Prevalence, extent, and independent predictors of silent myocardial infarction

The ABCA1 gene polymorphisms rs1800977 and rs2230806 are differentially associated with the risk for myocardial infarction in Slovenian subjects with type 2 diabetes mellitus

BACKGROUND

The adenosine triphosphate-binding cassette transporter A1 (ABCA1) is closely linked to various aspects of the regulation of whole-body cholesterol metabolism and atherosclerosis formation. The object of the study was to investigate the association between rs1800977 and rs2230806 polymorphisms in the ABCA1 gene and myocardial infarction (MI) in Slovenian subjects with type 2 diabetes mellitus (T2DM).

METHODS

1590 T2DM patients (484 subjects with MI and 1106 controls) were included in this retrospective cross-sectional case-control study. After genotyping, Pearson χ2 test was used to compare the distribution of genotypes and alleles among the two groups. Logistic regression analysis adjusted for several risk factors for MI was performed.

RESULTS

Genotype distribution showed significant association with MI in T2DM subjects for both selected polymorphisms in ABCA1 gene (p = 0.009 for rs2230806 and p = 0.042 for rs1800977). After applying corrections for confounding variables like age, waist circumference, diastolic blood pressure, serum high-density lipoprotein levels, gender and smoking several genetic models still showed significant associations with MI (dominant model for rs2230806 and dominant, overdominant and co-dominant for rs1800977).

CONCLUSION

Our study showed that presence of the T allele of the rs2230806 ABCA1 gene is associated with higher risk of MI, while the A allele of the rs1800977 conferred protection against MI in Slovenian T2DM subjects.

Effect of statin use for the primary prevention of cardiovascular disease among older adults: a cautionary tale concerning target trials emulation

OBJECTIVES

Evidence concerning the effect of statins in primary prevention of cardiovascular disease (CVD) among older adults is lacking. Using Quebec population-wide administrative data, we emulated a hypothetical randomized trial including older adults >65 years on April 1, 2013, with no CVD history and no statin use in the previous year.

STUDY DESIGN AND SETTING

We included individuals who initiated statins and classified them as exposed if they were using statin at least 3 months after initiation and nonexposed otherwise. We followed them until March 31, 2018. The primary outcome was the composite endpoint of coronary events (myocardial infarction, coronary bypass, and percutaneous coronary intervention), stroke, and all-cause mortality. The intention-to-treat (ITT) effect was estimated with adjusted Cox models and per-protocol effect with inverse probability of censoring weighting.

RESULTS

A total of 65,096 individuals were included (mean age = 71.0 ± 5.5, female = 55.0%) and 93.7% were exposed. Whereas we observed a reduction in the composite outcome (ITT-hazard ratio (HR) = 0.75; 95% CI: 0.68-0.83) and mortality (ITT-HR = 0.69; 95% CI: 0.61-0.77) among exposed, coronary events increased (ITT-HR = 1.46; 95% CI: 1.09-1.94). All multibias E-values were low indicating that the results were not robust to unmeasured confounding, selection, and misclassification biases simultaneously.

CONCLUSION

We cannot conclude on the effectiveness of statins in primary prevention of CVD among older adults. We caution that an in-depth reflection on sources of biases and careful interpretation of results are always required in observational studies.

Myocardial scar and left ventricular ejection fraction classification for electrocardiography image using multi-task deep learning

Myocardial scar (MS) and left ventricular ejection fraction (LVEF) are vital cardiovascular parameters, conventionally determined using cardiac magnetic resonance (CMR). However, given the high cost and limited availability of CMR in resource-constrained settings, electrocardiograms (ECGs) are a cost-effective alternative. We developed computer vision-based multi-task deep learning models to analyze 12-lead ECG 2D images, predicting MS and LVEF < 50%. Our dataset comprises 14,052 ECGs with clinical features, utilizing ground truth labels from CMR. Our top-performing model achieved AUC values of 0.838 (95% CI 0.812-0.862) for MS and 0.939 (95% CI 0.921-0.954) for LVEF < 50% classification, outperforming cardiologists. Moreover, MS predictions in a prevalence-specific test dataset recorded an AUC of 0.812 (95% CI 0.810-0.814). Extracted 1D signals from ECG images yielded inferior performance, compared to the 2D approach. In conclusion, our results demonstrate the potential of computer-based MS and LVEF < 50% classification from ECG scan images in clinical screening offering a cost-effective alternative to CMR.

Upholding te mana o te wā: Māori patients and their families' experiences of accessing care following an out-of-hospital cardiac event

Objective

The purpose of this study was to explore the experiences of Māori patients and their families accessing care for an acute out-of-hospital cardiac event and to identify any barriers or enablers of timely access to care.

Design

Eleven interviews with patients and their families were conducted either face-to-face or using online conferencing. Interviews were audio-recorded and transcribed for thematic analysis using Kaupapa Māori methodology.

Results

Data analysis identified three themes: (1) me and the event, (2) the people (3) upholding te mana ō te wā or self-determined heart wellbeing. Knowledge of symptoms and a desire to maintain personal dignity at the time of the event affected emergency medical service initiation. Participants described relationships with health professionals, the importance of good quality information, having family support, and drawing on cultural practices as vital for their health care journey.

Conclusion

Systemic barriers including racism, discrimination, and inadequate resourcing exist for Māori journeying to and through care following an out of hospital cardiac event. Improving the cultural safety of health professionals, better access to community defibrillation, and improving understanding of the life-long impacts a cardiac event has on patients and whānau is recommended.

Association of silent myocardial infarction on electrocardiogram and coronary artery calcium: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Silent myocardial infarction (SMI) on electrocardiogram (ECG) is associated with atherosclerotic cardiovascular disease, but the relationship between SMI on ECG and coronary artery calcium (CAC) remains poorly understood.

OBJECTIVE

Characterize the relationship between SMI on ECG and CAC.

METHODS

Eligible participants from the Multi-Ethnic Study of Atherosclerosis study had ECG and CAC scoring at study enrollment (2000-2002). SMI was defined as ECG evidence of myocardial infarction in the absence of a history of clinical cardiovascular disease. CAC was modeled both continuously and categorically. The cross-sectional relationships between SMI on ECG and CAC were assessed using logistic regression and linear regression.

RESULTS

Among 6705 eligible participants, 178 (2.7%) had baseline SMI. Compared to participants without SMI, those with SMI had higher CAC (median [IQR]: 61.2 [0-261.7] vs. 0 [0-81.5]; p < .0001). Participants with SMI were more likely to have non-zero CAC (74% vs. 49%) and were more likely to have CAC ≥ 100 (40% vs. 23%). In a multivariable-adjusted logistic model, SMI was associated with higher odds of non-zero CAC (odds ratio 2.17, 95% CI 1.48-3.20, p < .0001) and 51% higher odds of CAC ≥ 100 (odds ratio 1.51, 95% CI 1.06-2.16, p = .02).

CONCLUSION

An incidental finding of SMI on ECG may serve to identify patients who have a higher odds of significant CAC and may benefit from additional risk stratification to further refine their cardiovascular risk. Further exploration of the utility of CAC assessment in this patient population is needed.

