Acute Myocardial Infarction Death Research Articles

Parkinson disease and risk of acute myocardial infarction: A population-based, propensity score–matched, longitudinal follow-up study

Previous studies on the risk of acute myocardial infarction (AMI) in patients with Parkinson disease (PD) have generated inconsistent results. The purpose of this population-based longitudinal follow-up study was to investigate whether incident PD is associated with an increased risk of AMI. A total of 3,211 subjects with at least 2 ambulatory visits with the principal diagnosis of PD in 2001 were enrolled in the PD group. The non-PD group consisted of 3,211 propensity score-matched subjects without PD. The propensity scores were computed using a logistic regression model that included age, sex, preexisting comorbidities, and socioeconomic status. The 3-year AMI-free survival rates of the 2 groups were estimated using the Kaplan-Meier method. Stratified Cox proportional hazard regression with patients matched by propensity score was used to estimate the effect of PD on subsequent occurrence of AMI. During the 3-year follow-up period, 83 subjects in the PD group and 53 in the non-PD group developed AMI (either fatal or nonfatal) events. The hazard ratio of AMI for the PD group compared with the non-PD group was 1.67 (95% CI 1.15-2.41, P = .0067). The AMI-free survival rate of the PD group was significantly lower than that of the non-PD group (P = .0032). The hazard ratios associated with PD for the combined end point 1 (AMI or cardiovascular death) and combined end point 2 (AMI or all-cause death) were 1.46 (95% CI 1.14-1.88, P = .0029) and 1.42 (95% CI 1.24-1.64, P < .0001), respectively. This study shows that PD is related to an increased risk of AMI. Further studies are required to investigate the mechanism underlying this association.

Abstract 13052: Stability of Hospital Rankings for Acute Myocardial Infarction

Background: Although hospital mortality for acute myocardial infarction (AMI) varies widely, little is known regarding the trajectory of mortality over time at hospitals with high and low mortality at baseline. Methods: We studied 623,488 Medicare AMI patients at 1923 hospitals during 2007-2010. We used 30-day risk-standardized mortality rates (RSMR) to stratify hospitals as bottom 25% and top 25% in 2007 (baseline) and compared their performance on AMI mortality during next 3 years. We also ranked top 25% and bottom 25% hospitals into quartiles of RSMR, each year during 2008-2010 (0 = worst mortality quartile, to 3 = lowest mortality quartile), and summed quartile ranks for each year to yield a composite score (CS: range = 0 to 9). We examined which bottom 25% and top 25% hospitals achieved low ( &lt; 1) and high CS (≤ 8). Results: Average RSMR in 2007 was 15.5% (range: 11.2%-21.6%). During 2008-2010, there was considerable overlap in AMI mortality at 481 hospitals that were top 25% (blue bars) and bottom 25% (red bars), respectively (Figure). Of bottom 25% hospitals, only 107 (22%) had persistently high mortality over next 3 years (CS &lt; 1) where as 37 (8%) hospitals had marked improvement in AMI mortality (CS ≤ 8). Similarly, only 127 (26%) of top 25% hospitals had persistently low mortality over next 3 years (CS ≤ 8) and 37 (8%) had marked worsening in AMI mortality (CS &lt; 1). Average RSMR at hospitals with persistently high mortality was 18.5% vs. 13.7% at hospitals with persistently low mortality, which led to an additional 834 Medicare deaths at high mortality hospitals. Patient and hospital characteristics were limited in differentiating hospitals with persistently high and persistently low mortality. Conclusions: Among hospitals with high and low mortality at baseline, performance on AMI mortality does not persist during subsequent years. Concentrating quality improvement efforts at a few hospitals with persistently high mortality could avoid a substantial number of AMI deaths.

GW25-e3177 β2 adrenergic receptor selective agonist clenbuterol protects cardiac arrhythmia after reperfusion

Our Previous study has demonstrated that β2 adrenergic receptor (β2AR) activation reduces infarct size and myocardial apoptosis after myocardial ischemia/reperfusion. Cardiac arrhythmias are a major manifestation of reperfusion injury, which results in sudden death in acute myocardial infarction.

Outcomes after first percutaneous coronary intervention for acute myocardial infarction according to patient funding source.

