Andreas Synetos

Recent advances in technology, crossing techniques and learning skills, have significantly increased the success rates of Percutaneous Coronary Interventions (PCIs) in Chronic Total Occlusions (CTOs). Successful PCI for CTO has been reported to reduce angina symptoms, improve functional status, decrease the need for bypass surgery, and may improve patient survival. In addition, when an antegrade approach is not feasible or fails, a retrograde approach to CTO has been widely adopted with a high success rate and acceptable complication rate

Atrial fibrillation (AF) is a well-known predisposing factor for stroke. Most of the thrombi responsible for these ischemic events originate in the left atrial appendage. Left atrium appendage (LAA) occlusion is a potential alternative to warfarin in patients with atrial fibrillation who have contraindications to anticoagulation. The Percutaneous LAA Transcatheter Occlusion (PLAATO System, ev3 Inc., Plymouth, Minnesota) and the WATCHMAN LAA system (Atritech Inc., Plymouth, Minnesota), are currently the two devices specifically designed for LAA occlusion. Although available data are still limited, LAA occlusion is technically feasible, with good intermediate results, but its long-term safety and ability to reduce stroke incidence remains unproven. Randomized studies will clarify the usefulness of the LAA occlusion devices as an alternative treatment strategy to long-term anticoagulation.

Capecitabine is a new oral chemotherapeutic agent that is considered highly specific for sensitive tumor cells. We present the case of a patient who, after treatment with capecitabine for colorectal cancer, presented to our hospital with angina pectoris and electrocardiographic changes indicative of myocardial ischemia. The absence of epicardial coronary stenosis on the coronary angiogram ruled out atherosclerotic coronary disease as the cause of ischemia. The occurrence of coronary spasm, although not evident during coronary angiography, seems to be a possible explanation of the patient's symptoms.

ST segment resolution after thrombolysis is stratified by Schröder into 3 categories (complete resolution, ≥70%; partial resolution, <70% to ≥30%; and no resolution, <30%). Aim of the present study was to investigate the effects of thro-mbolysis on vectorcardiographic (VCG) descriptors of ventricular repolarization in association with ST segment resolution. The study population consisted of 70 consecutively recruited patients with acute myocardial infarction (AMI) who underwent digital 12-lead electrocardio-grams (ECG) before and at 3 hours after thrombolysis. The alterations in the VCG descriptors spatial T amplitude and spatial QRS-T angle from the pre-to the post-thrombolysis ECG, as well as the ST segment resolution, were calculated. Angiography revealed patency of the infarct-related coronary artery after thrombolysis in 52 (74%) patients (Group A) and occlusion in 18 (26%) (Group B). The spatial T amplitude was decreased significantly more in Group A than in Group B pati...

Radial artery spasm may hinder completion of transradial angiography or PCI, leading to access site crossover, prolonged procedure times and complications. The aim of this study was to derive a radial artery spasm risk score in patients undergoing elective percutaneous coronary intervention (PCI), prospectively validate it, and apply it in a real-life clinical setting. The study population consisted of 3 cohorts of patients undergoing elective PCI with transradial access: the derivation cohort (N=1006), the validation cohort (N=518) and the intervention cohort (N=140), consisting of patients with high risk score, in whom intensified spasm-preventive measures were applied. Multivariable analysis in the derivation cohort showed that 5 weighted factors could be used to construct a risk score for spasm: body-mass index, height, current smoking, hypertension and peripheral artery disease (c-statistic 0.945, with an optimal cut-off of 4). In the validation cohort, the cut-off of 4 predict...

The impact of drug-eluting stents (DES) has not been extensively investigated in patients with moderate to severe renal dysfunction, as these patients are consistently excluded from randomised studies. We sought to assess prospectively the effectiveness and safety of the new-generation DES in patients with moderate chronic kidney disease (CKD) and an isolated de novo lesion in the proximal segment of the left anterior descending artery (pLAD). We evaluated 400 consecutive patients with a pLAD lesion. There were 96 patients with moderate CKD (estimated glomerular filtration rate 59 ml/min/1.73 m2) and 304 without CKD. Major adverse cardiac events (MACE) were defined as death, non-fatal myocardial infarction and target lesion revascularisation (TLR). Clinical or telephone follow up was performed. There was a significantly higher incidence of mortality in patients with CKD (n=4) as compared with non-CKD (n=2) (4.16% versus 0.65%, respectively, p=0.03). The rate of non-fatal myocardial ...

Several studies have demonstrated that resting heart rate is an important correlate of cardiovascular and all-cause mortality and that the mortality benefit of some cardiovascular drugs seems to be related in part to their heart rate-lowering effects. Since the currently available classes of drugs with heart-rate lowering effect (e.g. beta-blockers and calcium channel antagonists) also exert multiple structural and functional actions on the cardiovascular system, which may be in some cases undesired, the introduction of a new class of agents exclusively affecting the pacemaker activity of the sinus node is of particular interest. The first molecule of this class - sinus node modulators or I(f)-current inhibitors - to reach clinical application is ivabradine. Cardiac pacemaker cells generate a spontaneous slow diastolic depolarisation that drives the membrane voltage away from a hyperpolarised level towards the threshold level for initiating a subsequent action potential, generating ...

Atrial fibrillation (AF) is the most common cardiac arrhythmia seen in clinical practice. The understanding of the pathophysiology of AF has changed drastically during the last several decades. Recent observations have challenged the concept of the multiple circuit reentry model in favor of single focus or single circuit reentry models. Atrial electrical dysfunction provides a favorable substrate and transmembrane ionic currents are key determinants. Recent research is focusing increasingly on the atrial structural remodeling, which underlies the development of AF in different pathological conditions. This has led to concepts about how interfering with the substrate might prevent AF development and recurrence. Particular interest has been generated in the role of renin angiotensin system (RAS) blockade in reversing the electrical and structural remodeling of diseased atria. The mechanisms for the preventive effect of angiotensin converting enzyme inhibitors (ACEi) or angiotensin-II ...

A population of 105 patients with recent onset (< 72 h) atrial fibrillation was randomly treated with propafenone as a single oral loading dose of 450 mg (Regimen A) or 600 mg (Regimen B) or with placebo. A 24-h Holter was performed. Criteria of efficacy were conversion to sinus rhythm at 2, 4 and 8 h compared to placebo and also significant reduction of mean ventricular rate in persistent atrial fibrillation. After 2 h, regimen B was more effective than either regimen A (43% vs. 8%; p = 0.001) or placebo (11%; p = 0.004). At 4 h, both the active treatments were more effective than placebo (17% vs. 46% regimen A and 57% vs. regimen B; p < 0.04 and p < 0.001, respectively). Sinus rhythm resumed within 24 h in 71%, 80% and 69% of the patients with regimen A, B and placebo, respectively (p = not significant). The mean ventricular rate reduction after 1 h was 8%, 11% and 4% for regimen A, B and placebo, respectively (p < 0.005 vs. regimen B), and 17%, 25% and 6% respectively...

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. 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. 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). 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.

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.