Increased Epicardial Adipose Tissue and Heart Characteristics Are Correlated with BMI and Predict Silent Myocardial Infarction in Sudden Cardiac Death Subjects: An Autopsy Study

BACKGROUND

Sudden cardiac death (SCD) is a significant global public health issue and the leading cause of death worldwide. Its etiopathogenesis is complex and multilayered, involving dynamic factors interacting with a preexistent cardiovascular pathology, frequently unknown, and resulting in cardiac rhythm disorders and cardiac arrest; Methods: This study conducted a retrospective descriptive analysis over a one-year period, identifying 321 autopsy cases of sudden deaths from the Institute of Legal Medicine in Mures County, Romania, in 2019. From the 321 sudden death cases, 189 autopsy reports were selected for analysis based on inclusion and exclusion; Results: The autopsies had a mean age of 61.16 years and included 140 males and 49 females. No significant differences were found between the silent myocardial infarction (SMI) and no-SMI groups regarding demographic data. The SMI group exhibited higher thickness of LV (left ventricle), IV (interventricular septum), EAT LCx (epicardial adipose tissue at left circumflex artery), EAT LAD (epicardial adipose tissue at left anterior descending artery), heart weight, and BMI (body mass index). The left coronary artery showed a higher incidence of type V plaques, while the right coronary artery showed higher incidences of type V and type VI plaque. The SMI group also exhibited a higher incidence of moderate and severe valvular atherosclerosis, severe left ventricle dilatation, and a lower incidence of mild left ventricle dilatation. In addition, the SMI group showed a higher presence of contraction band necrosis on histological examination. Multivariate analysis revealed that type V and type VI plaques for the right and left coronary arteries, moderate and severe valvular atherosclerosis, severe left ventricle dilatation, heart weight, EAT LCx, EAT LAD, LV thickness, IV thickness, BMI, and the presence of contraction band necrosis are all independent predictors of SMI; Conclusions: The findings suggest that SCD is a complex condition, and its etiopathogenesis involves dynamic factors interacting with pre-existing cardiovascular pathology. The risk factors of SCD are similar to those of ischemic heart disease. The findings of this study could guide clinicians in identifying patients at risk of SCD and implementing preventive measures.

Precision Medicine and the future of Cardiovascular Diseases: A Clinically Oriented Comprehensive Review

Cardiac diseases form the lion's share of the global disease burden, owing to the paradigm shift to non-infectious diseases from infectious ones. The prevalence of CVDs has nearly doubled, increasing from 271 million in 1990 to 523 million in 2019. Additionally, the global trend for the years lived with disability has doubled, increasing from 17.7 million to 34.4 million over the same period. The advent of precision medicine in cardiology has ignited new possibilities for individually personalized, integrative, and patient-centric approaches to disease prevention and treatment, incorporating the standard clinical data with advanced "omics". These data help with the phenotypically adjudicated individualization of treatment. The major objective of this review was to compile the evolving clinically relevant tools of precision medicine that can help with the evidence-based precise individualized management of cardiac diseases with the highest DALY. The field of cardiology is evolving to provide targeted therapy, which is crafted as per the "omics", involving genomics, transcriptomics, epigenomics, proteomics, metabolomics, and microbiomics, for deep phenotyping. Research for individualizing therapy in heart diseases with the highest DALY has helped identify novel genes, biomarkers, proteins, and technologies to aid early diagnosis and treatment. Precision medicine has helped in targeted management, allowing early diagnosis, timely precise intervention, and exposure to minimal side effects. Despite these great impacts, overcoming the barriers to implementing precision medicine requires addressing the economic, cultural, technical, and socio-political issues. Precision medicine is proposed to be the future of cardiovascular medicine and holds the potential for a more efficient and personalized approach to the management of cardiovascular diseases, contrary to the standardized blanket approach.

Comparison between Machine Learning and Multiple Linear Regression to Identify Abnormal Thallium Myocardial Perfusion Scan in Chinese Type 2 Diabetes

Type 2 diabetes mellitus (T2DM) patients have a high risk of coronary artery disease (CAD). Thallium-201 myocardial perfusion scan (Th-201 scan) is a non-invasive and extensively used tool in recognizing CAD in clinical settings. In this study, we attempted to compare the predictive accuracy of evaluating abnormal Th-201 scans using traditional multiple linear regression (MLR) with four machine learning (ML) methods. From the study, we can determine whether ML surpasses traditional MLR and rank the clinical variables and compare them with previous reports.In total, 796 T2DM, including 368 men and 528 women, were enrolled. In addition to traditional MLR, classification and regression tree (CART), random forest (RF), stochastic gradient boosting (SGB) and eXtreme gradient boosting (XGBoost) were also used to analyze abnormal Th-201 scans. Stress sum score was used as the endpoint (dependent variable). Our findings show that all four root mean square errors of ML are smaller than with MLR, which implies that ML is more precise than MLR in determining abnormal Th-201 scans by using clinical parameters. The first seven factors, from the most important to the least are:body mass index, hemoglobin, age, glycated hemoglobin, Creatinine, systolic and diastolic blood pressure. In conclusion, ML is not inferior to traditional MLR in predicting abnormal Th-201 scans, and the most important factors are body mass index, hemoglobin, age, glycated hemoglobin, creatinine, systolic and diastolic blood pressure. ML methods are superior in these kinds of studies.

Relation of Glycemic Status with Unrecognized MI and the Subsequent Risk of Mortality: The Jackson Heart Study

Background

Almost 1/3 to 1/2 of initial myocardial infarctions (MI) may be silent or unrecognized (UMI), which forecasts future clinical events. Further, limited data exist to describe the potential risk for UMI in African-Americans. The relationship of glucose status with UMI was examined in the Jackson Heart Study: a cohort of African-American individuals.

Methods and results

At baseline, there were 5,073 participants with an initial 12-lead electrocardiogram (ECG) and fasting glucose measured. Of these participants, 106(2.1%) had a UMI, and 268(4.2%) had a recognized MI. This population consisted of 3,233 (63.7%) participants with normal fasting glucose (NFG), 533 (10.5%) with IFG, and 1,039 (20.4%) with DM. Logistic regression investigated the relationship between glucose status and UMI. Cox proportional hazard models determined the significance of all-cause mortality during follow-up by MI status. The sample was 65% female with a mean age of 55.3 ± 12.9 years. Over a mean follow-up of 10.4 years, there were 795 deaths. Relative to NFG, the crude odds ratio (OR) estimates for UMI at baseline with IFG and DM were 1.00(95% CI:0.48–2.14) and 3.22(2.15–4.81), respectively. With adjustment, DM continued to be significantly associated with UMI [2.30 (1.42–3.71)]. Overall, participants with a baseline UMI had an adjusted Hazard ratio (HR) of 2.00(1.39–2.78) of death compared to no prior MI. Compared to those with no MI, those with a recognizedMI had an adjusted HR of 1.70(1.31–2.17) for mortality.

Conclusions

DM is associated with UMI in African-Americans. Further, a UMI carried similar risk of death compared to those with a recognized MI.

