The Effect of Slow Coronary Artery Flow on Microvolt T-Wave Alternans.

BACKGROUND: Slow coronary artery flow (SCF) is characterized by angiographically confirmed delayed vessel opacification in the absence of any evidence of obstructive epicardial coronary artery disease. Microvolt T-wave alternans (MTWA) is defined as beat-to-beat changes in shape, amplitude, or timing of ST segments and T waves, and is utilized in predicting sudden cardiac death and life-threatening malign ventricular arrhythmias in high-risk patients. In our study, we aimed to evaluate the effects of slow coronary artery flow on MTWA. METHODS: Thirty-nine consecutive patients (SCF group: 6 women and 33 men; mean age, 49 ± 10 years) with angiographally documented SCF in at least 1 major epicardial artery and 39 patients (control group: 13 women and 26 men; mean age, 50 ± 10 years) with normal coronary arteries were included in the study. Coronary flow rates of all patients were calculated by thrombolysis in myocardial infarction frame count (TFC). The MTWAs of all patients were analyzed using the time-domain modified moving average method by means of a treadmill exercise stress test. RESULTS: The age distribution , body mass index, and diastolic and systolic blood pressure (BP) were similar in the SCF and control group. In the SCF group, the three epicardial coronary artery corrected TFCs and mean TFCs were significantly higher than in the control group (for all, p < 0.001). MTWA positivity in the SCF group was statistically significant compared to the control group (p = 0.006). Spearman's correlation analysis, showed a positive correlation between MTWA and right coronary artery (RCA) TFC and mean TFC (r = 0.368, p = 0.001 and r = 0.271, p = 0.016, respectively). In linear regression analysis, only the right coronary artery TFC was correlated with positive MTWA (p = 0.001). CONCLUSIONS: The results of our study suggest that diagnosed SCF is associated with MTWA positivity. Furthermore, we determined that only RCA TFC was predictive of positive MTWA. KEY WORDS: Microvolt T-wave alternans; Slow coronary flow.

Assessment of the relationship between endocan and obstructive sleep apnea severity.

INTRODUCTION: Obstructive sleep apnea (OSA) and endothelial dysfunction are associated with cardiovascular risk factors and the development of atherosclerosis. Endocan is a marker of endothelial dysfunction, while obstructive sleep apnea is one of the causes of endothelial dysfunction. In this study, we investigated the relationship between endocan and obstructive sleep apnea severity. MATERIAL AND METHODS: A total of 179 patients with snoring complaints were included. All patients underwent polysomnography, and based on the results, the participations were allocated to the control group (n = 39) or to the obstructive sleep apnea group (n = 140). The OSA group was classified as having mild (apnea-hypopnea index (AHI) = 5-15; n = 43), moderate (AHI = 15-30; n = 42), or severe OSA (AHI > 30; n = 55). All participations had their endocan levels measured. RESULTS: Endocan levels in OSA patients were significantly higher than in the control group (11.8 (3.13-200) vs 3.13 (3.13-23) ng/ml, p < 0.001). Also, endocan levels were significantly higher in the severe OSA group than moderate and mild obstructive OSA (13.2 (3.13-200), 12.6 (3.13-200) and 8.44 (3.13-50.5) ng/ml, p = 0.015, respectively). Multiple logistic regression analysis showed that smoking, age and endocan levels were independent predictors of OSA severity (p = 0.024, p = 0.037, p = 0.004, respectively). CONCLUSIONS: Endocan seems to be a potential risk stratification marker in this patient population.

Galectin-3 is associated with coronary plaque burden and obstructive sleep apnoea syndrome severity.

