Importance and limits of pre-hospital electrocardiogram in patients with ST elevation myocardial infarction undergoing percutaneous coronary angioplasty.

BACKGROUND: The purpose of this study is to present data on the effects of pre-hospital electrocardiogram (PH-ECG) on the outcome of ST elevation myocardial infarction (STEMI) patients treated with percutaneous coronary angioplasty (PCI) included in a registry undertaken in the Italian region of Lombardy. Pre-hospital 12-lead electrocardiogram is recommended by current guidelines in order to achieve faster times to reperfusion in patients with STEMI. METHODS: The registry includes 3901 STEMI patients who underwent primary PCI over an 18-month period. RESULTS: Mean age was 63 ± 12 years. Admission through the emergency medical system (EMS) occurred in 1603 patients (40%): they were older, more frequently had previous MI, TIMI flow = 0 at entry and were more frequently in Killip class >1 than patients who were not admitted through the EMS. Among the patients admitted through the EMS, PH-ECG was obtained in 475 patients (12%). These patients had less frequently an anterior MI, but more frequently had absence of TIMI flow at entry than patients whose ECG was not teletransmitted. Moreover, they had a significantly shorter first medical contact-to-balloon time and a trend toward a lower 30-day death rate (5.3% vs 7.9 %, p = 0.06). However, only patients in Killip class 2-3 had a significantly lower mortality when the diagnostic ECG was transmitted, whereas no difference was found in Killip class 1 or Killip class 4 patients. CONCLUSIONS: In this registry, PH-ECG significantly decreased first medical contact-to-balloon time. Attempts to achieve faster reperfusion times should be undertaken, as this may result in improved outcome, particularly in patients with mild to moderate symptoms of heart failure.

Abnormalities of resting-state EEG in patients with prodromal and overt dementia with Lewy bodies: Relation to clinical symptoms.

OBJECTIVE: Here we tested if cortical sources of resting state electroencephalographic (rsEEG) rhythms may differ in sub-groups of patients with prodromal and overt dementia with Lewy bodies (DLB) as a function of relevant clinical symptoms. METHODS: We extracted clinical, demographic and rsEEG datasets in matched DLB patients (N = 60) and control Alzheimer's disease (AD, N = 60) and healthy elderly (Nold, N = 60) seniors from our international database. The eLORETA freeware was used to estimate cortical rsEEG sources. RESULTS: As compared to the Nold group, the DLB and AD groups generally exhibited greater spatially distributed delta source activities (DLB > AD) and lower alpha source activities posteriorly (AD > DLB). As compared to the DLB "controls", the DLB patients with (1) rapid eye movement (REM) sleep behavior disorders showed lower central alpha source activities (p < 0.005); (2) greater cognitive deficits exhibited higher parietal and central theta source activities as well as higher central, parietal, and occipital alpha source activities (p < 0.01); (3) visual hallucinations pointed to greater parietal delta source activities (p < 0.005). CONCLUSIONS: Relevant clinical features were associated with abnormalities in spatial and frequency features of rsEEG source activities in DLB patients. SIGNIFICANCE: Those features may be used as neurophysiological surrogate endpoints of clinical symptoms in DLB patients in future cross-validation prospective studies.

Emergency percutaneous coronary intervention in patients with ST-elevation myocardial infarction complicated by out-of-hospital cardiac arrest: early and medium-term outcome.

BACKGROUND: The role of emergency reperfusion therapy in patients with ST-elevation myocardial infarction (STEMI) resuscitated after an out-of-hospital cardiac arrest (OHCA) has not been clearly established yet. The aim of this study was to evaluate the in-hospital and postdischarge outcomes of STEMI patients surviving OHCA and undergoing emergency angioplasty (percutaneous coronary intervention [PCI]) within an established regional network. METHODS: We prospectively collected data on 2,617 consecutive patients with STEMI treated with emergency PCI in 2005; in-hospital and 6-month outcomes of 99 patients who had experienced OHCA were compared with those of 2,518 patients without OHCA. The OHCA patients also underwent a cerebral performance evaluation after 12 months. RESULTS: OHCA patients were at higher clinical risk at presentation (cardiogenic shock 26% vs 5%, P < .0001). Percutaneous coronary intervention was successful in 80% of the OHCA and 89% of the non-OHCA patients (P = NS). In-hospital mortality rates were 22% and 3%, respectively (P < .0001). Independent predictors of in-hospital mortality among OHCA patients were longer delay between the call to the emergency medical system and the start of cardiopulmonary resuscitation (odds ratio [OR] 3.5, P = .03), nonshockable initial rhythms (OR 10.5, P = .002), cardiogenic shock (OR 3.05, P = .035), and a Glasgow Coma Scale score of 3 on admission (OR 2.9, P = .032). The 6-month composite rate of death, myocardial infarction, and revascularization among OHCA patients surviving the acute phase was comparable to that of non-OHCA patients (16% vs 13.9%, P = NS), and 87% of them showed a favorable neurologic recovery after 1 year. CONCLUSIONS: Resuscitated OHCA patients undergoing emergency PCI for STEMI have worse clinical presentation and higher in-hospital mortality compared to those without OHCA. However, subsequent cardiac events are similar, and neurologic recovery is more favorable than reported in most previous series.