BackgroundDisparities in the use of invasive coronary artery revascularisation procedures to manage acute myocardial infarction (AMI) have been found in several developed economies. Factors such as socio-economic status, income and funding source may influence the use of invasive procedures and have also been associated with ongoing care. The objectives of this study were to determine whether outcomes for patients at one and five years after AMI treated with first-ever percutaneous coronary intervention (PCI) were the same for public and privately funded patients.MethodsRetrospective, population-based cohort study using linked data to identify 30-day survivors of AMI treated with PCI in the index admission between 1995 and 2008 in Western Australian hospitals. The main outcome measures were admission for another PCI, re-AMI, and all-cause and cardiac mortality at one and five years.ResultsAt one year, private patients were at greater adjusted risk for another PCI (HR 1.62 [1.36 – 1.94]; p < 0.001) than public patients, and more likely to have an additional revascularisation procedure from 90 days to 5 years (HR 1.33 [1.11 – 1.58]; p < 0.001). They were at less risk for all-cause death within five years (HR 0.69 [0.62–0.91]; p = 0.01) with a trend to reduced risk for cardiac death and re-AMI.ConclusionsTreatment as a private patient for AMI with first PCI is associated with an increased likelihood of additional coronary revascularisation procedure within 12 months and to five years, and a reduced risk for all-cause mortality to 5 years. While additional procedures were not associated with poorer outcomes, there was no clear relationship between better outcomes and additional procedures. Other lifestyle and health care factors may contribute to the significant reduction in all-cause mortality and the trends to reduced hazard for AMI and cardiac death among private patients.

Association between intensification of metformin treatment with insulin vs sulfonylureas and cardiovascular events and all-cause mortality among patients with diabetes.

Preferred second-line medication for diabetes treatment after metformin failure remains uncertain. To compare time to acute myocardial infarction (AMI), stroke, or death in a cohort of metformin initiators who added insulin or a sulfonylurea. Retrospective cohort constructed with national Veterans Health Administration, Medicare, and National Death Index databases. The study population comprised veterans initially treated with metformin from 2001 through 2008 who subsequently added either insulin or sulfonylurea. Propensity score matching on characteristics was performed, matching each participant who added insulin to 5 who added a sulfonylurea. Patients were followed through September 2011 for primary analyses or September 2009 for cause-of-death analyses. Risk of a composite outcome of AMI, stroke hospitalization, or all-cause death was compared between therapies with marginal structural Cox proportional hazard models adjusting for baseline and time-varying demographics, medications, cholesterol level, hemoglobin A1c level, creatinine level, blood pressure, body mass index, and comorbidities. Among 178,341 metformin monotherapy patients, 2948 added insulin and 39,990 added a sulfonylurea. Propensity score matching yielded 2436 metformin + insulin and 12,180 metformin + sulfonylurea patients. At intensification, patients had received metformin for a median of 14 months (IQR, 5-30), and hemoglobin A1c level was 8.1% (IQR, 7.2%-9.9%). Median follow-up after intensification was 14 months (IQR, 6-29 months). There were 172 vs 634 events for the primary outcome among patients who added insulin vs sulfonylureas, respectively (42.7 vs 32.8 events per 1000 person-years; adjusted hazard ratio [aHR], 1.30; 95% CI, 1.07-1.58; P = .009). Acute myocardial infarction and stroke rates were statistically similar, 41 vs 229 events (10.2 and 11.9 events per 1000 person-years; aHR, 0.88; 95% CI, 0.59-1.30; P = .52), whereas all-cause death rates were 137 vs 444 events, respectively (33.7 and 22.7 events per 1000 person-years; aHR, 1.44; 95% CI, 1.15-1.79; P = .001). There were 54 vs 258 secondary outcomes: AMI, stroke hospitalizations, or cardiovascular deaths (22.8 vs 22.5 events per 1000 person-years; aHR, 0.98; 95% CI, 0.71-1.34; P = .87). Among patients with diabetes who were receiving metformin, the addition of insulin vs a sulfonylurea was associated with an increased risk of a composite of nonfatal cardiovascular outcomes and all-cause mortality. These findings require further investigation to understand risks associated with insulin use in these patients.

Impact of stepwise introduction of smoke-free legislation on population rates of acute myocardial infarction deaths in Flanders, Belgium

ObjectiveMany studies demonstrated a decline in hospital admissions for cardiovascular diseases after the implementation of a smoking ban, but evidence for reductions in cardiovascular mortality is more limited. In Belgium,...

