Andreas Synetos

U‐shaped relationship between mortality and admission blood pressure in patients with acute stroke

Objective.  To evaluate the relationship between systolic blood pressure (SBP) or diastolic blood pressure (DBP) on admission and early or late mortality in patients with acute stroke.

Oxidative Stress and Early Atherosclerosis: Novel Antioxidant Treatment

Atherosclerotic lesions initiate in regions characterized by low shear stress and reduced activity of endothelial atheroprotective molecules such as nitric oxide, which is the key molecule managing vascular homeostasis. The generation of reactive oxygen species from the vascular endothelium is strongly related to various enzymes, such as xanthine oxidase, endothelial nitric oxide synthase and nicotinamide-adenine dinucleotide phosphate oxidase. Several pharmaceutical agents, including angiotensin converting enzyme inhibitors, angiotensin receptors blockers and statins, along with a variety of other agents, have demonstrated additional antioxidant properties beyond their principal role. Reports regarding the antioxidant role of vitamins present controversial results, especially those based on large scale studies. In addition, there is growing interest on the role of dietary flavonoids and their potential to improve endothelial function by modifying the oxidative stress status. However, the vascular-protective role of flavonoids and especially their antioxidant properties are still under investigation. Indeed, further research is required to establish the impact of the proposed new therapeutic strategies in atherosclerosis.

Red blood cell and platelet microparticles in myocardial infarction patients treated with primary angioplasty.

BACKGROUND Red blood cell and platelet microparticles (RBCm and PLTm, respectively) have drawn research attention as to their potential prothrombotic and vasoconstrictive effects in experimental settings. However, the relevance of circulating microparticles in clinical settings is largely undetermined. METHODS Circulating microparticles were quantified with a flow cytometric method in blood samples from consecutive STEMI patients after primary PCI. A matched cohort of healthy volunteers was used to derive reference values for comparison. STEMI patients were followed for 6 months for a composite clinical endpoint. RESULTS Fifty-one STEMI patients (age 59.8 ± 8.8 years) and 50 controls (age 56.2 ± 9.2 years; p=0.155) were enrolled. RBCm concentration was 18,198 ± 6062/μl in the reference cohort versus 33,740 ± 21,169/μl in STEMI patients (p<0.001). RBCm count was not correlated to total RBCs (standardized beta 0.018; p=0.861). PLTm did not differ between groups (17,529 ± 16,292/μl in STEMI patients versus 14,372 ± 6211/μl in controls; p=0.203). RBCm c-statistic was 0.832 (95% confidence interval 0.720 to 0.944), while PLTm prognostic value was not statistically significant (c-statistic 0.614, 95% confidence interval 0.444 to 0.784). In the multivariate analysis, RBCm concentration was independently associated with the occurrence of the clinical endpoint, after adjustment for age, ejection fraction, serum creatinine and presence of diabetes (adjusted p=0.034). CONCLUSIONS The present study demonstrates for the first time that erythrocyte microparticles are elevated in patients with STEMI treated with primary PCI, with levels approximately double those measured in a reference population of healthy volunteers, and their concentrations appear to be positively associated with adverse clinical events.

Spatial aspects of ventricular repolarization in postinfarction patients.

DILAVERIS, P., et al.: Spatial Aspects of Ventricular Repolarization in Postinfarction Patients. QT dispersion has been proposed to reflect the heterogeneity of ventricular repolarization, but a poor reproducibility limits its clinical usefulness. Spatial vectorcardiographic descriptors constitute a novel approach to quantify ventricular repolarization. To test the ability of vectorcardiographic descriptors to discriminate among different subsets of postinfarction patients, 50 consecutively recruited patients with acute MI, 50 patients with history of an old (> 6 months) MI, and 50 healthy controls were evaluated. The maximum and minimum QT and JT intervals and QT and JT dispersion were manually measured from a digitally recorded 12‐lead ECG. X, Y, and Z leads were reconstructed from the 12‐lead ECG. The amplitude of the maximum spatial T vector (spatial T amplitude), the angle between the maximum spatial QRS and T vectors (spatial QRS‐T angle), and the frontal plane QRS‐T angle were automatically calculated. The spatial T amplitude and the spatial QRS‐T angle did not differ between patients with a recent and those with an old MI (P = 1). QT dispersion was significantly lower in patients with an old MI than in patients with a recent one (P = 0.002). The spatial repolarization descriptors showed better short‐term reproducibility than the dispersion indices. In conclusion, the spatial T amplitude and the spatial QRS‐T angle are accurate measures of ventricular repolarization that do not differ between patients with recent and those with old MI. The different QT dispersion values observed in this study between the two post‐MI groups should be considered cautiously because of the low accuracy of the manual measurements.

