Characteristics of presenting electrocardiograms of acute myocardial infarction from a community-based population predict short- and long-term mortality

Admission ECG changes predict short term-mortality after acute myocardial infarction less reliable in patients with diabetes

Prior studies examined association between short-term mortality and certain changes in the admission ECG in acute myocardial infarction (AMI). Nevertheless, little is known about possible differences between patients with diabetes and without diabetes in this regard. So the aim of the study was to investigate the association between 28-day case fatality according to certain ECG changes comparing AMI cases with and without diabetes from the general population. From 2000 until 2017 a total of 9756 AMI cases was prospectively recorded in the study Area of Augsburg, Germany. Each case was assigned to one of the following groups according to admission ECG: ‘ST-elevation’, ‘ST-depression’, ‘only T-negativity’, ‘predominantly bundle branch block’, ‘unspecific changes’ and ‘normal ECG’ (the last two were put together for regression analyses). Multivariable adjusted logistic regression models were calculated to compare 28-day case-fatality between the ECG groups for the total sample and separately for diabetes and non-diabetes cases. For the non-diabetes group, the parsimonious logistic regression model revealed significantly better 28-day-outcome for the ‘normal ECG / unspecific changes’ group (OR: 0.47 [0.29–0.76]) compared to the reference group (STEMI). Contrary, in AMI cases with diabetes the category ‘normal ECG / unspecific changes’ was not significantly associated with lower short-term mortality (OR: 0.87 [0.49–1.54]). Neither of the other ECG groups was significantly associated with 28-day-mortality in the parsimonious logistic regression models. Consequently, the absence of AMI-typical changes in the admission ECG predicts favorable short-term mortality only in non-diabetic cases, but not so in patients with diabetes.

Prognostic Significance of Right Bundle Branch Block for Patients with Acute Myocardial Infarction: A Systematic Review and Meta-Analysis

Background

The aim of the current meta-analysis was to assess the effect of right bundle branch block (RBBB) on mortality outcome in patients with acute myocardial infarction (AMI).

Material/Methods

Embase, PubMed, and Cochrane databases were searched through January 2015 using the keywords “RBBB”, “mortality”, “AMI”, “Coronary Heart Disease”, and “cardiovascular”. An odds ratio (OR) of RBBB on mortality endpoints was calculated using random-effects models.

Results

RBBB was associated with significantly increased overall mortality in patients with AMI. The OR of RBBB for deaths was 1.56 [95% confidence interval (CI), 1.44 to 1.68, p<0.001]. Moreover, RBBB showed a considerable effect on both in-hospital mortality (OR: 1.94, 95% CI: 1.60 to 2.37, p=0.002) and long-term mortality (OR: 1.49, 95% CI: 1.37 to 1.62, p<0.001).

Conclusions

RBBB is associated with an increased risk of all-cause mortality and indicates a poorer prognosis in patients with AMI.

Electrocardiographic presentation of global ischemia in acute coronary syndrome predicts poor outcome

BACKGROUND

Global ischemia (GI) electrocardiogram (ECG), wide-spread ST depression with inverted T waves maximally in leads V(4-5), and lead aVR ST elevation (STE), is a marker of an adverse outcome in patients with non-ST elevation acute coronary syndromes (ACS), perhaps because this pattern is indicative of left main stenosis. The prognostic value of this ECG pattern has not been established.

AIMS

The distribution of ECG changes and the prognostic value of the GI ECG were studied.

METHODS

ECGs of consecutive patients admitted with suspected ACS (n = 1,188) were classified into seven ECG categories: STE, Q waves without STE, left bundle branch block, left ventricular hypertrophy, GI ECG, other ST depression and/or T wave inversion, and other findings.

RESULTS

The GI ECG pattern predicted a high rate (48%) of composite end-points (mortality, re-infarction, unstable angina, resuscitation, or stroke) at 10-month follow-up compared to the other ECG categories (36%) (HR 1.78; CI 95% 1.31-2.41; P < 0.001). In multivariate analysis, the GI ECG pattern was associated with a higher rate of composite end-points (HR 1.40; CI 95% 1.02-1.91; P = 0.035). The multivariate analysis furthermore identified age, creatinine level, and diabetes as independent predictors of prognosis.