Validation of an accelerated high‐sensitivity troponin T assay protocol in an Australian cohort with chest pain

To validate an accelerated biomarker strategy using a high-sensitivity cardiac troponin T (hs-cTnT) assay for diagnosing acute myocardial infarction (AMI) in patients presenting to the emergency department with chest pain; and to validate this strategy in combination with the National Heart Foundation of Australia/Cardiac Society of Australia and New Zealand risk stratification model. Single-centre, prospective, observational cohort study of 764adults presenting to a tertiary hospital with symptoms of possible acute coronary syndrome between November 2008and February 2011. AMI or cardiac death within 24hours of presentation (primary), and major adverse cardiac events within 30days (secondary). An elevated hs-cTnT assay result above the 99th percentile at either the 0h or 2h time points had sensitivity of 96.4% (95% CI, 87.9%-99.0%), specificity of 82.6% (95% CI, 79.7%-85.2%), negative predictive value of 99.7% (95% CI, 98.8%-99.9%) and positive predictive value of 30.5% (95% CI, 24.2%-37.6%) for diagnosing AMI. Compared with a traditional 6h cardiac troponin testing strategy, the accelerated strategy led to reclassification of risk in only two patients with adverse cardiac outcomes, with no net effect on appropriate management. In patients presenting with chest pain, an accelerated biomarker strategy using the hs-cTnT assay performed well in the initial diagnosis of AMI. The accelerated strategy was also effective when incorporated into a comprehensive strategy of risk stratification that included clinical and demographic factors. The time saved by this approach could have a major impact on health service delivery. Australian New Zealand Clinical Trials Registry ACTRN12610000053022.

Cost-Effectiveness of Optimal Use of Acute Myocardial Infarction Treatments and Impact on Coronary Heart Disease Mortality in China

The cost-effectiveness of the optimal use of hospital-based acute myocardial infarction (AMI) treatments and their potential impact on coronary heart disease (CHD) mortality in China is not well known. The effectiveness and costs of optimal use of hospital-based AMI treatments were estimated by the CHD Policy Model-China, a Markov-style computer simulation model. Changes in simulated AMI, CHD mortality, quality-adjusted life years, and total healthcare costs were the outcomes. The incremental cost-effectiveness ratio was used to assess projected cost-effectiveness. Optimal use of 4 oral drugs (aspirin, β-blockers, statins, and angiotensin-converting enzyme inhibitors) in all eligible patients with AMI or unfractionated heparin in non-ST-segment-elevation myocardial infarction was a highly cost-effective strategy (incremental cost-effectiveness ratios approximately US $3100 or less). Optimal use of reperfusion therapies in eligible patients with ST-segment-elevation myocardial infarction was moderately cost effective (incremental cost-effectiveness ratio ≤$10,700). Optimal use of clopidogrel for all eligible patients with AMI or primary percutaneous coronary intervention among high-risk patients with non-ST-segment-elevation myocardial infarction in tertiary hospitals alone was less cost effective. Use of all the selected hospital-based AMI treatment strategies together would be cost-effective and reduce the total CHD mortality rate in China by ≈9.6%. Optimal use of most standard hospital-based AMI treatment strategies, especially combined strategies, would be cost effective in China. However, because so many AMI deaths occur outside of the hospital in China, the overall impact on preventing CHD deaths was projected to be modest.

Performance of Risk Stratification for Acute Coronary Syndrome with Two-hour Sensitive Troponin Assay Results

Risk stratification processes for patients with possible acute coronary syndrome (ACS) recommend the use of serial sensitive troponin testing over at least 6h. Troponin assays vary in their analytical performance. Utility in accurate risk stratification at 2h post-presentation is unknown. A diagnostic accuracy study of patients presenting to the emergency department (ED) with symptoms of ACS was performed. Troponin was measured at 0, 2 and 6h post-presentation. Acute myocardial infarction (AMI) was adjudicated by cardiologists and incorporated the 0 and 6h troponin values measured by a sensitive troponin assay. Results were described using standard measures of test accuracy. Of the 685 patients, 51 (7.4%) had 30-day AMI or cardiac death, and 76 (11.1%) had secondary outcomes (all cause death, ACS and revascularisation procedures). There was no significant difference in the diagnostic accuracy of early versus late biomarker strategies when used with the current risk stratification processes. Incorporation of a significant delta did not improve the stratification at 2h post-presentation. Accelerated risk stratification of patients with ACS symptoms may occur at 2h post-presentation using troponin results measured by a sensitive assay. Incorporation of such a strategy could support improvements in patient flow within EDs.

