Ventricular fibrillation in acute myocardial infarction in Spanish patients: Results of the ARIAM database

Clinical and angiographic characteristics of out-of-hospital cardiac arrest among patients with ST-segment elevation myocardial infarction

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is the most severe complication of ST-segment elevation myocardial infarction (STEMI). Nevertheless, clinical and angiographic characteristics associated with OHCA among patients with STEMI have not been studied extensively.

AIM

To evaluate the clinical and angiographic characteristics of consecutive patients who presented with STEMI associated or not with OHCA.

METHODS

This was an observational study including consecutive patients treated for STEMI associated or not with OHCA. Baseline clinical and angiographic characteristics, biological characteristics and mortality were compared between patients with STEMI who experienced OHCA and patients with STEMI who did not.

RESULTS

Among the 686 included patients with STEMI, 148 (21.6%) presented with concomitant OHCA. Multivariable analysis revealed that culprit lesion localized on the left system (odds ratio [OR] 1.94, 95% confidence interval [CI] 1.24-3.13; P<0.01), culprit lesion at the level of a bifurcation lesion (OR 1.87, 95% CI 1.21-2.88; P<0.01) and the presence of chronic total occlusion on another artery (OR 3.39, 95% CI 1.93-5.99; P<0.001) were associated with the occurrence of OHCA, whereas dyslipidaemia, familial history of coronary artery disease and hypertension were found to be negatively associated with the occurrence of OHCA in patients with STEMI: OR 0.47, 95% CI 0.29-0.75 (P<0.01); OR 0.09, 95% CI 0.02-0.25 (P<0.001); and OR 0.60, 95% CI 0.38-0.93 (P=0.02), respectively.

CONCLUSION

In this study of consecutive patients with STEMI, culprit lesion localized on the left system, culprit lesion at the level of a bifurcation lesion and the presence of chronic total occlusion on a non-culprit artery were associated with OHCA.

ST-segment elevation predicts the occurrence of malignant ventricular arrhythmia events in patients with acute ST-segment elevation myocardial infarction

BACKGROUND

ST-segment elevation (STE) represents a repolarization dispersion marker underlying arrhythmogenesis in ST-segment elevation myocardial infarction (STEMI); however, its value for predicting malignant ventricular arrhythmia events (MVAEs) remains uncertain.

METHODS

In total, 285 patients with STEMI and those with or without MVAEs who presented within 6 h of symptom onset were enrolled. The relationships between STE and clinical characteristics of MVAEs (defined as ventricular tachycardia or ventricular fibrillation) were analyzed using t-test, chi-square test, binary multivariate logistic regression, and receiver operating characteristic curve analysis.

RESULTS

Patients with STEMI and MVAEs had a shorter time from symptom onset to balloon time (p = 0.0285) and greater STE (p < 0.01) than those without MVAEs. The symptom-to-balloon time, age, and STE were associated with MVAEs after stepwise regression analysis in all cases. Only STE was significantly associated with the occurrence of MVAEs (all, p < 0.01). The area under the curve (AUC) of STE for predicting MVAEs was 0.905, and the cut-off value was 4.5 mV. When only infarct-related arteries were included in the analysis, the AUC of the left anterior descending artery was 0.925 with a cut-off value of 4.5 mV, that of the right coronary artery was 0.915 with a cut-off value of 4.5 mV, and that of the left circumflex artery was 0.929 with a cut-off value of 4.0 mV.

CONCLUSIONS

In patients with STEMI presenting within 6 h of symptom onset, age, symptom-to-balloon time, and STE were the main predictors for MVAEs. However, among these, STE was the strongest predictor for MVAEs and was an index for repolarization dispersion of cardiomyocytes in infarcted and non-infarcted areas.

Clinical and Angiographic Features of Patients With Out-of-Hospital Cardiac Arrest and Acute Myocardial Infarction

BACKGROUND

Sudden cardiac arrest is a serious complication of acute myocardial infarction (MI). Although in-hospital mortality from MI has decreased, the mortality of MI patients complicated with out-of-hospital cardiac arrest (OHCA) remains high. However, the features of acute MI patients with OHCA have not been well known.

