardioprotection. Approximately assessed through serial blood sampling, it can be accurately measured by imaging techniques, e.g. cardiac magnetic resonance imaging, which is the actual gold standard for infarct size determination but with limited availability in daily practice. We developed a mathematical biomarker kinetic model based on pharmacokinetic compartment models to easily and accurately estimate infarct size using individual data from five clinical trials evaluating the impact of conditioning therapies in STEMI between 2005 and 2013. Serial blood sampling was available in all studies with data regarding creatine kinase (CK), CK specific of cardiomyocytes (CK-MB) and cardiac troponin I. Our model allowed an accurate estimation of biomarker release as a surrogate marker of infarct size and a powerful assessment of conditioning treatments. This biomarker kinetic modelling approach identified CK-MB as the most accurate biomarker in determining infarct size and supports the development of limited sampling strategies that estimate total biomarker amount released with a lower number of samples. It will certainly be a useful add-on to future studies in the field of STEMI and cardioprotection.

Early Diagnostic Performance of Heart-Type Fatty Acid Binding Protein in Suspected Acute Myocardial Infarction: Evidence From a Meta-Analysis of Contemporary Studies

BACKGROUND

Although cardiac troponin is the cornerstone in diagnosis of acute myocardial infarction (AMI), the accuracy is still suboptimal in the early hours after chest pain onset. Due to its small size, heart-type fatty acid-binding protein (H-FABP) has been reported accurate in diagnosis of AMI, however, this remains undetermined. The aim is to investigate the diagnostic performance of H-FABP alone and in conjunction with high-sensitivity troponin (hs-Tn) within 6 hours of symptom onset. Furthermore, accuracy in 0h/3h algorithm was also assessed.

METHODS

Medline and EMBASE databases were searched; sensitivity, specificity and area under ROC curve (AUC) were used as measures of the diagnostic accuracy. We pooled data on bivariate modelling, threshold effect and publication bias was applied for heterogeneity analysis.

RESULTS

Twenty-two studies with 6602 populations were included, pooled sensitivity, specificity and AUC of H-FABP were 0.75 (0.68-0.81), 0.81 (0.75-0.86) and 0.85 (0.82-0.88) within 6 hours. Similar sensitivity (0.76, 0.69-0.82), specificity (0.80, 0.71-0.87) and AUC (0.85, 0.82-0.88) of H-FABP were observed in 4185 (63%) patients in 0h/3h algorithm. The additional use of H-FABP improved the sensitivity of hs-Tn alone but worsened its specificity (all p<0.001), and resulted in no improvement of AUC (p>0.99). There was no threshold effect (p=0.18) and publication bias (p=0.31) in this study.

CONCLUSIONS

H-FABP has modest accuracy for early diagnosis of AMI within 3 and 6 hours of symptom onset. The incremental value of H-FABP seemed much smaller and was of uncertain clinical significance in addition to hs-Tn in patients with suspected AMI. Routine use of H-FABP in early presentation does not seem warranted.

The effect of a supportive educational intervention developed based on the Orem's self-care theory on the self-care ability of patients with myocardial infarction: a randomised controlled trial

AIMS AND OBJECTIVES

The aim of this study was to assess the effect of a supportive educational intervention developed based on the Orem's self-care theory on the self-care ability of patients with myocardial infarction.

BACKGROUND

Patients with cardiovascular disease suffer from the lack of knowledge about the disease and consequently are not able to fulfil their own self-care needs.

DESIGN

This was a randomised controlled trial conducted in 2012.

METHODS

We recruited a random sample of 66 patients with myocardial infarction who had been recently discharged from coronary care unit. The study setting was two university hospitals located in Khorasan, Iran. Patients were randomly allocated to either the experimental or the control groups. Patients in the experimental group received education, support, and counselling while patients in the control group received no intervention. We employed a demographic questionnaire and the Myocardial Infarction Self-Care Ability Questionnaire for data collection and spss version 16.00 for data analysis.

FINDINGS

After the study, patients in the experimental group had higher levels of self-care knowledge, motivation and skills compared to the prestudy readings and the control group.

CONCLUSION

The supportive educational intervention developed based on the Orem's self-care theory can improve nonhospitalised patients' self-care ability and positively affect public health outcomes. Consequently, using the developed programme for providing follow-up care to nonhospitalised patients is recommended.