Intracoronary ST-segment shift soon after elective percutaneous coronary intervention accurately predicts periprocedural myocardial injury.

BACKGROUND: Elevation of cardiac biomarkers after coronary angioplasty (percutaneous coronary intervention [PCI]) reflects periprocedural myocardial damage and is associated with adverse cardiac events. We assessed whether periprocedural myocardial damage that occurs despite successful PCI could be rapidly and easily identified by intracoronary ST-segment recording with the use of a catheter guidewire. METHODS AND RESULTS: In 108 consecutive stable patients undergoing elective single-vessel PCI, we recorded unipolar ECG from the intracoronary guidewire in the distal coronary before PCI and 2 minutes after the last balloon inflation. After PCI, intracoronary ST-segment shift > or = 1 mm from baseline was considered significant. Troponin I levels were measured at baseline and at 8 and 24 hours after intervention, and myocardial damage was defined as troponin I increase above the upper normal value after intervention. All patients had normal cardiac marker values before PCI, and PCI was successful in all (residual stenosis < 20%, Thrombolysis in Myocardial Infarction grade 3 flow). After PCI, long-term follow-up data were collected; myocardial damage was detected in 50 patients (46%), although abnormal creatine kinase-MB values were documented in only 11 (10%). Significant intracoronary ST-segment shift after PCI was present in 40 patients (37%; group A) and absent in the remaining 68 (63%; group B). Procedural myocardial damage was documented in 37 group A patients (93%) and in 13 group B patients (19%; P<0.001); significant ECG changes were found on standard ECG after intervention in only 5 patients (13%) and 1 patient (1%) (P<0.05). Sensitivity of intracoronary ST-segment shift for predicting myocardial damage was 74%, and specificity was 95%, with positive and negative predictive values of 93% and 81%, respectively. On multivariate analysis, intracoronary ST-segment shift was the sole independent predictor of myocardial damage (odds ratio, 54.1; 95% confidence interval, 12.1 to 240; P<0.0001). At a median follow-up of 12+/-5 months, major coronary event-free survival was significantly worse in group A patients (log-rank test chi2=4.0; P<0.05). CONCLUSIONS: After successful single-vessel PCI, intracoronary ST-segment shift allows the prompt and inexpensive identification of patients developing myocardial injury, who may require adjunctive therapy and longer in-hospital stay.

Defining high-risk patients with ST-segment elevation acute myocardial infarction undergoing primary percutaneous coronary intervention: a comparison among different scoring systems and clinical definitions.

BACKGROUND: Identification of high-risk patients with ST-segment elevation acute myocardial infarction (STEMI) is of the utmost importance for adequate patient stratification and evaluation of additive treatments. However, there is no consensus on the optimal definition of high-risk patients. METHODS: We therefore compared 5 scoring systems in the assessment of the risk of 30-day mortality in 3214 patients with STEMI treated with primary percutaneous coronary intervention (PCI). RESULTS: Clinical scores showed a large variability in risk stratifying patients. Identification of high-risk patients ranged from 15% (PAMI score ≥ 9) to 66% (McNamara definition). McNamara, Antoniucci and Brodie definitions had the best sensitivity (0.87-0.88 and 95% confidence intervals (CI) ranging from 0.82-0.93) while PAMI ≥ 9 had the best specificity (0.87 with 95% CI of 0.86-0.88), while its sensitivity was quite low (0.42). In a sample size simulation of a trial aimed at demonstrating a 33% difference in 30-day mortality between two hypothetical treatments, the number of STEMI patients needed to be screened varied from 4712 for the Brodie definition to 9038 for the PAMI ≥ 9 score. CONCLUSIONS: There is a large variability in risk stratification, sensitivity, specificity and predictive values among different scoring systems. These considerations should be taken into account when designing randomised trials.

Intracoronary electrocardiogram ST segment shift evaluation during intravenous adenosine infusion: a comparison with fractional flow reserve.