CONCLUSIONS

The GI ECG pattern predicted an unfavorable outcome, when compared to other ECG patterns in patients with ACS.

20-year trends in clinical characteristics, therapy and short-term prognosis in acute myocardial infarction according to presenting electrocardiogram: the MONICA/KORA AMI Registry (1985-2004)

OBJECTIVES

To examine the extent to which evidence-based beneficial therapy is applied in practice, whether this is changing over time and is associated with improved outcomes.

BACKGROUND

Randomized trials have proved efficacy of several treatments for acute myocardial infarction (AMI) with ST-elevation (STEMI), non-ST-elevation (NSTEMI) and bundle branch block (BBB).

DESIGN AND SETTING

We prospectively examined all 6748 consecutive patients with AMI aged 25-74 years hospitalized in the study region's major clinic stratified into four time-periods: 1985-1989 (n = 1622), 1990-1994 (n = 1588), 1995-1999 (n = 1450) and 2000-2004 (n = 2088).

RESULTS

The increase in numbers of AMI in the last period was mainly, but not exclusively driven by NSTEMI cases. Evidence-based pharmacological therapy increased steeply over time. Invasive procedures increased mainly in the last period with percutaneous coronary intervention and coronary artery bypass graft performed in 30% and 15% in 1998 and 66.0% and 22%, respectively, in 2004. In-hospital complications and 28-day-case fatality decreased significantly from period 1 to period 4 in all patients with AMI. Marked reductions in 28-day-case fatality were mostly seen in BBB patients during the last period (25.3% vs. 10.3%, P < 0.001). Of interest, the odds in 28-day-case fatality reduction was diminished after correction for recanalization therapy (from 0.35, 95% CI: 0.16-0.74 to 0.52, 95% CI: 0.19-1.45).

CONCLUSIONS

Over the past 20 years, there were substantial changes in pharmacological and interventional therapies in AMI accompanied by reductions in in-hospital complications and 28-day-case fatality in all infarction types with marked reductions in 28-day-case fatality in BBB patients. The latter observation may mainly be because of the increased use of interventional therapy.

Electrocardiographic findings at presentation, in relation to in-hospital mortality and 30-day outcome of patients with Acute Coronary Syndromes; The GREECS study

BACKGROUND

We sought to evaluate the impact of initial electrocardiographic findings at presentation on in-hospital mortality and 30-day outcome of patients with acute coronary syndromes (ACS).

METHODS

From October 2003 to September 2004, a sample of 6 hospitals located in several urban and rural Greek regions was selected, and almost all survivors 24 h after an admission for ACS were enrolled into the study (2172 patients were included in the study; 76% were men and 24% women). ECG and biochemical indices of myocardial damage were considered in all patients. Electrocardiographic findings at presentation were categorized as ST-elevation (STE), non-STE and non-diagnostic ECG abnormalities.

RESULTS

Of the 2172 patients, 34% had STE, 24% had non-STE and the 32% of them had non-diagnostic ECG abnormalities. After adjusting for age, sex and various other risk factors we observed that patients with STE had 3.3 (95% CI 1.4 to 7.7) higher risk of dying during hospitalization compared to those who had non-diagnostic ECG abnormalities. Furthermore, patients with non-STE had 1.5 (95% CI 0.9 to 2.5) higher risk of having an event (death or re-hospitalization due to CVD) during the first 30-days following discharge as compared to those who had non-diagnostic ECG abnormalities. All patients presented with non-STE ACS had higher 30-day event rates.

CONCLUSION

Patients with STE had higher in-hospital mortality, but lower longer term event rate after ACS in our population, irrespective of age, gender and other characteristics.

Characteristics and outcome of patients with acute myocardial infarction according to presenting electrocardiogram (from the MONICA/KORA Augsburg Myocardial Infarction--Registry)

