Location of acute myocardial infarction and associated arrhythmias and outcome

Nanotechnology in coronary heart disease

Coronary heart disease (CHD) is one of the major causes of death and disability worldwide, especially in low- and middle-income countries and among older populations. Conventional diagnostic and therapeutic approaches have limitations such as low sensitivity, high cost and side effects. Nanotechnology offers promising alternative strategies for the diagnosis and treatment of CHD by exploiting the unique properties of nanomaterials. In this review, we use bibliometric analysis to identify research hotspots in the application of nanotechnology in CHD and provide a comprehensive overview of the current state of the art. Nanomaterials with enhanced imaging and biosensing capabilities can improve the early detection of CHD through advanced contrast agents and high-resolution imaging techniques. Moreover, nanomaterials can facilitate targeted drug delivery, tissue engineering and modulation of inflammation and oxidative stress, thus addressing multiple aspects of CHD pathophysiology. We discuss the application of nanotechnology in CHD diagnosis (imaging and sensors) and treatment (regulation of macrophages, cardiac repair, anti-oxidative stress), and provide insights into future research directions and clinical translation. This review serves as a valuable resource for researchers and clinicians seeking to harness the potential of nanotechnology in the management of CHD. STATEMENT OF SIGNIFICANCE: Coronary heart disease (CHD) is the one of leading cause of death and disability worldwide. Nanotechnology offers new strategies for diagnosing and treating CHD by exploiting the unique properties of nanomaterials. This review uses bibliometric analysis to uncover research trends in the use of nanotechnology for CHD. We discuss the potential of nanomaterials for early CHD detection through advanced imaging and biosensing, targeted drug delivery, tissue engineering, and modulation of inflammation and oxidative stress. We also offer insights into future research directions and potential clinical applications. This work aims to guide researchers and clinicians in leveraging nanotechnology to improve CHD patient outcomes and quality of life.

Reversible Causes of Atrioventricular Block

Atrioventricular blocks may be caused by a variety of potentially reversible conditions, such as ischemic heart disease, electrolyte imbalances, medications, and infectious diseases. Such causes must be always ruled out to avoid unnecessary pacemaker implantation. Patient management and reversibility rates depend on the underlying cause. Careful patient history taking, monitoring of vital signs, electrocardiogram, and arterial blood gas analysis are crucial elements of the diagnostic workflow during the acute phase. Atrioventricular block recurrence after the reversal of the underlying cause may pose an indication for pacemaker implantation, because reversible conditions may actually unmask a preexistent conduction disorder.

Reversible Causes of Atrioventricular Block

Atrioventricular blocks may be caused by a variety of potentially reversible conditions, such as ischemic heart disease, electrolyte imbalances, medications, and infectious diseases. Such causes must be always ruled out to avoid unnecessary pacemaker implantation. Patient management and reversibility rates depend on the underlying cause. Careful patient history taking, monitoring of vital signs, electrocardiogram, and arterial blood gas analysis are crucial elements of the diagnostic workflow during the acute phase. Atrioventricular block recurrence after the reversal of the underlying cause may pose an indication for pacemaker implantation, because reversible conditions may actually unmask a preexistent conduction disorder.

Assessment Framework for Recognizing Clinical Deterioration in Patients With ACS Undergoing PCI

TOPIC

Patients with acute coronary syndrome undergoing primary percutaneous coronary intervention are at risk of clinical deterioration that results in similar general signs and symptoms regardless of its cause. However, specific causes and forms of clinical deterioration are associated with key differences in assessment findings. Focused clinical assessments using a modified primary survey enable nurses to rapidly identify the cause and form of clinical deterioration, facilitating targeted treatment.

CLINICAL RELEVANCE

Clinical deterioration during percutaneous coronary intervention is associated with increased mortality and morbidity. Previous studies identified nursing inconsistencies when recognizing clinical deterioration, with inconsistent collection of cues and prioritization of cues related to cardiac performance over more sensitive indicators of clinical deterioration.