OBJECTIVES

We sought to characterize the clinical and angiographic features of acute MI patients with OHCA comparing with those without OHCA.

METHODS

We retrospectively analyzed 480 consecutive patients with acute MI undergoing percutaneous coronary intervention. Patients complicated with OHCA were compared with patients without OHCA.

RESULTS

Of the patients, 141 (29%) were complicated with OHCA. Multivariate analysis revealed that age (odds ratio [OR]: 0.8; 95% confidence interval [CI]: 0.7 to 0.9 per 5 years; p < 0.001), estimated glomerular filtration rate (OR: 0.8; 95% CI: 0.7 to 0.8 per 10 ml/min/1.73 m²; p < 0.001), peak creatine kinase-myocardial band (OR: 1.3; 95% CI: 1.2 to 1.4 per 10² U/l; p < 0.001), calcium-channel antagonists use (OR: 0.4; 95% CI: 0.2 to 0.7; p = 0.002), the culprit lesion at the left main coronary artery (OR: 5.3; 95% CI: 1.9 to 15.1; p = 0.002), and the presence of chronic total occlusion (OR: 2.9; 95% CI: 1.5 to 5.7; p = 0.001) were significantly associated with OHCA.

CONCLUSIONS

Younger age, no use of calcium-channel antagonists, worse renal function, larger infarct size, culprit lesion in the left main coronary artery, and having chronic total occlusion were associated with OHCA.

Vulnerability to cardiac arrest in patients with ST elevation myocardial infarction: Is it time or patient dependent? Results from a nationwide observational study

AIM

Cardiac arrest is a common complication of ST elevation myocardial infarction and is associated with high mortality. We evaluated whether vulnerability to cardiac arrest follows a circadian rhythm and whether it is related to specific patient characteristics.

METHODS

A total of 24,164 ST elevation myocardial infarction patients who were admitted to 60 Belgian hospitals between 2008-2017 were analysed. The proportion of patients with cardiac arrest before initiation of reperfusion therapy was calculated for different time periods (hour of the day, months, seasons) and related to patient characteristics using stepwise logistic regression analysis.

RESULTS

Cardiac arrest occurred in 10.8% of the ST elevation myocardial infarction patients at a median of 65 min (interquartile range 33-138 min) after onset of pain. ST elevation myocardial infarction patients with cardiac arrest showed a biphasic pattern with one peak in the morning and one peak in the late afternoon. Multivariate analysis identified the following independent factors associated with cardiac arrest: cardiogenic shock (odds ratio=28), left bundle branch block (odds ratio=3.7), short (<180 min) ischaemic period (odds ratio=2.2), post-meridiem daytime presentation (odds ratio=1.4), anterior infarction (odds ratio=1.3). Overall in-hospital mortality was 30% for cardiac arrest patients versus 3.7% for non-cardiac arrest patients (p<0.0001).

CONCLUSION

In the present study population, cardiac arrest in ST elevation myocardial infarction showed an atypical circadian rhythm with not only a morning peak but also a second peak in the late afternoon, suggesting that cardiac arrest and ST elevation myocardial infarction triggers are, at least partially, different. In addition, specific patient characteristics, such as short ischaemic period, cardiogenic shock and left bundle branch block, increase the vulnerability to cardiac arrest.

In-hospital major arrhythmias, arrhythmic death and resuscitation after successful primary percutaneous intervention for acute transmural infarction: a retrospective single-centre cohort study

BACKGROUND

Transmural acute myocardial infarction (AMI) is associated with a high risk for ventricular arrhythmia before, during and after treatment. Consequently, it is recommended that patients diagnosed with transmural AMI be monitored in a cardiac care unit (CCU) so life-threatening arrhythmias can be treated promptly. We examined the incidence and timing of in-hospital malignant ventricular arrhythmias, sudden cardiac or arrhythmic death (SCD/AD) and resuscitation requirements in patients with transmural AMI recovering from percutaneous coronary intervention (PCI) undertaken within 12 h of symptom onset and without antecedent thrombolysis.