Acute myocardial infarctions (AMIs) are categorized according to presenting electrocardiography into ST-elevation (STE), non-STE, and bundle branch block AMIs. Data on the characteristics and risks of these categories originate mainly from voluntary registries or clinical trials and may be hampered by selection and information bias. This study evaluated these different categories, with the additional differentiation of non-STE AMIs into ST-depression (STD) AMIs and those with nonspecific electrocardiographic signs (no-ST) in an unselected cohort. From 1985 to 2004, all consecutive patients aged 25 to 74 years who were hospitalized with AMI at the study region's major clinic were registered prospectively. A total of 6,748 patients were identified, of whom 45.8% had STE, 14.0% STD, 32.4% no-ST, and 7.8% bundle branch block AMIs, respectively. There were substantial differences in medical history, presentation, and therapy among the AMI types. Even after adjusting for the latter factors, the odds ratios of 28-day case fatality compared with no-ST were 1.26 (95% confidence interval 1.01 to 1.59) for STE, 1.84 (95% confidence interval 1.39 to 2.44) for STD, and 3.18 (95% confidence interval 2.37 to 4.27) for bundle branch block. In conclusion, after considering in-hospital therapy, the difference between STE and no-ST was nonsignificant, whereas the case-fatality difference between no-ST and STD persisted, suggesting some other unknown underlying factors associated with STD.

Cellular alternans: a mechanism linking calcium cycling proteins to cardiac arrhythmogenesis

Essentially all previous research on alternans has been restricted to normal myocardium, whereas sudden cardiac death (SCD) occurs most commonly in patients with ventricular dysfunction (i.e., heart failure), which is associated with marked disruption of proteins responsible for normal calcium cycling in myocytes. Several lines of evidence from studies in normal hearts suggest a link between impaired calcium cycling which characterizes ventricular mechanical dysfunction and impaired calcium cycling that is responsible for alternans. In normal myocardium, cells which exhibit the slowest calcium cycling, and not the slowest repolarization, are most susceptible to alternans. Decreased expression of key calcium cycling proteins is observed in alternans-prone cells. Sarcoplasmic reticulum ATPase (SERCA2a) expression is decreased, suggesting a mechanism for the slower sarcoplasmic reticulum (SR) calcium reuptake observed in alternans-prone cells. In addition, diminished ryanodine receptor (RyR) function leading to abnormal calcium release from the SR is also linked to cellular alternans. Although impaired contractile function clearly predisposes to SCD, the mechanisms linking mechanical to electrophysiological dysfunction in the heart are unclear. We propose that cellular calcium alternans may be an important mechanism linking mechanical dysfunction to cardiac arrhythmogenesis.

Long-term outcomes of left bundle branch block in high-risk survivors of acute myocardial infarction: The VALIANT experience

BACKGROUND

In survivors of myocardial infarction (MI), new left bundle branch block (LBBB) is associated with adverse outcomes, but its impact is not well described in post-MI patients with left ventricular (LV) systolic dysfunction and/or heart failure (HF).

OBJECTIVES

The aim of this study was to determine if new LBBB is an independent predictor of long-term fatal and nonfatal outcomes in high-risk survivors of MI by reviewing data from the VALsartan In Acute myocardial iNfarcTion (VALIANT) trial.

METHODS

In VALIANT, 14,703 patients with LV systolic dysfunction and/or HF were randomized to valsartan, captopril, or both a mean of 5 days after MI. Baseline ECG data were available from 14,259 patients. We assessed the predictive value of new LBBB for death and major cardiovascular outcomes after 3 years, adjusting for multiple baseline covariates including LV ejection fraction.

RESULTS

At follow-up, patients with new LBBB (608 [4.2%]) compared with patients without new LBBB had more comorbidities and increased adjusted risk of death (hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.2-1.6), cardiovascular death (HR 1.4, 95% CI 1.2-1.7), HF (HR 1.3, 95% CI 1.1-1.6), MI (HR 1.5, 95% CI 1.2-1.9), and the composite of death, HF, or MI (HR 1.4, 95% CI 1.2-1.6).

CONCLUSION

In post-MI survivors with LV systolic dysfunction and/or HF, new LBBB was an independent predictor of all major adverse cardiovascular outcomes during long-term follow-up. This readily available ECG marker should be considered a major risk factor for long-term cardiovascular complications in high-risk patients after MI.

Left bundle branch block as a risk factor for progression to heart failure

The prevalence of conduction disturbances, particularly left bundle branch block (LBBB), is strongly correlated with age and with the presence of cardiovascular disease. LBBB has been reported to affect approximately 25% of the heart failure (HF) population and it is likely that the deleterious role of such conduction disorders in the progression to HF has been underestimated. The purpose of this article is to review the data from the literature indicating that LBBB may have a causative role, mediated through the resulting intra-ventricular asynchrony, in the deterioration of cardiac function and the development of cardiac remodelling and HF. It also aims to address the potential for future clinical therapies for this conduction disorder.

