Management of acute myocardial infarction in patients presenting with persistent ST-segment elevation: the Task Force on the Management of ST-Segment Elevation Acute Myocardial Infarction of the European Society of Cardiology

Penehyclidine hydrochloride regulates mitochondrial dynamics and apoptosis through p38MAPK and JNK signal pathways and provides cardioprotection in rats with myocardial ischemia-reperfusion injury

AIM

The potential mechanism of penehyclidine hydrochloride (PHC) against myocardial ischemia-reperfusion (I/R) injury has not been fully elucidated. The aim of the present study was to reveal whether mitochondrial dynamics, apoptosis, and MAPKs were involved in the cardioprotective effect of this drug on myocardial I/R injury.

METHODS

Ninety healthy adult male Wistar rats were separately pretreated with normal saline (0.9%); PHC; and signal pathway blockers of MAPKs, Drp1, and Bcl-2. Coronary artery ligation and subsequent reperfusion were performed to induce myocardial I/R injury. Echocardiography was performed. Myocardial enzymes and oxidative stress markers were detected. Myocardial cell apoptotic rates and infarct sizes were measured. Mitochondrial function was evaluated. Expression levels of MAPKs, mitochondria regulatory proteins (Drp1, Mfn1/2), and apoptosis-related proteins (Bcl-2, Bax) were determined.

RESULTS

PHC pretreatment improved myocardial abnormalities (dysfunction, injury, infarct size, and apoptotic rate), mitochondrial abnormalities (dysfunction and fission), and excessive oxidative stress and inhibited the activities of p38MAPK and JNK signal pathways in rats with myocardial I/R injury (P < 0.05). Additionally, p38MAPK and JNK blockers (SB239063 and SP600125, respectively) had an effect on rats same as that of PHC. Although Drp1 blocker (Mdivi-1) showed a similar cardioprotective effect (P < 0.05), it did not affect the expression of MAPKs and apoptosis-related proteins (P > 0.05). In addition, Bcl-2 blocker (ABT-737) caused a high expression of Drp1 and a low expression of Mfn1/2 (P < 0.05).

CONCLUSION

PHC regulated mitochondrial dynamics and apoptosis through p38MAPK and JNK signal pathways and provided cardioprotection in rats with myocardial I/R injury.

CYP2C19 or CYP3A5 Genotyping Does Not Predict Clinical Response to Clopidogrel

Along with aspirin, clopidogrel has been a widely used antiplatelet therapeutic regimen. Although generally well tolerated, its efficacy varies among individuals, with the main hypothesis that its bioavailability relies on its bioconversion to the active compound, which, in turn, depends on the genetic background and/or interactions with other drugs. To determine which factors influenced response in our patients, 368 patients receiving combined antiaggregation therapy with aspirin and clopidogrel were followed for 1 year to record 30 novel cardiovascular acute events. This clinical relapse was considered a surrogate end point to measure therapeutic response under the influence of the CYP2C19*2, *3, and *17 and CYP3A5*3 alleles, as well as the effects of concomitant medication and the presence of known cardiovascular risk factors and comorbidity. We show that either single CYP2C19 or CYP3A5 genotyping or combined were not useful to predict clinical efficacy in this cohort. Rather than genetic testing, we have found that clinical observations such as suffering type 2 diabetes mellitus requiring insulin, having several vessels affected, and concurrent medication with calcium channel blockers, regardless of CYP3A5 genotype or drug class were, in that order, the strongest independent predictors of disease relapse.

Impact of time of admission on short- and long-term mortality in the Vienna STEMI registry

BACKGROUND

Several studies have shown contradictive findings regarding mortality and hospital admission time in patients presenting with ST-elevation myocardial infarction (STEMI). The aim of this study was to assess the impact of "on-" or "off-hour" admission on short- and long-term all-cause mortality of patients in the advanced Vienna STEMI network between 2003 and 2009.

METHODS AND RESULTS

In total, 2829 patients were included into this analysis. Patients were stratified according to admission time into "on-hour" admission (07:30 until 15:00h on weekdays) and "off-hour" admission (15:00-7:30h on weekdays and 24h on weekends). As endpoint of interest, all-cause mortality was investigated after 30days and 3years of follow-up, the latter for all patients and as Landmark analysis for survivors of the index event. Mean age was 60.5±13.3years, 2048 (72.4%) patients were male and 1260 (44.5%) patients presented with anterior wall infarction. 683 (24.1%) patients were admitted "on-hours", 2146 (75.9%) patients were admitted "off-hours". All-cause death occurred in 176 (6.2%) patients after a follow-up of 30days and in 337 (11.9%) patients after 3years. For short- and long-term all-cause mortality no significant differences could be detected between "on-" and "off-hour" admission in univariate and multivariate Cox proportional hazard analyses as well as for propensity score adjusted outcome analysis.

CONCLUSION

In the Vienna STEMI network, "on-" or "off-hour" admission had no impact on short- and long-term mortality for all-comers presenting with acute STEMI. Our findings confirm the imperative need for well-structured STEMI networks of care, as previous data repeatedly demonstrated increased adverse cardiovascular outcome for "off-hour" admission.

Prognostic Significance of Complex Ventricular Arrhythmias Complicating ST-Segment Elevation Myocardial Infarction

The aim of the study was to assess the clinical significance of complex ventricular arrhythmias (VAs) (sustained ventricular tachycardia [sVT] and ventricular fibrillation [VF]) in patients with ST-segment elevation myocardial infarction (STEMI) depending on timing of arrhythmia. We analyzed 4,363 consecutive patients with STEMI treated invasively between 2004 and 2014. The median follow-up was 69.6 months (range: 0 to 139.8 months). The study population was divided into 2 main groups; VA group encompassed 476 patients (10.91%) with VAs, whereas 3,887 subjects (89.09%) without VT or VF were included into the control group. In VA population, prereperfusion VA (34.24%; n = 163) was the most common arrhythmia, whereas reperfusion-induced, early postreperfusion, and late postreperfusion VAs were diagnosed in 103 (21.64%), 103 (21.64%), and 107 (22.48%) patients, respectively. Every type of sVT or VF complicating STEMI portended significantly worse in-hospital prognosis, however a late onset arrhythmia was associated with the highest (over fivefold) and reperfusion-induced VA with the lowest (less than threefold) increase in mortality risk compared with the control group. On the contrary, long-term mortality was significantly increased only in subjects with late postreperfusion and prereperfusion VAs compared with VA-free population (43.93% and 36.81%, respectively vs 22.58%; p <0.001). Apart from cardiogenic shock on admission, late postreperfusion (hazard ratio 3.39) and prereperfusion VAs (hazard ratio 2.76) were the strongest independent predictors of death in the analyzed population. In conclusion, 1 in 10 patients with STEMI treated invasively was affected by sVT or VF. The clinical impact of VAs was strongly dependent on timing of arrhythmia.