PURPOSE OF PAPER

To describe a framework to help nurses optimize physiological cue collection to improve recognition of clinical deterioration during periprocedural care of patients undergoing percutaneous coronary intervention for unstable acute coronary syndrome.

CONTENT COVERED

Literature analysis revealed 7 forms of clinical deterioration in patients undergoing percutaneous coronary intervention: coronary artery occlusion, stroke, ventricular rupture, valvular insufficiency, lethal cardiac arrhythmias, access-site and non-access-site bleeding, and anaphylaxis. Evidence for the pathophysiology, incidence, severity, and clinical features of each form of clinical deterioration is identified. A framework is proposed to help nurses conduct highly focused patient assessments, enabling prompt recognition of and response to the specific forms of clinical deterioration that occur in patients undergoing percutaneous coronary intervention.

Clinical impact of complete atrioventricular block in patients with ST-segment elevation myocardial infarction

Complete atrioventricular block (CAVB) is a common complication of ST-segment elevation myocardial infarction (STEMI). Although STEMI patients complicated with CAVB had a higher mortality in the thrombolytic era, little is known about the impact of CAVB on STEMI patients who underwent primary percutaneous coronary intervention (PCI). The study aimed at evaluating the clinical impact of CAVB on STEMI patients in the primary PCI era. We consecutively enrolled 1295 STEMI patients undergoing primary PCI within 24 hours from onset. Patients were divided into two groups according to the infarct location: anterior STEMI (n = 640) and nonanterior STEMI (n = 655). The outcomes were all-cause death and major adverse cardiocerebrovascular events (MACCE) with a median follow-up period of 3.8 (1.7-6.6) years. Eighty-one patients (6.3%) developed CAVB. The incidence of CAVB was lower in anterior STEMI patients than in nonanterior STEMI (1.7% vs 10.7%, p < .05). Anterior STEMI patients with CAVB had a higher incidence of all-cause deaths (82% vs 20%, p < .05) and MACCE (82% vs 25%, p < .05) than those without CAVB. Although higher incidence of all-cause deaths was found more in nonanterior STEMI patients with CAVB compared with those without CAVB (30% vs 18%, p < .05), there was no significant difference in the incidence of MACCE (24% vs 19%). Multivariate analysis showed that CAVB was an independent predictor for all-cause mortality and MACCE in anterior STEMI patients, but not in nonanterior STEMI. CAVB is rare in anterior STEMI patients, but remains a poor prognostic complication even in the primary PCI era.

First-degree atrioventricular block in acute anterior myocardial infarction

BACKGROUND

There is paucity of data regarding the prognostic implications of first-degree atrioventricular block in patients with acute anterior myocardial infarction as a distinct group. The aim of this study was to elucidate the association of prolonged PR interval with hospital clinical outcomes in patients with treated with thrombolysis.

METHODS

Three hundred consecutive patients with a first acute anterior ST-segment elevation myocardial infarction undergoing thrombolysis between October 2017 and March 2018, were retrospectively enrolled in this study. They were divided into two groups based on PR interval on admission: PR interval ≤200 ms, and PR interval > 200 ms. Hospital mortality and complications were compared between the 2 groups.

RESULTS

Of the 300 patients, 26 (8.66%) had first-degree atrioventricular block on initial presentation. Overall, hospital death occurred in 20 (6.66%) patients. Patients with PR interval > 200 ms had a higher hospital mortality rate (26.9%) than those without (4.7%, p < 0.001). In multivariate Cox regression analysis, only left ventricular systolic function and PR interval were independent predictors of hospital mortality (odds ratio = 1.031; 95% confidence interval: 1.008-1.056, p = 0.009 for PR interval).

CONCLUSION

In patients with a first acute anterior ST-segment elevation myocardial infarction treated with thrombolysis, first-degree atrioventricular block was associated with increased hospital mortality and a worse prognosis.

Consecutive electrocardiographic changes during percutaneous coronary intervention for acute coronary syndrome with high-grade atrioventricular block: a case report

Background

Acute coronary syndrome (ACS) with high-grade atrioventricular block (HAVB) still has a poor mortality risk, even in the current percutaneous coronary intervention (PCI) era. However, early PCI for ACS with HAVB is associated with improved in-hospital survival and a 6-month survival similar to that of ACS without HAVB.

