Nikolay Dimitrov

Reproducibility of arterial stiffness indices in different vascular territories and between different observers.

Background: Increased arterial stiffness (AS) corresponds to an increase in cardiovascular risk. According to recent guidelines AS parameters can be measured on all superficial arteries. Objective: Proceeding from the assumption that viscoelastic properties differ along the arterial tree we set ourselves the task to study the reproducibility of AS indices measured at the common carotid, brachial and femoral arteries. Methods: The initial study population included 75 patients (40 ± 14.5 years, 45% males) with a variable distribution of cardiovascular risk factors and without clinical evidence of coronary artery disease. AS parameters were measured at the common carotid, brachial and femoral arteries in all patients using echo‐tracking (ET) technique. In a subgroup of 36 patients we tested the interobserver variability in the three vascular territories. Results: We found that there was a significant correlation between AS indices measured at the common carotid and femoral artery (with the only exception for augmentation index) and that AS parameters measured at the brachial artery did correlate neither with common carotid nor with femoral artery indices. The interobserver variability of ET derived AS parameters was good when they were measured at the carotid or femoral artery. The values of AS indices at the brachial artery however showed considerably lower interobserver agreement. Conclusion: The reproducibility of ET derived AS parameters was good when AS was measured at the common carotid or femoral arteries. On the basis of our results brachial artery is probably not a reliable site for AS measurement. (Echocardiography 2011;28:448‐456)

Clinical Evaluation of a Mobile Heart Rhythm Telemonitoring System

Purpose. To evaluate the clinical applicability of a telemonitoring system: telemetric system for collection and distant surveillance of medical information (TEMEO). Methods. We evaluated 60 patients, applying simultaneously standard Holter ECG and telemonitoring. Two different comparisons were performed: (1) TEMEO ECG with standard 12-lead ECG; (2) TEMEO Holter with standard ECG Holter. Results. We found a very high coincidence rate (99.3%) between TEMEO derived ECGs and standard ECGs. Intraclass correlation coefficient analysis revealed high and significant correlation coefficients regarding average, maximal, and minimal heart rate, % of time in tachycardia, single supraventricular ectopic beats (SVEB), and single and couplets of ventricular ectopic beats (VEB) between Holter ECG and TEMEO derived parameters. Couplets of SVEB were recorded as different by the two monitoring systems, however, with a borderline statistical significance. Conclusions. TEMEO derived ECGs have a very high coincidence rate with standard ECGs. TEMEO patient monitoring provides results that are similar to those derived from a standard Holter ECG.

Flow-mediated dilatation has an additive value to stress ECG for the diagnosis of angiographically significant coronary atherosclerosis.

The objective of this study is to determine if flow-mediated endothelial-dependent vasodilatation (FMD) performed after stress electrocardiogram (ECG) test has an additive value for the diagnosis of significant coronary artery disease (CAD). We studied 322 patients who underwent stress ECG test, coronary arteriography (CAG), and FMD evaluation. The pretest probability (preTP) for the presence of significant CAD (>or=50% stenosis) was 73%. The probability for the disease after positive or negative ECG test (postTP) was 75% and 62%, respectively. A positive FMD response after a positive stress test resulted in 86% postTP with prevalence of advanced CAD in this subgroup -70.4%. A negative FMD response after a positive treadmill test decreased the postTP to 50% (prevalence of significant CAD 25.5%) and could change clinical behavior--additional tests before proceeding to CAG. After negative stress test the postTP increased to 78% when FMD was positive (prevalence of the disease 50%), necessitating the performance of CAG. It decreased to 36% after a negative FMD (prevalence of the disease 11.5%), directing to conservative behavior. In a group with a high pretest probability for the presence of advanced coronary atherosclerosis, FMD has an additive value to stress ECG for the diagnosis of significant CAD and could guide clinical behavior.

Telemonitoring Boosts Atrial Fibrillation Detection in Cryptogenic Stroke Patients – Preliminary Findings.

Background: Approximately 25% of strokes are cryptogenic in origin and identifying atrial fibrillation (AF) as an etiologic factor in this situation has major therapeutic implication. Standard Holter ECG has alow sensitivity for AF detection in this patient group. Aim: To assess the diagnostic yield of prolonged ambulatory noninvasive ECG telemonitoring for AF detection in cryptogenic stroke or transitory ischemic attack (TIA) patients. Methods and Results: We prospectively included 36 patients (mean age 53 ± 15 years, 17% women) with cryptogenic stroke or TIA in the previous 3 months and without previously documented episodes of AF. We employed a validated ECG telemonitoring system (TEMEO). The median monitoring period was 22 days, ranging from 13 to 36 days. AF was detected in 10 patients (27%): in 7 patients (70%) AF episodes lasted <30 sec and in the other 3 episodes of absolute arrhythmia were longer. AF runs were OriginalResearch Article

Timing of invasive strategy in diabetic and non-diabetic patients with non-ST-segment elevation acute coronary syndrome.