The greatest benefit of enoxaparin over unfractionated heparin in acute coronary syndromes is achieved in patients presenting with ST-segment changes: the Enoxaparin in Non-Q-Wave Coronary Events (ESSENCE) Electrocardiogram Core Laboratory Substudy

BACKGROUND

We undertook a prospective electrocardiogram (ECG) substudy in the ESSENCE trial and hypothesized that patient subgroups with ST-segment deviation would experience greater benefit from enoxaparin, as compared with unfractionated heparin (UFH).

METHODS

Of the 3171 patients in the trial, 3087 had a qualifying ECG available for analysis by the core laboratory. Patients were divided into 4 mutually exclusive groups based upon the qualifying ECG: (1) ST-segment elevation, (2) ST-segment depression, (3) T-wave inversions, or (4) others.

RESULTS

The 30-day and 1-year primary outcomes (death, myocardial infarction, or recurrent angina) were significantly lower among patients with ST elevation or ST depression who received enoxaparin, as compared with UFH (20.8% vs 28.0%, P = .0019 and 32% vs 40.4%, P = .0011, respectively). The greatest absolute benefit of enoxaparin over UFH was seen in patients with ST depression (primary end point at 30 days, 24.6% vs 32.4%, P = .018; at 1 year, 35.5% vs 44.5%, P = .012).

CONCLUSION

Specific recognition of patients with ST-segment depression appears to identify those not only at high risk for adverse outcome, but also patients most likely to derive the greatest benefit from enoxaparin, as compared with UFH therapy.

Performance of the Thrombolysis in Myocardial Infarction (TIMI) ST-elevation myocardial infarction risk score in a national cohort of elderly patients

BACKGROUND

The TIMI ST-elevation myocardial infarction (STEMI) score was developed and validated in a randomized controlled trial population. We sought to assess its accuracy in a community-based cohort of elderly patients hospitalized with STEMI.

METHODS

We evaluated the TIMI STEMI score in 47,882 patients aged > or = 65 years hospitalized with STEMI in US hospitals from 1994 to 1996. We assessed TIMI STEMI score discrimination and calibration for 30-day mortality and compared observed and published TIMI mortality rates.

RESULTS

The cohort's median TIMI score was 6 (25th-75th percentile 4, 8). Thirty-day mortality rates were higher among patients with higher TIMI scores (TIMI score 2: 4.4% vs TIMI score > 8: 35.6%, P < .0001 for trend). However, the TIMI score provided only modest discrimination (c = 0.67) and calibration (goodness-of-fit P < .0001). Mortality rates for TIMI scores differed between patients who did and did not receive reperfusion therapy (P < .0001 for TIMI score x reperfusion therapy interaction). Thirty-day mortality rates in the cohort were higher than published TIMI estimates (P = .001; eg, TIMI score 2: 4.4% cohort vs 2.2% published rate).

CONCLUSIONS

The TIMI score provided modest prognostic discrimination and calibration among elderly patients with STEMI. Our findings highlight the difficulties in applying risk scores developed in randomized controlled trial cohorts to elderly patients.

Comparison of the prognostic effect of left versus right versus no bundle branch block on presenting electrocardiogram in acute myocardial infarction patients treated with primary angioplasty in the primary angioplasty in myocardial infarction trials