Clinical Events After Discontinuation of β‐Blockers in Patients Without Heart Failure Optimally Treated After Acute Myocardial Infarction

Background:

β-blockers have been among the first medications shown to improve outcomes after acute myocardial infarction (AMI). With the advent of reperfusion therapy and other secondary-prevention medications, their role has become uncertain, and large-scale experience after AMI in the contemporary era is lacking. In particular, the effect of stopping β-blockers in patients initially treated after AMI is unknown.

Methods and Results:

Using the French healthcare databases, 73 450 patients (<80 years of age), admitted for AMI in 2007 to 2012, without acute coronary syndrome (ACS) in the previous 2 years and no evidence of heart failure, having received optimal treatment with myocardial revascularization and all recommended medications in the 4 months after index admission, and not having discontinued β-blockers before 1 year, were followed for 3.8 years on average. β-Blocker discontinuation was defined as 4 consecutive months without exposure. If β-blocker treatment was resumed later on, follow-up was stopped. Both the risk of the composite outcome of death or admission for ACS and the risk of all-cause mortality were assessed in relation with β-blocker discontinuation during follow-up. Adjusted hazard ratios were estimated using marginal structural models accounting for time-varying confounders affected by previous exposure. A similar analysis was performed with statins. Of 204 592 patient-years, 12 002 (5.9%) corresponded to discontinued β-blocker treatment. For β-blocker discontinuation, the adjusted hazard ratio for death or ACS was 1.17 (95% confidence interval, 1.01–1.35); for all-cause death, the adjusted hazard ratio was 1.13 (95% confidence interval, 0.94–1.36). In contrast, for statin discontinuation, the adjusted hazard ratios for death or ACS and for all-cause death were 2.31 (95% confidence interval, 2.01–2.65) and 2.57 (95% confidence interval, 2.19–3.02), respectively.

Conclusions:

In routine care of patients without heart failure, revascularized and optimally treated after AMI, discontinuation of β-blockers beyond 1 year after AMI was associated with an increased risk of death or readmission for ACS, while statistical significance was not reached for the association with all-cause mortality. A contemporary randomized clinical trial is needed to precise the role of β-blockers in the long-term treatment after AMI.

Expert Consensus Document on Management of ST-Elevation Myocardial Infarction: Adaptation of 2012 ESC Guidelines

In 2012, the European Society of Cardiology (ESC) guidelines provided recommendations on the management of ST-elevation myocardial infarction (STEMI). The recommendation from these guidelines is restricted to the European subcontinent. To adapt the updated recommendations for Indian subset of STEMI patients, a panel of experts in the management of STEMI provided their expert opinions. This document provides expert consensus on adapting 2012 ESC STEMI guidelines recommendations in Indian setting. Document also discussed "India-specific" relevant literature to support the consensus opinions provided in the management of STEMI.

Favourable impact of statin use on diastolic blood pressure levels: analysis of a large database of 24-hour ambulatory blood pressure monitoring

INTRODUCTION

Assumption of lipid-lowering drugs, mostly statins, is recommended at bed-time and evidence demonstrated a strong and independent correlation between night-time blood pressure (BP) and increased risk of cardiovascular events.

AIM

To evaluate the effects of statins on night-time BP levels.

METHODS

We analysed data derived from a large cohort of adult individuals, who consecutively underwent home, clinic and ambulatory BP monitoring at our Unit. All BP measurements were performed and BP thresholds were set according to recommendations from European guidelines. Study population was stratified according to statin use.

RESULTS

We included an overall sample of 5634 adult individuals (women 48.9%, age 60.5 ± 11.6 years, BMI 27.0 ± 4.6 kg/m, clinic BP 144.3 ± 18.4/90.9 ± 12.4 mmHg, 24-h BP 130.7 ± 13.4/79.0 ± 9.7 mmHg), among whom 17.3% received and 82.7% did not received statins. Treated outpatients were older, had higher BMI and prevalence of risk factors and comorbidities than those who were untreated (P < 0.001 for all). Patients treated with statins showed lower DBP levels at all BP measurements, including night-time (67.3 ± 9.4 vs. 70.9 ± 9.7 mmHg; P < 0.001) periods, than those observed in untreated patients. Also, statin use resulted an independent factor associated with 24-h [odds ratio (95% confidence interval): 1.513(1.295-1.767); P < 0.001] and night-time [odds ratio (95% confidence interval): 1.357(1.161-1.587); P < 0.001] BP control, even after adjusting for age, sex, BMI, diabetes, number of antihypertensive drugs (model 1) or presence/absence of antihypertensive treatment (model 2).

CONCLUSION

Statin use was associated with significantly lower DBP levels. These effects were independently observed, even after correction for cardiovascular risk factors and comorbidities, as well as number of antihypertensive drugs.

Suppressed MMP-9 Activity in Myocardial Infarction-Related Cardiogenic Shock Implies Diminished Rage Degradation

BACKGROUND

Receptor for advanced glycation end products (RAGE) and its cleavage fragment soluble RAGE (sRAGE) are opposite players in inflammation. Enhanced monocytic RAGE expression and decreased plasma sRAGE levels are associated with higher mortality in infarction-related cardiogenic shock. Active matrix metalloproteinase-9 (MMP-9) has been implied in RAGE ectodomain cleavage and subsequently sRAGE shedding in vitro. We investigated MMP-9 activity in myocardial infarction-induced cardiogenic shock with regard to RAGE/sRAGE regulation.

METHODS AND RESULTS

We determined MMP-9 serum activity by zymography and tissue inhibitor of matrix metalloproteinases (TIMP-1) expression by Western blot and correlated it to RAGE/sRAGE data in patients with cardiogenic shock after acute myocardial infarction (CS, n = 30), in patients with acute myocardial infarction without shock (AMI, n = 20) and in healthy volunteers (n = 20).MMP-9 activity is increased in AMI (P = 0.02 versus controls), but significantly decreased in CS with lowest levels in non-survivors (n = 13, P = 0.02 versus AMI). In all patients, MMP-9 activity correlated inversely with RAGE expression on circulating monocytes (r = -0.57; P = 0.0001; n = 50).TIMP-1 levels showed an inverse regulation in comparison to active MMP-9 with significantly decreased levels in AMI as compared with controls (P = 0.02 versus controls) and highest levels in non-survivors of CS (P <0.001 versus AMI).

