The 2023 Dengue Outbreak in Bangladesh: Exploring the Epidemiology in Hospitalized Patients.

For the past two decades, Bangladesh has faced recurrent dengue outbreaks, with the most recent occurring in 2023. We investigated the socioeconomic, clinical, and laboratory aspects of patients diagnosed with dengue during this outbreak. This observational study was conducted from July to September 2023 at Dhaka Medical College Hospital and Chittagong Medical College Hospital, and included 450 confirmed cases of dengue. Sociodemographic information was collected via face-to-face interviews, clinical examinations, and laboratory testing, which was done within 24 hours of admission. Dengue severity was classified according to the 2009 WHO dengue guidelines. Notably, 17% of patients experienced severe dengue, and 89% of those with nonsevere cases exhibited at least one warning sign. Most patients were young adults (mean age, 33 years), with a nearly equal male-to-female ratio. Common clinical presentations included fever (95%), myalgia (62%), and headache (58%), whereas warning signs such as vomiting (54%) and abdominal pain (39%) were prevalent. Plasma leakage indicators, including ascites, pleural effusion, and edema, were found predominantly in severe cases. Laboratory findings revealed leukopenia, thrombocytopenia, and elevated hepatic enzymes (alanine aminotransferase and aspartate aminotransferase) in nearly half the patients. An elevated hematocrit level was associated with severe dengue. We report that a substantial number of patients developed severe dengue during the epidemic in 2023, and provide detailed clinical-epidemiological profiles of the patients, offering valuable insight into management of dengue cases.

Leveraging machine learning to evaluate factors influencing vitamin D insufficiency in SLE patients: A case study from southern Bangladesh.

Vitamin D insufficiency appears to be prevalent in SLE patients. Multiple factors potentially contribute to lower vitamin D levels, including limited sun exposure, the use of sunscreen, darker skin complexion, aging, obesity, specific medical conditions, and certain medications. The study aims to assess the risk factors associated with low vitamin D levels in SLE patients in the southern part of Bangladesh, a region noted for a high prevalence of SLE. The research additionally investigates the possible correlation between vitamin D and the SLEDAI score, seeking to understand the potential benefits of vitamin D in enhancing disease outcomes for SLE patients. The study incorporates a dataset consisting of 50 patients from the southern part of Bangladesh and evaluates their clinical and demographic data. An initial exploratory data analysis is conducted to gain insights into the data, which includes calculating means and standard deviations, performing correlation analysis, and generating heat maps. Relevant inferential statistical tests, such as the Student's t-test, are also employed. In the machine learning part of the analysis, this study utilizes supervised learning algorithms, specifically Linear Regression (LR) and Random Forest (RF). To optimize the hyperparameters of the RF model and mitigate the risk of overfitting given the small dataset, a 3-Fold cross-validation strategy is implemented. The study also calculates bootstrapped confidence intervals to provide robust uncertainty estimates and further validate the approach. A comprehensive feature importance analysis is carried out using RF feature importance, permutation-based feature importance, and SHAP values. The LR model yields an RMSE of 4.83 (CI: 2.70, 6.76) and MAE of 3.86 (CI: 2.06, 5.86), whereas the RF model achieves better results, with an RMSE of 2.98 (CI: 2.16, 3.76) and MAE of 2.68 (CI: 1.83,3.52). Both models identify Hb, CRP, ESR, and age as significant contributors to vitamin D level predictions. Despite the lack of a significant association between SLEDAI and vitamin D in the statistical analysis, the machine learning models suggest a potential nonlinear dependency of vitamin D on SLEDAI. These findings highlight the importance of these factors in managing vitamin D levels in SLE patients. The study concludes that there is a high prevalence of vitamin D insufficiency in SLE patients. Although a direct linear correlation between the SLEDAI score and vitamin D levels is not observed, machine learning models suggest the possibility of a nonlinear relationship. Furthermore, factors such as Hb, CRP, ESR, and age are identified as more significant in predicting vitamin D levels. Thus, the study suggests that monitoring these factors may be advantageous in managing vitamin D levels in SLE patients. Given the immunological nature of SLE, the potential role of vitamin D in SLE disease activity could be substantial. Therefore, it underscores the need for further large-scale studies to corroborate this hypothesis.

Cellulose Nanocrystal-Based All-3D-Printed Pyro-Piezoelectric Nanogenerator for Hybrid Energy Harvesting and Self-Powered Cardiorespiratory Monitoring toward the Human-Machine Interface.