BACKGROUND: By measuring the pressure decline caused by coronary narrowing, fractional flow reserve (FFR) is an index of the physiological significance of a vessel stenosis. Intracoronary electrocardiogram (IC-ECG) recording from an angioplasty guidewire is more sensitive than standard ECG in detecting regional myocardial ischemia. The aim of the study was to assess if unipolar IC-ECG ST segment recording from angioplasty guidewire during maximal pharmacologic vasodilation could be used as an indirect estimation of FFR results. METHODS: Forty-eight clinically stable patients with intermediate stenosis underwent FFR evaluation and IC-ECG recording during intravenous adenosine infusion. RESULTS: FFR values were ≤ 0.80 in 26 (54%) patients and > 0.80 in 22 (46%). After adenosine, standard ECG was abnormal in only nine (19%) patients, while IC-ECG showed a significant ST segment shift (IST) in 24 (50%) patients: ST elevation in 19 patients and depression in five). IST was documented in 21/26 patients with FFR ≤ 0.80 (81%) and in 3/22 with FFR > 0.80 (p < 0.001). Sensitivity of IST for predicting an abnormal FFR value was 81%, specificity 86%, positive and negative predictive accuracies were 88% and 79%, respectively. CONCLUSIONS: Intracoronary ST segment shift evaluation during adenosine infusion may be of value in assessing the functional significance of a borderline stenosis. The presence of IST during adenosine infusion could obviate the need for additional FFR evaluation.

LombardIMA: a regional registry for coronary angioplasty in ST-elevation myocardial infarction.

BACKGROUND: Percutaneous coronary intervention (PCI) has been shown to be the best reperfusion therapy for acute myocardial infarction with ST-elevation (STEMI), but data from registries show differences in patient populations and outcomes between randomized trials and real life. OBJECTIVES: We sought to provide information about the current status of this treatment with a registry collecting data in Lombardy, the most densely populated region in Italy, with widespread availability of cathlabs and a well-established network for the treatment of STEMI. METHODS AND RESULTS: Patient enrollment was performed by 32 hub centres recruiting 3901 STEMI patients who underwent PCI procedures within 12 h of the onset of symptoms, of whom 3317 patients underwent primary PCI, 376 'facilitated' PCI, and 208 rescue PCI in cathlabs located, in 77% of cases, in the same hospital of admission. In-hospital and 30-day total death were 4.4 and 6.6%, respectively. At multivariate analysis independent negative predictors of 30-day mortality were Killip class 3-4, number of involved ECG leads, chronic renal failure and age, whereas positive predictors were ST resolution more than 50% and postprocedural grade 3 thrombolysis in myocardial infarction flow. CONCLUSIONS: LombardIMA PCI registry enrolled STEMI patients representing a real-world population treated with PCI. Findings presented in this study may provide a benchmark for similar registries undertaken in other Italian regions and may be helpful to assess future possible developments of care for STEMI patients.

Prognostic implications of ST-segment elevation resolution in patients with ST-segment elevation acute myocardial infarction treated with primary or facilitated percutaneous coronary intervention.

Scant data are available on the relation between ST-segment elevation (STE) resolution and 30-day mortality in patients with STE acute myocardial infarction treated with percutaneous coronary intervention in contemporary, real world, clinical practice. Furthermore, whether the prognostic value of STE resolution is influenced by the patient clinical risk profile or postprocedural Thrombolysis In Myocardial Infarction (TIMI) flow has never been investigated. Lombardima was an observational registry implemented in Lombardy, a Northern Italian region. The clinical characteristics, electorcardiographic parameters, and procedural data were prospectively entered into a Web-based database. In the present study, we enrolled 3,403 patients. STE resolution occurred in 2,452 patients (group 1) and did not in 951 patients (group 2). The mortality rate was 2.4% in group 1 and 11.3% in group 2 (p <0.001). After stratifying patients according to their TIMI risk index, we observed that STE resolution was an independent predictor of 30-day mortality across all spectrum of clinical risk. Furthermore, in patients with TIMI 3 flow, STE resolution remained an independent predictor of 30-day mortality (p <0.0001). In conclusion, STE resolution was a strong and independent predictor of 30-day mortality in patients with STE acute myocardial infarction undergoing percutaneous coronary intervention across all spectrum of clinical risk.

Stochastic acceleration in turbulent electric fields generated by 3D reconnection.

Electron and proton acceleration in three-dimensional electric and magnetic fields is studied through test particle simulations. The fields are obtained by a three-dimensional magnetohydrodynamic simulation of magnetic reconnection in slab geometry. The nonlinear evolution of the system is characterized by the growth of many unstable modes and the initial current sheet is fragmented with formation of small scale structures. We inject at random points inside the evolving current sheet a Maxwellian distribution of particles. In a relatively short time (less than a millisecond) the particles develop a power-law tail. The acceleration is extremely efficient and the electrons absorb a large percentage of the available energy in a small fraction of the characteristic time of the MHD simulation, suggesting that resistive MHD codes are unable to represent the full extent of particle acceleration.