Sudden Death from Ischemic Heart Disease While Driving: Cardiac Pathology, Clinical Characteristics, and Countermeasures

BACKGROUND Sudden death from ischemic heart disease while driving is an important cause of traffic accidents. This study discusses causes of traffic accidents in relation to risk factors for acute myocardial infarction such as hypertension and overwork and provides references for the early prevention and regulation of drivers' health conditions. MATERIAL AND METHODS Data on 21 cases of sudden death by ischemic heart disease while driving from January 2015 to December 2019 were collected. Age, symptoms, and cardiac pathological changes of patients were summarized by systematic anatomical and medical history data. RESULTS Patients were 21 men with an average age of 47±7.27 years (most aged 40 to 60 years), and the average weight of their hearts was 439.45±76.3 g. Twelve patients had a history of hypertension, 8 had previous myocardial infarction, and 4 had fatty liver. All had at least 1 severe narrowing of a major coronary artery. Twelve patients died within a short period; 9 died more than 12 h after myocardial infarction onset. Ten patients had worked more than 80 h of overtime per month, 4 patients, more than 45 h, and 7 patients, less than 45 h. CONCLUSIONS Regular physical examination and information about ischemic heart disease should be emphasized for men aged 40 to 60 years who drive frequently, especially for those with hypertension, overwork, or previous myocardial infarction. Incorporating objective evaluation criteria for the severity of ischemic heart disease and overwork into health condition-related driving regulations is needed.

Dietary capsaicin normalizes CGRP peptidergic DRG neurons in experimental diabetic peripheral neuropathy

Diabetic sensory neuropathy leads to impairment of peripheral sensory nerves and downregulation of calcitonin gene-related peptide (CGRP) in a functionally specific subset of peripheral sensory neurons mediating pain. Whether CGRP plays a neuroprotective role in peripheral sensory nerve is unclear. We evaluated alterations in noxious thermal sensation and downregulation of CGRP in the 8 weeks after induction of diabetes in rats. We supplemented capsaicin in the diet of the animals to upregulate CGRP and reversed the downregulation of the neuropeptide in the dorsal root ganglion (DRG) neurons dissociated from the diabetic animals, via gene transfection and exogenous CGRP, to test disease-preventing and disease-limiting effects of CGRP. Significant preservation of the nociceptive sensation, CGRP in spinal cord and DRG neurons, and number of CGRP-expressing neurons was found in the diabetic animals given capsaicin. Improvement in the survival of the neurons and the outgrowth of neurites was achieved in the neurons transfected by LV-CGRP or by exogenous CGRP, paralleling the correction of abnormalities of intracellular reactive oxygen species and mitochondrial transmembrane potentials. The results suggest that downregulation of CGRP impairs viability, regeneration and function of peripheral sensory neurons while capsaicin normalizes the CGRP peptidergic DRG neurons and function of the sensory nerves.

Association of Silent Myocardial Infarction and Sudden Cardiac Death

Importance

Myocardial infarction in the absence of major or unrecognized symptoms are characterized as silent (SMI). The prevalence of SMI among individuals who experience sudden cardiac death (SCD), with or without concomitant electrocardiographic (ECG) changes, has not previously been described in detail from large studies to our knowledge.

Objective

To determine the prevalence of SMI in individuals who experience SCD without a prior diagnosis of coronary artery disease (CAD) and to detect ECG abnormalities associated with SMI-associated SCD.

Design, Setting, and Participants

This case-control study compared autopsy findings, clinical characteristics, and ECG markers associated with SMI in a consecutive cohort of individuals in the Finnish Genetic Study of Arrhythmic Events (Fingesture) study population who were verified to have had SCD. The Fingesture study consists of individuals who had autopsy-verified SCD in Northern Finland between 1998 and 2017. Individuals who had SCD with CAD and evidence of SMI were regarded as having had cases; those who had SCD with CAD without SMI were considered control participants. Analyses of ECG tests were carried out by investigators blinded to the SMI data. Data analysis was completed from October 2018 through November 2018.

Main Outcomes and Measures

Silent MI was defined as a scar detected by macroscopic and microscopic evaluation of myocardium without previously diagnosed CAD. Clinical history was obtained from medical records, previously recorded ECGs, and a standardized questionnaire provided to the next of kin. The hypothesis tested was that SMI would be prevalent in the population who had had SCD with CAD, and it might be detected or suspected from findings on ECGs prior to death in many individuals.

Results

A total of 5869 individuals were included (2459 males [78.8%]; mean [SD] age, 64.9 [12.4] years). The cause of SCD was CAD in 4392 individuals (74.8%), among whom 3122 had no history of previously diagnosed CAD. Two individuals were excluded owing to incomplete autopsy information. An ECG recorded prior to SCD was available in 438 individuals. Silent MI was detected in 1322 individuals (42.4%) who experienced SCD without a clinical history of CAD. The participants with SMI were older than participants without MI scarring (mean [SD] age, 66.9 [11.1] years; 65.5 [11.6] years; P < .001) and were more often men (1102 of 1322 [83.4%] vs 1357 of 1798 [75.5%]; P < .001). Heart weight was higher in participants with SMI (mean [SD] weight, 483 [109] g vs 438 [106] g; P < .001). In participants with SMI, SCD occurred more often during physical activity (241 of 1322 [18.2%] vs 223 of 1798 [12.4%]; P < .001). A prior ECG was abnormal in 125 of the 187 individuals (66.8%) who had SCD after SMI compared with 139 of 251 (55.4%) of those who had SCD without SMI (P = .02).

Conclusions and Relevance

Many individuals who experienced SCD associated with CAD had a previously undetected MI at autopsy. Previous SMI was associated with myocardial hypertrophy and SCD during physical activity. Premortem ECGs in a subset with available data were abnormal in 67% of the individuals who had had a SCD after an SMI.

Non-alcoholic fatty liver disease is not independent risk factor for cardiovascular disease event: A cohort study

BACKGROUND

There are no consistent results between previous studies for an independent association between non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease (CVD) events.

AIM

To determine if there is an independent association between NAFLD and CVD events.

METHODS

In the present study, valid outcome data of 4808 subjects were available for phase 2 of our cohort study. These subjects had been followed up for seven years from phase 1, beginning in 2009-2010 to phase 2 during 2016-2017. Simple and multiple Cox proportional models were used to determine the association between NAFLD in the primary phase of the cohort and subsequent fatal and non-fatal CVD events during follow-up.

RESULTS

The incidence of non-fatal CVD events in males with NAFLD was significantly higher (P = 0.004) than in males without NAFLD. A positive association was demonstrated between NAFLD and non-fatal CVD events in males (Hazard ratio = 1.606; 95%CI: 1.166-2.212; P = 0.004) by the simple Cox proportional hazard model, but no independent association was detected between these in the multiple Cox models.

CONCLUSION

No independent association was detected between NAFLD and CVD. It is likely that diabetes mellitus and age may be the principle mediators in this regard.

Association Between Unrecognized Myocardial Infarction and Cerebral Infarction on Magnetic Resonance Imaging

Importance

It is uncertain whether unrecognized myocardial infarction (MI) is a risk factor for cerebral infarction.