METHODS

This was a retrospective cohort study using the Duisburg Heart Center (Germany) cardiac patient registry. In total, 975 patients met the inclusion criteria. The composite endpoint was post-PCI ventricular fibrillation or tachycardia, SCD/AD or requirement for resuscitation. We compared the demographic and clinical characteristics of patients who met the composite endpoint with those who did not, recorded the timing of endpoint episodes, and used multivariable logistic regression analysis to identify factors associated with the endpoint criteria.

RESULTS

There was no significant difference in the length of CCU or hospital stay between the groups. In-hospital mortality was 6.5%, and the composite endpoint was met in 7.4% of cases. Malignant ventricular tachyarrhythmia occurred in 2.8% of the patients, and SCD/AD occurred in 0.3% of the cases. There was a biphasic temporal distribution of endpoint events; specifically, 76.7% occurred < 96 h after symptom onset, and 12.6% occurred 240-360 h after symptom onset. Multivariable regression analysis identified positive associations between an endpoint episode and the following: age (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.05] per year); left ventricular ejection fraction (LVEF) < 30% (OR 3.66, 95% CI 1.91-6.99); peak serum creatine phosphokinase concentration (OR 1.01, 95% CI 1.00-1.02 per 100 U/dl); leucocytosis (OR 1.86, 95% CI 1.04-3.32), and coronary thrombus (OR 1.85, 95% CI 1.04-3.27).

CONCLUSIONS

Most post-PCI malignant ventricular arrhythmias, SCD/AD and resuscitation episodes occurred within 96 h of transmural AMI (76.7%). A substantial minority (12.6%) of these events arose 240-360 h after symptom onset. Further study is needed to establish the influence of age, LVEF < 30%, peak serum creatine phosphokinase concentration, leucocytosis and coronary thrombus on post-PCI outcomes after transmural AMI.

Implant of permanent pacemaker during acute coronary syndrome: Mortality and associated factors in the ARIAM registry

BACKGROUND

Patients with acute coronary syndrome complicated with high degree atrioventricular block still have a high mortality. A low percentage of these patients need a permanent pacemaker (PPM) but mortality and associated factors with the PPM implant in acute coronary syndrome patients are not known. We assess whether PPM implant is an independent variable in the mortality of acute coronary syndrome patients. Also, we explored the variables that remain independently associated with PPM implantation.

METHODS

This was an observational study on the Spanish ARIAM register. The inclusion period was from January 2001 to December 2011. This registry included all Andalusian acute coronary syndrome patients. Follow-up for global mortality was until November 2013.

RESULTS

We selected 27,608 cases. In 62 patients a PPM was implanted (0.024%). The mean age in PPM patients was 70.71±11.214 years versus 64.46±12.985 years in patients with no PPM. PPM implant was associated independently with age (odds ratio (OR) 1.031, 95% confidence interval (CI) 1.007-1.055), with left ventricular branch block (OR 6.622, 95% CI 2.439-18.181), with any arrhythmia at intensive care unit admission (OR 2.754, 95% CI 1.506-5.025) and with heart failure (OR 3.344, 95% CI 1.78-8.333). PPM implant was independently associated with mortality (OR 11.436, 95% CI 1.576-83.009). In propensity score analysis PPM implant was still associated with mortality (OR 5.79, 95% CI 3.27-25.63).

CONCLUSION

PPM implant is associated with mortality in the acute coronary syndrome population in the ARIAM registry. Advanced age, heart failure, arrhythmias and left ventricular branch block at intensive care unit admission were found associated factors with PPM implant in acute coronary syndrome patient.

Arrhythmias in patients with acute coronary syndrome in the first 24 hours of hospitalization

OBJECTIVES

In patients with acute coronary syndrome (ACS), we sought to: 1) describe arrhythmias during hospitalization, 2) explore the association between arrhythmias and patient outcomes, and 3) explore predictors of the occurrence of arrhythmias.

METHODS

In a prospective sub-study of the IMMEDIATE AIM study, we analyzed electrocardiographic (ECG) data from 278 patients with ACS. On emergency department admission, a Holter recorder was attached for continuous 12-lead ECG monitoring.