Case presentation

A 70-year-old man was admitted to our hospital for ACS with HAVB. ECG showed complete AV block, complete right bundle branch block (CRBBB), and left axis deviation. Cardiac enzymes were elevated. He underwent temporary pacemaker insertion and coronary angiography, which showed severe stenosis of the proximal right coronary artery (RCA), 99% stenosis of the distal RCA with Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow, and total occlusion of the proximal left anterior descending artery (LAD). We performed primary PCI in both the RCA and LAD, which resulted in TIMI grade 3 flow in both. After PCI, the HAVB recovered to normal sinus rhythm with CRBBB; a normal QRS interval returned within three days. The patient was discharged from the hospital without complications.

Conclusion

In this case of ACS with HAVB, early intensive coronary artery reperfusion resulted in long-term patient survival. The blood supply to the AV node and bilateral bundle branches is complex. Multivessel ischemia may compromise both primary and collateral blood flows to the AV node and septum, resulting in severe conduction impairment. Clinicians performing PCI should be aware of this anatomy and physiology.

Electrocardiographic early repolarization is associated with future ventricular arrhythmia after acute myocardial infarction-Systematic Review and Meta-Analysis

BACKGROUND

Early repolarization (ER) has been linked to ventricular arrhythmia (VA) and sudden cardiac death in patients without structural heart disease. We aimed to assess the latest evidence on whether ER is associated with future VA after acute myocardial infarction (AMI).

METHODS

We performed a comprehensive search on the topic that assesses ER and VA/adverse cardiovascular events in AMI. We included studies with sufficient details on ER and VA, we also performed a meta-analysis on their morphology.

RESULTS

A total of 3350 subjects from 9 studies were included. Five hundred and twenty-one (15.55%) had ER and 2829 (84.45%) did not. On meta-analysis, ER (+) in AMI was associated with VA with a pooled odds ratio (OR) of 3.58 (2.70-4.73), P < 0.001; heterogeneity I 2 34%. Subgroup analysis of patients with ST-segment elevation myocardial infarction (STEMI) showed an OR of 2.79 [1.98-3.93], P < 0.001; heterogeneity I 2 0%. Inferior location of ER (+) was associated with VA OR 3.98 [1.86-8.53], P = 0.008; I 2 67%. Notching had a 5.41 [3.52-8.32], P < 0.001; low heterogeneity I 2 0% of having VA. Pooled OR for J-point elevation was 4.72 [2.63-8.46], P < 0.001; I 2 25%. Horizontal ST-segment was associated with VA with an OR of 4.30 [1.89-975], P < 0.001; I 2 59%. Lateral location and slurred morphology were not associated with VA. Upon sensitivity analysis for inferior location and horizontal ST-segment, removal of a study reduces heterogeneity significantly.

CONCLUSION

Early repolarization especially those with the inferior location, notching morphology, an elevated J-point and horizontal ST-segment had a higher likelihood of VA in AMI including STEMI patients.

Factors Affecting Early Mortality and 1-Year Outcomes in Young Women With ST-Segment-Elevation Myocardial Infarction Aged Less Than or Equal to 45 Years