Objective

To determine whether unrecognized MI detected by cardiac magnetic resonance imaging (MRI) is associated with cerebral infarction.

Design, Setting, and Participants

This is a cross-sectional study of ICELAND MI, a cohort substudy of the Age, Gene/Environment Susceptibility-Reykjavik Study conducted in Iceland. Enrollment occurred from January 2004 to January 2007 from a community-dwelling cohort of older Icelandic individuals. Participants aged 67 to 93 years who underwent both brain MRI and late gadolinium enhancement cardiac MRI were included. Data analysis was performed from September 2018 to March 2019.

Exposures

Unrecognized MI identified by cardiac MRI.

Main Outcomes and Measures

Unrecognized MI was defined as cardiac MRI evidence of MI without a history of clinically evident MI. Recognized MI was defined as cardiac MRI evidence of MI with a history of clinically evident MI. Cerebral infarctions on brain MRI were included regardless of associated symptoms. Multiple logistic regression was used to evaluate the association between MI status (no MI, unrecognized MI, or recognized MI) and cerebral infarction after adjustment for demographic factors and vascular risk factors. In addition, we evaluated the association between unrecognized MI and embolic infarcts of undetermined source.

Results

Five enrolled participants had nondiagnostic brain MRI studies and were excluded. Among 925 participants, 480 (51.9%) were women; the mean (SD) age was 75.9 (5.3) years. There were 221 participants (23.9%) with cardiac MRI evidence of MI, of whom 68 had recognized MI and 153 unrecognized MI. There were 308 participants (33.3%) with brain MRI evidence of cerebral infarction; 93 (10.0%) had embolic infarcts of undetermined source. After adjustment for demographic factors and vascular risk factors, the likelihood (odds ratio) of having cerebral infarction was 2.0 (95% CI, 1.2-3.4; P = .01) for recognized MI and 1.5 (95% CI, 1.02-2.2; P = .04) for unrecognized MI. After adjustment for demographics and vascular risk factors, unrecognized MI was also associated with embolic infarcts of undetermined source (odds ratio, 2.0 [95% CI, 1.1-3.5]; P = .02).

Conclusions and Relevance

In a population-based sample, we found an association between unrecognized MI and cerebral infarction. These findings suggest that unrecognized MI may be a novel risk factor for cardiac embolism and cerebral infarction.

Kounis Syndrome as First Manifestation of Allergic Sensitization

Mast cells are abundant in the heart, among myocardial fibers, around coronary arteries, within arterial intima and intramural vessels, and in atherosclerotic plaques. Their mediators can be released during anaphylaxis and be responsible for acute coronary syndrome. This condition has been described as Kounis syndrome (KS). We report three cases of acute myocardial ischemia, which fulfill the definition for KS. In Cases 1 and 2, the association of intense chest pain with acute urticaria after an allergenic contact (wasp sting and betalactam antibiotic administration, respectively) was suspected to be an attack of angina related to an allergic reaction. No signs of an allergic reaction were observed in Case 3, but only the history of a wasp sting suggested its relationship to loss of consciousness and heart ischemia when hypersensitivity to venom was ascertained. These cases strongly recommend measurement of anaphylactic biomarkers, such as tryptase, during acute coronary syndromes to detect the possible involvement of an allergic reaction. Conversely, measurement of cardiac biomarkers during anaphylaxis, even without obvious signs of myocardial ischemia, might identify patients at risk of myocardial injury.

Is sex associated with adverse outcomes after percutaneous coronary intervention for CTO?

BACKGROUND

Conflicting results have been reported regarding sex differences in percutaneous coronary intervention (PCI), but their potential influence on clinical outcomes after chronic total coronary occlusion (CTO) PCI remains unknown. We aimed to identify sex-related differences in long-term clinical outcomes after CTO PCI.

METHODS AND RESULTS

All consecutive patients undergoing CTO PCI between 2004 and 2012 were included in a prospective registry. Baseline, procedural characteristics and clinical outcomes were compared according to sex. Out of 1343 patients, 194 were female (14.4%). Women were older (68.5 ± 9.9 vs 62.3 ± 10.8 years, p < 0.001), more frequently diabetic (33.5% vs 26.4%, p = 0.026) and hypertensive (70.1% vs 57.4%, p < 0,001), whereas males were more frequently smokers (28.5% vs 15.5%, p < 0.001). J-CTO score was similar between both sexes (1.59 ± 0.91 vs 1.51 ± 0.88). The procedural success rate was also similar in men and women (74.0% vs 77.3%, respectively). At 8 years' follow-up, successful CTO PCI was associated with reduced mortality in women (14.8% vs 36.2%, p = 0.003) and men (18.5% vs 29.1%, p < 0.001). In successful CTO PCI cases, no sex-related differences were observed in terms of major adverse cardiac events.

CONCLUSIONS

Our study suggests an equal benefit of CTO interventions with a marked reduction in mortality after successful CTO PCI in women and men alike.

Asymptomatic myocardial ischemia forecasts adverse events in cardiovascular magnetic resonance dobutamine stress testing of high-risk middle-aged and elderly individuals

BACKGROUND

Current guidelines for assessing the risk of experiencing a hospitalized cardiovascular (CV) event discourage stress testing of asymptomatic individuals; however, these recommendations are based on evidence gathered primarily from those aged < 60 years, and do not address the possibility of unrecognized "silent myocardial ischemia" in middle aged and older adults.

METHODS

We performed dobutamine cardiovascular magnetic resonance (CMR) stress testing in 327 consecutively recruited participants aged > 55 years without CV-related symptoms nor known coronary artery disease, but otherwise at increased risk for a future CV event due to pre-existing hypertension or diabetes mellitus for at least 5 years. After adjusting for the demographics and CV risk factors, log-rank test and Cox proportional hazards models determined the additional predictive value of the stress test results for forecasting hospitalized CV events/survival. Either stress-induced LV wall motion abnormalities or perfusion defects were used to indicate myocardial ischemia.

RESULTS

Participants averaged 68 ± 8 years in age; 39% men, 75% Caucasian. There were 38 hospitalized CV events or deaths which occurred during a mean follow-up of 58 months. Using Kaplan-Meier analyses, myocardial ischemia identified future CV events/survival (p <  0.001), but this finding was more evident in men (p <  0.001) versus women (p = 0.27). The crude hazard ratio (HR) of myocardial ischemia for CV events/survival was 3.13 (95% CI: 1.64-5.93; p < 0.001). After accounting for baseline demographics, CV risk factors, and left ventricular ejection fraction/mass, myocardial ischemia continued to be associated with CV events/survival [HR: 4.07 (95% CI: 1.95-8.73) p < 0.001].

CONCLUSIONS

Among asymptomatic middle-aged individuals with risk factors for a sentinel CV event, the presence of myocardial ischemia during dobutamine CMR testing forecasted a future hospitalized CV event or death. Further studies are needed in middle aged and older individuals to more accurately characterize the prevalence, significance, and management of asymptomatic myocardial ischemia.