Biomaterials with spontaneous piezoelectric property are highly emerging in recent times for the generation of electricity from mechanical energy sources that are amply available in nature. In this context, pyroelectricity, an integral property of piezoelectric materials, might be an interesting tool in harvesting thermal energy from the fluctuations of temperature. On the other hand, respiration and heart pulse are the significant human vital signs that can be used for early detection and prevention of cardiorespiratory diseases. Here, we report an all-three-dimensional (3D)-printed pyro-piezoelectric nanogenerator (Py-PNG) based on the most abundant and completely biodegradable biopolymer on earth, i.e., cellulose nanocrystal (CNC) for hybrid (mechanical as well as thermal) energy harvesting, and interestingly, the NG could be used as an e-skin sensor for application in self-powered noninvasive cardiorespiratory monitoring for personal healthcare. Notably, the CNC-based device will be biocompatible and economically advantageous due to its biomaterial-based supremacy and huge availability. This is an original approach with 3D geometrical advancement in designing a NG/sensor, where the unique all-3D-printed manner is adopted, and certainly, it has promising potential in reducing the number of processing steps to required equipment during the multilayer fabrication. The all-3D-printed NG/sensor shows outstanding mechano-thermal energy harvesting performance along with sensitivity and is capable of accurate detection of heart pulse as well as respiration, whenever and whichever required without the need of any battery or an external power supply. In addition, we have also extended its application in demonstrating a smart mask-based breath monitoring system. Thus, the real-time cardiorespiratory monitoring provides notable and fascinating information in medical diagnosis, stepping toward biomedical device development and human-machine interface.

Three-Dimensional Printed Highly Porous and Flexible Conductive Polymer Nanocomposites with Dual-Scale Porosity and Piezoresistive Sensing Functions.

Highly flexible, deformable, and ultralightweight structures are required for advanced sensing applications, such as wearable electronics and soft robotics. This study demonstrates the three-dimensional (3D) printing of highly flexible, ultralightweight, and conductive polymer nanocomposites (CPNCs) with dual-scale porosity and piezoresistive sensing functions. Macroscale pores are established by designing structural printing patterns with adjustable infill densities, while the microscale pores are developed by phase separation of the deposited polymer ink solution. A conductive polydimethylsiloxane solution is prepared by mixing polymer/carbon nanotubes with non-solvent and solvent phases. Silica nanoparticles are utilized to modify the rheological properties of the ink, making direct ink writing (DIW) feasible. 3D geometries with various structural infill densities and polymer concentrations are deposited using DIW. The solvent is evaporated during a stepping heat treatment, leading to non-solvent droplet nucleation and growth. The microscale cellular network is developed by removing the droplets and curing the polymer. Up to 83% tunable porosity is achieved by independently controlling the macro- and microscale porosity. The effect of macroscale/microscale porosity and printing nozzle sizes on the mechanical and piezoresistive behavior of the CPNC structures is explored. The electrical and mechanical tests demonstrate a durable, extremely deformable, and sensitive piezoresistive response without sacrificing mechanical performance. The flexibility and sensitivity of the CPNC structure are enhanced up to 900 and 67% with the development of dual-scale porosity. The application of the developed porous CPNCs as piezoresistive sensors for detecting human motion is also evaluated.

Funnel-Shaped Floating Vessel Oil Skimmer with Joule Heating Sorption Functionality.

Floating vessel-type oil collecting devices based on sorbent materials present potential solutions to oil spill cleanup that require a massive amount of sorbent material and manual labor. Additionally, continuous oil extraction from these devices presents opportunities for highly energy-efficient oil skimmers that use gravity as the oil/water separation mechanism. Herein, a sorbent-based oil skimmer (SOS) is developed with a novel funnel-shaped sorbent and vessel design for efficient and continuous extraction of various oils from the water surface. A carbon black (CB) embedded polydimethylsiloxane (PDMS) sponge material is characterized and used as the sorbent in the SOS. The nanocomposite sponge formulation is optimized for high reusability, hydrophobicity, and rapid oil absorption. Joule heating functionality of the sponge is also explored to rapidly absorb highly viscous oils that are a significant challenge for oil spill cleanup. The optimized sponge material with the highest porosity and 15 wt% CB loading is tested in the SOS for large-scale oil spill extraction tests and shows effective cleaning of oil spilled on the water surface. The SOS demonstrates a high maximum extraction rate of 200 mL/min for gasoline and maintains a high extraction rate performance upon reuse when the sponge funnel is cleaned and dried.