Given that up to 2% of patients with myocardial infarction (MI) are young women, the purpose of this study was to evaluate factors affecting outcomes in young women with ST-segment-elevation myocardial infarction (STEMI) aged less than or equal to 45 years. We evaluated 796 women with STEMI aged less than or equal to 45 years between 2007 and 2014, and mortality was 4.0%. Death occurred more often in women with prehospital sudden cardiac arrest, and severe symptoms of heart failure; less commonly, the women were subjected to percutaneous coronary intervention (PCI), with a higher rate of incomplete revascularization. Beta blockers (BB) and angiotensin converting enzyme inhibitors were frequently used in the survivor group. The independent predictor of 30-day mortality was as follows: inability to undergo PCI (odds ratio [OR] 4.6, 95% confidence interval [CI] 1.45-14.76, P = 0.009), sudden cardiac arrest (OR 4.5, 95% CI 1.5-18.3, P = 0.04). An increase in systolic blood pressure for every 5 mm Hg was associated with lower mortality, OR 0.90, 95% CI 0.76-0.97 in patients without cardiogenic shock (CS) and OR 0.69, 95% CI 0.61-0.78, P < 0.0001 in the group with CS. Predictors for 1-year mortality were the inability to undergo PCI (hazard ratio [HR] 84, 95% CI 1.6-43.1, P = 0.01) and CS (HR 6.97, 95% CI 1.39-34.7, P = 0.01). An increase of 5% in left ventricular ejection fraction reduced the mortality rate for 60% (HR 0.40, 95% CI 0.26-0.63, P < 0.0001) and an increase in systolic blood pressure for every 5 mm Hg reduced mortality for 34% (HR 0.66, 95% CI 0.52-0.84, P = 0.02). Both short- and long-term outcomes in young women aged less than or equal to 45 years with STEMI are good. The strongest predictor for both 30-day and 1-year mortality was the inability to undergo PCI. Suboptimal use of beta blockers and angiotensin converting enzyme inhibitors affect the outcomes in young women. Hypotension in the acute phase of MI increased mortality in young women, independent of coexisting CS.

Bloc auriculoventriculaire du troisième degré et infarctus du myocarde à la prise en charge initiale

Les descriptions de l’incidence, de la gravité et des modalités de prise en charge des blocs auriculoventriculaires du troisième degré (BAV3) compliquant la phase aiguë des infarctus du myocarde, avec sus-décalage du segment ST (STEMI), sont rares et anciennes. Par ailleurs, les modalités de prise en charge des STEMI aigus ont beaucoup évolué. Le but de notre étude est d’évaluer l’incidence, de décrire la gravité et les modalités de prise en charge des BAV3 survenant à la phase aiguë des STEMI dans un contexte contemporain.

Matériel et méthodes : Nous avons réalisé une étude observationnelle rétrospective de la prise en charge des STEMI aigus à partir du registre prospectif des STEMI du Réseau nord alpin des urgences (RENAU) sur les 19 hôpitaux des Alpes du Nord entre 2009 et 2012. Les patients présentant un BAV3 à la phase initiale de leur prise en charge ont été identifiés.

Résultats : Deux mille sept cent neuf patients avec STEMI aigu ont été inclus sur la période d’étude. Cinquante-sept ont présenté un BAV3 (2 %). Cent cinquante-deux des 2 648 patients sans BAV3 (6 %) sont décédés à la phase hospitalière contre 7 des 57 patients (12 %) avec BAV3 (p = 0,047). Parmi les patients en BAV3, un traitement par atropine a été utilisé pour 26 patients et s’est révélé efficace pour (15 %) d’entre eux. L’isoprénaline a été utilisée pour huit patients et a induit une hypotension artérielle pour quatre d’entre eux. Une stimulation ventriculaire droite percutanée a été utilisée pour six patients et a toujours été efficace. Quatorze patients ont été thrombolysés (25 %). Une angioplastie de sauvetage a été nécessaire chez 10 des 14 patients en BAV3 traités par thrombolyse (71 %), comparés aux 325 des 840 patients sans BAV3 traités par thrombolyse (39 % ; p = 0,013).

Conclusion : L’incidence des BAV3 à la phase aiguë des STEMI est faible. Le BAV3 représente un facteur de sévérité. Les stratégies thérapeutiques sont d’efficacité inégale, avec des effets indésirables induits par l’isoprenaline. La thrombolyse chez ces patients est moins efficace.

Brain Natriuretic Peptide and Particular Left Ventricle Segment Asynergy Associated with Cardioembolic Stroke from Old Myocardial Infarction

BACKGROUND

It is important to determine the usage of anticoagulants by defining the actual risk of cardioembolic stroke in patients with old myocardial infarction. In the present study, we aimed to more precisely evaluate the risks of each segment associated with cardioembolic stroke using a 16-segment model. The usage of the plasma brain natriuretic peptide (BNP) associated with cardioembolic stroke was also evaluated in comparison with a left ventricle ejection fraction less than 40%.