Two-Peak Temporal Distribution of Stroke Onset in Greek Patients

A circadian distribution with a single peak of stroke onset in the morning hours has been described in various countries. Analysis of the temporal pattern of symptom onset in a series of 1,253 Greek first-ever stroke patients revealed a circadian distribution with two incidence peaks between 08.00 and 10.00 h, and between 16.00 and 18.00 h. Considering the different etiopathogenic types of stroke, the same two-peak time pattern was evaluated in all stroke subgroups with the only exception of lacunar stroke, which seems to predominantly occur during night and sleep. A secondary stroke onset peak in the late afternoon has not been previously described in such detail. A relation between the second, however lower, frequency peak and the traditional Greek habit of afternoon sleep (siesta) could be assumed and deserves further investigation.

Interatrial conduction time and incident atrial fibrillation: a prospective cohort study.

BACKGROUND Atrial electrical conduction properties have been implicated in atrial fibrillation (AF) pathogenesis. OBJECTIVE The purpose of this study was to prospectively assess the potential association of interatrial conduction time (IACT) with incident AF. METHODS The study included persons referred for invasive electrophysiologic study (EPS), aged ≥50 years, without AF history or valvular disease. IACT was defined as the interval between the high right atrium electrogram and the distal coronary sinus atrial electrogram. RESULTS Six hundred twelve subjects were included (median follow-up 43 months, interquartile range 40-47). AF incidence was 21.7 cases per 1000 person-years. IACT was a significant predictor of AF with a c-statistic of 0.770 (95% confidence interval 0.702-0.838). In time-dependent analysis, IACT was a significant stratifier of AF risk (log-rank 28.0, P <.001). The corresponding incidences of AF in each tertile of IACT were 3, 17, and 46 per 1000 person-years, respectively (all differences between tertiles were significant). IACT remained significant in multivariable Cox regression analysis, after adjustment for age, sex, hypertension, and left atrial diameter, with each millisecond of prolonged IACT corresponding to 7% (95% confidence interval 2%-12%) higher adjusted risk of incident AF. CONCLUSION IACT is independently associated with incident AF. The invasive nature of the measurement is a limitation for its use as a clinical risk stratifier (although it could be used in patients referred for EPS), but these results are of interest in themselves because they suggest a strong pathophysiologic connection between atrial conduction times and substrate alterations ultimately leading to AF.

Outcome of patients with acute myocardial infarction admitted in hospitals with or without catheterization laboratory: results from the HELIOS registry.

Aims To compare the treatment and outcomes of myocardial infarction patients in hospitals with and without catheterization laboratory. Methods and results The Hellenic Infarction Observation Study was a countrywide registry of acute myocardial infarction, conducted during 2005-2006. The registry enrolled 1840 patients with myocardial infarction from 31 hospitals with a proportional representation of all types of hospitals and of all geographical areas. Out of these patients, 645 (35%) were admitted in 11 hospitals with and 1195 (65%) in 20 hospitals without catheterization laboratory. Patients admitted in hospitals with catheterization laboratory in comparison with patients admitted in hospitals without were younger (66 ± 14 vs. 68 ±13, P < 0.004) with less diabetes (27 vs. 33%, P < 0.001), but without other baseline differences (female 27 vs. 25%, prior myocardial infarction 20 vs. 17%, Killip class >1 22 vs. 23%). Reperfusion rates for ST-segment elevation myocardial infarction were 67% (43% lytic, 24% primary percutaneous coronary interventions) versus 56% (55% lytic, 1% percutaneous coronary interventions; P < 0.01). In-hospital outcomes in hospitals with versus in hospitals without laboratory were: mortality 6.5 versus 8.3% (NS), stroke 2.2 versus 1.1% (NS), major bleeding 1.1 versus 0.6% (NS), and heart failure 11 versus 16% (P < 0.01). In multivariate regression analysis, being admitted in a hospital without catheterization laboratory was not an independent predictor of increased in-hospital mortality (odds ratio = 1.18, 95% confidence interval: 0.72-1.93, P = 0.505). Conclusion Although the majority of acute myocardial infarction patients was admitted in hospitals without catheterization laboratory, these patients do not have a survival disadvantage, provided they are treated with lytic therapy, medical secondary prevention drugs, and eventual revascularization according to current guidelines. Eur J Cardiovasc Prev Rehabil 16:85-90