Disparities in three critical maternal health indicators amongst Muslims: Vis-a-vis the results reflected on National Health Mission.

BACKGROUND: The post national health mission era has been recognized for India's accelerating improvement in maternal health care utilization. Concurrent investigations with the purview of examining inequalities in maternal care utilisation have rigorously examined across various socio-economic groups, focusing on Muslim women. The present study examined socio-economic differentials in maternal health care utilisation among Muslims and the delineated factors which are contributing for these inequalities. METHODS: Study used the data from National Family Health Survey (NFHS) conducted in 2005-06 and 2015-16. the present study applied concentration index and Wagstaff-type decomposition analysis to measure and decompose the inequality in maternal health services. RESULTS: This study found that utilisation of full antenatal care (full ANC), skilled attendants at birth (SBAs) and postnatal care was increased during 2005-06 to 2015-16. However, the least improvement was observed in full antenatal care whereas substantial improvement was achieved in utilising skilled attendants at birth. Further, the poor and non-poor gap in maternal health care utilisation mostly prevailed among the educated, urban resident, other backward castes among Muslims. The inequality has been declined largely in SBA utilisation compared to full ANC and PNC, especially in the southern India. Higher education, mass media exposure, higher birth order and urban residence contribute and explain most of these inequalities in maternal care among Muslim women CONCLUSIONS: Despite the fact that free and cash benefitted health programmes, wealth, mass media exposure and education etc welfare programs benefitted a large number of citizens, it also produced most of the inequalities among Muslims in India. The results focus on the significance of wealth, education, and mass media exposure in bridging the socioeconomic gap in maternal health care utilization among Muslims.

PDMS Sponges with Embedded Carbon Nanotubes as Piezoresistive Sensors for Human Motion Detection.

Porous piezoresistive sensors offer promising flexible sensing functionality, such as human joint motion detection and gesture identification. Herein, a facile fabrication method is developed using a microwave-based rapid porogen removal technique for the manufacturing of porous nanocomposite sponges consisting of polydimethylsiloxane (PDMS) and well-dispersed carbon nanotubes (CNTs). The porogen amounts and CNT loadings are varied to tailor the porosity and electrical properties of the porous sensors. The sponges are characterized by a scanning electron microscope (SEM) to compare their microstructures, validate the high-quality CNT dispersion, and confirm the successful nanofiller embedding within the elastomeric matrix. Sponges with a 3 wt% CNT loading demonstrate the highest piezoresistive sensitivity. Experimental characterization shows that the sponges with low porosity have long durability and minimal strain rate dependence. Additionally, the developed sponges with 3 wt% CNTs are employed for the human motion detection using piezoresistive method. One experiment includes fingertip compression measurements on a prosthetic hand. Moreover, the sensors are attached to the chest, elbow, and knee of a user to detect breathing, running, walking, joint bending, and throwing motions.

Interfacial Properties of ZnO Nanowire-Enhanced Carbon Fiber Composites: A Molecular Dynamics Simulation Study.

The interfacial properties of ZnO nanowire (NW)/carbon fiber-reinforced epoxy composites are investigated using molecular dynamics (MD) simulations. An atomistic representative volume element (RVE) is developed in which a single ZnO NW is aligned on carbon fiber and embedded in the cross-linked epoxy. Effects of ZnO NWs on the fiber-matrix adhesion are studied by evaluating the fiber and the enhanced matrix interaction. The traction-separation behavior in both sliding mode (shear separation) and opening mode (normal separation) is evaluated. The cohesive parameters, including the peak traction and adhesion energy, are calculated in each mode. Different numbers of cross-linked epoxy units in the system are studied and validated. The interfacial properties of the hybrid system are compared with the simulated bare RVE containing fiber and epoxy. MD results showed that the interfacial strength is increased from 485 MPa to 1066 MPa with the ZnO NWs. The adhesion energy in both opening and sliding modes is significantly improved by growing ZnO NWs on the carbon fibers. In addition, the hybrid system shows more rate-independent behavior compared with the bare system in the opening mode.

Rapid Microwave Polymerization of Porous Nanocomposites with Piezoresistive Sensing Function.