RELEVANCE TO CLINICAL PRACTICE

Having the ability to develop caring systems based on the nursing theories is a prerequisite to standard nursing practice. Identifying patients' educational needs is a fundamental prerequisite to patient education. Our findings revealed that the supportive educational intervention developed based on the Orem's self-care theory can help health care providers identify and fulfil patients' self-care needs.

Universal Definition of Myocardial Infarction: Clinical Insights

Aims: The universal definition of myocardial infarction (MI) classifies acute ischaemia into different classes according to lesion mechanism. Our aim was to perform a detailed comparison between these different types of MI in terms of baseline characteristics, management and prognosis. Methods and Results: An observational retrospective single-centre cohort study was performed, including 1,000 consecutive patients admitted for type 1 (76.4%) or type 2 MI (23.6%). Type 2 MI patients were older, had a higher prevalence of comorbidities and worse medical status at admission. In-hospital mortality did not differ significantly between the MI groups (8.8 vs. 9.7%, p = 0.602). However, mortality during follow-up was almost 3 times higher in type 2 MIs (HR 2.75, p < 0.001). Type 2 MI was an independent all-cause mortality risk marker, adding discriminatory power to the GRACE model. Finally, important differences in traditional risk score performances (GRACE, CRUSADE) were found between both MI types. Conclusions: Several important baseline differences were found between these MI types. Regarding prognosis, long-term survival is significantly compromised in type 2 MIs, potentially translating patients' higher medical complexity and frailty. Distinction between type 1 and type 2 MI seems to have important implications in clinical practice and likely also in the results of clinical trials.

Genetic deletion of the adaptor protein p66Shc increases susceptibility to short-term ischaemic myocardial injury via intracellular salvage pathways

AIMS

Several intracellular mediators have been implicated as new therapeutic targets against myocardial ischaemia and reperfusion injury. However, clinically effective salvage pathways remain undiscovered. Here, we focused on the potential role of the adaptor protein p66(Shc) as a regulator of myocardial injury in a mouse model of cardiac ischaemia and reperfusion.

METHODS AND RESULTS

Adult male p66(Shc) deficient (p66(Shc) (-/-)) and C57Bl/6 wild-type (WT) mice were exposed to 30, 45, or 60 min of ischaemia and reperfusion (5, 15 min, or 24 h). Infarct size, systemic and intracardiac inflammation and oxidants, as well as cytosolic and mitochondrial apoptotic pathways were investigated. Following 30, but not 45 or 60 min of ischaemia, genetic p66(Shc) deficiency was associated with larger infarcts. In WT mice, in vivo p66(Shc) knock down by siRNA with transient protein deficiency confirmed these findings. P66(Shc) inhibition was not associated with any modification in post-infarction inflammation, oxidative burst nor cardiac vessel density or structure. However, in p66(Shc) (-/-) mice activation of the protective and anti-apoptotic Reperfusion Injury Salvage Kinases and Survivor Activating Factor Enhancement pathways were blunted and mitochondrial swelling and cellular apoptosis via the caspase-3 pathway increased compared with WT.

CONCLUSIONS

Genetic deletion of p66(Shc) increased susceptibility to myocardial injury in response to short-term ischaemia and reperfusion in mice. Still, additional studies are needed for assessing the role of this pathway in acute coronary syndrome patients.

New myocardial infarction definition affects incidence, mortality, hospitalization rates and prognosis

AIMS

To analyse differences in myocardial infarction incidence, mortality and hospitalization rates, 28-day case-fatality and two-year prognosis using two myocardial infarction case definitions: the classical World Health Organization definition (1994) and the European Society of Cardiology/American College of Cardiology definition (2000), which added cardiac troponin as a diagnostic biomarker.

DESIGN

Population-based cohort of 4170 consecutive myocardial infarction patients aged 35-74 years from Girona (Spain) recruited between 2002 and 2009.

METHODS

Incidence, mortality rates standardized to the European population and 28-day case-fatality were calculated. To estimate the association between case definition and prognosis, Cox models were fitted.