CONCLUSIONS

Serum MMP-9 activity is increased in acute myocardial infarction, but markedly suppressed in cardiogenic shock. Maintaining MMP-9 activity could be a therapeutic target to limit RAGE-induced deleterious inflammation in cardiogenic shock.

Mitophagy in Cardiomyocytes and in Platelets: A Major Mechanism of Cardioprotection Against Ischemia/Reperfusion Injury

Mitophagy, a process that selectively removes damaged organelles by autolysosomal degradation, is an early cellular response to ischemia. Mitophagy is activated in both cardiomyocytes and platelets during ischemia/reperfusion (I/R) and heart disease conditions. We focus on the molecular regulation of mitophagy and highlight the role of mitophagy in cardioprotection.

Temporal trends in clinical characteristics and management according to sex in patients with cardiogenic shock after acute myocardial infarction: The FAST-MI programme

BACKGROUND

Cardiogenic shock (CS) complicating acute myocardial infarction (AMI) occurs more frequently in women, but little is known about its potential specificities according to sex.

AIMS

To analyse the incidence, management and 1-year mortality of CS according to sex using the FAST-MI programme.

METHODS

The FAST-MI programme consists of four nationwide French surveys carried out 5 years apart from 1995 to 2010, including consecutive patients with AMI over a 1-month period, and with a 1-year follow-up.

RESULTS

Among the 10,610 patients included in the surveys, the incidence of CS was 4.8% in men and 8.2% in women (P<0.001). Absolute incidence of CS decreased from 1995 to 2010 in both sexes. Mean age in patients with CS tended to decrease in men (from 72±12 to 69±13 years) and to increase in women (from 78±10 to 80±9 years). One-year mortality decreased significantly in men (from 70% in 1995 to 48% in 2010) and in women (from 81% to 54%). Using Cox multivariable analysis, female sex was not an independent correlate of 1-year mortality [hazard ratio (HR): 0.98, 95% confidence interval (CI): 0.78-1.22]. Early use of percutaneous coronary intervention was, however, an independent predictor of 1-year survival in women (HR: 0.55, 95% CI: 0.37-0.81), but showed only a non-significant trend in men (HR: 0.85, 95% CI: 0.61-1.19).

CONCLUSIONS

The incidence of CS-AMI has decreased in both men and women, but remains higher in women. One-year mortality has significantly decreased for both men and women, and the role of early percutaneous coronary intervention as a potential mediator of decreased mortality seems greater in women than in men.

Cardioprotection and thyroid hormones

The evolution of cardiac disease after an acute ischemic event depends on a complex and dynamic network of mechanisms alternating from ischemic damage due to acute coronary occlusion to reperfusion injury due to the adverse effects of coronary revascularization till post-ischemic remodeling. Cardioprotection is a new purpose of the therapeutic interventions in cardiology with the goal to reduce infarct size and thus prevent the progression toward heart failure after an acute ischemic event. In a complex biological system such as the human one, an effective cardioprotective strategy should diachronically target the network of cross-talking pathways underlying the disease progression. Thyroid system is strictly interconnected with heart homeostasis, and recent studies highlighted its role in cardioprotection, in particular through the preservation of mitochondrial function and morphology, the antifibrotic and proangiogenetic effect and also to the potential induction of cell regeneration and growth. The objective of this review was to highlight the cardioprotective role of triiodothyronine in the complexity of post-ischemic disease evolution.

Risk stratification based on components of the complete blood count in patients with acute coronary syndrome: A classification and regression tree analysis

To develop a risk stratification model based on complete blood count (CBC) components in patients with acute coronary syndrome (ACS) using a classification and regression tree (CART) method. CBC variables and the Global Registry of Acute Coronary Events (GRACE) scores were determined in 2,693 patients with ACS. The CART analysis was performed to classify patients into different homogeneous risk groups and to determine predictors for major adverse cardiovascular events (MACEs) at 1-year follow-up. The CART algorithm identified the white blood cell count, hemoglobin, and mean platelet volume levels as the best combination to predict MACE risk. Patients were stratified into three categories with MACE rates ranging from 3.0% to 29.8%. Kaplan-Meier analysis demonstrated MACE risk increased with the ascending order of the CART risk categories. Multivariate Cox regression analysis showed that the CART risk categories independently predicted MACE risk. The predictive accuracy of the CART risk categories was tested by measuring discrimination and graphically assessing the calibration. Furthermore, the combined use of the CART risk categories and GRACE scores yielded a more accurate predictive value for MACEs. Patients with ACS can be readily stratified into distinct prognostic categories using the CART risk stratification tool on the basis of CBC components.

The Severity of Coronary Arterial Stenosis in Patients With Acute ST-Elevated Myocardial Infarction: A Thrombolytic Therapy Study

Background

It is widely believed that ST-elevated myocardial infarction (STEMI) generally occurs at the site of mild to moderate coronary stenosis. The aim of this study was to determine the degree of stenosis of infarct-related artery (IRA) in STEMI patients who underwent coronary angiography (CAG) after successful reperfusion with thrombolytic therapy (TT).

Methods

A total of 463 consecutive patients between January 2008 and December 2013 with acute STEMI treated with TT were evaluated retrospectively. The patients in whom reperfusion failed (n = 120), death occurred before CAG (n = 12), IRA cannot be determined (n = 10), and CAG was not performed in index hospitalization (n = 54) were excluded from the study. To determine the severity of stenosis of IRA, two experienced cardiologists who were unaware of each other used quantitative CAG analysis. Significant stenosis was defined as a ≥ 50% stenosis in the coronary artery lumen. A total of 267 patients who were successfully reperfused with TT and in whom CAG was performed during hospitalization with median 8 (1 - 17) days after myocardial infarction were included in the study.

Results

The mean age of patients was 55.7 ± 10.8 years (85.5% male). Most of the patients had a significant stenosis in IRA ( ≥ 50%, n = 236, group 1) after successful TT; whereas only 11.6% had stenosis < 50% (n = 31, group 2). In addition, majority of the patients had ≥ 70.4% (n = 188, 70.4%) stenosis in IRA. Average of stenosis in IRA was 74±16%.