RESULTS

Approximately 22% of patients had more than 50 premature ventricular contractions (PVCs) per hour. Non-sustained ventricular tachycardia (VT) occurred in 15% of patients. Very few patients (≤ 1%) had a malignant arrhythmia (sustained VT, asystole, torsade de pointes, or ventricular fibrillation). Only more than 50 PVCs/hour independently predicted an increased length of stay (p < .0001). No arrhythmias predicted mortality. Age greater than 65 years and a final diagnosis of acute myocardial infarction independently predicted more than 50 PVCs per hour (p = .0004).

CONCLUSIONS

Patients with ACS seem to have fewer serious arrhythmias today, which may have implications for the appropriate use of continuous ECG monitoring.

Sudden Cardiac Death in a Case of Non-Dominant Coronary Artery Obstruction Without Depressed Left Ventricular Function

Acute myocardial infarction complicated with lethal cardiac arrhythmia remains the major cause of sudden death. The possible clinical presentation leading to lethal ventricular arrhythmia has been demonstrated but the data are limited. The previous study revealed no significant correlation between sudden cardiac death and the location of coronary obstruction site. And the possible mechanism of sudden cardiac death in non-dominant coronary artery obstruction is unclear. We presented a case of acute myocardial infarction with mid left circumflex artery occlusion complicated with new onset atrial fibrillation initially. The rhythm degenerated into ventricular fibrillation immediately and sudden cardiac death occurred. After resuscitation, he received coronary angioplasty, and the rhythm recovered to sinus after the occluded coronary artery reopened. We thick new onset atrial fibrillation could be a potential risk factor leading to sudden death in acute myocardial infarction with obstruction of non-dominant coronary artery. Control of ventricular rate and early restoration of sinus rhythm may be potential benefit.

Evaluation of the performance of echocardiography in acute coronary syndrome patients during their stay in coronary units

OBJECTIVES

To evaluate the frequency and the factors associated with performance of echocardiography in acute coronary syndrome (ACS) patients during their stay in intensive care units or coronary care units (ICU/CCU).

METHODS

Retrospective cohort study including all patients diagnosed with acute coronary syndrome-unstable angina (UA), acute myocardial infarction (AMI)-included in the 'ARIAM' Spanish multi-centre register. The study period was from June 1996 to December 2005. The follow-up period is limited to the time of stay in the Intensive Care Units or Coronary Care Units (ICUs/CCUs). A univariate analysis was carried out on the patients with UA and AMI according to whether or not echocardiograms were performed during their stay in ICU/CCU. In addition the data was evaluated for any temporal variation in the performance of echocardiography, and two multivariate analyses were carried out to evaluate the factors associated with performance of echocardiography in UA and AMI patients.

RESULTS

The study period included 45,688 AMI patients and 17,277 UA patients. Echocardiograms were performed in 26.87% AMI patients and 16.75% UA patients. In total, 15,172 echocardiograms were performed in ACS patients (23.6%). The multivariate analysis demonstrated that the variables associated with the performance of echocardiography in UA were: Killip and Kimball class, cigarette smoking, family history of cardiovascular events, cardiogenic shock, uncontrolled angina, mechanical ventilation and treatment with ACE inhibitors, while the presence of previous AMI was associated with fewer echocardiograms being performed. In AMI, the multivariate analysis showed the following variables to be associated with the performance of echocardiography: Killip and Kimball class, Q-AMI, right heart failure, the need for insertion of Swan-Ganz catheter, cardiogenic shock, high-degree AV block and the administration of ACE inhibitors, while age was associated with fewer being performed. Over the 10 years of the study period, there was a discrete but significant increase in the use of echocardiography in patients in ICU/CCU.

CONCLUSIONS

Echocardiography is not commonly used in ACS patients while in ICU/CCU. UA and AMI patients who did have echocardiograms during their stay in ICU/CCU were chiefly those presenting heart failure and major complications, and represent a subpopulation with poor prognosis. The performance of echocardiography in ACS patients increased slightly over the length of their stay in ICU/CCU.