In this paper, polydimethylsiloxane (PDMS) and multi-walled carbon nanotube (MWCNT) nanocomposites with piezoresistive sensing function were fabricated using microwave irradiation. The effects of precuring time on the mechanical and electrical properties of nanocomposites were investigated. The increased viscosity and possible nanofiller re-agglomeration during the precuring process caused decreased microwave absorption, resulting in extended curing times, and decreased porosity and electrical conductivity in the cured nanocomposites. The porosity generated during the microwave-curing process was investigated with a scanning electron microscope (SEM) and density measurements. Increased loadings of MWCNTs resulted in shortened curing times and an increased number of small well-dispersed closed-cell pores. The mechanical properties of the synthesized nanocomposites including stress-strain behaviors and Young's Modulus were examined. Experimental results demonstrated that the synthesized nanocomposites with 2.5 wt. % MWCNTs achieved the highest piezoresistive sensitivity with an average gauge factor of 7.9 at 10% applied strain. The piezoresistive responses of these nanocomposites were characterized under compressive loads at various maximum strains, loading rates, and under viscoelastic stress relaxation conditions. The 2.5 wt. % nanocomposite was successfully used in an application as a skin-attachable compression sensor for human motion detection including squeezing a golf ball.

Multiscale Modeling of Fiber Fragmentation Process in Aligned ZnO Nanowires Enhanced Single Fiber Composites.

A three-dimensional multiscale modeling framework is developed to analyze the failure procedure of radially aligned zinc oxide (ZnO) enhanced single fiber composites (SFC) under tensile loading to understand the interfacial improvement between the fiber and the matrix. The model introduces four levels in the computational domain. The nanoscale analysis calculates the size-dependent material properties of ZnO nanowires. The interaction between ZnO nanowires and the matrix is simulated using a properly designed representative volume element at the microscale. At the mesoscale, the interface between the carbon fiber and the surrounding area is modeled using the cohesive zone approach. A combination of ABAQUS Finite element software and the failure criteria modeled in UMAT user subroutine is implemented to simulate the single fiber fragmentation test (SFFT) at the macroscale. The numerical results indicate that the interfacial shear strength of SFC can be improved up to 99% after growing ZnO nanowires on the fiber. The effect of ZnO nanowires geometries on the interfacial shear strength of the enhanced SFC is also investigated. Experimental ZnO nanowires enhanced SFFTs are performed on the fabricated samples to validate the results of the developed multiscale model. A good agreement between the numerical and the experimental results was observed.

Enhanced Electrical Conductivity of Carbon Nanotube-Based Elastomer Nanocomposites Prepared by Microwave Curing

Nanocomposites consisting of polydimethylsiloxane (PDMS) and well-dispersed carbon nanotubes (CNT) can be cured by microwave radiation within a minute, forming a conductive network within the cured materials. Microwave irradiation delivers energy directly to the inner core of the nanocomposites by heating CNTs and initiating rapid polymerization of the elastomer. In this paper, nanocomposites were fabricated with CNT loadings between 0.5 wt.%­2.5 wt.% via microwave irradiation. Key properties of the nanocomposites including electrical conductivity, microstructures, CNT distribution, density, and surface effects were all characterized. The properties of microwave-cured nanocomposites were compared with those manufactured by the thermal method using a conventional oven. The microwave-curing method substantially increased the electrical conductivity of the nanocomposites due to the improved nanoparticle dispersion and likely CNT alignment. Optimal microwave-curing parameters were identified to further improve the conductivity of the nanocomposites with lowest CNT loading. A conductivity enhancement of 142.8% over thermally cured nanocomposites was achieved for nanocomposites with 1 wt.% CNTs cured via one-step microwave irradiation.

Coronary stent implantation technique: prolonged inflation time maximizes stent expansion.