METHODS

There were a total of 190 ischemic stroke patients who had premorbid myocardial infarction. The study included a total of 143 ischemic stroke patients with old myocardial infarction who were available for evaluation and excluded patients with atrial fibrillation or acute myocardial infarction. Their left ventricle wall motion abnormality and the level of plasma BNP at their admission were analyzed.

RESULTS

Hypertension and a plasma BNP level of 206.9 pg/mL or higher, determined from the receiver operating characteristic curve, were independently associated with cardioembolic stroke (χ(2) = 35.6, R(2) = .30, P < .001). Adjusting for these factors, statistically independent high risk was observed at the basal-inferior, basal-inferolateral, mid-anterior, mid-anteroseptal, apical-anterior, and apical-septal left ventricles.

CONCLUSION

High plasma BNP levels and left ventricular wall motion abnormalities in the segments perfused with left anterior descending coronary artery or right coronary artery show a high risk for cardioembolic stroke in patients with old myocardial infarction. Considering these factors, it could be possible to more precisely define the risk of cardioembolic stroke and to perform appropriate antithrombotic treatments in old myocardial infarction patients.

High-degree atrioventricular block, asystole, and electro-mechanical dissociation complicating non-ST-segment elevation myocardial infarction

Non-ST-segment myocardial infarction (NSTEMI) can be complicated by high-degree atrioventricular (AV) block, asystole, or electromechanical dissociation (EMD), but these events are not well characterized in the contemporary era. This analysis assesses the incidence of and factors associated with these dysrhythmias in acute NSTEMIs.

METHODS

Patients with NSTEMI in the EARLY ACS, PLATO, and TRACER trials were included in the pooled cohort (N = 29,677). Logistic regression was used to identify factors associated with in-hospital high-degree AV block and asystole or EMD, and Kaplan-Meier methods were used to assess mortality.

RESULTS

High-degree AV block occurred in 112 (0.4%) patients, asystole in 157 (0.5%), and EMD in 38 (0.1%). Pacemakers were inserted in 241 patients (0.8%) during the index hospitalization: 30 (12%) for AV block. Among patients with high-degree AV block, we observed more frequent right coronary artery lesions (47% vs 29%). Age, diabetes, lower heart rate, and lower blood pressure were associated with high-degree AV block. Higher Killip class, ST-segment depression, prior myocardial infarction, and peripheral vascular disease were most strongly associated with asystole or EMD. Ten-day unadjusted survival was 90% for patients with high-degree AV block and 43% for those with asystole or EMD.

CONCLUSIONS

Although high-degree AV block, asystole, and EMD were infrequent complications of NSTEMI, they were associated with substantial short-term mortality. Only 1 in 8 pacemakers placed in NSTEMI patients during the acute hospitalization was for high-degree AV block.

Prophylactic lidocaine for myocardial infarction

BACKGROUND

Coronary artery disease is a major public health problem affecting both developed and developing countries. Acute coronary syndromes include unstable angina and myocardial infarction with or without ST-segment elevation (electrocardiogram sector is higher than baseline). Ventricular arrhythmia after myocardial infarction is associated with high risk of mortality. The evidence is out of date, and considerable uncertainty remains about the effects of prophylactic use of lidocaine on all-cause mortality, in particular, in patients with suspected myocardial infarction.

OBJECTIVES

To determine the clinical effectiveness and safety of prophylactic lidocaine in preventing death among people with myocardial infarction.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 3), MEDLINE Ovid (1946 to 13 April 2015), EMBASE (1947 to 13 April 2015) and Latin American Caribbean Health Sciences Literature (LILACS) (1986 to 13 April 2015). We also searched Web of Science (1970 to 13 April 2013) and handsearched the reference lists of included papers. We applied no language restriction in the search.

SELECTION CRITERIA

We included randomised controlled trials assessing the effects of prophylactic lidocaine for myocardial infarction. We considered all-cause mortality, cardiac mortality and overall survival at 30 days after myocardial infarction as primary outcomes.