Is There a Correlation Between Emergency Department Crowding Measures and Acute Myocardial Infarction Mortality?

The National Quality Forum has endorsed crowding measures which include emergency department (ED) length of stay (LOS) and rates of left without being seen (LWBS). Little is known about the association these performance measures have with patient outcomes for time-sensitive diseases such as acute myocardial infarction (AMI). To evaluate the association of both ED LOS for admitted patients and rate of LWBS with the outcome of 30-day mortality rate of AMI while controlling for other differences that may influence patient outcomes. Using merged 2008 data from Centers for Medicare & Medicaid Services and University HealthSystem Consortium (UHC) we examined Medicare patients ages 65 and older with a principal diagnosis of AMI from 23 hospitals across the US. We limited the cohort to patients admitted to UHC facilities. The facilities were categorized into quartiles for each of the two quality measures. Using a multivariate logistic regression model to account for clustering, we examined the association of the 2 quality measures as predictor variables for the outcome of 30-day mortality after adjustment for comorbidities, age, sex, and race. A total of 3825 patients with an average age of 77.0 (SD 7.9) and 53.5% male were included in the analysis. The average ED LOS of admitted patients across the four quartiles was 5.40, 6.95, 8.41, and 12.22 hours, while the proportion of LWBS was 1.44%, 2.94%, 5.07% and 9.81%. The crude 30-day AMI mortality rate for each quartile for ED LOS of admitted patients was 10.7% for the 1st (shortest ED LOS) quartile, 10.1% for the 2nd quartile, 9.2% for the 3rd quartile, and 12.3% for the fourth (longest ED LOS) quartile. When comparing the 3rd quartile to the 4th (longest ED LOS) for admitted patients quartile, the risk-adjusted OR of 30-day mortality was 0.74 (95% CI = 0.57 to 0.95 When comparing the 1st quartile (the lowest LWBS rate) to the 2nd quartile, the risk-adjusted OR of 30-day mortality was 0.77 (95% CI = 0.60 to 0.99). None of the other quartile comparisons for mean ED LOS, nor any of the LWBS quartiles were significantly different. There was a 26% lower odds of 30-day AMI death among patients admitted to hospitals in the 3rd quartile of ED LOS for admitted patients measure compared to hospitals who were in the 4th or longest quartile. There was a 23% lower odds or 30-day AMI death among patients admitted to hospitals in the quartile with the lowest LWBS rate when compared to the 2nd quartile. This study shows that future policies should not incentivize hospitals who have the quickest ED stays for admitted patients, but should further evaluate why hospitals in the 3rd quartile have a significantly lower AMI mortality than those in the 4th quartile. LWBS rates are important; however, further evaluations must be done to determine the correlation between LWBS and AMI 30-day mortality rates.

GW24-e2168 Cost-effectiveness of Improving Acute Myocardial Infarction Treatments and the impact on mortality rate of coronary heart disease in China

ObjectivesTo explore the cost-effectiveness of improving acute myocardial infarction (AMI) acute treatments and the potential impact on coronary heart disesease (CHD) mortality in China.MethodsThe effectiveness and costs of improving utilisation...

Risk factors analysis of in-hospital death of acute myocardial infarction patients following percutaneous coronary intervention

Objective To explore the risk factors of in-hospital death of acute myocardial infarction(AMI) patients following percutaneous cornary intervenion(PCI).Methods We retrospectively analyzed the clinical data of 275 AMI patients,including the general condition,medical history,admission,intra-and post-operation condition,and complication.The patients underwent PCI in our hospital from January 2009 to September 2011.Logistic regression analysis was used to predict the risk factor of in-hospital death of AMI patients following PCI.Results Logistic regression analysis found that female sex(P = 0.047,OR = 2.91),extensive anterior myocardial infarction(P = 0.044,OR = 3.07),history of renal insufficiency(P = 0.021,OR = 7.98),cardiogenic shock(P = 0.008,OR = 15.71),postoperative thrombolysis in myocardial infarction(TIMI) flow grade3(P = 0.016,OR = 5.61),and placement of the intra-aortic balloon pump(IABP,P = 0.043,OR = 3.49) were associated with an increased risk of in-hospital mortality of AMI patients following PCI.Conclusion Female sex,extensive anterior myocardial infarction,placement of the IABP,postoperative TIMI flow grade3,history of renal insufficiency,and cardiogenic shock are the risk factors of in-hospital death of AMI patients following PCI.