Emergency medical kits on board commercial aircraft: a comparative study

BACKGROUND

In cases of critical medical situations on board commercial aircraft, access to emergency medical kits can be lifesaving. Thus, this comparative study investigated acute care medication and equipment supplied in emergency medical kits on board both low-cost carriers and full-service carriers.

METHODS

Thirty-two European airlines (sixteen low-cost carriers and sixteen full-service-carriers) were asked to provide anonymous data on the contents of their emergency medical kits. All emergency medical equipment and medication carried on board were subject to a descriptive analysis with regards to International Civil Aviation Organization (ICAO) standards for emergency medical kits, as well as variation and differences between low-cost carriers and full-service carriers.

RESULTS

A total of twelve airlines (seven full-service carriers and five low-cost carriers) participated in this study. None complied with ICAO standards. Emergency medical kits from both full-service carriers and low-cost carriers exhibited a high degree of variability. Two European low-cost carriers were assessed as being insufficiently equipped for a medical emergency requiring acute care.

CONCLUSIONS

This study demonstrates the high degree of variability in the contents of emergency medical kits. Additionally, some airlines were equipped insufficiently for a critical medical situation on board their aircraft. Frequent checks of national authorities and further evaluation of acute care equipment are required to prepare for potentially life-threatening critical conditions occurring in special environments, such as in airplane during flight.

APACHE-II score and Killip class for patients with acute myocardial infarction

OBJECTIVE

To analyse the influence on the prognosis of intensive care unit (ICU) patients with acute myocardial infarction (AMI): prognostic index score, Killip class, AMI site, thrombolysis and other variables that might improve prognostic capacity and functioning of the APACHE-II index.

DESIGN

Cohort study using prospectively gathered ARIAM project data.

SETTING

ICUs from 129 Spanish hospitals.

PATIENTS

ICU-admitted AMI patients in ARIAM database during 4-year period were retrospectively studied.

MEASUREMENTS AND MAIN RESULTS

The sample comprised 6,458 patients, 76.8% males, age 64.97 +/- 12.56 years, APACHE-II score 9.49 +/- 7.03 points and ICU mortality 8.9%. Mortality was higher for females (p < 0.001), anterior AMI site (p < 0.001), previous AMI (p < 0.001), delay-to-hospital arrival >180 min (p = 0.003) and non-receipt of thrombolysis (p = 0.015). ICU mortality was related to age (p < 0.001) and APACHE-II score (p < 0.001). In multivariate analysis, it was related to APACHE-II (OR 1.16), age (OR 1.05), gender (OR 1.64), previous AMI (OR 1.57), anterior AMI (OR 2.05) and delay >180 min (OR 1.37). Killip class, gathered in 1,893 patients, was significantly associated with ICU mortality, and two predictive models were constructed for this group using multivariate analysis. Area under ROC curve was 0.94 in one (Killip class, age, gender, APACHE-II) versus 0.92 in the other (same variables without APACHE-II).

CONCLUSIONS

APACHE-II score and Killip class are useful for assessing the severity of patients with AMI and are complementary. Each can be used with a few commonly gathered clinical variables to construct prognostic models to assess severity. Their joint application yields a model with excellent discrimination capacity.

Thirty-year trends (1975-2005) in the magnitude, patient characteristics, and hospital outcomes of patients with acute myocardial infarction complicated by ventricular fibrillation

Limited contemporary data are available describing the incidence rates, hospital prognosis, and factors associated with the occurrence of ventricular fibrillation (VF) in patients hospitalized with acute myocardial infarction (AMI). The objectives of our study were to examine 3-decade-long trends (1975 to 2005) in the magnitude, predictors, and hospital case-fatality rates associated with VF in residents of a large New England metropolitan area hospitalized at all area medical centers with an uncomplicated AMI. The study population consisted of 7,472 residents of the Worcester (Massachusetts) metropolitan area hospitalized with an uncomplicated AMI in 15 annual periods from 1975 to 2005. The overall proportion of patients who developed VF was 4.2%. The incidence rates of VF remained stable from 1975 to 1995 but decreased thereafter, reaching their lowest frequency in 2005 (1.9%). Hospital case-fatality rates were significantly higher in patients with (40.9%) compared with those without (2.5%) VF. Decreases in hospital death rates over time were observed in patients with and without VF, with the decreases in death rates being greater for patients with VF. Patients who developed a Q-wave MI or a left or right bundle branch block were at particularly increased risk for developing VF. In conclusion, our results indicate that the incidence and hospital death rates associated with VF have decreased during recent years.