Conclusions

In contrast to the general opinion, we detected that majority of STEMI patients had a significant stenosis in IRA.

rLj-RGD3, a novel recombinant toxin protein from Lampetra japonica, prevents coronary thrombosis-induced acute myocardial infarction by inhibiting platelet functions in rats

Recombinant Lampetra japonica RGD-peptide (rLj-RGD3), a soluble protein containing three RGD sequences, was acquired from the oral salivary glands of Lampetra japonica using recombinant DNA technology. The aim of this study was to investigate the protective effects of rLj-RGD3 against acute myocardial infarction (AMI) induced by coronary artery thrombosis, as well as the underlying mechanisms. A rat model of AMI caused by ferric chloride-induced thrombosis on the surface of the left anterior descending (LAD) coronary artery was successfully established. Rats were given various doses of rLj-RGD3 (12 μg/kg, 24 μg/kg and 48 μg/kg) via sublingual intravenous delivery 10 min before AMI. ST segment elevation was recorded by electrocardiogram (ECG) until the end of the model. Left ventricular Evans blue content and histopathological changes were examined. Blood samples were collected to determine 5-hydroxytryptamine (5-HT), β-thromboglobulin (β-TG), platelet factor 4 (PF4) and cAMP levels. The effects of rLj-RGD3 on platelet aggregation, adhesion and intracellular calcium concentrations were also measured. rLj-RGD3 significantly reduced ST segment elevation, prevented thrombus formation in the coronary artery and decreased Evans blue content in the left ventricular myocardium. Meanwhile, rLj-RGD3 exerted an inhibitory effect on adenosine diphosphate (ADP)-induced platelet aggregation and blocked platelet adhesion to collagen. Treatment with rLj-RGD3 prevented 5-HT, β-TG and PF4 release and significantly elevated intracellular cAMP levels in a dose-dependent manner but decreased the level of cytosolic-free Ca²⁺, an aggregation-inducing molecule. These results show that rLj-RGD3 can effectively reduce coronary thrombosis in AMI rats by strongly inhibiting platelet function, indicating that the recombinant RGD toxin protein rLj-RGD3 may serve as a potent clinical therapeutic agent for AMI.

Prevalence and clinical outcomes of white-coat and masked hypertension: Analysis of a large ambulatory blood pressure database

The aim of this study was to analyze prevalence and clinical outcomes of the following clinical conditions: normotension (NT; clinic BP < 140/90 mm Hg; 24-hour BP < 130/80 mm Hg), white-coat hypertension (WCHT; clinic BP ≥ 140 and/or ≥90 mm Hg; 24-hour BP < 130/80 mm Hg), masked hypertension (MHT; clinic BP < 140/90 mm Hg; 24-hour BP ≥ 130 and/or ≥80 mm Hg), and sustained hypertension (SHT; clinic BP ≥ 140 and/or ≥90 mm Hg; 24-hour BP ≥ 130 and/or ≥80 mm Hg) in a large cohort of adult untreated individuals. Systematic research throughout the medical database of Regione Lazio (Italy) was performed to estimate incidence of myocardial infarction (MI), stroke, and hospitalizations for HT and heart failure (HF). Among a total study sample of 2209 outpatients, 377 (17.1%) had NT, 351 (15.9%) had WCHT, 149 (6.7%) had MHT, and 1332 had (60.3%) SHT. During an average follow-up of 120.1 ± 73.9 months, WCHT was associated with increased risk of hospitalization for HT (OR 95% CI: 1.927 [1.233-3.013]; P = .04) and HF (OR 95% CI: 3.449 [1.321-9.007]; P = .011). MHT was associated with an increased risk of MI (OR 95% CI: 5.062 [2.218-11.550]; P < .001), hospitalization for HT (OR 95% CI: 2.553 [1.446-4.508]; P = .001), and for HF (OR 95% CI: 4.214 [1.449-12.249]; P = .008). These effects remained statistically significant event after corrections for confounding factors including age, BMI, gender, smoking, dyslipidaemia, diabetes, and presence of antihypertensive therapies.

Postoperative Bleeding Following Preoperative Clopidogrel Administration in Patients with Haemoglobin Level Above 110 g/L Undergoing Urgent CABG

INTRODUCTION

Patients with acute coronary syndrome usually receive dual antiplatelet therapy (DAPT) (usually clopidogrel + aspirin) prior to coronary catheterization, and approximately 10% of these patients require coronary artery bypass grafting (CABG). DAPT has favorable effects on prevention of thrombus formation, but it can have deleterious effects on surgical hemostasis. Anaemia, if present, gives additional risk to such patients. The aim of this study was to examine if DAPT affects postoperative bleeding in patients with haemoglobin levels above 110 g/L, who underwent urgent or emergent CABG, less than five days after stopping DAPT therapy.

METHODS

Data were collected prospectively on 122 CABG patients, operated by a surgical team from March 2008 to August 2013. Patients were stratified into two groups: group 1 received DAPT within 5 days of CABG (n=65), and group 2 where DAPT was discontinued for more than 5 days prior to CABG (n=57). All patients were diagnosed with acute coronary syndrome preoperatively, and all of them had haemoglobin levels above 110 g/L. Patients who needed reoperation, combined procedures, or off-pump revascularization were excluded.

RESULTS

There was no hospital mortality. Mean chest tube losses after the surgical revascularization did not differ significantly, but group 1 received a higher quantity of transfused red blood cells and platelets.

CONCLUSION

Urgent and emergent surgical revascularization using extracorporeal circulation in patients with acute coronary syndrome whose preoperative haemoglobin levels are above 110 g/L is a safe and effective procedure. We suggest that, where indicative, one may perform CABG in less than 5 days after the clopidogrel discontinuation.

Fibrinolytic treatment of ST-elevation myocardial infarction

Primary percutaneous coronary intervention (PPCI) is the preferred reperfusion therapy in ST-elevation myocardial infarction (STEMI), as long as it can be delivered within 90-120 minutes from patient’s first medical contact, and is the leading reperfusion strategy in most European countries. However, as PPCI cannot be offered in a timely manner to all patients, fibrinolytic therapy (FT) is the recommended choice in patients with an anticipated delay to PPCI of >90-120 minutes, presenting early after symptom onset and without contra-indications. FT should preferably be started in the pre-hospital setting. Following FT, all patients should be transferred to a PCI-center for rescue PCI or routine coronary angiography with PCI as indicated. Such a pharmaco-invasive strategy, combining FT with invasive treatment, has recently been shown to be non-inferior to PPCI in patients living in areas with long transfer delays to PCI (>60 minutes).