Impact of Cardiometabolic Risk Factors on Major Cardiovascular Events in Patients With Familial Combined Hyperlipidemia

Familial combined hyperlipidemia (FCH) is an inherited lipid disorder associated with premature cardiovascular disease. It has not been established whether the cardiometabolic risk factors, which frequently accompany FCH, such as diabetes, metabolic syndrome (MetS) and hypertension, modulate cardiovascular risk in FCH patients. In this single-center, retrospective study, 695 FCH patients with adequate follow-up were enrolled (mean age, 48.9 years; 455 male). Risk factors including lipid levels were evaluated before the initiation of treatment. Acute myocardial infarction (AMI) and cardiovascular death were recorded during a mean follow-up of 9 years. The combined endpoint (AMI and/or cardiovascular death) occurred in 41 patients (5.9% of the total). Those FCH patients who reached the combined endpoint had lower high-density lipoprotein cholesterol (HDL-C) than those who did not, but levels of other lipid variables were similar. Presence of hypertension, diabetes or MetS was a predictor of the combined endpoint on univariate Kaplan-Meier analysis (all P<0.005). Multivariate Cox proportional analysis showed that hypertension and MetS were associated with the combined endpoint independently of age, gender, HDL-C and presence of coronary artery disease at enrollment (adjusted hazard ratios [HRs], 3.00; 95% confidence interval [CI]: 1.46-6.17, P=0.003; HR, 2.43; 95CI%: 1.11-5.33, P=0.026, respectively). Cardiometabolic risk factors such as hypertension and MetS are independent predictors of major cardiovascular events in FCH patients.

Gaseous air pollution and acute myocardial infarction mortality in Hong Kong: A time-stratified case-crossover study

Acute myocardial infarction (AMI) is a common disease with serious consequences in mortality and morbidity. An association between gaseous air pollution and AMI has been suggested, but the epidemiological evidence is still limited. For the study period 1998–2010, daily counts of AMI deaths were collected, as well as daily air pollution data including concentrations of particulates (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3) and carbon monoxide (CO) were also obtained. The associations between gaseous air pollutants and AMI mortality were estimated using time-stratified case-crossover analyses. NO2 and SO2 were found to be significantly associated with increased AMI mortality. The odds ratios (ORs) were 1.0455 (95% confidence interval (CI): 1.017–1.0748) and 1.0256 (95% CI: 1.0027–1.0489) for an interquartile range (IQR) increase in the current day's NO2 and SO2 concentration, respectively, and this association persisted in 2-pollutant models; and no association was observed for CO and O3. It is likely that exposure to elevated ambient NO2 and SO2 air pollution contributed to increased AMI mortality.

A case-crossover study on the association between heat waves and daily deaths caused by acute myocardial infarction