TRIAL REGISTRATION

( ClinicalTrials.gov identifier): NCT00542503 and was retrospectively registered on October 11th, 2007.

Abnormal Fasting Glucose Increases Risk of Unrecognized Myocardial Infarctions in an Elderly Cohort

OBJECTIVES

To investigate glucose levels as a risk factor for unrecognized myocardial infarctions (UMIs).

DESIGN

Cohort SETTING: Cardiovascular Health Study.

PARTICIPANTS

Individuals aged 65 and older with fasting glucose measurements (N=4,355; normal fasting glucose (NFG), n = 2,041; impaired fasting glucose (IFG), n = 1,706; DM: n = 608; 40% male, 84% white, mean age 72.4 ± 5.6).

MEASUREMENTS

The relationship between glucose levels and UMI was examined. Participants with prior coronary heart disease (CHD) or UMI on initial electrocardiography were excluded. Using Minnesota codes, UMI was identified according to the presence of pathological Q-waves or minor Q-waves with ST-T abnormalities. Crude and adjusted hazard ratios (HRs) were calculated. Analyses were adjusted for age, sex, body mass index (BMI), hypertension, antihypertensive and lipid-lowering medication use, total cholesterol, high-density lipoprotein cholesterol, and smoking status.

RESULTS

Over a mean follow-up of 6 years, there were 459 incident UMIs (NFG, n=202; IFG, n=183; DM, n=74). Participants with IFG were slightly more likely than those with NFG to experience a UMI (hazard ratio (HR)=1.11, 95% confidence interval (CI)=0.91-1.36, p = .30), and those with DM were more likely than those with NFG to experience a UMI (HR=1.65, 95% CI=1.25-2.13, p < .001). After adjustment HR for UMI in IFG those with IFG were no more likely than those with NFG to experience a UMI (HR=1.01, 95% CI=0.82-1.24, p = .93), whereas those with DM were more likely than those with NFG to experience a UMI (HR=1.37, 95% CI=1.02-1.81, p = .03). The 2-hour oral glucose tolerance test was not statistically significantly associated with UMI.

CONCLUSION

Fasting glucose status, particularly in the diabetic range, forecasted UMI during 6 years of follow-up in elderly adults. Further studies are needed to clarify the level of glucose at which risk is greater. J Am Geriatr Soc 67:43-49, 2019.

Small and large vessel disease in persons with unrecognized compared to recognized myocardial infarction: The Tromsø Study 2007-2008

BACKGROUND

Unrecognized myocardial infarction (MI) is a frequent condition with unknown underlying reason. We hypothesized the lack of recognition of MI is related to pathophysiology, specifically differences in underlying small and large vessel disease.

METHODS

6128 participants were examined with retinal photography, ultrasound of the carotid artery and a 12‑lead electrocardiography (ECG). Small vessel disease was defined as narrower retinal arterioles and/or wider retinal venules measured on retinal photographs. Large vessel disease was defined as carotid artery pathology. We defined unrecognized MI as ECG-evidence of MI without a clinically recognized event. We analyzed the cross-sectional relationship between MI recognition and markers of small and large vessel disease, adjusted for age and sex.

RESULTS

Unrecognized MI was present in 502 (8.2%) and recognized MI in 326 (5.3%) of the 6128 participants. Compared to recognized MI, unrecognized MI was associated with small vessel disease indicated by narrower retinal arterioles (OR 1.66, 95% CI 1.05-2.62, highest vs. lowest quartile). Unrecognized MI was less associated with wider retinal venules (OR 0.55, 95% CI 0.35-0.87, lowest vs. highest quartile). Compared to recognized MI, unrecognized MI was less associated with large vessel disease indicated by presence of plaque in the carotid artery (OR for presence of carotid artery plaque in unrecognized MI 0.51, 95% CI 0.37-0.69). No significant sex interaction was present.

CONCLUSIONS

Unrecognized MI was more associated with small vessel disease and less associated with large vessel disease compared to recognized MI. These findings suggest that the pathophysiology behind unrecognized and recognized MI may differ.

Asymptomatic ST elevation myocardial infarction

BACKGROUND

A 71-year-old non-smoking female with a history of diabetes, hypertension, hyperlipidemia and end-stage renal disease presented to the emergency department for right leg pain due to an ankle fracture.

CASE

The patient's initial electrocardiogram (ECG) revealed ST segment elevations in the anterior leads. She denied any chest pain, shortness of breath, fatigue, lightheadedness, palpitations, nausea or diaphoresis. Her initial laboratory Troponin I resulted 35.9 ng/mL. Coronary catheterization demonstrated 99% occlusion of the left anterior descending (LAD) coronary artery. The patient had 2 drug eluting stents placed in the LAD with 10% residual stenosis.

CONCLUSION

Although witnessing an ongoing asymptomatic ST elevation myocardial infarction (STEMI) is rare, this case highlights the importance of early revascularization when the ECG demonstrates a STEMI, even in the absence of symptoms for patients at risk for silent myocardial infarctions.

Automatically computed ECG algorithm for the quantification of myocardial scar and the prediction of mortality

BACKGROUND

Myocardial scar is associated with adverse cardiac outcomes. The Selvester QRS-score was developed to estimate myocardial scar from the 12-lead ECG, but its manual calculation is difficult. An automatically computed QRS-score would allow identification of patients with myocardial scar and an increased risk of mortality.

OBJECTIVES

To assess the diagnostic and prognostic value of the automatically computed QRS-score.

METHODS

The diagnostic value of the QRS-score computed automatically from a standard digital 12-lead was prospectively assessed in 2742 patients with suspected myocardial ischemia referred for myocardial perfusion imaging (MPI). The prognostic value of the QRS-score was then prospectively tested in 1151 consecutive patients presenting to the emergency department (ED) with suspected acute heart failure (AHF).

RESULTS

Overall, the QRS-score was significantly higher in patients with more extensive myocardial scar: the median QRS-score was 3 (IQR 2-5), 4 (IQR 2-6), and 7 (IQR 4-10) for patients with 0, 5-20 and > 20% myocardial scar as quantified by MPI (p < 0.001 for all pairwise comparisons). A QRS-score ≥ 9 (n = 284, 10%) predicted a large scar defined as > 20% of the LV with a specificity of 91% (95% CI 90-92%). Regarding clinical outcomes in patients presenting to the ED with symptoms suggestive of AHF, mortality after 1 year was 28% in patients with a QRS-score ≥ 3 as opposed to 20% in patients with a QRS-score < 3 (p = 0.001).

CONCLUSIONS

The QRS-score can be computed automatically from the 12-lead ECG for simple, non-invasive and inexpensive detection and quantification of myocardial scar and for the prediction of mortality. TRIAL-REGISTRATION: http://www.clinicaltrials.gov . Identifier, NCT01838148 and NCT01831115.

Diagnostic and prognostic utility of cardiovascular magnetic resonance imaging in heart failure with preserved ejection fraction - implications for clinical trials

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is a poorly characterized condition. We aimed to phenotype patients with HFpEF using multiparametric stress cardiovascular magnetic resonance imaging (CMR) and to assess the relationship to clinical outcomes.