In this overview, we will briefly present the evidence for the benefit of FT in STEMI, and discuss the role of FT in the current era of PPCI as well as the optimal treatment following pharmacologic reperfusion.

Analysis of the CYP2C19 genotype associated with bleeding in Serbian STEMI patients who have undergone primary PCI and treatment with clopidogrel

PURPOSE

Bleeding is one of the possible adverse events during clopidogrel therapy. The CYP2C19 gene is the most significant genetic factor which influences response to clopidogrel treatment. We aimed to examine the contribution of the CYP2C19 gene to bleeding occurrence during clopidogrel therapy in Serbian patients with ST segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

METHODS

This case-control study included 53 patients who experienced bleeding and 55 patients without bleeding. Bleeding events were defined and classified using the Bleeding Academic Research Consortium (BARC) criteria. All patients were prescribed daily doses of clopidogrel during the 1-year follow-up after PCI. The CYP2C19*17 (c.-806C>T, rs12248560), rs11568732 (c.-889T>G, CYP2C19*20), CYP2C19*2 (c.681G>A; rs4244285) and CYP2C19*3 (c.636G>A; rs4986893) variants were analysed in all 108 patients. Additionally, sequencing of all nine exons, 5'UTR and 3'UTR in the rs11568732 carriers was performed.

RESULTS

Association between bleeding (BARC type ≥ 2) and the CYP2C19*17 variant was not observed [odds ratio (OR), 0.53; 95% confidence interval (CI), 0.2-1.1; p = 0.107). The rs11568732 variant showed significant association with bleeding (OR, 3.7; 95% CI, 1.12-12.44; p = 0.025). Also, we found that the rs11568732 variant appears independently of haplotype CYP2C19*3B, which is contrary to the previous findings.

CONCLUSIONS

Our results indicate the absence of CYP2C19*17 influence and turn the attention to the potential significance of the rs11568732 variant in terms of adverse effects of clopidogrel. However, it is necessary to conduct an independent conformation study in order to verify this finding. Also, an analysis of the functional implication of the rs11568732 variant is necessary in order to confirm the significance of this variant, both in relation to its influence on gene expression and in relation to its medical significance.

Platelet function variability and non-genetic causes

Dual antiplatelet therapy (DAPT) has been established for the treatment of coronary artery disease, especially in and after acute coronary syndromes, and after coronary interventions. Data suggest that a significant percentage of individuals treated with clopidogrel do not receive the expected therapeutic benefit because of a decreased responsiveness of their platelets, which is caused by several extrinsic and intrinsic mechanisms. The clinical consequence of clopidogrel non-responsiveness is severe cardiovascular complications. Besides genetic variability in response to antiplatelet therapy, non-genetic causes such as drug interactions (proton-pump inhibitors, statins, calcium-channel blockers, coumarine derivates, antibiotics, antimycotics) and co-morbidities (diabetes mellitus, renal failure, obesity) are responsible for this phenomenon. Large clinical trials with standardised laboratory methods and hard clinical endpoints are needed to identify these interactions with clopidogrel and predictors for its non-responsiveness.

Receptors to interleukin-6 and adhesion molecules on circulating monocyte subsets in acute myocardial infarction

The role of individual monocyte subsets in inflammation and recovery post-myocardial infarction (MI) is insufficiently understood. It was the objective of this study to evaluate the dynamics of monocyte expression of receptors to vascular cell adhesion molecule (VCAM-1r), intercellular adhesion molecule (ICAM-1r), and interleukin-6 (IL-6r) following MI and their relation to inflammatory cytokines, fibrinolytic factors and annexin V-binding microparticles. Expression of VCAM-1r, ICAM-1r, IL-6r on CD14++CD16–(Mon1), CD14++CD16+(Mon2), CD14+CD16++(Mon3) monocyte subsets were quantified by flow cytometry in patients with ST-elevation MI (STEMI, n=50), non-STEMI (n=48) and stable coronary artery disease (n=40). In STEMI, parameters were measured on days 1, 3, 7, 30. On admission with STEMI, VCAM-1r expression was reduced on Mon1 (p=0.007), Mon2 (p=0.036), Mon3 (p=0.005), whilst in NSTEMI there was significant up-regulation of expression by Mon2 (p=0.024) and Mon3 (p=0.049). VCAM-1r on Mon1 correlated positively with plasma IL-1β levels (p=0.001). IL-6r was reduced on Mon2 in acute STEMI, with upregulation of the receptor on Mon1 and Mon2 during follow-up. IL-6r density correlated negatively with plasma levels of tissue-type plasminogen activator (p=0.0005 for Mon1, p=0.001 for Mon2 and Mon3), and positively with annexin V-binding microparticles (p=0.03 for Mon1, p=0.005 for Mon2 and p=0.005 for Mon3). There was no change in monocyte ICAM-1r expression. In conclusion, expression of IL-6r and VCAM-1r is reduced on circulating monocyte subsets involved in inflammatory responses in STEMI. This may represent a regulatory feed-back mechanism aiming to re-balance the marked inflammation which is typically present following acute MI or selective homing of monocytes with high receptor expression to damaged myocardium.

Note: The review process for this manuscript was fully handled by Christian Weber, Editor in Chief.

High-dose atorvastatin versus moderate dose on early vascular protection after ST-elevation myocardial infarction

Background and aim

Clinical benefits of early high-dose statin therapy after acute coronary syndromes are widely known; however, there is poor evidence on the specific setting of ST-elevation myocardial infarction (STEMI) and dose-dependent effects of this therapy on endothelial function and inflammatory biomarkers in the most vulnerable phase after acute coronary syndromes: the postdischarge period. In our study, we compared the short-term effects of high (80 mg) vs moderate doses of atorvastatin (20 mg) in patients with STEMI undergoing primary percutaneous coronary intervention on endothelial function and vascular inflammation. The aim of our study was the evaluation of dose-dependent short-term effects.

Subjects and methods

We enrolled 52 patients within 48 hours of a STEMI to atorvastatin 80 mg (n=26) or 20 mg (n=26). Every patient underwent endothelial function evaluation by the reactive hyperemia–peripheral arterial tonometry (RH-PAT) index on the first day and 1 month after the STEMI. At the same time, we measured lipid profile and serum levels of high-sensitivity CRP, IL6, TNFα, and oxidized LDL.