The presence of bundle branch block (BBB) has been associated with poor outcomes in patients who have acute myocardial infarction. Whether this is true in the angioplasty era is not known. We sought to evaluate the outcome of patients with acute myocardial infarction and BBB who were treated with primary angioplasty. We evaluated 3,053 patients who underwent emergency catheterization in the PAMI trials. Patients who had left BBB (n = 48, 1.6%) on presenting electrocardiogram were compared with patients who had right BBB (n = 95, 3.1%) or no BBB (n = 2,910, 95.3%). Patients who had BBB were older and more frequently had diabetes mellitus, peripheral vascular disease, and previous coronary artery bypass grafting. They had lower ejection fraction and more multivessel disease. There were no significant differences in door-to-balloon time, final Thrombolysis In Myocardial Infarction flow grade or stent use. In-hospital major adverse cardiac events (death, ischemic target vessel revascularization, and reinfarction) were higher in patients who had BBB due primarily to increased in-hospital death (left BBB 14.6%, right BBB 7.4%, no BBB 2.8%, p < 0.0001). In multivariate logistic regression analysis, left BBB was an independent predictor of in-hospital death (odds ratio 5.53, 95% confidence interval 1.89 to 16.1, p = 0.002). In conclusion, patients who have acute myocardial infarction and BBB have increased co-morbidities and higher mortality rates despite treatment with primary angioplasty. Despite early identification of multivessel disease with triage to angioplasty or coronary artery bypass grafting, if necessary, similar treatment times, and final Thrombolysis In Myocardial Infarction grade 3 flow, the presence of left BBB on admission electrocardiogram in patients who have acute myocardial infarction is an independent predictor of in-hospital mortality. Because 85% of deaths in patients who have left BBB occur within the first week, these patients should be recognized early and receive prompt and aggressive treatment.

ST-segment depression on the initial electrocardiogram in acute myocardial infarction-prognostic significance and its effect on short-term mortality: A report from the National Registry of Myocardial Infarction (NRMI-2, 3, 4)

This study analyzed 255,256 patients who had acute myocardial infarction and were enrolled in the National Registry of Myocardial Infarction 2, 3, and 4 (1994 to 2002). The objective was to determine in-hospital mortality rate among patients who had ST-segment depression on the initial electrocardiogram. Patients who had ST-segment depression had an in-hospital mortality rate (15.8%) similar to that of patients who had ST-segment elevation or left bundle branch block (15.5%). After adjusting for observed differences, ST-segment depression was associated with only a slightly lower odds ratio (0.91) of mortality compared with ST-segment elevation or left bundle branch block.

Coagulation, inflammation and myocardial dysfunction in unstable coronary artery disease and the influence of glycoprotein IIb/IIIa inhibition and low molecular weight heparin

Patients with unstable coronary artery disease (CAD) have an increased risk of subsequent myocardial infarction and death. This study evaluated the safety and efficacy of treatment with glycoprotein IIb/IIIa inhibition in addition to aspirin, low molecular-weight heparin and its influence on coagulation and inflammation. Also, early and differentiated risk assessment utilising markers of inflammation, myocardial damage and dysfunction were evaluated. The Global Utilisation of Strategies To open Occluded arteries-IV (GUSTO-IV) trial randomised 7800 patients with unstable CAD to 24 or 48 hours infusion of abciximab or placebo in addition to routine treatment with aspirin and heparin or dalteparin. Baseline levels of creatinine, C-reactive protein (CRP), troponin T (TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were analysed. At selected sites, all patients received subcutaneous dalteparin (n=974), in stead of heparin infusion (n=6826). In a sub-population of dalteparin treated patients (n=404), serial measurements of markers of coagulation, fibrinolysis and inflammation were also performed. Addition of abciximab to dalteparin as the primary treatment of unstable CAD was not associated with any significant reduction in cardiac events but a doubled risk of bleedings. The combination of abciximab with dalteparin seemed as safe when used with heparin. Despite full dose dalteparin and aspirin there was a simultaneous activation of the inflammation, coagulation and fibrinolysis systems without any influence of the abciximab treatment. Elevated levels of CRP, TnT, and NT-proBNP and reduced creatinine clearance were independently related to short and long-term mortality. The best prediction of high and low risk was provided by a combination of NT-proBNP and creatinine clearance. Any detectable elevation of TnT and reduced creatinine clearance, but neither elevation of CRP nor NT-proBNP, were also independently associated to a raised risk of subsequent myocardial infarction.

Diagnosing acute myocardial infarction in the setting of left bundle branch block: prevalence and observer variability from a large community study

BACKGROUND

Despite the known benefit of thrombolysis it remains under-utilized among eligible patients with acute myocardial infarction (AMI) and left bundle branch block (LBBB). We sought to determine the test characteristics and observer reliability of well-known criteria for the diagnosis of AMI when LBBB is present on the electrocardiogram (ECG).

METHODS

Four hundred and fourteen ECGs with LBBB from a large cohort of AMI patients (7.4% of the total) and 85 ECGs with LBBB not in the setting of acute coronary syndromes were interpreted for the presence of the Sgarbossa criteria.