Predictors of cardiac arrest occurring in the context of acute myocardial infarction

BACKGROUND

Cardiac arrest (CA) concurrent with acute myocardial infarction (AMI) claims the life of many patients with coronary artery disease (CAD). In this study, we investigated the predictors of CA during AMI.

METHOD

Patients admitted with CA concurrent with AMI (n = 31) were matched by age, gender, race, and left ventricular ejection fraction (LVEF) to patients with AMI but no CA (n = 70). All patients underwent coronary angiography. Binary logistic regression was used to identify independent predictors of CA during AMI.

RESULTS

A total of 101 patients (age = 61 +/- 13 years, men 76%, Caucasians 98%, LVEF 33 +/- 12%) admitted to the University of Pittsburgh Medical Center with AMI were included in this analysis. Patients with CA concurrent with the AMI were more likely to have proximal rather than distal coronary artery culprit lesions (odds ratio (OR) = 7.2, P = 0.019). Other predictors of CA in the context of AMI included negative family history of CAD (OR = 8.0, P = 0.026) and absence of sinus rhythm upon hospital admission (OR = 5.1, P = 0.030).

CONCLUSION

Proximity of culprit coronary lesion and presence of rhythm other than sinus rhythm at hospital admission are two strong predictors of CA in the context of AMI. The implication is that the mechanism of CA is primarily that of a large area of myocardial ischemia leading to lethal ventricular arrhythmia. Other predispositions such as genetic make-up cannot be ruled out.

Ventricular arrhythmias after acute myocardial infarction: a 20-year community study

BACKGROUND

Although myocardial infarction (MI) severity is declining, the occurrence of ventricular arrhythmia (VA) after MI and its effect on outcome is unknown. This study was undertaken to examine the frequency and timing of VA and the effect of VA on mortality after MI.

METHODS

Myocardial infarctions recorded between 1979 and 1998 were validated. Baseline characteristics, occurrence of VA, and survival were determined. Ventricular arrhythmias were categorized as primary ventricular fibrillation (VF), nonprimary VF, and ventricular tachycardia (VT). Logistic regression was used to analyze associations between VA and baseline characteristics. Temporal trends were assessed with the Mantel-Haenszel chi2. Survival was analyzed with the Kaplan-Meier method. Proportional hazards regression was used to examine the association between death and occurrence of VA.

RESULTS

Among 2317 persons with incident MI, 7.5% experienced VA (3.6% nonprimary VF, 2.1% primary VF, 1.8% VT). Ventricular arrhythmia-associated factors were younger age, female sex, higher Killip class, ST elevation, and atrial fibrillation. Ventricular arrhythmias were associated with increased risk of death at 30 days.

CONCLUSION

Ventricular arrhythmias after MI are relatively common, particularly among persons with more severe MI and no prior history of coronary disease. Over time, the incidence of VF declined, whereas VT did not change. Ventricular arrhythmia after MI was associated with a 6-fold increase in morality. Thus, identification of high-risk MI survivors and prevention of VA could markedly improve outcomes. Further studies are needed to determine the cause of the shift in distribution of VA subtype.

Prehospital thrombolysis perfomed by a ship's nurse with on-line physician consultation

Prehospital thrombolysis for acute ST-elevation myocardial infarction (STEMI) has been shown to improve recovery from myocardial function. We describe prehospital thrombolytic treatment in two patients suffering from STEMI complicated by ventricular fibrillation (VF) on a passenger ship. The importance of a functioning Emergency Medical Service (EMS) system providing guidance for paramedical personnel is discussed briefly. Both our patients survived and returned back to normal life. It is concluded that EMS physician guided prehospital thrombolytic treatment may offer an important therapeutic option for nurses or paramedics in locations out of reach of ordinary EMS services.