Results

After 1 month of therapy, we observed differences in high-sensitivity CRP levels (0.04±0.02 mg/dL vs 0.36±0.3 mg/dL, P=0.001), IL6 (1.12±0.93 pg/mL vs 3.13±2.84 pg/mL, P=0.03), and improvement in RH-PAT index (1.96±0.16 vs 1.72±0.19, P=0.002) in the group treated with high-dose vs moderate-dose atorvastatin. There was no significant difference in levels of TNFα or oxidized LDL with atorvastatin 20 mg, while there was a reduction in these variables in the group treated with atorvastatin 80 mg. We observed a correlation between high-sensitivity polymerase chain reaction and RH-PAT index on the 30th day after STEMI (r=0.5, P=0.001).

Conclusion

Higher dose statin therapy in patients with STEMI undergoing primary percutaneous coronary intervention showed early greater vascular protective effects that moderate dose.

Early determination of clopidogrel responsiveness by platelet reactivity index identifies patients at risk for cardiovascular events after myocardial infarction

While acute myocardial infarction (MI) is associated with impaired clopidogrel responsiveness, systematic evaluation is lacking due to the inability of functional aggregation-based assays to analyse clopidogrel responsiveness in the presence of glycoprotein IIb/IIIa inhibitors. Using the P2Y12-specific, non-aggregation-based platelet-reactivity-index (PRI) we assessed clopidogrel responsiveness in patients with acute MI. Clopidogrel responsiveness was determined 24 hours (h) after loading with 600 mg clopidogrel in 54 patients with acute MI admitted for coronary intervention. A PRI > 50% was considered as suboptimal inhibition. Overall response in MI patients was suboptimal with a median PRI of 58%. Diabetes, low high-density lipoprotein and pre-hospital clopidogrel loading were associated with impaired clopidogrel responsiveness. Patients loaded at first medical contact had a significantly weaker platelet inhibition by clopidogrel after 24 h (PRI 63%) compared to those loaded peri-interventionally (PRI 54%, p=0.014). Clinical outcome was assessed as a combination of cardiac death, non-fatal MI, stent thrombosis, ischaemic stroke, and urgent target vessel revascularisation after 12 months. The pre-selected cut-off of PRI ≤ 50% yielded a sensitivity of 87% at a specificity of 26%, whereas a PRI ≤ 57% determined by receiver-operating characteristics (ROC)-analysis yielded a sensitivity of 80% at a specificity of 56% (event rate: PRI ≤ 57%: 12.0%; PRI > 57%: 41.4%, p=0.0136). In conclusion, PRI detects clopidogrel responsiveness in acute MI patients requiring glycoprotein IIb/IIIa antagonism; and impaired clopidogrel responsiveness predisposes to clinical events. Pre-hospital clopidogrel loading was associated with impaired response and more adverse events challenging the concept of earliest oral clopidogrel loading in MI patients.

A randomized study of prourokinase during primary percutaneous coronary intervention in acute ST-segment elevation myocardial infarction

OBJECTIVES

To evaluate the efficacy and safety of intracoronary administration of prourokinase via balloon catheter during primary percutaneous coronary interventions (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI).

METHODS

Acute STEMI patients underwent primary PCI were randomly divided into two groups: intracoronary prourokinase (IP) group (n = 118) and control group (n = 112). During primary PCI, prourokinase or saline were injected to the distal end of the culprit lesion via balloon catheter after balloon catheter dilatation. Demographic and clinical characteristics, infarct size, myocardial reperfusion, and cardiac functions were evaluated and compared between two groups. Hemorrhagic complications and MACE occurred in the 6-months follow up were recorded.

RESULTS

No significant differences were observed between two groups with respect to baseline demographic, clinical, and angiographic characteristics (P > 0.05). In IP group, more patients had complete ST segment resolution (>70%) compared with control group (P < 0.05). Patients in IP group showed lower levels of serum CK, CK-MB and TnI, and a much higher myocardial blood flow (MBF) than those in control group (P < 0.05). No significant differences of TIMI major or minor bleeding complications were observed between the two groups (P > 0.05). At 6-months follow-up, there was a trend that patients in the IP group had a less chance to have MACE, though it was not statistically different (8.5% vs 12.5%, P > 0.05).

CONCLUSIONS

Intracoronary administration of prourokinase via balloon catheter during primary PCI effectively improved myocardial perfusion in STEMI patients.

Parenteral anticoagulants in heart disease: Current status and perspectives (Section II)

Anticoagulants are a mainstay of cardiovascular therapy, and parenteral anticoagulants have widespread use in cardiology, especially in acute situations. Parenteral anticoagulants include unfractionated heparin, low-molecular-weight heparins, the synthetic pentasaccharides fondaparinux, idraparinux and idrabiotaparinux, and parenteral direct thrombin inhibitors. The several shortcomings of unfractionated heparin and of low-molecular-weight heparins have prompted the development of the other newer agents. Here we review the mechanisms of action, pharmacological properties and side effects of parenteral anticoagulants used in the management of coronary heart disease treated with or without percutaneous coronary interventions, cardioversion for atrial fibrillation, and prosthetic heart valves and valve repair. Using an evidence-based approach, we describe the results of completed clinical trials, highlight ongoing research with currently available agents, and recommend therapeutic options for specific heart diseases.

Differences in the Korea Acute Myocardial Infarction Registry Compared with Western Registries

The Korea Acute Myocardial Infarction Registry (KAMIR) is the first nationwide registry that reflects current therapeutic approaches and acute myocardial infarction (AMI) management in Korea. The results of the KAMIR demonstrated different risk factors and responses to medical and interventional treatments. The results indicated that the incidence of ST-elevation myocardial infarction (STEMI) was relatively high, and that the prevalence of dyslipidemia was relatively low with higher triglyceride and lower high-density lipoprotein cholesterol levels. Percutaneous coronary intervention (PCI) rates were high for both STEMI and non-ST-elevation myocardial infarction (NSTEMI) with higher use of drug-eluting stents (DESs). DES were effective and safe without increased risk of stent thrombosis in Korean AMI patients. Triple antiplatelet therapy, consisting of aspirin, clopidogrel, and cilostazol, was effective in preventing adverse clinical outcomes after PCI. Statin therapy was effective in Korean AMI patients, including those with very low levels of low-density lipoprotein cholesterol and those with cardiogenic shock. The KAMIR score had a greater predictive value than Thrombolysis in Myocardial Infarction (TIMI) and Global Registry of Acute Coronary Events (GRACE) scores for long-term mortality in AMI patients. Based on these results, the KAMIR will be instrumental for establishing new therapeutic strategies and effective methods for secondary prevention of AMI and guidelines for Asian patients.