RESULTS

Use of the 2000 European Society of Cardiology/American College of Cardiology definition significantly increased myocardial infarction incidence per 100,000 population (238.3 vs. 274.5 in men and 54.1 vs. 69.7 in women). Applying this definition decreased the 28-day case-fatality rate from 26.9% to 23.4% in men, and from 31.0% to 24.1% in women. In the acute phase, patients diagnosed only by increased troponins were significantly less treated with thrombolysis (34.4% vs. 2.0%), angiotensin-converting enzyme inhibitors (71.7% vs. 65.0%) and percutaneous coronary intervention (41.1% vs. 31.7%). Case-fatality at 28 days was significantly better in cases diagnosed only by troponin increase (0.2 % vs. 9.7%), but two-year cardiovascular mortality was higher (7.5% vs. 3.7%).

CONCLUSIONS

Inclusion of cardiac troponins in myocardial infarction diagnosis increased annual incidence and decreased case-fatality. Diagnosis based only on increased troponins was associated with worse outcome. This group of patients at high risk of death should receive aggressive secondary prevention therapy.

Predicting major adverse cardiac events in spine fusion patients: is the revised cardiac risk index sufficient?

STUDY DESIGN

Observational cohort study.

OBJECTIVE

To determine the accuracy of the Revised Cardiac Risk Index (RCRI) in predicting major adverse cardiac events in patients undergoing spine fusion surgery of 3 levels or more.

SUMMARY OF BACKGROUND DATA

Preoperative cardiac testing is extensively guided by the RCRI, which was developed and validated in thoracic, abdominal, and orthopedic surgical patients. Because multilevel spine fusion surgery is often associated with major transfusion, we hypothesize that the RCRI may not accurately characterize the risk of cardiovascular morbidity in these patients.

METHODS

After institutional review board approval, perioperative data were collected from 547 patients who underwent 3 or more levels of spinal fusion with instrumentation. Postoperative cardiac morbidity was defined as any combination of the following: arrhythmia requiring medical treatment, myocardial infarction (either by electrocardiographic changes or troponin elevation), or the occurrence of demand ischemia. The surgical complexity was categorized as anterior surgery only, posterior cervical and/or thoracic fusion, posterior lumbar fusion, or any surgery that included transpedicular osteotomies. Logistic regression analysis was performed to determine RCRI performance.

RESULTS

The RCRI performed no better than chance (area under the curve = 0.54) in identifying the 49 patients (9%) who experienced cardiac morbidity.

CONCLUSION

The RCRI did not predict cardiac morbidity in our patients undergoing major spine fusion surgery, despite being extensively validated in low-risk noncardiac surgical patients. Preoperative testing and optimization decisions, previously based on the RCRI, may need to be revised to include more frequent functional cardiac imaging and more aggressive implementation of pharmacologic modalities that may mitigate cardiac morbidity, similar to the preoperative evaluation for major vascular surgery.

LEVEL OF EVIDENCE

3.

Impact of albuminuria on the incidence of periprocedural myocardial injury in patients undergoing elective coronary stent implantation

Albuminuria has traditionally been associated with an elevated risk of cardiovascular events. However, few studies have examined the potential relation between albuminuria and periprocedural risk in percutaneous coronary intervention (PCI). The aim of this study was to evaluate the impact of albuminuria on the incidence of periprocedural myocardial injury (PMI) in patients who underwent PCI. The study included 252 consecutive patients who underwent PCI. The incidence of PMI was significantly higher in patients with albuminuria than in those with normoalbuminuria (31.9% vs 43.3%, respectively, p = 0.014). Even after adjustment for confounders, the presence of albuminuria predicted PMI (odds ratio 2.07, 95% confidence interval 1.08 to 3.97, p = 0.029). Furthermore, patients with albuminuria and preserved estimated glomerular filtration rate had a 4.2-fold higher risk for PMI than did patients with normoalbuminuria and preserved estimated glomerular filtration rate. In conclusion, albuminuria was a strong predictor of PMI in patients who underwent PCI.