To explore the effects of heat wave on daily deaths caused by acute myocardial infarction (AMI) in Beijing. A case-crossover design was used to study the impact of 5 heat waves on the daily number of AMI deaths from Jan. 1, 1999 to Jun. 30, 2000. The effect of heat wave on death in different gender or age groups was also compared. The 7th day before and after death occurred was chosen as its own bi-directional self-control. The OR value and its corresponding risk period was used to reflect the impact of heat wave on daily number of AMI deaths, lag days and duration. There were five heat waves during the study period. The first heat wave sustained 9 days and the maximum temperature was 38.8°C with average humidity as 46.7%. The OR value for the AMI death was 1.437 (95%CI: 1.066 - 1.937). The second heat wave lasted 3 days, with the maximum temperature of 36.8°C and average humidity of 61.0%. The OR value for the AMI death was 1.846 (95%CI: 0.671 - 5.076). The third heat wave continued 7 days, with the maximum temperature of 41.5°C with average humidity of 58.5%. The OR value for the daily death counts caused by AMI was 2.427 (95%CI: 1.825 - 3.229). The fourth lasted for 3 days, with the maximum temperature of 39.6°C and average humidity as 31.9%. The OR value for the AMI deaths was 2.857 (95%CI: 1.088 - 7.506). The fifth heat wave lasted for 4 days, with the maximum temperature as 37.4°C, and average humidity as 42.0% during this period. The OR value for daily death counts caused by AMI was 1.500 (95%CI: 0.632 - 3.560). The OR value of the first heat wave for daily death counts of men and women caused by AMI were 1.153 (95%CI: 0.756 - 1.758) and 1.818 (95%CI: 1.185 - 2.790) respectively. The OR value for daily death counts of under 65 age was 1.200 (95%CI: 0.669 - 2.153), with the OR value for the older than 64 age group was 1.534 (95%CI: 1.083 - 2.173). The OR value for daily death counts of older than 64 age women was 1.818 (95%CI: 1.109 - 2.981). The OR values of the third heat wave for daily death counts of men and women caused by AMI were 2.392 (95%CI: 1.649 - 3.470) and 2.514 (95%CI: 1.613 - 3.919) respectively. The OR value for daily death counts of under 65 age group was 2.000 (95%CI: 1.149-3.482) and the OR value for the older than 64 age group was 2.623 (95%CI: 1.880 - 3.660). The OR value for daily death counts of older than 64 age group women was 2.800 (95%CI: 1.676 - 4.678). (1) Significant increase for daily death counts of AMI in Beijing was noticed during the heat wave and usually causing hysteretic effect. The lag phase was 0 - 2 days in general. (2) The increase of maximum temperature was greater at the beginning day when the heat wave occurred in the previous day, with shorter lag time and greater risk of AMI death. (3) The risk of AMI death in women was greater than in men during the heat wave period. (4) The risk of AMI death among those older than 64 age group was greater than the under 65 year olds. (5) The impact of heat wave to the elderly female was greater.

Lyubertsy Study of mortality in patients with acute myocardial infarction (LIS): the analysis of anamnestic predictors of in-hospital mortality

Aim. To identify the main anamnestic predictors of mortality in the acute phase of acute myocardial infarction (AMI). Material and methods. The study included all patients admitted to Lyubertsy District hospitals and diagnosed with AMI (n=1133). Results. Out of 1133 hospitalised patients, 172 died in the hospital; in-hospital lethality was 15,2%. Mean age of diseased patients was significantly higher than that in those survived. The risk of in-hospital death was significantly and independently associated with older age (relative risk 1,07). After adjustment for age and sex, other independent predictors of in-hospital AMI death included diabetes mellitus (DM), low physical activity, and selected psychosocial factors. Conclusion. The in-hospital lethality levels, observed in the LIS Study, were typical for the Russian Federation. The main anamnestic predictors of in-hospital death were low physical activity, DM, and psychosocial risk factors.

Incidence and 30-day case fatality for acute myocardial infarction in England in 2010: national-linked database study

Background: There are limited national population-based epidemiological data on acute myocardial infarction (AMI) in England, making the current burden of disease, and clinical prognosis, difficult to quantify. The aim of this study was to provide national estimates of incidence and 30-day case fatality rate (CFR) for first and recurrent AMI in England. Methods: Population-based study using person-linked routine hospital and mortality data on 79 896 individuals of any age, who were admitted to hospital for AMI or who died suddenly from AMI in 2010. Results: Of 82 252 AMI events in 2010, 83% were first. Age-standardized incidence of first AMI per 100 000 population was 130 (95% CI 129–131) in men and 55.9 (95% CI 55.3–56.6) in women. Age-standardized 30-day overall CFRs including sudden AMI deaths for men and women, respectively, were 32.4% (95% CI 32.0–32.9) and 30.3% (95% CI 29.8–30.9) for first AMI and 29.7% (95% CI 28.7–30.7) and 26.7% (95% CI 25.5–27.9) for recurrent AMI. Age-standardized hospitalized 30-day CFR was 12.0% (95% CI 11.6–12.3) for men and 12.3% (95% CI 11.9–12.7) for women. Conclusions: While the majority of AMIs are not fatal, of those that are, two-thirds occur as sudden AMI deaths. About one in six of all AMIs are recurrent events. These findings reinforce the importance of primary and secondary prevention in reducing AMI morbidity and mortality.