DATA COLLECTION AND ANALYSIS

We performed study selection, risk of bias assessment and data extraction in duplicate. We estimated risk ratios (RRs) for dichotomous outcomes and measured statistical heterogeneity using I(2). We used a random-effects model and conducted trial sequential analysis.

MAIN RESULTS

We identified 37 randomised controlled trials involving 11,948 participants. These trials compared lidocaine versus placebo or no intervention, disopyramide, mexiletine, tocainide, propafenone, amiodarone, dimethylammonium chloride, aprindine and pirmenol. Overall, trials were underpowered and had high risk of bias. Ninety-seven per cent of trials (36/37) were conducted without an a priori sample size estimation. Ten trials were sponsored by the pharmaceutical industry. Trials were conducted in 17 countries, and intravenous intervention was the most frequent route of administration.In trials involving participants with proven or non-proven acute myocardial infarction, lidocaine versus placebo or no intervention showed no significant differences regarding all-cause mortality (213/5879 (3.62%) vs 199/5848 (3.40%); RR 1.02, 95% CI 0.82 to 1.27; participants = 11727; studies = 18; I(2) = 15%); low-quality evidence), cardiac mortality (69/4184 (1.65%) vs 62/4093 (1.51%); RR 1.03, 95% CI 0.70 to 1.50; participants = 8277; studies = 12; I(2) = 12%; low-quality evidence) and prophylaxis of ventricular fibrillation (76/5128 (1.48%) vs 103/4987 (2.01%); RR 0.78, 95% CI 0.55 to 1.12; participants = 10115; studies = 16; I(2) = 18%; low-quality evidence). In terms of sinus bradycardia, lidocaine effect is imprecise compared with effects of placebo or no intervention (55/1346 (4.08%) vs 49/1203 (4.07%); RR 1.09, 95% CI 0.66 to 1.80; participants = 2549; studies = 8; I(2) = 21%; very low-quality evidence). In trials involving only participants with proven acute myocardial infarction, lidocaine versus placebo or no intervention showed no significant differences in all-cause mortality (148/2747 (5.39%) vs 135/2506 (5.39%); RR 1.01, 95% CI 0.79 to 1.30; participants = 5253; studies = 16; I(2) = 9%; low-quality evidence). No significant differences were noted between lidocaine and any other antiarrhythmic drug in terms of all-cause mortality and ventricular fibrillation. Data on overall survival 30 days after myocardial infarction were not reported. Lidocaine compared with placebo or no intervention increased risk of asystole (35/3393 (1.03%) vs 14/3443 (0.41%); RR 2.32, 95% CI 1.26 to 4.26; participants = 6826; studies = 4; I(2) = 0%; very low-quality evidence) and dizziness/drowsiness (74/1259 (5.88%) vs 16/1274 (1.26%); RR 3.85, 95% CI 2.29 to 6.47; participants = 2533; studies = 6; I(2) = 0%; low-quality evidence). Overall, safety data were poorly reported and adverse events may have been underestimated. Trial sequential analyses suggest that additional trials may not be needed for reliable conclusions to be drawn regarding these outcomes.

AUTHORS' CONCLUSIONS

This Cochrane review found evidence of low quality to suggest that prophylactic lidocaine has very little or no effect on mortality or ventricular fibrillation in people with acute myocardial infarction. The safety profile is unclear. This conclusion is based on randomised controlled trials with high risk of bias. However (disregarding the risk of bias), trial sequential analysis suggests that additional trials may not be needed to disprove an intervention effect of 20% relative risk reduction. Smaller risk reductions might require additional higher trials.

Predicting the burden of acute myocardial infarction in a country with limited resources: combining data from routine sources

BACKGROUND

Prior to implementation of a national surveillance system for cardiovascular disease in Barbados, a small island state with limited health resources, the national burden of acute myocardial infarction (MI) was unknown.