The influence of microvascular injury on native T1 and T2* relaxation values after acute myocardial infarction: implications for non-contrast-enhanced infarct assessment

Objectives

Native T1 mapping and late gadolinium enhancement (LGE) imaging offer detailed characterisation of the myocardium after acute myocardial infarction (AMI). We evaluated the effects of microvascular injury (MVI) and intramyocardial haemorrhage on local T1 and T2* values in patients with a reperfused AMI.

Methods

Forty-three patients after reperfused AMI underwent cardiovascular magnetic resonance imaging (CMR) at 4 [3-5] days, including native MOLLI T1 and T2* mapping, STIR, cine imaging and LGE. T1 and T2* values were determined in LGE-defined regions of interest: the MI core incorporating MVI when present, the core-adjacent MI border zone (without any areas of MVI), and remote myocardium.

Results

Average T1 in the MI core was higher than in the MI border zone and remote myocardium. However, in the 20 (47%) patients with MVI, MI core T1 was lower than in patients without MVI (MVI 1048±78ms, no MVI 1111±89ms, p=0.02). MI core T2* was significantly lower in patients with MVI than in those without (MVI 20 [18-23]ms, no MVI 31 [26-39]ms, p<0.001).

Conclusion

The presence of MVI profoundly affects MOLLI-measured native T1 values. T2* mapping suggested that this may be the result of intramyocardial haemorrhage. These findings have important implications for the interpretation of native T1 values shortly after AMI.

Key points

• Microvascular injury after acute myocardial infarction affects local T1 and T2* values.

• Infarct zone T1 values are lower if microvascular injury is present.

• T2* mapping suggests that low infarct T1 values are likely haemorrhage.

• T1 and T2* values are complimentary for correctly assessing post-infarct myocardium.

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-017-5010-x) contains supplementary material, which is available to authorized users.

Significance of Atrial Fibrillation Complicating ST-Segment Elevation Myocardial Infarction

The aim of the present study is to assess the clinical impact of atrial fibrillation (AF) in patients with ST-segment elevation myocardial infarction (STEMI) complicated by new-onset AF depending on STEMI location and timing of arrhythmia. We analyzed 4,363 consecutive STEMI patients treated invasively. Finally, 4,099 subjects were included into further analysis, as 264 patients were excluded because of previous AF history. In total, 1,800 (43.9%) subjects with anterior infarction were included into Group 1, whereas Group 2 encompassed 2,299 (56.1%) patients with nonanterior infarction. Subsequently, both groups were divided into patients with new-onset AF (AF Group 1 and 2, respectively) and without AF (Control Group 1 and 2). New-onset AF was recognized in 225 patients (5.5%): 96 (5.3%) with an anterior wall infarction (AF Group 1) and 129 (5.6%) with a nonanterior wall infarction (AF Group 2). The incidence of early-onset arrhythmia (within 24 hours after admission) was significantly higher in AF Group 2 than in AF Group 1: 71.3% versus 35.4% (p <0.001). In Group 1, both early- and late-onset AFs were associated with significantly increased in-hospital mortality compared with AF-free population (17.7% and 27.4%, respectively vs 6.3%; p <0.05), whereas in Group 2, in-hospital mortality was increased only in subjects with late-onset AF compared with AF-free population (13.5% vs 4.2%, p <0.05). New-onset AF was the independent predictor of death only in Group 1 (hazard ratio 2.16) and this effect was stronger for late-onset AF (hazard ratio 2.86). In conclusion, 1 in 20 patients with STEMI treated invasively was affected by new-onset AF. The predictive value of new-onset AF was strongly related with STEMI location and timing of arrhythmia.

Influence of minor deterioration of renal function after PCI on outcome in patients with ST-elevation myocardial infarction

OBJECTIVES

Our aim was to assess the possible impact of a deterioration of renal function (DRF) not fulfilling the criteria for acute kidney injury after percutaneous coronary intervention (PCI) on outcome in patients with ST-elevation myocardial infarction (STEMI) on 30-day and long-term outcomes.

BACKGROUND

Data is lacking on the influence of DRF after PCI on outcome in patients with STEMI.

METHODS

The present study is an analysis of 2572 STEMI patients who underwent PCI. The group with DRF (1022 patients) and the group without DRF (1550 patients) were compared. Thirty-day and long-term all-cause mortality were observed. Data was analyzed using descriptive statistics.

RESULTS

Similar mortality was observed in both groups at day 30 (4.2% patients with DRF died vs 3.2% without DRF; ns) but more patients had died in the DRF group (18.9% patients with DRF vs 14.0% without DRF; P = 0.001) by the end of the observation period. After adjustments, DRF did not independently predict long-term mortality. Age more than 70 years, bleeding, hyperlipidemia, renal dysfunction on admission, anemia on admission, diabetes, PCI of LAD, the use of more than 200 mL contrast, but not DRF after PCI, were identified as independent prognostic factors for increased long-term mortality. Renal dysfunction, bleeding, contrast >200 mL, hyperlipidemia, age >70 years, anemia, and PCI LAD predicted DRF.

CONCLUSION

DRF identified patients at increased risk of higher long-term mortality but was not independently associated with mortality.

Development and validation of a risk model for long-term mortality after percutaneous coronary intervention: The IDEA-BIO Study

OBJECTIVES

We aimed to develop a model to predict long-term mortality after percutaneous coronary intervention (PCI), to aid in selecting patients with sufficient life expectancy to benefit from bioabsorbable scaffolds.

BACKGROUND

Clinical trials are currently designed to demonstrate superiority of bioabsorbable scaffolds over metal devices up to 5 years after implantation.

METHODS

From 2000 to 2011, 19.532 consecutive patients underwent PCI in a tertiary referral hospital. Patients were randomly (2:1) divided into a training (N = 13,090) and validation (N = 6,442) set. Cox regression was used to identify determinants of long-term mortality in the training set and used to develop a risk model. Model performance was studied in the training and validation dataset.

RESULTS

Median age was 63 years (IQR 54-72) and 72% were men. Median follow-up was 3.6 years (interquartile range [IQR] 2.4-6.8). The ratio elective vs. non-elective PCIs was 42/58. During 88,620 patient-years of follow-up, 3,156 deaths occurred, implying an incidence rate of 35.6 per 1,000. Estimated 5-year mortality was 12.9%.Regression analysis revealed age, body mass index, diabetes mellitus, renal insufficiency, prior myocardial infarction, PCI indication, lesion location, number of diseased vessels and cardiogenic shock at presentation as determinants of mortality. The long-term risk model showed good discrimination in the training and validation sets (c-indices 0.76 and 0.74), whereas calibration was appropriate.