METHODS

One hundred and fifty four patients (51% male, mean age 72 ± 10 years) with a diagnosis of HFpEF underwent transthoracic echocardiography and CMR during a single study visit. The CMR protocol comprised cine, stress/rest perfusion and late gadolinium enhancement imaging on a 3T scanner. Follow-up outcome data (death and heart failure hospitalization) were captured after a minimum of 6 months.

RESULTS

CMR detected previously undiagnosed pathology in 42 patients (27%), who had similar baseline characteristics to those without a new diagnosis. These diagnoses consisted of: coronary artery disease (n = 20, including 14 with 'silent' infarction), microvascular dysfunction (n = 11), probable or definite hypertrophic cardiomyopathy (n = 10) and constrictive pericarditis (n = 5). Four patients had dual pathology. During follow-up (median 623 days), patients with a new CMR diagnosis were at higher risk of adverse outcome for the composite endpoint (log rank test: p = 0.047). In multivariate Cox proportional hazards analysis, a new CMR diagnosis was the strongest independent predictor of adverse outcome (hazard ratio: 1.92; 95% CI: 1.07 to 3.45; p = 0.03).

CONCLUSIONS

CMR diagnosed new significant pathology in 27% of patients with HFpEF. These patients were at increased risk of death and heart failure hospitalization.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03050593 . Retrospectively registered; Date of registration: February 06, 2017.

Quality of life as predictor for the development of cardiac ischemia in high-risk asymptomatic diabetic patients

BACKGROUND

Ischemia induced by psychological stress and depression is a common phenomenon in stable coronary artery disease (CAD). We evaluated the quality of life (QoL) of diabetic patients screened for CAD and assessed the prognostic value of mental and physical QoL scores to predict the development of new cardiac ischemia.

METHODS

Prospective multicentre outcome study. The study comprised 400 asymptomatic diabetic patients without history or symptoms of CAD. They underwent myocardial perfusion single-photon emission computed tomography (MPS) and assessment of QoL by two questionnaires: Hospital Depression and Anxiety Scale (HADS-D and HADS-A) and Medical Outcomes Study Short Form 36 (SF-36) at baseline and after 2 years. Patients with normal MPS received usual care; those with abnormal MPS received medical or combined invasive and medical management.

RESULTS

Only mental QoL scores but not physical QoL scores or traditional cardiovascular risk factors were predictive of new ischemia (n = 11/306) during follow-up. The prognostic value for new ischemia as quantified by the area under the receiver operating characteristics curve (AUC) amounted to 0.784 (95% confidence interval (CI) 0.654-0.914, P = 0.002) for HADS-D and to 0.737 (95% CI 0.580-0.893, P = 0.011) for HADS-A. This finding was confirmed by SF-36 mental sum score (AUC 0.688, 95% CI 0.539-0.836, P = 0.036), but not SF-36 physical sum score. QoL scores did not change after 2 years in patients with ischemia at baseline.

CONCLUSIONS

QoL scores assessing mental health, particularly depression and anxiety, predicted the development of new cardiac ischemia in asymptomatic diabetic patients. The study is limited by a small number of events (new ischemia) and so the results should be considered hypothesis generating rather than conclusive.

Prevalence of electrocardiographic unrecognized myocardial infarction and its association with mortality

BACKGROUND

Identifying unrecognized myocardial infarction (MI) is important for secondary prevention. The aim of this study is to determine the prevalence and correlates of unrecognized MI and the association with mortality in the general population.

METHODS

All participants ≥18years participating in the Lifelines population, a three-generation Cohort Study and Biobank, were included (n=152,180). Participants with unrecognized MI were matched with controls without MI (1:2) based on age and gender. Unrecognized MI was defined when no history of MI was reported in combination with electrocardiographic (ECG) signs corresponding to MI. A history of MI was defined as a reported history of MI in combination with ECG signs and/or the use of antithrombotic medication.

RESULTS

MI was present in 1881(1.2%) of participants and was unrecognized in 431 (22.9%) participants. Under the age of 50years, percentages of unrecognized MI relative to the total amount of MI were 34% and 55% in men and women respectively. Compared to recognized MI, classical cardiovascular risk factors were less prevalent in participants with unrecognized MI. During a median follow- up time of 5, 4 and 4years, 4.4%, 6.4% and 2.2% of participants with unrecognized MI, recognized MI and without MI died, respectively. In a multivariable logistic regression unrecognized MI was an independent predictor of death.

CONCLUSIONS

The prevalence of unrecognized MI is substantial and classical cardiovascular risk factors are less prevalent in participants with unrecognized MI. Nevertheless, unrecognized MI is associated with mortality. Risk stratification and early diagnosis is necessary to reduce the morbidity and mortality after MI.

Pentraxin 3, ficolin-2 and lectin pathway associated serine protease MASP-3 as early predictors of myocardial infarction - the HUNT2 study

The lectin complement pathway is suggested to play a role in atherogenesis. Pentraxin-3 (PTX3), ficolin-1, ficolin-2, ficolin-3, MBL/ficolin/collectin-associated serine protease-3 (MASP-3) and MBL/ficolin/collectin-associated protein-1 (MAP-1) are molecules related to activation of the lectin complement pathway. We hypothesized that serum levels of these molecules may be associated with the incidence of myocardial infarction (MI). In a Norwegian population-based cohort (HUNT2) where young to middle-aged relatively healthy Caucasians were followed up for a first-time MI from 1995-1997 through 2008, the 370 youngest MI patients were matched by age (range 29-62 years) and gender to 370 controls. After adjustments for traditional risk factors, the two highest tertiles of PTX3 and the highest tertiles of ficolin-2 and MASP-3 were associated with MI, with odds ratios (95% confidence interval) of 1.65 (1.10-2.47) and 2.79 (1.83-4.24) for PTX3, 1.55 (1.04-2.30) for ficolin-2, and 0.63 (0.043-0.94) for MASP-3. Ficolin-1, ficolin-3 and MAP-1 were not associated with MI. In a multimarker analysis of all associated biomarkers, only PTX3 and MASP-3 remained significant. PTX-3 and MASP-3 enhanced prediction of MI compared to the traditional Framingham risk score alone (AUC increased from 0.64 to 0.68, p = 0.006). These results support the role of complement-dependent inflammation in the pathophysiology of cardiovascular disease.

Pain Tolerance in Persons With Recognized and Unrecognized Myocardial Infarction: A Population-Based, Cross-Sectional Study

BACKGROUND

Unrecognized myocardial infarction (MI) is a prevalent condition associated with a similar risk of death as recognized MI. It is unknown why some persons experience MI with few or no symptoms; however, one possible explanation is attenuated pain sensitivity. To our knowledge, no previous study has examined the association between pain sensitivity and recognition of MI.