Lessons learned from the design and implementation of myocardial infarction adjudication tailored for HIV clinical cohorts

We developed, implemented, and evaluated a myocardial infarction (MI) adjudication protocol for cohort research of human immunodeficiency virus. Potential events were identified through the centralized Centers for AIDS Research Network of Integrated Clinical Systems data repository using MI diagnoses and/or cardiac enzyme laboratory results (1995-2012). Sites assembled de-identified packets, including physician notes and results from electrocardiograms, procedures, and laboratory tests. Information pertaining to the specific antiretroviral medications used was redacted for blinded review. Two experts reviewed each packet, and a third review was conducted if discrepancies occurred. Reviewers categorized probable/definite MIs as primary or secondary and identified secondary causes of MIs. The positive predictive value and sensitivity for each identification/ascertainment method were calculated. Of the 1,119 potential events that were adjudicated, 294 (26%) were definite/probable MIs. Almost as many secondary (48%) as primary (52%) MIs occurred, often as the result of sepsis or cocaine use. Of the patients with adjudicated definite/probable MIs, 78% had elevated troponin concentrations (positive predictive value = 57%, 95% confidence interval: 52, 62); however, only 44% had clinical diagnoses of MI (positive predictive value = 45%, 95% confidence interval: 39, 51). We found that central adjudication is crucial and that clinical diagnoses alone are insufficient for ascertainment of MI. Over half of the events ultimately determined to be MIs were not identified by clinical diagnoses. Adjudication protocols used in traditional cardiovascular disease cohorts facilitate cross-cohort comparisons but do not address issues such as identifying secondary MIs that may be common in persons with human immunodeficiency virus.

Incidence of myocardial infarction in Hungary. Population study in five districts of Budapest and Szabolcs-Szatmár-Bereg county

Introduction: In the last few decades data on the incidence of acute myocardial infarction are not available in Hungary. Aim: The aim of the authors was to define the incidence of myocardial infarction using the Hungarian Infarction Registry according to the number of in- and out-of-hospital cases in five districts of the capital (districts II, III, IX, X and XVII) and Szabolcs-Szatmár-Bereg county. Method: Besides using the Hungarian Infarction Registry, databases of the National Public Health and Medical Officer Service and that of the Hungarian Central Statistical Office were used in order to define the incidence of prehospital cases, according to the regulations presented in an earlier proposal of the Data Protection Ombudsman of Hungary. Results: For 10 000 residents the incidence of myocardial infarction in the capital was 28.63 in males and 16.21 in females, while in Szabolcs-Szatmár-Bereg county the mean incidence was 32.49 for males and 18.59 for females. The mean incidence of myocardial infarction in the five districts of the capital in males and females did not differ from the mean values of Szabolcs-Szatmár-Bereg county. When comparing the incidence values in different districts of the capital to the countryside, the Szabolcs-Szatmár-Bereg county had significantly higher values for both males and females compared to districts II and III of the capital, while in district X the incidence of myocardial infarction in males was significantly lower compared to the values in the countryside. Conclusions: Using the mean incidence results projected to the capital and countryside population according to age and gender, 20 000 new myocardial infarction cases might be expected per year in Hungary. Orv. Hetil., 2013, 154, 1106–1110.

Implications of changing definitions of myocardial infarction on number of events and all-cause mortality: the WHO 1979, ESC/ACC 2000, AHA 2003, and Universal 2007 definitions revisited

PURPOSE

To analyse the impact of four different definitions of acute myocardial infarction (AMI) on number of events and all-cause mortality after AMI.

METHODS

We retrospectively examined number of AMI events and mortality according to four different definitions of AMI, among 1494 patients admitted to Haukeland University Hospital in Norway from March 2002 to February 2003. Eligible for analysis were 815 patients with a discharge diagnosis of an AMI, and 679 patients without any AMI discharge diagnosis but with elevated cardiac troponin I level during admission.

RESULTS

Applying the WHO 1979 definition resulted in 566 definite AMIs among the 1494 patients and was used as reference. According to the other definitions, there were 455 (-20%) definite AMIs by the original troponin 'rise and fall' version of the ESC/ACC 2000 definition, 729 (+29%) by the troponin 'rise or fall' interpretation of the ESC/ACC 2000 definition, 761 (+34%) by the AHA 2003 definition, and 743 (+31%) by the Universal 2007 definition (all p < 0.001). The 28-day, 1-year, 5-year, and 8-year mortality for definite AMI applying the WHO 1979 definition was 12, 19, 32, and 40%, whereas applying the Universal 2007 definition resulted in a mortality of 14, 21, 35, and 43%, respectively.

CONCLUSIONS

The change of definitions of AMI during the last decades has had a significant impact on the number of AMI events and a moderate impact on the AMI mortality among hospitalized patients.