BACKGROUND: Obstructive sleep apnoea syndrome (OSAS) is reported to be associated with hypertension, coronary artery disease, atrial fibrillation, and heart failure. Galectin-3 plays an important role in the regulation of inflammation, development of cardiac fibrosis, and remodelling. A significant relationship between galectin-3 and the total number of coronary plaques and the macrocalcified plaque structures of patients with type 2 diabetes mellitus has been reported. AIM: The aim of this study was to investigate the association between galectin-3 level and coronary plaque burden as well as OSAS severity in patients with OSAS. METHODS: A total of 87 consecutive patients with a diagnosis of OSAS and 21 age- and gender-matched control subjects were recruited for the present study. The patients with OSAS were also categorised according to their apnoea hypopnoea index (AHI) as follows: mild (AHI = 5-15), moderate (AHI = 15-30), and severe (AHI > 30). All study subjects underwent coronary computed tomography angiography to detect coronary atherosclerosis. Also, all participants of serum galectin-3 concentrations were measured. RESULTS: Mean galectin-3 level was significantly higher in patients with OSAS compared to control subjects (p < 0.001) and in the severe OSAS group, compared to the moderate and mild OSAS groups (p < 0.001). Correlation analysis indicated significant positive relationships between galectin-3 concentrations and the total number of coronary plaques (p < 0.001), high-sensitivity C-reactive protein (p = 0.001), and severity of OSAS (p < 0.001). In multivariate analysis, galectin-3 (p = 0.01) and age (p = 0.025) were significant independent predictors of coronary atherosclerosis, after adjusting for other risk factors. Also, it has been found that galectin-3 concentration is a predictor of OSAS severity (p = 0.001). CONCLUSIONS: Galectin-3 is associated with coronary atherosclerosis and OSAS severity in OSAS patients.

The prognostic value of admission mean platelet volume to platelet count ratio in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND: Mean platelet volume to platelet count (MPV/Plt) ratio has been demonstrated to be a good indicator of long-term mortality in patients with non-ST-segment elevation myocardial infarction (NSTEMI). However, the prognostic value of MPV/Plt in ST-elevation myocardial infarction (STEMI) is not reported. AIM: To determine whether the MPV/Plt ratio on admission has any predictive value for major adverse cardiac events including short- and long-term mortality in STEMI. METHODS: In this prospective study, 470 STEMI patients who underwent primary percutaneous coronary intervention (PCI) were enrolled. The patients were divided into three tertiles based on the MPV/Plt ratio on admission. The first tertile (n = 149) was defined as MPV/Plt ratio ≤ 0.029, second tertile (n = 154) 0.029-0.038, and third tertile (n = 159) ≥ 0.038. Primary clinical outcomes consisted of the sum of cardiovascular (CV) mortality, non-fatal re-infarction, and stroke. Secondary clinical outcomes were CV mortality, non-fatal re-infarction, target-vessel revascularisation, stroke, and advanced heart failure. RESULTS: There was no difference between study groups regarding the primary (p > 0.05) and the secondary outcomes (p > 0.05) except for one-year non-fatal re-infarction rate, which was found to be significantly higher in the highest MPV/Plt ratio group (p = 0.045). Age, Killip class > 1, and left ventricular ejection fraction were found to be independent predictors of long-term CV mortality in multivariate analysis (p = 0.009, p = 0.035, and p < 0.001, respectively). CONCLUSIONS: While the MPV/Plt ratio was demonstrated to be associated with one-year non-fatal re-infarction, it was not related to in-hospital, one-month, and one-year CV mortality in patients with STEMI, who underwent primary PCI.

High sensitive troponin-I in patients with slow coronary flow pattern.

HYPOTHESIS: We examined the hypothesis that a specific myocardial injury marker, namely high sensitive cardiac troponin-I (HsTn-I), is elevated in patients with slow coronary flow (SCF) pattern. AIM: To examine the above hypothesis by studying a group of patients who had undergone coronary angiography for the detection of their chest pain aetiology with SCF pattern despite an angiographically normal coronary arteriogram. METHODS: We evaluated and performed coronary angiography (CAG) of 97 patients with chest discomfort. The indication forCAG was at least Canada class 3 angina and/or proven myocardial ischaemia according to noninvasive diagnostic tests. We further divided patients into three subgroups according to CAG images and compared HsTn-I plasma levels in 39 patients with SCF pattern, 28 patients with coronary artery disease (CAD), and 30 patients with normal coronary arteries. We researched the association between qualitative HsTn-I positivity and demographic features including cardiovascular risk factors, inflammation markers and TIMI frame count for each of the epicardial coronary arteries. RESULTS: TIMI frame count for each epicardial coronary artery was significantly higher in patients with SCF pattern than in patients with CAD and normal coronary arteries (p < 0.001). HsTn-I positivity was not statistically different between patients with SCF pattern and normal coronary arteries (p = 512), but it was significantly higher in the CAD group than the other two group of patients (p < 0.001). CONCLUSIONS: In patients with SCF, HsTn-I may be detectable, but it is not elevated as in patients with normal coronary arteries.