METHODS AND RESULTS

We conducted a population-based cross-sectional study with 4849 included participants who underwent the cold pressor test (a common experimental pain assay) and ECG. Unrecognized MI was present in 387 (8%) and recognized MI in 227 (4.7%) participants. Participants with unrecognized MI endured the cold pressor test significantly longer than participants with recognized MI (hazard ratio for aborting the cold pressor test, 0.64; CI, 0.47-0.88), adjusted for age and sex. The association was attenuated and borderline significant after multivariable adjustment. The association between unrecognized MI and lower pain sensitivity was stronger in women than in men, and statistically significant in women only, but interaction testing was not statistically significant (P for interaction=0.14).

CONCLUSIONS

Our findings suggest that persons who experience unrecognized MI have reduced pain sensitivity compared with persons who experience recognized MI. This may partially explain the lack of symptoms associated with unrecognized MI.

Pathology of Human Coronary and Carotid Artery Atherosclerosis and Vascular Calcification in Diabetes Mellitus

The continuing increase in the prevalence of diabetes mellitus in the general population is predicted to result in a higher incidence of cardiovascular disease. Although the mechanisms of diabetes mellitus-associated progression of atherosclerosis are not fully understood, at clinical and pathological levels, there is an appreciation of increased disease burden and higher levels of arterial calcification in these subjects. Plaques within the coronary arteries of patients with diabetes mellitus generally exhibit larger necrotic cores and significantly greater inflammation consisting mainly of macrophages and T lymphocytes relative to patients without diabetes mellitus. Moreover, there is a higher incidence of healed plaque ruptures and positive remodeling in hearts from subjects with type 1 diabetes mellitus and type 2 diabetes mellitus, suggesting a more active atherogenic process. Lesion calcification in the coronary, carotid, and other arterial beds is also more extensive. Although the role of coronary artery calcification in identifying cardiovascular disease and predicting its outcome is undeniable, our understanding of how key hormonal and physiological alterations associated with diabetes mellitus such as insulin resistance and hyperglycemia influence the process of vascular calcification continues to grow. Important drivers of atherosclerotic calcification in diabetes mellitus include oxidative stress, endothelial dysfunction, alterations in mineral metabolism, increased inflammatory cytokine production, and release of osteoprogenitor cells from the marrow into the circulation. Our review will focus on the pathophysiology of type 1 diabetes mellitus- and type 2 diabetes mellitus-associated vascular disease with particular focus on coronary and carotid atherosclerotic calcification.

Prediabetes and the association with unrecognized myocardial infarction in the multi-ethnic study of atherosclerosis

BACKGROUND

With one-quarter of initial myocardial infarctions (MI) being unrecognized MI (UMI), recognition is critical to minimize further cardiovascular risk. Diabetes mellitus is an established risk factor for UMI. If impaired fasting glucose (IFG) also increased the risk for UMI, it would represent a significant public health challenge due to the rapid worldwide increase in IFG prevalence. We compared participants with IFG to those with normal fasting glucose (NFG) to determine if IFG was associated with UMIs.

METHODS

We performed cross-sectional analyses from the MESA, a population-based cohort study. There were 6,814 participants recruited during July 2000 to September 2002 from the general community at 6 field sites. After excluding those with diabetes mellitus or missing variables, 5,885 participants were included. At baseline, there were 4,955 participants with NFG and 930 participants with IFG. The main outcome was an UMI defined by the presence of pathological Q waves or minor Q waves with ST-T abnormalities on initial 12-lead electrocardiogram. Logistic regression was used to generate crude ORs and adjust for covariates.

RESULTS

There was a higher prevalence of UMI in those with IFG compared with those with NFG [3.5% (n = 72) vs 1.4% (n = 30)]. After adjustment for multiple risk factors, there was a higher odds of an UMI among those with IFG compared with those with NFG [OR: 1.60 (95% CI: 1.0-2.5); P = .048].

CONCLUSIONS

Impaired fasting glucose is associated with unrecognized myocardial infarctions in a multi-ethnic population free of baseline cardiovascular disease.

Myocardial ischaemia after hip and knee arthroplasty: incidence and risk factors

PURPOSE

Because the occurrence of postoperative myocardial ischaemia (MI) predicts subsequent cardiac morbidity and mortality, we determined the prevalence of and risk factors for MI in hip and knee arthroplasty patients.

METHODS

High-sensitivity cardiac troponin T (hs-cTnT) was measured on stored samples from postoperative day two in 394 hip and knee arthroplasty patients ≥ 65 years of age enrolled in the Genetics-InFormatics Trial (GIFT).

RESULTS

Fifty-three (13.5 %) participants had MI, of whom only three were diagnosed clinically during their hospitalisation. The risk of MI increased with age [odds ratio (OR) 3.52 per decade, 95 % confidence interval (CI) 2.00-6.19] and diabetes (OR 2.23, 95 % CI 1.04-4.77). MI was rarer with statins (OR 0.74, 95 % CI 0.40-1.35) and more common with hypertension, coronary artery disease and tobacco use, although these were not statistically significant.

CONCLUSIONS

Subclinical MI occurs frequently after arthroplasty. Diabetic and elderly patients are at highest risk.

Sudden cardiac death during physical exercise: Characteristics of victims and autopsy findings

OBJECTIVE

To provide data on the risk factors and characteristics of subjects who experience sudden cardiac death (SCD) during physical exercise.

METHODS AND RESULTS

We assessed the characteristics and the medico-legal autopsy findings of SCD victims who had experienced a witnessed fatal cardiac arrest at rest (n = 876) or in relation to physical exercise (n = 328) in the Finnish Study of Genotype and Phenotype Characteristics of SCD (FinGesture). A total of 876 (73%) witnessed SCDs occurred at rest (R group) and 328 (27%) during or immediately after physical exercise (PE group). Male gender was more common in the PE group compared to the R group (309/328, 94% versus 678/876, 77%, P < 0.001). Coronary artery disease was a more common structural heart disease than non-ischemic disease at autopsy when SCD was exercise-triggered (299/328, 91% versus 657/876, 75%, P < 0.001). Myocardial scarring and cardiac hypertrophy were more commonly found at autopsy in the PE group (194/328, 59% versus 370/876, 42%, P < 0.001; 243/328, 74% versus 585/876, 67%, P = 0.012, respectively). Skiing, cycling, and snow shoveling were the most common modes of exercise at the time of SCD.

CONCLUSIONS

SCD during or immediately after exercise is related to male gender, ischemic heart disease, cardiac hypertrophy, and myocardial scarring.

Unrecognised myocardial infarction in patients with schizophrenia

OBJECTIVE

Schizophrenia is associated with a reduction of the lifespan by 20 years, with type II diabetes and cardiovascular disease contributing the most to the increased mortality. Unrecognised or silent myocardial infarction (MI) occurs in ~30% of the population, but the rates of unrecognised MI in patients with schizophrenia have only been sparsely investigated.

METHOD

Electrocardiograms (ECG) from three psychiatric hospitals in Denmark were manually interpreted for signs of previous MI. Subsequently, ECGs were linked to the National Patient Registry in order to determine whether patients had a diagnosis consistent with previous MI.