ABSTRACT INTRODUCTION: Patients with acute coronary syndrome without ST segment elevation are a heterogeneous group with respect to the risk of having a major adverse cardiac event (MACE). A history of diabetes mellitus (DM) is no doubt one of the factors that define a patient as being at a higher risk of having the syndrome. AIM: To compare early invasive strategy with selective invasive strategy indicated for patients with and without DM. PATIENTS AND METHODS: The study enrolled 178 patients with unstable angina or non-ST elevation myocardial infarction (UA/NSTEMI), and of these 52 (29.2%) had DM. Patients were randomly assigned to an early invasive strategy (these were scheduled to undergo coronary arteriography and percutaneous coronary intervention within 24 hours after admission) or to a selective invasive strategy (at first these were medically stabilized, with coronary arteriography required only in case of angina recurrence and/or evidence of inducible myocardial ischemia). The patients were followed up for a mean period of 22.8 ± 14 months. RESULTS: In the follow up the diabetics allocated to an early invasive strategy were found to have a significantly lower angina recurrence incidence (p = 0.005), rehospitalization rate (p = 0.001), fewer arteriographies (p = 0.001) and coronary interventions (p = 0.001) and low cumulative incidence of MACE (p = 0.008) in comparison with the diabetics assigned to selective invasive strategy. We also found, using the Kaplan-Meier curves survival analysis, that the time to MACE in patients assigned to an early invasive strategy was significantly longer than that in the group of selective invasive strategy. In the follow-up of non-diabetics we found no significant difference in MACE rate between the patients allocated to early invasive strategy and those assigned to selective invasive strategy. In the selective invasive strategy group, however, the cardiovascular adverse events tended to occur earlier than in the early invasive strategy group. CONCLUSIONS: Early invasive strategy in diabetic patients with non-ST-segment elevation acute coronary syndrome is associated with a reduced MACE rate compared with the selective invasive strategy used in these patients. Early invasive strategy applied in diabetic patients is also associated with a significantly longer time to MACE. In non-diabetics the advantages of early over selective invasive strategy are not so clearly differentiated. РЕЗЮМЕ ВВЕДЕНИЕ Пациенты с острым коронарным син- дромом - ОКС- без элевации ST сегмента не пред- ставляют однородную группу с точки зрения риска наступления неблагоприятных сердечно-сосудистых осложнений (MACE). Наличие сахарного диабета - СД - несомненно один из факторов, определяющий более высокорисковую подгруппу. ЦЕЛЬ: Сопоставить раннюю инвазивную страте- гию по отношению к селективной инвазивной стра- тегии в группах пациентов с или без наличия СД. ПАЦИЕНТЫ И МЕТОДЫ: Обследовано 178 пациентов с нестабильной стенокардией или с инфарктом ми- окарда без элевации ST сегмента (НАП / NSTEMI). 52 (29.2%) из них имеют СД. Пациенты распреде- лены на случайном принципе на раннюю инвазивную стратегию (коронарная артериография - СКАГ и эвентуально перкутанная интервенция - РСІ в рамках первых 24 ч. от начала госпитализации) или на селективую инвазивную стратегию - первона- чальный опыт для медикаментозной стабилизации и проведения СКАГ при рецидиве стенокардии и/ или данные об индуцированной ишемии миокарда. Прослеживание пациентов в среднем длилось 22.8 ± 14 мес. РЕЗУЛЬТАТЫ: В группе диабетиков в ходе про- слеживания наблюдаются значительная редукция частоты рецидива стенокардии р = 0.005, по- вторная госпитализация - р = 0.001, СКАГ - р = 0.001 , интервенция - р = 0.001 и общая частота МАСЕ - р = 0.008 при выборе ранней инвазивной стратегии по сравнению со селективной инвазив- ной стратегии. Установлена также с помощью Каплан-Майера анализа разница во время наступ- ления МАСЕ у больных с СД снова в пользу ранней инвазивной стратегии. На фоне отсутствия СД прослеживание пока- зывает, что пациенты, разделенные на раннюю и селективную инвазивную стратегию, не отличаются значимо по частоте наблюдаемых сердечно-сосуди- стых осложнений. В группе с выбором селективной инвазивной стратегии, однако, сердечно-сосудистые повреждения наступают раньше по сравнению с этими при ранней инвазивной стратегии. З АКЛЮЧЕНИЕ: Выбор ранней инвазивной страти- гии у пациентов с ОКС без элевации ST сегмента на фоне наличия СД связан со значительно более низкой частотой нежелательных сердечно-сосуди- стых событий по сравнению с группой диабети- ков, где выбором является селективная инвазивная стратегия. Ранняя инвазивная стратегия на фоне наличия СД связана со значительным удлинением периода, свободного от МАСЕ. В группе без СД преимущества ранней инвазивной стратегии не так ясно выражены.