OBJECTIVES: To determine whether longer periods of stent balloon inflation result in greater minimal luminal diameter (MLD) as measured by quantitative coronary analysis (QCA), and to determine whether measured size correlated with that predicted by pressure-diameter nomograms. METHODS: Seventy-four stents were implanted in 52 patients. Stent acquisitions at a steady inflation pressure were taken at 10 s, 30 s, and 60 s. The stent MLD at each of these intervals was measured by QCA. Comparisons were made between (1) stent diameter obtained at these time intervals; and (2) nomogram-predicted pressure-related stent diameters. RESULTS: Measured stent size increased significantly between each time point measured, with the most marked increment in size (0.15 ± 0.02 mm) observed between 10 s and 30 s (P<.0001), with a smaller but still significant increment between 30 s and 60 s (0.06 ± 0.02 mm; P=.0034). Although there was good correlation between measured size and expected size at 10 s and 30 s (r² = 0.60 and 0.58, respectively), the correlation at 60 s inflation was strongest (r² = 0.65). CONCLUSIONS: Longer durations of stent inflation increase MLD. A minimum duration of 30 seconds is recommended. However, even after 60 s, the MLD does not match the nomogram-derived expected diameter.

Severe primary hypothyroidism presenting with torsades de pointes.

An 85-year-old lady presented to our institution following multiple episodes of transient loss of consciousness. Her admission ECG revealed a junctional bradycardia with significant QT prolongation. Telemetry captured a torsades de pointes arrhythmia. Possible offending drugs (digoxin and hydroxychloroquine) were stopped and she was given intravenous magnesium and potassium. Despite this, she continued to have runs of torsades. An isoprenaline infusion was commenced to increase her resting heart rate. Her QT interval shortened and she had no further arrhythmia. Investigation into the cause of her bradycardia and prolonged QT revealed profound hypothyroidism. Levothyroxine was commenced but the patient remained bradycardia and required a permanent pacemaker. She had no further arrhythmia and was discharged home safely. This is a very rare case of severe primary hypothyroidism presenting with torsades de pointes.

Successful treatment of ST elevation myocardial infarction caused by septic embolus with the use of a thrombectomy catheter in infective endocarditis.

A 71-year-old patient suffered a transmural (ST elevation) myocardial infarction (MI) as a result of a septic embolus from an infected tissue aortic valve replacement. Following failed fibrinolysis, his MI was successfully treated with thrombectomy using an export catheter. He suffered bleeding complications following the administration of tenectaplase and required aortic valve and root replacement due to ongoing systemic embolisation.

Decreasing operators' radiation exposure during coronary procedures: the transradial radiation protection board.

AIM: Transradial coronary procedures are associated with decreased vascular access site complications and other benefits compared to the femoral approach. There is some concern however about high-recorded radiation doses for interventional cardiologists using the transradial route. We therefore designed and investigated the effect of a transradial radiation protection board (TRPB) on operator radiation exposure during coronary procedures. METHODS AND RESULTS: One hundred and six patients were randomly assigned by time period to undergo radial coronary procedures either with or without a TRPB. This is a grooved arm board with a detachable 0.5-mm lead equivalent shield designed to rest between the patient's arm and side. Individual case-specific radiation exposures were measured using electronic personal dosimeter worn on the left outer pocket of the lead apron at chest level. The TRPB was used in addition to standard lead apron and thyroid shielding, below-table leaded flaps, and leaded glass. Operator radiation exposure was significantly decreased in the TRPB group overall: 28 [18-65] microSV versus 19.5 [10.5-35] microSV, P = 0.003. There were no significant differences in procedure duration, total fluoroscopy dose, or contrast load between the two groups. conclusion: Identification of methods to reduce operator radiation dose is important. The use of the TRPB can significantly reduce radiation exposure to radial operators.

Paravalvular regurgitation one year after transcatheter aortic valve implantation.

OBJECTIVES: The aim of this study was to assess the natural history of paravalvular regurgitation at 1 year in patients undergoing TAVI. BACKGROUND: The immediate incidence of paravalvular regurgitation is estimated to be between 65 and 85% following transcatheter aortic valve implantation (TAVI). There is limited data as to whether this deteriorates during follow-up. METHODS: Forty-six patients were recruited from a TAVI programme at our institute. All patients underwent an assessment of prosthetic valve function periprocedurally with aortography and immediately postprocedurally with transthoracic echocardiography. Twenty-one patients with a median age was 83 (66-91) years of whom 14 were male reached 1 year follow-up, 13 of whom were available for repeat transthoracic echocardiography. RESULTS: The incidence of paravalvular regurgitation immediately following TAVI was 86%. Of them 57% had < or = mild regurgitation and 29% had > mild regurgitation. At 1 year the incidence of paravalvular regurgitation was 77%. 54% had < or = mild regurgitation and 34% > mild regurgitation. No patient had severe regurgitation. The degree of regurgitation reduced in 6 (46%), stayed the same in 3 (23%), and increased in 4 (31%) of patients. CONCLUSIONS: Patients undergoing TAVI have an immediate postprocedural risk of regurgitation of 86%. In the majority of cases the degree of paravalvular CoreValve regurgitation is mild, and remains stable in 70% of patients during medium term follow-up.