METHODS

We retrospectively estimated national acute MI incidence rates (IRs) per 100,000 during the decade before registry implementation (1999-2008), using easily accessible routine data from different sources, assessing changes over time through Poisson regression. Future events (2009-2013) were estimated using simple sensitivity analysis to incorporate prediction uncertainty. Model predictions were compared with actual IRs from initial years of the registry.

RESULTS

In 2000, crude IR was 85.5 (95% CI: 74.9-97.2), rising to 92.1 (81.2-103.9) in 2008. Accounting for population ageing, the model anticipated IR of 115.9 in 2010 (99.7-132.1), vs actual crude IR 129.7 (115.9-144.6).

CONCLUSIONS

Despite no electronic medical record system in Barbados, data were simple to collect, and provided a rough baseline for acute MI burden. We show that, in countries with small populations, limited resources and in absence of surveillance, national mortality statistics and routine hospital data can be combined to adequately model national estimates of acute MI incidence. This cheap and simple, yet fairly accurate method could be a key tool for other low-resource countries with ageing populations and increasing cardiovascular disease levels.

Influence of second- and third-degree heart block on 30-day outcome following acute myocardial infarction in the drug-eluting stent era

This study was conducted to investigate the prognostic value of heart block among patients with acute myocardial infarction (AMI) treated with drug-eluting stents. A total of 13,862 patients with AMI, registered in the nation-wide AMI database from January 2005 to June 2013, were analyzed. Second- (Mobitz type I or II) and third-degree atrioventricular block were considered as heart block in this study. Thirty-day major adverse cardiac events (MACE) including all causes of death, recurrent myocardial infarction, and revascularization were evaluated. Percutaneous coronary intervention with implantation of drug-eluting stent was performed in 89.8% of the patients. Heart block occurred in 378 patients (2.7%). Thirty-day MACE occurred in 1,144 patients (8.2%). Patients with heart block showed worse clinical parameters at initial admission, and the presence of heart block was associated with 30-day MACE in univariate analyses. However, the prognostic impact of heart block was not significant after adjustment of potential confounders (p = 0.489). Among patients with heart block, patients with a culprit in the left anterior descending (LAD) coronary artery had worse clinical outcomes than those of patients with a culprit in the left circumflex or right coronary artery. LAD culprit was a significant risk factor for 30-day MACE even after controlling for confounders (odds ratio 5.28, 95% confidence interval 1.22 to 22.81, p = 0.026). In conclusion, despite differences in clinical parameters at the initial admission, heart block was not an independent risk factor for 30-day MACE in adjusted analyses. However, a LAD culprit was an independent risk factor for 30-day MACE among patients with heart block.

Current cigarette smoking is an independent risk factor for subacute stent thrombosis in acute myocardial infarction patients

BACKGROUND

Acute myocardial infarction (AMI) is prevalent and has serious consequences including re-infarction and death. Cigarette smoking is a coronary risk factor for AMI, although a "smoker's paradox" for AMI has been reported in Western countries. On the other hand, some researchers have reported that smoking is associated with subacute stent thrombosis (SAST) after AMI. However, the occurrence of this condition is not well documented in Japan. The aim of this study was to clarify how prior smoking status may affect prognosis, including SAST, in Japanese patients with AMI.

METHODS

A total of 266 consecutive patients with AMI were enrolled retrospectively in the study if they had undergone emergency coronary intervention (bare metal stent) within 24h of symptom onset, and had a 5-10 month follow-up examination. The patients were divided into three groups based on their cigarette smoking status (non-smokers, past smokers, and current smokers).

RESULTS

Current smokers were significantly younger than the other two groups, although their levels of low density lipoprotein-cholesterol and triglyceride were significantly higher. White blood cell count and hemoglobin level on admission were also significantly higher in current smokers compared with the other two groups. The incidence of SAST was significantly higher in current smokers than in the other groups, although the occurrence of heart failure after AMI was similar in the three groups. On the other hand, improvement in left ventricular ejection fraction was observed in non-smokers and past smokers, but not in current smokers. Multiple logistic analysis revealed that current smoking was an independent risk factor for SAST (odds ratio 5.4; p<0.05). Current smokers were about five times more likely to have a SAST compared with non-smokers.