RESULTS

Agreement for the various Sgarbossa criteria ranged from only fair to moderate. The three-way comparison kappa values were significantly better for ST depression than for both discordant (P<0.001) and concordant (P=0.001) ST-segment elevation. Concordant ST-segment elevation [6.3%, 95% confidence interval (CI) 4.3-9.1%] and depression (3.1%, 95% CI 1.8-5.4%) were infrequently seen in the setting of AMI and rarely seen otherwise. Discordant ST-segment elevation was seen more frequently (19.0%, 95% CI 15.5-23.1%). Concordant ST elevation and ST depression in V1-V3 were highly specific, but insensitive, for the diagnosis of AMI. The presence of discordant ST elevation was neither sensitive nor specific.

CONCLUSION

The low prevalence, poor sensitivity and marked observer variability make the Sgarbossa criteria for AMI in the setting of LBBB less than adequate. Although use of these criteria would be an advance over contemporary practice, it would still fall short among this high-risk subset.

Validity of a simple ST-elevation acute myocardial infarction risk index: are randomized trial prognostic estimates generalizable to elderly patients?

BACKGROUND

Risk-stratification scores derived from randomized clinical trial (RCT) data should be evaluated in community-based populations. A simple risk-stratification index for patients with ST-segment elevation myocardial infarction derived from an RCT population was recently proposed, but it has not been validated in a community-based cohort.

METHODS AND RESULTS

We evaluated the simple risk index using data from 49 711 patients > or =65 years of age hospitalized with ST-elevation myocardial infarction. We evaluated the distribution of patients in the 5 simple risk index groups, compared observed and published 30-day mortality rates, and assessed the score's discrimination and calibration. The simple risk index provided poor discrimination (c=0.62) and calibration (goodness of fit P<0.001) for survival at 30 days. Risk score distribution was skewed, because two thirds (66.1%) of all patients were classified in the highest-risk group, whereas fewer than 11.0% were classified in the 3 lowest-risk groups. Thirty-day mortality estimates were lower than those observed in the cohort (risk group 2 to 5: 1.9% to 17.4% versus 5.3% to 27.9%). Risk index discrimination, calibration, score distribution, and mortality estimates were worse among patients who did not receive acute reperfusion therapy than among those who did.

CONCLUSIONS

The limited performance of the simple risk index highlights the limitations of applying prognostic models derived in RCT populations to the general population of patients 65 years and older. Prognostic scores must be validated in community-based cohorts before integration into clinical practice.

Intercessory prayer and cardiovascular disease progression in a coronary care unit population: a randomized controlled trial

OBJECTIVE

To determine the effect of intercessory prayer, a widely practiced complementary therapy, on cardiovascular disease progression after hospital discharge.

PATIENTS AND METHODS

In this randomized controlled trial conducted between 1997 and 1999, a total of 799 coronary care unit patients were randomized at hospital discharge to the intercessory prayer group or to the control group. Intercessory prayer, ie, prayer by 1 or more persons on behalf of another, was administered at least once a week for 26 weeks by 5 intercessors per patient. The primary end point after 26 weeks was any of the following: death, cardiac arrest, rehospitalization for cardiovascular disease, coronary revascularization, or an emergency department visit for cardiovascular disease. Patients were divided into a high-risk group based on the presence of any of 5 risk factors (age = or >70 years, diabetes mellitus, prior myocardial infarction, cerebrovascular disease, or peripheral vascular disease) or a low-risk group (absence of risk factors) for subsequent primary events.

RESULTS

At 26 weeks, a primary end point had occurred in 25.6% of the intercessory prayer group and 29.3% of the control group (odds ratio [OR], 0.83 [95% confidence interval (CI), 0.60-1.14]; P=.25). Among high-risk patients, 31.0% in the prayer group vs 33.3% in the control group (OR, 0.90 [95% CI, 0.60-1.34]; P=.60) experienced a primary end point. Among low-risk patients, a primary end point occurred in 17.0% in the prayer group vs 24.1% in the control group (OR, 0.65 [95% CI, 0.20-1.36]; P=.12).

CONCLUSIONS

As delivered in this study, intercessory prayer had no significant effect on medical outcomes after hospitalization in a coronary care unit.