Prognostic significance of inverse spatial QRS-T angle circadian pattern in myocardial infarction survivors

BACKGROUND We investigated the predictive value of the spatial QRS-T angle (QRSTA) circadian variation in myocardial infarction (MI) patients. METHODS Analyzing 24-hour recordings (SEER MC, GE Marquette) from 151 MI patients (age 63 +/- 12.7), the QRSTA was computed in derived XYZ leads. QRS-T angle values were compared between daytime and night time. The end point was cardiac death or life-threatening ventricular arrhythmia in 1 year. RESULTS Overall, QRSTA was slightly higher during the day vs. the night (91 degrees vs. 87 degrees, P = .005). However, 33.8% of the patients showed an inverse diurnal QRSTA variation (higher values at night), which was correlated to the outcome (P = .001, odds ratio 6.7). In multivariate analysis, after entering all factors exhibiting univariate trend towards significance, inverse QRSTA circadian pattern remained significant (P = .036). CONCLUSION Inverse QRSTA circadian pattern was found to be associated with adverse outcome (22.4%) in MI patients, whereas a normal pattern was associated (96%) with a favorable outcome.

Simultaneous occlusion of two coronary arteries in a patient with acute myocardial infarction: A result of plaque rupture and plaque erosion

Rupture of the coronary vulnerable plaque is the most common cause of STsegment elevation acute myocardial infarction. In most of these cases a singe culprit lesion is recognized and treated; however multivessel occlusion, although uncommon, can occur. Although previously reported, the exact mechanism of multiple simultaneous coronary occlusions in acute myocardial infarction is still poorly understood. We report a case of a 55 year old male that was admitted to our hospital due to ST-segment elevation acute myocardial infarction (STEMI), and found to have thrombus occlusion of two coronary arteries. A 55 year old male presented to our emergency department due to chest pain after exercise. His past medical history included hypertension treated with angiotensin converting enzyme inhibitor. The auscultatory findings of the examination included galloping rhythm (S4) with no murmurs, his blood pressure was 130/85 mm Hg and he had no signs of heart failure. The electrocardiogram showed sinus rhythm with ST-segment elevation in leads II, III, AVF and V5–V6. The patient was treated with 600 mg clopidogrel and 100 mg aspirin together with intravenous nitrates and was immediately guided for catheterization. Coronary angiography revealed thrombus in the left circumflex artery (LCX) before the bifurcation to the marginal artery (Fig. 1A), as well as an obstructing thrombus in the distal part of the right coronary artery (RCA) (Fig. 1B). Since the lesion in the right coronary artery was the culprit, we firstly treated this lesion with aspiration that was followed with the deployment of a drug eluting stent (Fig. 1C), with an excellent angiographic result (Fig. 1D). Thereafter we aspirated the thrombus in the left circumflex artery, which had been moved more distally just after the bifurcation with the val of the identified; ex artery regression ization he

Prognostic clinical and angiographic characteristics for the development of a new significant lesion in remote segments after successful percutaneous coronary intervention

BACKGROUND The majority of cardiovascular events in patients undergoing PCI arise from the progression of NCL during the long-term follow-up period. The purpose of the study was to investigate the clinical and angiographic factors related to the progression of non-culprit lesions (NCL) of patients undergoing percutaneous coronary interventions (PCI). METHODS One hundred and seventeen patients that underwent two coronary angiograms with a time interval greater than 3 months were enrolled. All patients underwent PCI as a treatment for the culprit lesion. In the second coronary angiography we investigated whether they had a new culprit lesion clearly differentiated from the one of the first angiogram. The demographic characteristics, the clinical syndrome responsible for the first PCI and the procedural characteristics were recorded. Quantitative coronary angiography was performed at the culprit lesion of the second angiography and in the same lesion in the first angiography. RESULTS Multivariate analysis showed that the independent variables for the development of a significant lesion at the follow-up requiring intervention were: the presence of complex lesion (53.78% vs 36.22%, p<0.001, OR=39.42), acute myocardial infarction (AMI) at the initial diagnosis (36.3% vs 32.4%, p<0.001, OR=3.9), and smoking (46.15% vs 53.84%, p=0.03, OR=0.29). CONCLUSIONS Patients with AMI and complex morphology of NCL have increased risk for a new intervention after successful PCI. Smoking at the time of the follow up, was associated with fewer coronary interventions.