Pancreatitis and the broken heart.

We report the case of a 72-year-old lady who presented to our institute with acute pancreatitis. Seven days later, she experienced an acute episode of chest pain associated with the pronounced electrocardiographic changes and elevated cardiac enzymes. Although subsequent coronary angiography was normal, a left ventriculogram demonstrated a marked area of apical akinesia and hyperkinesia of the basal left ventricular walls. We believe this to be the first case of pancreatitis induced takotsubo cardiomyopathy in the international literature.

Polycystic ovary syndrome is associated with severe platelet and endothelial dysfunction in both obese and lean subjects.

Platelet hyporesponsiveness to the anti-aggregatory effects of nitric oxide (NO) occurs commonly in association with myocardial ischemia and coronary risk factors, often co-exists with endothelial dysfunction and represents an independent marker of long-term cardiovascular risk. We sought to determine whether polycystic ovary syndrome (PCOS), which has been postulated as a cardiovascular risk factor in women, is independently associated with this phenomenon. Twenty-four young women with PCOS (mean age 32.1+/-1.3) were evaluated in lean (n=12) and obese (n=12) subgroups, and compared with age-matched lean normals (n=12). Platelet aggregation and its inhibition by the nitric oxide donor sodium nitroprusside (SNP) were assessed and compared with vascular endothelial function. Plasma concentrations of malondialdehyde (MDA), N(G),N(G)-dimethyl-L-arginine (ADMA) and hs-CRP were measured as markers of oxidative stress, endothelial dysfunction and inflammation, respectively. Circulating endothelial progenitor cell (EPC) counts were also documented. In both PCOS subgroups, which demonstrated hyperaggregability to ADP, responses to SNP inhibition of aggregation (the principal end-point of the study) were significantly impaired (P<0.01 for both), as were their endothelium-dependent vascular responses to salbutamol (P<0.05 for both). However, vasomotor responses to nitroglycerin and circulating EPC counts did not vary between groups. PCOS subjects also had significantly elevated ADMA, MDA and hs-CRP levels relative to normals (all P<0.05). Impairment of SNP response remained unaltered after mean 30+/-2.4 months follow-up in PCOS subjects. We conclude that in PCOS subjects, independent of obesity and associated insulin resistance, profound and reproducible impairment of platelet responsiveness to NO is an additional component of cardiovascular homeostatic disturbance.

Coronary collaterals remain recruitable after percutaneous intervention.

BACKGROUND: Rapid loss of collateral support has been reported after percutaneous coronary intervention (PCI), leaving the myocardium susceptible to subsequent infarction. However, well-developed collaterals have been found in normal hearts, suggesting that collaterals exist even in the absence of an ischemic stimulus. We assessed the plasticity and determinants of collateral supply after PCI. METHODS AND RESULTS: Collateral flow index (CFI) was calculated in 60 patients as (P(w)-P(v))/(P(a)-P(v)) by measurement of aortic (P(a)), central venous (P(v)), and coronary wedge (P(w)) pressures. CFI was reassessed during transient balloon occlusion 5 minutes and 24 hours after PCI in the first 29 patients and at 6 months in the subsequent 25 patients. We also evaluated the relationship between collateral supply, lesion characteristics, and circulating hemopoietic cells numbers before and after successful PCI. CFI at baseline was 0.23+/-0.10, with no change 5 minutes and 1 day later (0.21+/-0.12, P=0.62; and 0.22+/-0.11, P=0.96, respectively). At 6 months, CFI was 0.14+/-0.07 or 63+/-27% of the baseline value (P<0.001). CFI was proportional to severity of the coronary lesion at baseline (r=0.63, P<0.0001) but not 6 months after PCI (r=-0.04, P=0.87). The number of circulating CD133+ and CD34+ cells was associated with CFI 6 months after PCI (CD133, r=0.59, P=0.035; CD34, r=0.63, P=0.037). CONCLUSIONS: Coronary collateral flow remains undiminished for at least 24 hours after successful PCI. Functional collateral support subsequently declines but does not regress completely.