CONCLUSIONS

A simple risk model, containing 9 baseline clinical and angiographic variables effectively predicts long-term mortality after PCI and may possibly be used to select suitable patients for bioabsorbable scaffolds.

Association Between Helicobacter Pylori Infection and Long-term Outcome in Patients with Drug-eluting Stent Implantation

To investigate the relationship between Helicobacter pylori (Hp) infection and the long-term outcome in acute coronary syndrome (ACS) patients with drug-eluting stent (DES) implantation and so as to explore the significance of Hp eradication therapy in preventing major adverse cardiac events (MACE) and upper gastrointestinal bleeding (UGIB). 539 ACS patients with DES implantation from January 1, 2010 to December 31, 2012 were analyzed. All the patients were divided into two groups according to the result of 13C urea breath test. 253 patients with Hp infection were put into group A (Hp+), and 286 cases without Hp infection were put into group B (Hp-). Demographic data was collected and all patients went through biochemical indicators and other routine blood examinations. We explored the correlations of Hp infection with MACE and UGIB after 3 to 5 years of follow-up using survival analysis. Survival analysis showed that Hp infection was a predictor of MACE and UGI. Sub-group analysis showed that patients with Hp eradication therapy had no relationship with MACE but had a lower rate of UGIB than those without Hp eradication therapy.

Baduanjin Exercise Prevents post-Myocardial Infarction Left Ventricular Remodeling (BE-PREMIER trial): Design and Rationale of a Pragmatic Randomized Controlled Trial

BACKGROUND

Left ventricular (LV) remodeling following myocardial infarction (MI) is an established prognostic factor for adverse cardiovascular events and the leading cause of heart failure. Empirical observations have suggested that Baduanjin exercise, an important component of traditional Chinese Qigong, may exert potential benefits on cardiopulmonary function. However, the impact of a Baduanjin exercise-based cardiac rehabilitation program for patients recovering from a recent MI has yet to be assessed. The aim of this trial is to evaluate the potential role of Baduanjin exercise in preventing the maladaptive progression to adverse LV remodeling in patients post-MI.

METHODS

A total of 110 clinically stable patients following an MI after undergoing successful infarct-related artery reperfusion will be randomly assigned to the Baduanjin exercise group or usual exercise control group. In addition to usual physical activity, participants in the Baduanjin exercise group will participate in a 45 min Baduanjin exercise training session twice a week, for a total of 12 weeks. The primary endpoint will be the percentage change in LV end-diastolic volume index (LVEDVi) assessed using echocardiography from baseline to 6 months.

CONCLUSION

The results of this study may provide novel evidence on the efficacy of Baduanjin exercise therapy in post-MI patients in reversing adverse LV remodeling and improving clinical outcome.

TRIAL REGISTRATION

Clinical Trials.gov: NCT02693795.

Percutaneous cardiac support during myocardial infarction drastically reduces mortality: perspectives from a swine model

BACKGROUND/AIMS

Acute myocardial infarction (AMI) with cardiogenic shock (CS) remains the leading cause of in-hospital death in acute coronary syndromes. In the AMI-CS pig model we tested the efficacy of temporary percutaneous cardiorespiratory assist device (PCRA) in rescuing the failing heart and reducing early mortality.

METHODS

In open-chest pigs we induced AMI by proximal left anterior descending coronary artery (LAD) ligation. Eight animals without PCRA (C group) were compared with 12 animals otherwise treated with PCRA (T group), starting approximately at 60 minutes post-occlusion and lasting 120-180 minutes. In 3 animals of the T group, regional myocardial oxygen content was also imaged by two-dimensional near infrared spectroscopy (2D-NIRS) with and without PCRA, before and after LAD reperfusion.

RESULTS

All animals without PCRA died despite unrelenting resuscitation maneuvers (120 minutes average survival time). Conversely, animals treated with PCRA showed a reduction in life-threatening arrhythmia and maintenance of aortic pressure, allowing interruption of PCRA in all cases early in the experiments, with sound hemodynamics at the end of the observation period. During LAD occlusion, NIRS showed severe de-oxygenation of the LAD territory that improved with PCRA. After PCRA suspension and LAD reperfusion, the residual de-oxygenated area proved to be smaller than the initial risk area.

CONCLUSIONS

In AMI, PCRA initiated during advanced CS drastically reduced early mortality from 100% to 0% in a 4-5 hour observation period. PCRA promoted oxygenation of the ischemic area during LAD occlusion. Results support the use of PCRA as first line of treatment in AMI-CS, improving myocardial rescue and short-term survival.

Necrotising coronaritis with fatal outcome

A 56-year-old woman presented with acute onset of typical chest pain. She was diagnosed with acute coronary syndrome with ST-segment elevation myocardial infarction. Although significant obstructive coronary artery disease was ruled out by coronary angiography, cardiac MRI showed transmural necrosis of the lateral free wall with extensive microvascular obstruction consistent with ischaemic heart disease. Within 48 hours after initial presentation, the patient suddenly arrested due to pulseless electrical activity with futile resuscitation efforts. Autopsy revealed myocardial perforation with extensive haematothorax due to pericardial laceration, caused by the mechanical chest compressions. Eventually, histology identified diffuse necrotising coronary vasculitis as a rare cause of ischaemic heart disease.

Privacy-Preserving Electrocardiogram Monitoring for Intelligent Arrhythmia Detection

Long-term electrocardiogram (ECG) monitoring, as a representative application of cyber-physical systems, facilitates the early detection of arrhythmia. A considerable number of previous studies has explored monitoring techniques and the automated analysis of sensing data. However, ensuring patient privacy or confidentiality has not been a primary concern in ECG monitoring. First, we propose an intelligent heart monitoring system, which involves a patient-worn ECG sensor (e.g., a smartphone) and a remote monitoring station, as well as a decision support server that interconnects these components. The decision support server analyzes the heart activity, using the Pan–Tompkins algorithm to detect heartbeats and a decision tree to classify them. Our system protects sensing data and user privacy, which is an essential attribute of dependability, by adopting signal scrambling and anonymous identity schemes. We also employ a public key cryptosystem to enable secure communication between the entities. Simulations using data from the MIT-BIH arrhythmia database demonstrate that our system achieves a 95.74% success rate in heartbeat detection and almost a 96.63% accuracy in heartbeat classification, while successfully preserving privacy and securing communications among the involved entities.