Maciej Sosnowski

Age-adjustment of HRV measures and its prognostic value for risk assessment in patients late after myocardial infarction

THE AIMS OF OUR STUDY WERE (1) to establish the normal limit of the heart rate variability (HRV) indices in a healthy population and in its four age-related subgroups, including a new HRV index, HRV fraction; and (2) to analyse the frequency and predictive value of abnormally low HRV in a population of post-infarction patients in respect to the cut-points chosen (raw or age-adjusted). METHODS Normal population of 296 healthy subjects (81 f, 215 m, aged 47+/-10 years) and post-infarction population of 298 patients (>3 months after acute MI, 65 f, 233 m, aged 56+/-10) were examined. The normal population was divided into 4 subsets based on age at entry: <35, 35-44, 45-54 and >54 years. Based on a 24 h ECG the standard HRV analysis was performed to obtain the following indices: mean RR interval, SDNN and SDANN. A new index of HRV, HRV fraction (HRVF, %) was calculated based on a numerical processing of the RR intervals return map. All patients were followed for 24 months. The endpoints of the study were death (of any reason) and cardiac death. RESULTS Means and normal limits for SDNN, SDANN and HRVF were: 147+/-36 ms [95% CI 89-220], 136+/-36 ms [79-212] and 53+/-9% [35-68]. The HRV values below the lower normal limit (LNL) were observed in 20-25% of post-MI patients. During a 2 year follow-up there were 36 deaths (total mortality 12.1%), while cardiac mortality was 9.1% (27 cases). The prognostic value of the analysed indices was similar (sens approximately 53-61%, spec approximately 79-84%, PPV 22-26%, NPV 93-94%) irrespective of the cut-points chosen (calculated either for the entire population or age-related). Multivariate Cox regression analysis showed that a decrease of any index below the LNL was associated with a approximately 2.5 and approximately 4-6 times greater risk for death and cardiac death, irrespective of the cut-points chosen. CONCLUSIONS The age-dependence of the HRV indices does not seem to significantly influence their prognostic value. Thus, a single cut-point of a particular HRV index, based on the entire population, is sufficient to be treated as a risk predictor. In the late phase of myocardial infarction the value of any global HRV index lying below the lower normal limit indicates independently an increased risk of death, especially cardiac death. The new index (HRV fraction) seems to be a promising substitute for currently used standard indices.

Negative calcium score and the presence of obstructive coronary lesions in patients with intermediate CAD probability

We intended to estimate how the zero coronary artery calcium (CAC) score in symptomatic patients with intermediate probability of coronary artery disease predicts the absence of obstructive non-calcified coronary plaques (NCAPs). CAC scoring and coronary arteries were evaluated by means of 64-multislice CT coronary angiography (CCTA). In 166 subject with CAC=0, Non-obstructive NCAPs (less than 50%) were found in 17 patients (10.2%), while significant stenosis were diagnosed in 3 (2%). In the female insignificant stenoses were more frequent (12%) than in men (6%), however, all 3 cases with significant stenosis were male. In our study, where CCTA has been used as diagnostic method for CAD diagnosing, the prevalence of non-calcified plaques in CAC=0 subjects is relatively high. Our study confirms a relatively low incidence of significant coronary stenosis in this subset of CAD-suspected subjects.

A User‐Friendly Method of Cardiac Venous System Visualization in 64‐Slice Computed Tomography

Background: Previsualization of the cardiac venous system is very important for some techniques, for example, cardiac resynchronization therapy (CRT). The aim of this study was to propose a new, user‐friendly method of cardiac venous system visualization in 64‐slice computed tomography (CT).

Heart Rate Variability Fraction—A New Reportable Measure of 24‐Hour R‐R Interval Variation

Background: The scatterplot of R‐R intervals has several unique features. Its numerical evaluation may produce a new useful index of global heart rate variability (HRV) from Holter recordings.

Comparison of pulmonary veins anatomy in patients with and without atrial fibrillation: analysis by multislice tomography.

UNLABELLED A possible role of anomalies in number and insertion of pulmonary veins (PV) in initiating atrial fibrillation (AF) has been suggested. It has been shown as well that changes in anatomy of PVs such as enlargement may have an effect on arrhythmogenesis. The aim of the study was to compare anatomy of the left atrium (LA) and PVs in patients with AF and control subjects. METHODS Eighty two patients were evaluated with 64-slice computed tomography (MSCT). Fifty one of them were referred to catheter ablation with history of highly symptomatic AF--AF(+) group. Thirty one control subjects had no history of AF and were referred to MSCT for noninvasive evaluation of different pathologies which finally were excluded--AF(-) group. Study groups did not differ in regard to age, sex, presence of hypertension and left ventricular systolic function. Diameters of PV ostia were measured in anterior-posterior (AP) and superior-inferior (SI) directions. Venous ostium index was calculated as a ratio between these measurements. RESULTS The diameter of LA was higher in AF(+) patients than in the AF(-) patients (39±6 mm vs. 35±4 mm, p<0.005). In 68.6% of AF(+) patients and in 83.9% of AF(-) patients the anatomical pattern was typical with two right and two left PVs. Additional PVs were detected in 6 patients, only in AF(+) group (p<0.05). Common ostia were more frequently found in AF(+) subjects (37.2% vs. 19.3, p=0,08), mainly left-sided. In AF(+) group mean SI diameters of both-sided superior PVs and left inferior veins were larger. All AP diameters except for right inferior PVs were also larger in AF(+) group than in control cases. CONCLUSIONS Variations in the PVs anatomy are more common and diameters of ostial portions of the veins are larger in AF patients than in control subjects. These findings suggest that further studies on the role of structural abnormalities of PVs in arrhythmogenesis are needed.