Electrophysiological Effects of Lysophosphatidylcholine on HL-1 Cardiomyocytes Assessed with a Microelectrode Array System

Background: Sudden death due to malignant ventricular arrhythmias is the most important cause of death in acute myocardial infarction. Improved knowledge about the pathophysiology underlying these arrhythmias is essential in the search for new anti-arrhythmic strategies. Lysophosphatidylcholine (LPC), a hydrolysis product of (membrane) phospholipid degradation, is one of the most potent pro-arrhythmic substances that accumulate in the human heart during myocardial ischemia. The aim of this study was to set up and validate an in vitro experimental system for studies on the effects of LPC on electrophysiological parameters in beating cardiomyocytes. Methods and Results: Spontaneously beating HL-1 cardiomyocytes were cultured on multielectrode array microchips for three days for the recording of electrical activities in the form of field potentials (FP). FPs were recorded at baseline and after addition of 2, 4, 8, 12, 16, 20, and 24 µM of LPC to the cell medium (n=9). We found that LPC could induce rapid effects on electrical parameters in the HL-1 cells. The overall half-maximal effective concentration (EC₅₀) of LPC was around 12 µM. The beating rate and peak-peak amplitude of FP thus decreased at concentrations ≥ 12 µM and were inversely proportional to increased LPC concentration. The duration of FP was significantly prolonged with LPC above 12 µM and was concentration-dependent. LPC delayed signal propagation, an effect which was mimicked by blocking gap junctions with heptanol and attenuated by pre-treatment with isoprenaline and atropine. Finally, asynchronous activity was induced by LPC at >12 µM. Conclusions: LPC induced prompt and pronounced electrophysiological alterations that may underlie its observed pro-arrhythmic properties. Our in vitro model with HL-1 cells and microelectrode array system may be a useful tool for preclinical studies of electrophysiological effects of various pathophysiological concepts.

Clopidogrel Use and Early Outcomes Among Older Patients Receiving a Drug-Eluting Coronary Artery Stent

Clopidogrel use after drug-eluting stent (DES) coronary artery implantation is essential for the prevention of early in-stent thrombosis, but clopidogrel use among older DES recipients has not been widely studied. We sought to identify characteristics associated with failure to fill a clopidogrel prescription and to examine the relationship between a clopidogrel prescription fill and hospitalization for acute myocardial infarction (AMI) or death. This study was a retrospective analysis of administrative data (20% sample) of 15 996 Medicare Part D enrollees who received a DES in 2006 to 2007. We modeled the adjusted probability and odds of clopidogrel prescription fill within 7 and 90 days of discharge and its association with AMI hospitalization or death. Of the study sample, 19.7% did not fill a clopidogrel prescription within 7 days of discharge, falling to 13.3% by day 90. The adjusted probability of filling a clopidogrel prescription within 7 or 90 days of discharge was lower for patients with dementia (20.2% less likely; 95% CI, 10.4%-30.1%), depression (10.7% less likely; 95% CI, 6.9%-14.5%), age >84 years compared to age 65 to 69 years (10.6% less likely; 95% CI, 8.6%-12.7%), black race (6.6% less likely; 95% CI, 4.2%-9.0%), intermediate levels of medication cost share (5.2% less likely; 95% CI, 2.9%-7.6%), and female sex (3.3% less likely; 95% CI, 2.1%-4.5%). It was higher for patients initially hospitalized for an AMI (12.5% more likely; 95% CI, 11.3%-13.6%). Failure to fill a clopidogrel prescription within 7 days of discharge was associated with a higher adjusted odds ratio of death during days 8 to 90 (2.44; 95% CI, 1.76-3.38) but was not associated with an increased risk of hospitalization for AMI. One in 5 patients failed to fill a prescription for clopidogrel at 7 days after DES placement, and 1 in 7 failed to do so by 3 months. Individual characteristics available at the time of hospital discharge were associated with a clopidogrel prescription fill. Those characteristics most strongly associated with nonadherence, including age >84 years, not having an AMI, depression, and dementia, may guide clinicians and health systems seeking to target this high-risk population and improve health outcomes after percutaneous coronary intervention.

The extension of smoke-free areas and acute myocardial infarction mortality: before and after study

ObjectivesRecent studies suggest that comprehensive smoking regulations to decrease exposure to second-hand smoke reduce the rates of acute myocardial infarction (AMI). The objective of this paper is to analyse if...