CONCLUSIONS

These findings indicate that current cigarette smoking predicts SAST after primary percutaneous coronary intervention for AMI in Japanese patients.

Hospitalizations for cardiovascular disease in African Americans and whites with HIV/AIDS

Therapeutic advances have resulted in an epidemiological shift in the predominant causes of hospitalization for patients with HIV/AIDS. An emerging cause for hospitalization in this patient population is cardiovascular disease (CVD); however, data are limited regarding how this shift affects different racial groups. The objective of this observational, retrospective study was to evaluate the association between race and hospitalization for CVD in African Americans and whites with HIV/AIDS and to compare the types of CVD-related hospitalizations between African Americans and whites with HIV/AIDS. Approximately 1.5 million hospital discharges from the US National Hospital Discharge Surveys for the years of 1996 to 2008 were identified. After controlling for potential confounders, the odds of CVD-related hospitalization in patients with HIV/AIDS were 45% higher for African Americans than whites (odds ratio [OR]=1.45, 95% CI, 1.39-1.51). Other covariates that were associated with increased odds of hospitalization for CVD included chronic kidney disease (OR=1.43, 95% CI, 1.36-1.51), age≥50 years (OR=3.22, 95% CI, 2.94-3.54), region in the Southern United States (OR=1.17, 95% CI, 1.11-1.23), and Medicare insurance coverage (OR=1.71, 95% CI, 1.60-1.83). Male sex was not significantly associated with the study outcome (OR=0.99, 95% CI, 0.96-1.02). Compared to whites with HIV/AIDS, African Americans with HIV/AIDS had more hospitalizations for heart failure and hypertension, but fewer hospitalizations for stroke and coronary heart disease. In conclusion, African Americans with HIV/AIDS have increased odds of CVD-related hospitalization as compared to whites with HIV/AIDS. Furthermore, the most common types of CVD-related hospitalizations differ significantly in African Americans and whites.

Gap junction heterogeneity as mechanism for electrophysiologically distinct properties across the ventricular wall

Gap junctions are critical to maintaining synchronized impulse propagation and repolarization. Heterogeneous expression of the principal ventricular gap junction protein connexin43 (Cx43) is associated with action potential duration (APD) dispersion across the anterior ventricular wall. Little is known about Cx43 expression patterns and their disparate impact on regional electrophysiology throughout the heart. We aimed to determine whether the anterior and posterior regions of the heart are electrophysiologically distinct. Multisegment, high-resolution optical mapping was performed in canine wedge preparations harvested separately from the anterior left ventricle (aLV; n = 8) and posterior left ventricle (pLV; n = 8). Transmural APD dispersion was significantly greater on the aLV than the pLV (45 +/- 13 vs. 26 +/- 8.0 ms; P < 0.05). Conduction velocity dispersion was also significantly higher (P < 0.05) across the aLV (39 +/- 7%) than the pLV (16 +/- 3%). Carbenoxolone perfusion significantly enhanced APD and conduction velocity dispersion on the aLV (by 1.53-fold and 1.36-fold, respectively), but not the pLV (by 1.27-fold and 1.2-fold, respectively), and produced a 4.2-fold increase in susceptibility to inducible arrhythmias in the aLV. Confocal immunofluorescence microscopy revealed significantly (P < 0.05) greater transmural dispersion of Cx43 expression on the aLV (44 +/- 10%) compared with the pLV wall (8.3 +/- 0.7%), suggesting that regional expression of Cx43 expression patterns may account for regional electrophysiological differences. Computer simulations affirmed that localized uncoupling at the epicardial-midmyocardial interface is sufficient to produce APD gradients observed on the aLV. These data demonstrate that the aLV and pLV differ importantly with respect to their electrophysiological properties and Cx43 expression patterns. Furthermore, local underexpression of Cx43 is closely associated with transmural electrophysiological heterogeneity on the aLV. Therefore, regional and transmural heterogeneous Cx43 expression patterns may be an important mechanism underlying arrhythmia susceptibility, particularly in disease states where gap junction expression is altered.