A computational assessment of a blood vessel's compliance: a procedure based on computed tomography coronary angiography

Cardiovascular mortality remains a leading health and social problem in many countries throughout the world. Therefore, it is obvious that current preventive measures include early detection of atherosclerosis process. Computed tomography (CT) is one of imaging modalities allowing for noninvasive detection of atherosclerotic lesion within coronary arteries in subjects with accumulation of risk factors (smoking, high lipids, hypertension, etc.). Functional analysis of coronary arteries is usually approached by means of invasive procedures. We aimed at finding solution for evaluation of another kind of functional analysis of coronary arteries, namely vessels wall compliance by means of CT coronary angiography. On the basis of the CT images of the vessels over entire cardiac cycles, the internal area of the blood vessel is measured and its changes during various phases of heartbeat (systole, diastole) are calculated. If the vessel wall has been changed by atherosclerotic plaque, either calcified or non-calcified, then its compliance will be reduced due to its stiffness. Calculation of coronary artery compliance requires a series of measurements, which is unreliable and impractical for doing manually. The overall methodology proposed in this paper assists in the preparation of a medical diagnosis.

Determinants of a Reduced Heart Rate Variability in Chronic Atrial Fibrillation

Background: We aimed to evaluate whether clinical factors, which influence heart rate variability (HRV) in the presence of undisturbed sinus rhythm, have any associations with HRV in patients with permanent atrial fibrillation (AF).

Frailty Syndrome in Heart Failure Patients who are Receiving Cardiac Resynchronization.

We hypothesized that patients with de novo cardiac resynchronization therapy (CRT) implantation had a more intense frailty syndrome when compared to the patients who qualified for a system upgrade.

Extra-media thickness and epicardial fat: Comparison of a novel carotid artery ultrasound index and a well-established cardiac magnetic resonance fat quantification method

BACKGROUND AND AIM Epicardial and pericardial fat are well-established surrogate markers of cardiovascular diseases and complications. Extra-media thickness (EMT) is a novel ultrasound index corresponding to arterial adventitia and adipose tissue. We aimed to evaluate the association between carotid EMT and epicardial fat (EF) and pericardial fat (PF) and their relation to cardiovascular risk and metabolic syndrome (MS). METHODS AND RESULTS One hundred consecutive patients (age: 51.7 ± 15.4 years; males 70%) scheduled for cardiac magnetic resonance (CMR) were prospectively included in the study. Anthropometric parameters, CMR indices of EF and PF, both common carotid arteries EMT, and ultrasound indices of visceral and subcutaneous fat were measured in patients. In our study group, 53% of patients represented a very high cardiovascular risk, overweight or obesity was found in 68%, high body fat in 45%, and MS in 59% of individuals. Mean EMT (662 ± 129 μm) was significantly associated with EF area (r = 0.46; p < 0.001) and PF area (r = 0.3; p < 0.001). Among all fat indices, only EMT (MS+ 736 ± 140 μm vs. MS-658 ± 97 μm; p = 0.002) and EF area (MS+ 870 ± 451 mm(2) vs. MS 668 ± 333 mm(2); p = 0.02) were significantly increased in patients with MS compared with individuals without MS. Multivariable regression analysis also showed that mean EMT is independently associated with number of cardiovascular risk factors (b = 0.005; p < 0.001). Moreover, very high cardiovascular risk subjects showed significantly increased EMT/BMI (p < 0.001) and EF area/BMI (p = 0.03) ratios. However, there was no significant association between EMT/BMI and EF area/BMI values (p = ns). CONCLUSIONS Our study showed the first findings on the relations between a novel ultrasound index EMT and EF assessed in a reference method of CMR. Carotid EMT may be a new surrogate marker, including both periarterial fat as a major component and arterial adventitia, which may provide additional data on cardiometabolic risk beyond that derived form a well-established EF alone.

The presence of endocardial leads may limit applicability of coronary CT angiography.

Abstract Objectives. Some indications that MSCT is necessary may be visible in patients with implanted pacemakers, CRTs and ICDs devices. Purpose. To evaluate whether the presence of endocardial leads influences the quality of visualization of the coronary arteries in MSCT. Design. In 37 patients a 64-slice MSCT (Aquilion 64, Toshiba) was performed due to a suspicion of ischemic heart disease (33 patients) or suspicion of lead perforation (four patients). The control group consists of 35 patients. Influence of the leads was evaluated independently by two cardiologists. Results. The total number of leads that were evaluated was 63. In 26 cases (41%) significant problems with the evaluation of coronary arteries occurred: LM–1 (2%) case, LAD–3 (5%) cases, LCx–4 (6%) cases, RCA–18 (28%) cases. The presence of a right ventricular lead did not influence the quality of the imaging of the left main coronary artery (LM) and its main branches (LAD and LCx). The main concerns were related to the RCA visualization–interpretable images in 18/63 (29%) of the analyzed leads. Conclusions. The presence of implanted endocardial leads may limit the applicability of coronary CT angiography in patients with implanted anti-arrhythmic devices.