RESULTS

A total of 937 ECGs were interpreted, 538 men (57.4%) and 399 women (42.6%). Mean age at the time of ECG acquisition was 40.6 years (95% CI: 39.7-41.5, range: 15.9-94.6). We identified 32 patients with positive ECG signs of MIs. Only two of these patients had a diagnosis of MI in the National Patient Registry. An additional number of eight patients had a diagnosis of MI in the Danish National Patient Registry, but with no ECG signs of previous MI. This means that 30 out of 40 (75%) MIs were unrecognised. Only increasing age was associated with unrecognised MI in a stepwise multiple logistic regression model compared with patients with no history of MI, OR: 1.03 per year of age, 95% CI: 1.00-1.06, p=0.021.

CONCLUSION

Unrecognised MI is common among patients with schizophrenia and may contribute to the increased mortality found in this patient group.

Decision limits and the reporting of cardiac troponin: Meeting the needs of both the cardiologist and the ED physician

Cardiac troponin is the preferred biomarker for defining the acute coronary syndrome and acute myocardial infarction. Currently, the only decision limit formally endorsed with regard to the cardiac troponins is the 99th percentile. This is a "rule-in" criterion, intended to ensure that only persons with the acute coronary syndrome are reviewed. The 99th percentile is an arbitrary cut point and there are many problems associated with its application, including defining a truly healthy population, the difficulty of standardisation of cardiac troponin assays, especially but not only cardiac troponin I, and the effects of age and sex on this parameter. The Emergency Department (ED) screens many more persons for possible acute coronary syndromes than actually have the condition and their needs are best met by a "rule-out" test that enables them to clear their busy departments of the many persons who do not actually have the condition. The needs of the ED are not optimally met using the 99th percentile. The index of individuality for the cardiac troponins is small and significant changes consistent with an acute coronary syndrome can occur without the 99th percentile being exceeded. It appears that the ED may be better served by use of delta troponin changes rather than the 99th percentile, but there are problems with this approach, particularly in persons who present late when troponin release has plateaued. In addition, there are many non-acute coronary syndrome causes for cardiac troponin release. The needs of the cardiologist and the ED physician are so different that it may be inappropriate for both groups to use the same diagnostic criteria for cardiac troponin, and it is of great importance that cardiac troponin measurement be used as only one part of the assessment of the person presenting with possible acute coronary syndrome.

Progression to overt or silent CAD in asymptomatic patients with diabetes mellitus at high coronary risk: main findings of the prospective multicenter BARDOT trial with a pilot randomized treatment substudy

OBJECTIVES

The purpose of this study was to evaluate prevalence, progression, treatment, and outcome of silent coronary artery disease (CAD) in asymptomatic patients with diabetes (DM) at high coronary risk.

BACKGROUND

Despite the close association of diabetes and CAD, general CAD screening in asymptomatic patients with DM is discouraged even though outcome data in patients at high coronary risk are lacking.

METHODS

Prospective multicenter outcome study-with a pilot randomized treatment substudy. The study comprised 400 asymptomatic patients with DM (type 2) without history or symptoms of CAD at high CAD risk. They underwent clinical evaluation and myocardial perfusion single-photon emission computed tomography (MPS) at baseline and after 2 years. Patients with normal MPS received usual care; those with abnormal MPS received medical or combined invasive and medical management.

RESULTS

An abnormal MPS was found in 87 of 400 patients (22%). In patients with normal MPS, MACE occurred in 2.9% and ischemia or new scar in 3.2%. Patients with abnormal MPS had more MACE (9.8%; hazard ratio: 3.44; 95% confidence interval [CI]: 1.32 to 8.95; p = 0.011) and ischemia or new scar (34.2%; odds ratio: 15.91; 95% CI: 7.24 to 38.03; p < 0.001) despite therapy, resulting in "overt or silent CAD progression" of 35.6% versus 4.6% (odds ratio: 11.53; 95% CI: 5.63 to 24.70; p < 0.001). Patients with abnormal MPS randomized to medical versus invasive-medical strategies had similar event rates (p = 0.215), but more ischemic or new scar findings (54.3% vs. 15.8%; p < 0.001).

CONCLUSIONS

High-risk asymptomatic patients with DM and normal MPS (78%) have a low rate of first manifestations of CAD. Patients with abnormal MPS at baseline (22%) have a 7-fold higher rate of progression to "overt or silent CAD," despite therapy. Randomized patients' outcomes suggest that a combined invasive and medical strategy for silent CAD may reduce scintigraphic but not symptomatic CAD progression versus medical therapy alone. (Trial of Invasive versus Medical therapy of Early coronary artery disease in Diabetes Mellitus ISRCTN87953632).

Atypical presentation of acute and chronic coronary artery disease in diabetics

In patients with diabetes mellitus, cardiovascular disease is the principal cause of mortality and chest pain is the most frequent symptom in patients with stable and acute coronary artery disease. However, there is little knowledge concerning the pervasiveness of uncommon presentations in diabetics. The symptomatology of acute coronary syndrome, which comprises both pain and non-pain symptoms, may be affected by traditional risk factors such as age, gender, smoking, hypertension, diabetes, and dyslipidemia. Such atypical symptoms may range from silent myocardial ischemia to a wide spectrum of non-chest pain symptoms. Worldwide, few studies have highlighted this under-investigated subject, and this aspect of ischemic heart disease has also been under-evaluated in the major clinical trials. The results of these studies are highly diverse which makes definitive conclusions regarding the spectrum of atypical presentation of acute and even stable chronic coronay artery disease difficult to confirm. This may have a significant impact on the morbidity and mortality of coronary artery disease in diabetics. In this up-to-date review we will try to analyze the most recent studies on the atypical presentations in both acute and chronic ischemic heart disease which may give some emphasis to this under-investigated topic.

Pyridostigmine restores cardiac autonomic balance after small myocardial infarction in mice

The effect of pyridostigmine (PYR) - an acetylcholinesterase inhibitor - on hemodynamics and cardiac autonomic control, was never studied in conscious myocardial infarcted mice. Telemetry transmitters were implanted into the carotid artery under isoflurane anesthesia. Seven to ten days after recovery from the surgery, basal arterial pressure and heart rate were recorded, while parasympathetic and sympathetic tone (ΔHR) was evaluated by means of methyl atropine and propranolol. After the basal hemodynamic recording the mice were subjected to left coronary artery ligation for producing myocardial infarction (MI), or sham operation, and implantation of minipumps filled with PYR or saline. Separate groups of anesthetized (isoflurane) mice previously (4 weeks) subjected to MI, or sham coronary artery ligation, were submitted to cardiac function examination. The mice exhibited an infarct length of approximately 12%, no change in arterial pressure and increased heart rate only in the 1st week after MI. Vagal tone decreased in the 1^st week, while the sympathetic tone was increased in the 1^st and 4^th week after MI. PYR prevented the increase in heart rate but did not affect the arterial pressure. Moreover, PYR prevented the increase in sympathetic tone throughout the 4 weeks. Concerning the parasympathetic tone, PYR not only impaired its attenuation in the 1^st week, but enhanced it in the 4^th week. MI decreased ejection fraction and increased diastolic and systolic volume. Therefore, the pharmacological increase of peripheral acetylcholine availability by means of PYR prevented tachycardia, increased parasympathetic and decreased sympathetic tone after MI in mice.