A Note on Efficient Computation of All Abelian Periods in a String

We derive a simple efficient algorithm for Abelian periods knowing all Abelian squares in a string. An efficient algorithm for the latter problem was given by Cummings and Smyth in 1997. By the way we show an alternative algorithm for Abelian squares. We also obtain a linear time algorithm finding all `long' Abelian periods. The aim of the paper is a (new) reduction of the problem of all Abelian periods to that of (already solved) all Abelian squares which provides new insight into both connected problems

The predictive value of complete blood count-derived indices for major adverse cardiovascular events in MINOCA patients at 5-year follow-up

Introduction: The authors analysed the potential of red blood cell and platelet indices such as red cell distribution width (RDW), mean corpuscular volume (MCV), and mean platelet volume (MPV) as predicting factors in myocardial infarction with non-obstructive coronary arteries (MINOCA) patients of 5-year outcomes. Material and methods: Between 2010–2015 were identified 112 patients who had final MINOCA diagnosis and available laboratory findings. The primary endpoint was the 5-year major adverse cardiovascular events rate, defined as cardiac death, myocardial infarction, or hospitalization due to angina. Results: Only RDW had a significant impact on long-term outcomes. 93 (83%) patients had RDW ≤ 14.5 (group 1), and 19 (17%) patients had RDW > 14.5 (group 2). The mean RDW value was 13.58 ± 1.11%. In group 1 and group 2, mean RDW values were 13.18 ± 0.55%, and 15.54 ± 1.06% (p < 0.001), respectively. Patients with abnormal RDW values (group 2) characterized lower value of left ventricular eject fraction (60 ± 8% vs. 53 ± 13%, p = 0.024), and higher NT-proBNP values (3,170 ± 5,285 pg/mL vs. 6,200 ± 4,223 pg/mL, p = 0.013) as well as troponin levels (501–2500 ng/mL: 31% vs. 53%, p = 0.02). A statistically significant difference was observed only for all-cause death. All-cause death rates for no RDW ≤ 14.5% vs. RDW > 14.5% were 2.2% vs. 21.1% (HR 5.09, 95% CI 1.03–25.2, p = 0.046), respectively. Conclusions: RDW was significantly associated with the increased risk of all-cause mortality in MINOCA patients at 5 years

Coronary slow flow is not an adverse prognostic factor in MINOCA patients in the 5-year follow-up

Introduction: The research aimed to compare the characteristics and outcomes of myocardial infarction with non-obstructive coronary arteries (MINOCA) patients with coronary slow flow (CSF) vs. normal coronary flow (no CSF) in a 5-year follow-up. Material and methods: Between 2010–2015 were identified 111 patients as having final MINOCA diagnosis and available calculated corrected TIMI frame count (cTFC). CSF was defined as cTFC greater than 27 frames per second in any of the three coronary arteries. The primary endpoint was the 5-year major adverse cardiovascular events rate, defined as cardiac death, myocardial infarction, or hospitalization due to angina. Results: The mean cTFC was 28.9 ± 6.1 frames per second (median: 28, IQR 24–33; min-max: 19–58). 62 (55.9%) patients had normal coronary flow, and 49 (44.1%) had CSF. Patients did not differ in sex (females no CSF vs. CSF: 58% vs. 61%, p = 0.7) or age (63 ± 15 years vs. 63 ± 13 years, p = 0.8). Patients with CSF characterized higher rates of chronic kidney disease (0 vs. 8.2%, p = 0.035). No statistically significant difference was observed for any of the analysed points. MACE rates for no CSF vs. CSF were 9.6% vs. 14.3% (HR 0.80, 95% CI 0.28–2.96, p = 0.7), respectively. Conclusions: CSF was not associated with a higher risk of adverse events among MINOCA patients at five years

Arterial hypertension as a risk factor for myocardial infarction with non-obstructive coronary arteries (MINOCA)

Myocardial infarction with non-obstructive coronary arteries (MINOCA) as a relatively new disease entity distinguished from the group of acute coronary syndromes (ACS) is not a rare clinical problem and it requires in-depth diagnostics. MINOCA accounts for 5–10% of all ACS cases. MINOCA is most common between the ages of 50–60 and predominates in females. Coronary microvascular dysfunction and coronary vasospasm are among the potential mechanisms. The latest guidelines for the treatment of ACS in patients presenting without persistent ST-segment elevation emphasize the importance of searching for the causes of angina in patients with insignificant lesions in the coronary arteries by extending invasive diagnostics (e.g., acetylcholine provocation test) and using noninvasive diagnostics (e.g., CMR or SPECT). In the context of MINOCA, among the typical risk factors for coronary artery disease, arterial hypertension (HTN) seems to be the most important by inducing coronary microcirculation remodeling (mostly hypertrophy) and hence the narrowing of the lumen. Studies comparing patients with MINOCA and obstructive coronary artery disease (MI-CAD) in the context of risk factors, in particular HTN, were analyzed. In five out of nine analyzed studies, HTN occurred significantly more often in patients with MINOCA compared to patients with MI-CAD. The current pharmacotherapy recommendations focus on slowing the progression of coronary microvascular dysfunction (CMD), i.e., adequate treatment of risk factors and comorbidities, such as HTN. Therefore, it seems reasonable to conduct studies directly analyzing the relationship between HTN and MINOCAin order to improve diagnostics and establish appropriate pharmacotherapy that will improve prognosis

Impact of the Balloon Inflation Time and Pattern on the Coronary Stent Expansion

Objectives. To assess the expansion pattern of coronary stents by using different balloon inflation times and pressures. Background. The selection of coronary stent size and its proper deployment is crucial in coronary artery interventions, having an impact on the success of the procedure and further therapy. Methods. Ten pairs of different stents were deployed under nominal pressure using sequential (5, 5, 10, and 10 seconds of repeated inflations, thus 30 seconds of summarized time) and continuous (30 seconds) deployment pattern. After each given time-point, intraluminal stent measurements were performed by optical coherence tomography (OCT) and intravascular ultrasound (IVUS). Results. Both in-stent diameters and cross-section areas (CSA) of paired stents measured by OCT at all sequential time-points were significantly smaller compared to given manufacturers charts’ values (90% to 94% for diameters and 81% to 88% for CSA, p<0.05). Significant increase of in-stent diameter and CSA was observed across the step-by-step deployment pattern. In-stent lumen measurements were significantly larger when sequential deployment pattern was applied compared to continuous deployment. Additional measurements were also done for overlapping segments of stents, showing smaller in-stent measurements of the latter compared to nonoverlapping segments. Validation of OCT and IVUS measurements using a phantom metallic tube showed perfect reproducibility with OCT and overestimation with IVUS (8% for diameters and 16% for CSA). Conclusions. Stent diameter after deployment is time-dependent and not only pressure-dependent. Different stent expansion behavior, depending on the applied deployment pattern (sequential and nonsequential), was observed